A method for distracting a pair of adjacent vertebrae and inserting an implant within the intervertebral space between the adjacent vertebrae using a posterior angle is described. The method employs a vertebral distractor-inserter comprising a housing, a pair of opposing arms in mechanical communication with the housing, a driving rod extending through at least a portion of the housing and between the arms, wherein the driving rod comprises an axis and a surface with a plurality of angled ratchet teeth on at least a portion of the surface, and a ratchet drive mechanism in mechanical communication with the driving rod.

BACKGROUND OF THE INVENTION

Spinal disc replacement and/or spinal fusion are sometimes necessary for patients having lumbar degenerative disc disease. It has been estimated that at least 30% of people aged 30 to 50 will have some degree of disc space degeneration, although not all will have pain or ever be diagnosed formally with degenerative disc disease. After a patient reaches 60, it is more normal than not to have some level of disc degeneration. A twisting injury often starts degenerative disc disease, but it can also be initiated by everyday wear and tear on the spine.

Lower back pain is the most common symptom of a compromised disc emblematic of degenerative disc disease. For most patients with lumbar degenerative disc disease, the pain is for the most part tolerable and low-grade, but continuous with occasional flaring of intense pain. Pain can be simply centered on the lower back, or it can radiate to the hips and legs. It can get worse by sitting, or it can be intensified by twisting, lifting, or bending. For some, the pain from the disease decreases over time, since a fully degenerated disc has no pain-causing inflammatory proteins, and the disc usually collapses into a stable position-eliminating the micro-motion that often generates the pain.

For many, non-surgical care can successfully treat the symptoms associated with degenerative disc disease. Doctors will often prescribe a regimen of anti-inflammatory medication, pain medication (injected or oral), exercise, physical therapy, and/or chiropractic manipulation. For others, however, surgery is the best option for treatment once the non-surgical care has not resulted in relief and/or the patient's normal activities have been significantly constrained by his symptoms.

One option for surgical relief is lumbar spinal fusion surgery. This treatment stops motion at the painful segment of the spine by fusing two or more vertebrae. Depending on how many segments of the spine need fusion, and which specific spine segments are to be fused, this surgery may remove some of the normal motion of the spine. Additionally, where multiple segments are fused, back movement may be significantly diminished, and may itself cause pain (fusion disease). Nevertheless, single-level fusion at the L5-S1 segment, the most likely level to break down for degenerative disc disease, for example, does not significantly change the mechanics in the back and is the most common form of fusion. While lumbar spinal fusion surgery is a major surgery, it can be an effective option for patients to enhance their activity level and overall quality of life, particularly when performed using minimally invasive techniques. However, while spinal fusion surgery has its benefits, and is effective in carefully selected patients, the cost of this success is the risk of accelerated degenerative change at adjacent segments.

Thus, another option to treat lumbar degenerative disc disease through surgery is disc replacement using either an artificial disc, a bone graft from the patient's own iliac crest, or a cadaver bone. One potential benefit of disc replacement is the decreased risk of adjacent segment degeneration. It is postulated that replacing the disc, instead of fusing adjacent vertebrae together, maintains more of the lumbar spine normal motion, thereby reducing the chance that adjacent levels of the spine will break down due to increased stress.

The standard surgical procedure for disc replacement approaches the cervical disc from the front (i.e. anterior approach). The entire worn-out disc is removed. A replacement disc is placed into the intervertebral disc space after the worn-out disc is removed. One goal of this procedure is retention of as much normal motion as possible, while keeping the motion segment stable.

As currently practiced, replacement surgery and spinal fusion from the anterior approach require simultaneous use of multiple tools to keep the spine exposed, to prepare the site for implantation, to distract the vertebrae, and to implant the new disc or graft in the vertebral space at the proper orientation and to the desired depth. For example, several tools are often used to prepare the intervertebral space through removal of the cartilaginous endplates of the vertebral bodies. These tools may include rongeurs, rasps, and curettes. Another tool, such as a sizing gauge, might be used to determine the appropriate position and size of the implant to be used. Another tool is used to distract the vertebrae. While this distracting tool is holding the vertebrae apart, yet another tool may be used to place the implant in the distracted space. In some instances, a slap-hammer type tool, or an impact-type driver is used to place the implant between the vertebrae, or to prepare the intervertebral space for the implant.

There is a need for improved tools to aid in disc replacement and/or spinal fusion, which allow a spinal surgeon to more easily access and position a replacement disc or bone graft within the vertebral space. Additionally there is a need for tools that allow a spinal surgeon to control the implantation depth of a replacement disc or bone graft. There is also a need for a tools that are multifunctional and allow for single-handed operation to reduce the number of tools required for performing multiple functions during disc replacement surgery or during spinal fusion surgery and to improve the ease and speed with which disc replacement and/or spinal fusion can be completed.

SUMMARY OF THE INVENTION

The foregoing and additional needs are met by embodiments of the invention, which provide a vertebral distractor-inserter (i.e. device), comprising a pair of opposing arms, a driving rod extending through at least a portion of the housing and between the pair of opposing arms. In some embodiments, the driving rod comprises an axis and a surface with a plurality of angled ratchet teeth on at least a portion of the surface, and a ratchet drive mechanism in mechanical communication with the driving rod. In some embodiments, the vertebral distractor-inserter comprises a housing in mechanical communication with the pair of opposing arms. In some embodiments, the vertebral distractor-inserter (i.e. device) comprises a handle attached to the housing. The terms “vertebral distractor-inserter,” “distractor-inserter,” and “device” are interchangeable as used herein.

In some embodiments, the vertebral distractor-inserter comprises a ratchet drive mechanism comprising an activating lever mounted to the housing by an activating lever pivot, a first ratchet pawl coupled to the activating lever and adapted to engage the ratchet teeth and move the driving rod distally relative to the housing, and a second ratchet pawl adapted to engage the ratchet teeth and oppose proximal motion of the driving rod relative to the housing.

In some embodiments, the vertebral distractor-inserter comprises a ratchet drive mechanism comprising an activating lever mounted to the housing by an activating lever pivot, a first ratchet pawl coupled to the activating lever and adapted to engage the ratchet teeth and move the driving rod distally relative to the housing, and an engaging element to oppose proximal motion of the driving rod relative to the housing.

In some embodiments the ratchet drive mechanism comprises an activating lever spring coupled to the activating lever and the handle, wherein the activating lever spring opposes proximal movement of the lever relative to the handle. In some embodiments of the distractor-inserter, the ratchet drive mechanism comprises a first pawl spring that opposes downward movement of the first pawl and a second pawl spring that opposes downward movement of the second pawl.

In some embodiments of the distractor-inserter, the driving rod comprises a distal end and an implant interface coupled to the distal end of the driving rod.

In some embodiments, the distractor-inserter comprises an implant in contact with the implant interface, whereby distal motion of the driving rod imparts distal motion to the implant through the implant interface; and distal motion of the implant forces the opposing arms apart.

In some embodiments, each opposing arm comprises an arm pivot. Some embodiments comprise a pair of opposing arms comprising an arm spring. Some embodiments comprise an arm comprising an arm depth guard. In some embodiments, the implant interface comprises an implant coupler.

In some embodiments, the vertebral distractor-inserter is adapted for single-handed use.

In some embodiments, the surface of the driving rod comprises an area that is substantially free of ratchet teeth on a contiguous longitudinal surface of the driving rod, and the driving rod is movable proximally relative to the housing upon rotation of the rod about its axis such that the ratchet pawls are in contact with the contiguous longitudinal surface that is free of ratchet teeth. In some embodiments, the ratchet teeth disengage from first and second ratchet pawls upon rotation of the driving rod about its axis. In some embodiments, the driving rod comprises a proximal end having a knob.

Some embodiments of the vertebral distractor-inserter comprise a drive mechanism comprising at least one gripping element which opposes proximal motion of the drive mechanism. The drive mechanism having a gripping element may additionally comprise at least one gripping spring.

In some embodiments of the distractor-inserter, the drive mechanism comprises a gripping element and a ratcheting drive mechanism as described previously. Some embodiments comprise other means for driving implant distally. These means can be other mechanical mechanisms capable of imparting unidirectional movement, along with a release mechanism for reversing such unidirectional movement. Some embodiments comprise other means for distracting the arms. For example, the arms may be distracted by a built-in distracting member, such as in implant interface adapted to force the arms apart.

In some embodiments, the vertebral distractor-inserter comprises a pair of opposing arms, a housing in mechanical communication with the pair of opposing arms and rotatable about an axis extending between the opposing arms, and a driving rod extending through at least a portion of the housing and between the pair of opposing arms. Some embodiments comprise a distal end having an implant interface, wherein the housing and at least a portion of the driving rod are rotatable relative to the pair of opposing arms and the implant interface. Some embodiments further comprise an implant interface comprising an interface rotation element, whereby the interface rotation element allows rod rotation relative to the pair of opposing arms. Some embodiments further comprise a housing comprising a housing rotation element, whereby the housing rotation element allows housing and rod rotation relative to the pair of opposing arms.

In some embodiments, the vertebral distractor-inserter comprises a pair of opposing arms, a housing in mechanical communication with the pair of opposing arms and rotatable about an axis extending between the opposing arms, a driving rod extending through at least a portion of the housing and between the pair of opposing arms, and a drive mechanism adapted to move the driving rod distally relative to the housing.

In some embodiments of a rotatable vertebral distractor-inserter, the vertebral distractor-inserter comprises a drive mechanism. Embodiments of the drive mechanism are described herein.

In some embodiments, the invention provides a vertebral distractor-inserter comprising a housing, a pair of opposing arms in mechanical communication with the housing, a driving rod extending through at least a portion of the housing and between the pair of opposing arms, a drive mechanism adapted to move the driving rod distally relative to the housing, and an implant depth adjustor that is adjustable to a plurality of implant depth settings and is adapted to push the distractor-inserter proximally upon insertion of an implant to a selected implant depth setting. The implant depth adjustor may optionally comprise an implant depth stop. Example drive mechanisms are described herein. This vertebral distractor-inserter may be ratcheting, gripping, a combination of these, etc. Any distractor-inserter described herein may be adapted for single-handed use. It may also or alternatively comprise an implant interface as described herein. It may also be adapted such that the housing and at least a portion of the driving rod are rotatable about an axis extending between the opposing arms, as described herein.

In some embodiments, the invention provides a method for distracting adjacent vertebrae and inserting an implant between the distracted vertebrae. The method comprises mounting the implant to a driving rod of a vertebral distractor-inserter having a housing, a pair of opposing arms in mechanical communication with the housing and having a distal end, and a drive mechanism in mechanical communication with the driving rod, wherein the driving rod extends through at least a portion of the housing and between the pair of opposing arms. The method further comprises positioning the distal end of the pair of arms between the vertebrae, distracting the vertebrae by single-handed operation of the vertebral distractor-inserter, inserting the implant between the distracted vertebrae by single-handed operation of the vertebral distractor-inserter, and retracting the pair of opposing arms from between the vertebrae.

In some embodiments, the invention further provides a method for distracting adjacent vertebrae and inserting an implant between the distracted vertebrae, wherein the distracting comprises activating the drive mechanism using one hand, and wherein the activating moves the implant distally and distracts the pair of opposing arms. In some embodiments, insertion comprises advancing the implant into the distracted space between the vertebrae. In some embodiments advancing the implant comprises activating the drive mechanism using one hand and extending the implant beyond the distal end of the pair of opposing arms. In some embodiments, the method comprises the additional step of releasing the implant from the distractor-inserter.

In some embodiments of the method for distracting adjacent vertebrae and inserting an implant between the distracted vertebrae, the method comprises urging the pair of arms between the vertebrae up to the position where a depth guard of the arms contacts the vertebrae. In some embodiments, the method comprises urging the pair of arms between the vertebrae up to a distal depth of at most about 75 mm, or at least about 25 mm, or between about 35 mm and 55 mm. When referring to distal depth herein, “about” refers to variations in depth of between 1 mm and 2 mm, or between 2 mm and 5 mm. In some embodiments, the distal depth is the distance from the depth guard to the distal end of the pair of opposing arms. In some embodiments, the arms are inserted between the vertebrae up to a distal depth such that the depth guard is proximal to, but not abutting, the proximal side of the vertebrae. In some embodiments, the depth guard is proximal to and abutting, or contacting, the proximal side of the vertebrae.

In some embodiments, mounting the implant comprises the step of adjusting the implant depth adjustor to control the maximum implant depth achievable during the inserting step. In a related embodiment, the implant depth achievable is a maximum of about 25 mm, a minimum of about 0 mm, or between about 3 mm and 8 mm. When referring to implant herein, “about” refers to variations in depth of between 1 mm and 2 mm, or between 2 mm and 5 mm. The implant depth is measured from the distal end of the depth stop to the distal end of the implant interface.

In some embodiments insertion of the implant comprises the step of retracting the pair of opposing arms from between the vertebrae by abutting the implant depth adjustor against a proximal side of the vertebrae and activating the drive mechanism using one hand.

In some embodiments, the invention provides a method comprising activating the drive mechanism comprising the step of ratcheting the driving rod distally. In some such embodiments, the driving rod comprises an axis and a surface with a plurality of angled ratchet teeth on at least a portion of the surface. In some embodiments, the drive mechanism comprises an activating lever capable of movement between a first position and a second position and mounted to the housing by an activating lever pivot. In some embodiments, the drive mechanism further comprises a first ratchet pawl coupled to the activating lever and adapted to engage the ratchet teeth and move the driving rod distally relative to the housing, and a second ratchet pawl adapted to engage the ratchet teeth and oppose proximal motion of the driving rod relative to the housing.

In some embodiments, the invention provides a method comprising gripping the rod and moving the driving rod distally wherein the distractor-inserter is an embodiment as described herein. In some embodiments, the step of ratcheting comprises the step of applying a force to the activating lever to move the lever toward the second position. In some embodiments, wherein the drive mechanism comprises a handle attached to the housing and an activating lever spring coupled to the activating lever and the handle, and wherein the activating lever spring opposes proximal movement of the lever relative to the handle, the step of ratcheting further comprises the steps of releasing the force on the activating lever and allowing the activating lever spring to move the activating lever toward the first position.

In some embodiments, the invention further provides a method comprising rotating the housing and at least a portion of the driving rod relative to the pair of opposing arms and to the implant, wherein the housing is rotatable about an axis extending between the opposing arms relative to the arms and to the implant, and wherein at least a portion of the driving rod is rotatable about the axis extending between the opposing arms relative to the pair of opposing arms and to the implant. This method may further comprise activating a drive mechanism wherein the activating moves the implant distally and distracts the pair of opposing arms. In some embodiments the step of inserting the implant comprises advancing the implant into the distracted space between the vertebrae. In some embodiments of the method for distracting adjacent vertebrae and inserting an implant between the distracted vertebrae, the advancing step comprises activating the drive mechanism and extending the implant beyond the distal end of the pair of opposing arms.

In some embodiments, the invention provides a method comprising mounting the implant to a driving rod of a vertebral distractor-inserter having a housing, a pair of opposing arms, and a ratchet drive mechanism in mechanical communication with the driving rod, wherein the driving rod extends through at least a portion of the housing and between the pair of opposing arms, positioning the distal end of the pair of arms between the vertebrae, distracting the vertebrae, wherein the distracting comprises activating the ratchet drive mechanism, inserting the implant between the distracted vertebrae, wherein the inserting comprises advancing the implant into the distracted space between the vertebrae, and wherein the advancing comprises activating the ratchet drive mechanism, and retracting the pair of opposing arms from between the vertebrae.

In some embodiments, the activating step moves the implant distally and distracts the pair of opposing arms. In some embodiments, advancing the implant comprises extending the implant beyond the distal end of the pair of opposing arms. In some embodiments, the activating the ratchet drive mechanism comprises ratcheting the driving rod distally, wherein the driving rod comprises an axis and a surface with a plurality of angled ratchet teeth on at least a portion of the surface, and wherein the ratchet drive mechanism comprises an activating lever capable of movement between a first position and a second position and mounted to the housing by an activating lever pivot, a first ratchet pawl coupled to the activating lever and adapted to engage the ratchet teeth and move the driving rod distally relative to the housing, and a second ratchet pawl adapted to engage the ratchet teeth and oppose proximal motion of the driving rod relative to the housing.

In some embodiments, the invention provides a method comprising a step of applying a force to the activating lever to move the lever from a first position toward a second position. In some embodiments the drive mechanism comprises a handle attached to the housing and an activating lever spring coupled to the activating lever and the handle, wherein the activating lever spring opposes proximal movement of the lever relative to the handle. In some embodiments, the step of ratcheting further comprises the steps of releasing the force on the activating lever and allowing the activating lever spring to move the activating lever toward the first position. In some embodiments wherein the implant was coupled to the distractor-inserter, the method comprises releasing the implant from the distractor-inserter.

In some embodiments, the invention provides a method comprising mounting the implant to a driving rod of a vertebral distractor-inserter having a pair of opposing arms having a distal end, a housing in mechanical communication with the pair of opposing arms which is rotatable about an axis extending between the opposing arms relative to the arms and to the implant, and a drive mechanism in mechanical communication with the driving rod, wherein the driving rod extends through at least a portion of the housing and between the pair of opposing arms and wherein at least a portion of the driving rod is rotatable about the axis extending between the opposing arms relative to the pair of opposing arms and to the implant, positioning the distal end of the pair of arms between the vertebrae, rotating the housing and at least a portion of the driving rod relative to the pair of opposing arms and to the implant, distracting the vertebrae, inserting the implant between the distracted vertebrae, and retracting the pair of opposing arms from between the vertebrae. The distracting may further comprise activating the drive mechanism, wherein the activating step comprises moving the implant distally and distracting the pair of opposing arms. Inserting the implant may comprise advancing the implant into the distracted space between the vertebrae. Advancing the implant may comprise activating the drive mechanism and extending the implant beyond the distal end of the pair of opposing arms.

The method may further comprise ratcheting the driving rod distally, wherein the driving rod comprises an axis and a surface with a plurality of angled ratchet teeth on at least a portion of the surface, and wherein the drive mechanism comprises an activating lever capable of movement between a first position and a second position and mounted to the housing by an activating lever pivot, a first ratchet pawl coupled to the activating lever and adapted to engage the ratchet teeth and move the driving rod distally relative to the housing, and a second ratchet pawl adapted to engage the ratchet teeth and oppose proximal motion of the driving rod relative to the housing. The ratcheting can comprise actions previously described herein.

Positioning the implant can further comprise using a depth adjustor to control the implantation depth between the vertebrae. Some embodiments of the method comprise mounting the implant to a driving rod of a vertebral distractor-inserter having a pair of opposing arms having a distal end and a depth guard, an implant depth adjustor that is adjustable to a plurality of implant depth settings, a housing in mechanical communication with the pair of opposing arms, and a drive mechanism in mechanical communication with the driving rod, wherein the driving rod extends through at least a portion of the housing and between the pair of opposing arms, and wherein the mounting comprises the step of adjusting the implant depth adjustor to control the maximum distal implant depth achievable during the inserting step, positioning the distal end of the pair of arms between the vertebrae, wherein the positioning comprises urging the pair of arms between the vertebrae up to the position where the depth guard contacts the vertebrae, distracting the vertebrae, inserting the implant between the distracted vertebrae, and retracting the pair of opposing arms from between the vertebrae.

In some embodiments, the invention provides a method comprising urging the pair of arms between the vertebrae. The step of urging is capable of moving the pair of arms between the vertebrae up to a distal depth of at most about 75 mm, or at least about 25 mm, or between about 35 mm and 55 mm. When referring to distal depth herein, “about” refers to variations in depth of between 1 mm and 2 mm, or between 2 mm and 5 mm. In some embodiments, the distal depth is the distance from the depth guard to the distal end of the pair of opposing arms. In some embodiments, the arms are inserted between the vertebrae up to a distal depth such that the depth guard is proximal to, but not abutting, the proximal side of the vertebrae. In some embodiments, the depth guard is proximal to and abutting, or contacting, the proximal side of the vertebrae.

In some embodiments, the implant depth achievable is a maximum of about 25 mm, a minimum of about 0 mm, or between about 3 mm and 8 mm. When referring to implant herein, “about” refers to variations in depth of between 1 mm and 2 mm, or between 2 mm and 5 mm. The implant depth is measured from the distal end of the depth stop to the distal end of the implant interface.

In some embodiments, the distractor-inserter has a housing and is adapted to push the housing proximally upon insertion of the implant to a selected implant depth setting, and the inserting comprises the step of retracting the pair of opposing arms from between the vertebrae by abutting the arm depth guard against a proximal side of the vertebrae and activating the drive mechanism.

In some embodiments, the invention provides a vertebral distractor-inserter, comprising a housing, a pair of opposing arms in mechanical communication with the housing, and a driving means for driving a rod and an implant at the distal end of the rod distally, wherein the driving means comprises an activating lever and a driving mechanism activated by the activating lever. The driving means may comprise a gripping means for gripping the rod while the activating lever drives the rod distally relative to the housing. The driving means may comprise a ratcheting means for incrementally ratcheting the rod distally as the activating lever is pulled proximally relative to the housing. The vertebral distractor-inserter may comprise a holding means for opposing proximal motion of the rod while resetting the lever after lever activation. The vertebral distractor-inserter may comprise a rotating means for allowing operator rotation of the housing relative to the pair of opposing arms about an axis extending between the opposing arms. The vertebral distractor-inserter may comprise a depth-controlling means for adjusting and controlling the depth to which an implant may be inserted by an operator between adjacent vertebrae.

Provided herein are a variety of methods for distracting adjacent vertebrae and for inserting an implant into the intervertebral space. One method includes a method of inserting a spinal implant between two vertebrae, comprising: (a) placing an intervertebral implant between a pair of opposing arms of a vertebral distractor-inserter, the distractor-inserted comprising: (i) the pair of opposing arms, having distal ends; (ii) a driving rod extending between the pair of opposing arms, wherein the driving rod comprises an axis and a surface with a plurality of angled ratchet teeth on at least a portion of the surface; and (iii) a drive mechanism in mechanical communication with the driving rod; (b) inserting said distal ends of the pair of opposing arms between a pair of vertebrae from a posterior angle; and (c) actuating said distractor-inserter, thereby distracting said vertebrae and inserting said implant between said vertebrae. In some embodiments, the method further provides for a device wherein the driving rod comprises an axis and a surface having a plurality of angled ratchet teeth on at least a portion of the surface. The method can further comprise a ratchet drive mechanism in communication with the angled ratchet teeth. Alternatively, the method can comprise the use of a device comprising a screw drive mechanism. The device can be introduced between the pair of vertebrae from a posterior angle, where the posterior angle is generally parallel to the axial plane and sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is substantially parallel to the axial plane but deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the other side of the spinous process. In some embodiments, the implant has laterally opposing walls that are substantially curved. In some embodiments of the method, one of the opposing walls is substantially parallel to the axis of insertion and the other opposing wall is substantially curved. In some embodiments of the method, the actuating step can further comprise inserting an implant having laterally opposing walls in the intervertebral space wherein the inserting of the implant comprises repositioning the implant in the intervertebral space by following the curvature of the implant. The method can further comprise the use of a distractor-inserter in which the distractor-inserter comprises a housing in mechanical communication with the pair of opposing arms, wherein the driving rod extends through at least a portion of the housing. The distractor-inserter can comprise a handle attached to the housing. Additionally, the method for inserting a spinal implant between two vertebrae can comprise the use of a ratchet drive mechanism, wherein the ratchet drive mechanism of the distractor-inserter comprises: (a) an activating lever mounted to the housing by an activating lever pivot; (b) a first ratchet pawl coupled to the activating lever and adapted to engage the ratchet teeth and move the driving rod distally relative to the housing; and (c) a second ratchet pawl adapted to engage the ratchet teeth and oppose proximal motion of the driving rod relative to the housing. Furthermore, the method can comprise the use of a distractor-inserter can comprise a handle attached to the housing and the ratchet drive mechanism comprises an activating lever spring coupled to the activating lever and the handle, wherein the activating lever spring opposes proximal movement of the lever relative to the handle. In some embodiments of the method, the ratchet-drive mechanism comprises: (a) a first pawl spring that opposes downward movement of the first pawl; and (b) a second pawl spring that opposes downward movement of the second pawl. The surface of the driving rod comprises an area that is substantially free of ratchet teeth on a contiguous longitudinal surface of the driving rod, and wherein the driving rod is movable proximally relative to the housing upon rotation of the rod about its axis such that the ratchet pawls are in contact with the contiguous longitudinal surface that is free of ratchet teeth. The ratchet teeth can disengage from the first and second ratchet pawls upon rotation of the driving rod about its axis.

Additionally provided herein is a method of inserting a spinal implant between two vertebrae, comprising: (a) placing an intervertebral implant between a pair of opposing arms of a vertebral distractor-inserter, the distractor-inserted comprising: (i) a pair of opposing arms having distal ends; (ii) a housing in mechanical communication with the pair of opposing arms and rotatable about an axis extending between the opposing arms; and (iii) a driving rod extending through at least a portion of the housing and between the pair of opposing arms; (b) inserting said distal ends of the pair of opposing arms between a pair of vertebrae from a posterior angle; and (c) actuating said distractor-inserter, thereby distracting said vertebrae and inserting said implant between said vertebrae. The method can further provide for the use of a distractor-inserter wherein the driving rod comprises a distal end having an implant interface, wherein the housing and at least a portion of the driving rod are rotatable relative to the pair of opposing arms and the implant interface. The implant interface can additionally comprises an interface rotation element, whereby the interface rotation element allows rod rotation relative to the pair of opposing arms. The housing can comprises a housing rotation element, whereby the housing rotation element allows housing and rod rotation relative to the pair of opposing arms. In some embodiments, the distractor-inserter is adapted for single-handed use. The method can further provide for a device that can be introduced between the pair of vertebrae from a posterior angle, where the posterior angle is generally parallel to the axial plane and sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is substantially parallel with respect to the axial plane but deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the other side of the spinous process. In some embodiments of the method, the implant has laterally opposing walls that are substantially curved. In some embodiments, one of the opposing walls is substantially parallel to the axis of insertion and the other opposing wall is substantially curved. In some embodiments of the method, the actuating step can further comprise inserting an implant having laterally opposing walls in the intervertebral space wherein the inserting of the implant comprises repositioning the implant in the intervertebral space by following the curvature of the implant.

Further provided herein is a method of inserting an implant between vertebrae, comprising: (a) placing a vertebral implant between a pair of opposing arms of a vertebral distractor-inserter, said distractor-inserter comprising: (i) a housing; (ii) a pair of opposing arms in mechanical communication with the housing; (iii) a driving rod extending through at least a portion of the housing and between the pair of opposing arms; and (iv) a drive mechanism in mechanical communication with the driving rod, wherein the drive mechanism is adapted to move the driving rod distally relative to the housing, and wherein the distractor-inserter is adapted for single-handed distraction of vertebrae and insertion of a vertebral implant; (b) inserting said distal ends of the pair of opposing arms between a pair of vertebrae from a posterior angle; and actuating said distractor-inserter, thereby distracting said vertebrae and inserting said implant between said vertebrae. The method can further provide for a device that can be introduced between the pair of vertebrae from a posterior angle, where the posterior angle is generally parallel to the axial plane and sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the device is introduced at a posterior angle that is substantially parallel to the axial plane but which deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the other side of the spinous process. In some embodiments, the implant has laterally opposing walls that are substantially curved. In some embodiments, one of the opposing walls is substantially parallel to the axis of insertion and the other opposing wall is substantially curved. In some embodiments of the method, the actuating step can further comprise inserting an implant having laterally opposing walls in the intervertebral space wherein the inserting of the implant comprises repositioning the implant in the intervertebral space by following the curvature of the implant.

Another method provided herein is a method for distracting adjacent vertebrae and inserting an implant between the distracted vertebrae from a posterior angle, comprising: (a) mounting the implant to a driving rod of a vertebral distractor-inserter having a pair of opposing arms, a distal end, and a drive mechanism in mechanical communication with the driving rod, wherein the driving rod extends between the pair of opposing arms; (b) positioning the distal end of the pair of arms between the vertebrae from a posterior angle; (c) distracting the vertebrae by single-handed operation of the vertebral distractor-inserter; (d) inserting the implant between the distracted vertebrae by single-handed operation of the vertebral distractor-inserter; and (e) retracting the pair of opposing arms from between the vertebrae. The distracting step can further comprise activating the drive mechanism using one hand, wherein the activating moves the implant distally and distracts the pair of opposing arms. In some embodiments of the method, the vertebral distractor-inserter has a housing in mechanical communication with the pair of opposing arms, wherein the driving rod extends through at least a portion of the housing. Additionally, the inserting step of the method for distracting adjacent vertebrae can further comprise advancing the implant into the distracted space between the vertebrae. The advancing step can comprise activating the drive mechanism using one hand and extending the implant beyond the distal end of the pair of opposing arms. In some embodiments, the method further comprises the additional step of releasing the implant from the distractor-inserter. The method provided can include the use of a distractor-inserter comprising a the pair of opposing arms comprising a depth guard, and wherein the positioning step comprises urging the pair of arms between the vertebrae up to the position where the depth guard contacts the vertebrae. In some embodiments of the method, the vertebral distractor-inserter has a housing in mechanical communication with the pair of opposing arms, wherein the driving rod extends through at least a portion of the housing, and wherein the activating the drive mechanism comprises the step of ratcheting the driving rod distally, wherein the driving rod comprises: (a) an axis and (b) a surface with a plurality of angled ratchet teeth on at least a portion of the surface, and wherein the drive mechanism comprises: (i) an activating lever capable of movement between a first position and a second position and mounted to the housing by an activating lever pivot, (ii) a first ratchet pawl coupled to the activating lever and adapted to engage the ratchet teeth and move the driving rod distally relative to the housing, and (iii) a second ratchet pawl adapted to engage the ratchet teeth and oppose proximal motion of the driving rod relative to the housing. The method can further provide for a device that can be introduced between the pair of vertebrae from a posterior angle, where the posterior angle is generally parallel to the axial and sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is substantially parallel to the axial plane but deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the other side of the spinous process. In some embodiments, the implant has laterally opposing walls that are substantially curved. In some embodiments, one of the opposing walls is substantially parallel to the axis of insertion and the other opposing wall is substantially curved. In some embodiments of the method, the actuating step can further comprise inserting an implant having laterally opposing walls in the intervertebral space wherein the inserting of the implant comprises repositioning the implant in the intervertebral space by following the curvature of the implant.

In some embodiments, further provided is a method for distracting adjacent vertebrae and inserting an implant between the distracted vertebrae from a posterior angle, comprising the steps of: (a) mounting the implant to a driving rod of a vertebral distractor-inserter having a pair of opposing arms, and a ratchet drive mechanism in mechanical communication with the driving rod, wherein the driving rod extends between the pair of opposing arms; (b) positioning the distal end of the pair of arms between the vertebrae from a posterior angle; (c) distracting the vertebrae, wherein the distracting comprises activating the ratchet drive mechanism; (d) inserting the implant between the distracted vertebrae, wherein the inserting comprises advancing the implant into the distracted space between the vertebrae, and wherein the advancing comprises activating the ratchet drive mechanism; and (e) retracting the pair of opposing arms from between the vertebrae. The activating step can further comprise moving the implant distally and distracting the pair of opposing arms. The step of activating the ratchet drive mechanism, in some embodiments, can further comprise the step of ratcheting the driving rod distally, wherein the driving rod comprises: (a) an axis; and (b) a surface with a plurality of angled ratchet teeth on at least a portion of the surface, and wherein the ratchet drive mechanism comprises: (i) an activating lever capable of movement between a first position and a second position and mounted to the housing by an activating lever pivot, (ii) a first ratchet pawl coupled to the activating lever and adapted to engage the ratchet teeth and move the driving rod distally relative to the housing, and (iii) a second ratchet pawl adapted to engage the ratchet teeth and oppose proximal motion of the driving rod relative to the housing. The device can be introduced between the pair of vertebrae from a posterior angle, where the posterior angle is generally parallel to the axial and sagittal planes. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is substantially parallel with respect to the axial plane but which deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the other side of the spinous process. In some embodiments, the implant has laterally opposing walls that are substantially curved. In some embodiments, one of the opposing walls is substantially parallel to the axis of insertion and the other opposing wall is substantially curved. In some embodiments of the method, the actuating step can further comprise inserting an implant having laterally opposing walls in the intervertebral space wherein the inserting of the implant comprises repositioning the implant in the intervertebral space by following the curvature of the implant.

Yet another embodiment of the method provided herein includes a method for distracting adjacent vertebrae and inserting an implant between the distracted vertebrae from a posterior angle, comprising the steps of: (a) mounting the implant to a driving rod of a vertebral distractor-inserter having: (i) a pair of opposing arms having a distal end, (ii) a housing in mechanical communication with the pair of opposing arms which is rotatable about an axis extending between the opposing arms relative to the arms and to the implant, and (iii) a drive mechanism in mechanical communication with the driving rod, wherein the driving rod extends through at least a portion of the housing and between the pair of opposing arms and wherein at least a portion of the driving rod is rotatable about the axis extending between the opposing arms relative to the pair of opposing arms and to the implant; (b) positioning the distal end of the pair of arms between the vertebrae from a posterior angle; (c) rotating the housing and at least a portion of the driving rod relative to the pair of opposing arms and to the implant; (d) distracting the vertebrae; (e) inserting the implant between the distracted vertebrae; and (f) retracting the pair of opposing arms from between the vertebrae. The distracting step can further comprise activating the drive mechanism, wherein the activating moves the implant distally and distracts the pair of opposing arms. Additionally, the inserting step of the method can further comprise advancing the implant into the distracted space between the vertebrae. The device can be introduced between the pair of vertebrae from a posterior angle, where the posterior angle is generally parallel to the axial plane and sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is substantially parallel to the axial plane but deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the other side of the spinous process. In some embodiments, the implant has laterally opposing walls that are substantially curved. In some embodiments, one of the opposing walls is substantially parallel to the axis of insertion and the other opposing wall is substantially curved. In some embodiments of the method, the actuating step can further comprise inserting an implant having laterally opposing walls in the intervertebral space wherein the inserting of the implant comprises repositioning the implant in the intervertebral space by following the curvature of the implant.

Another embodiment of the method provided herein comprises a method for distracting adjacent vertebrae and inserting an implant between the distracted vertebrae from a posterior angle, comprising the steps of: (a) mounting the implant to a driving rod of a vertebral distractor-inserter having (i) a pair of opposing arms having a distal end and a depth guard, (ii) an implant depth adjustor that is adjustable to a plurality of implant depth settings, (iii) a housing in mechanical communication with the pair of opposing arms, and (iv) a drive mechanism in mechanical communication with the driving rod, wherein the driving rod extends through at least a portion of the housing and between the pair of opposing arms, wherein the mounting comprises the step of adjusting the implant depth adjustor to control the maximum distal implant depth achievable during the inserting step; (b) positioning the distal end of the pair of arms between the vertebrae, wherein the positioning comprises urging the pair of arms between the vertebrae up to the position where the depth guard contacts the vertebrae; (c) distracting the vertebrae; (d) inserting the implant between the distracted vertebrae from a posterior angle; and (e) retracting the pair of opposing arms from between the vertebrae. The device can be introduced between the pair of vertebrae from a posterior angle, where the posterior angle is generally parallel to the axial plane and sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is substantially parallel to the axial plane but deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the other side of the spinous process. In some embodiments, the implant has laterally opposing walls that are substantially curved. In some embodiments, one of the opposing walls is substantially parallel to the axis of insertion and the other opposing wall is substantially curved. In some embodiments of the method, the actuating step can further comprise inserting an implant having laterally opposing walls in the intervertebral space wherein the inserting of the implant comprises repositioning the implant in the intervertebral space by following the curvature of the implant.

Further provided herein is a method of implanting an implant in an intervertebral space comprising: (a) providing a distractor-inserter comprising (i) a pair of opposing arms, having distal ends; (ii) a driving rod extending between the pair of opposing arms; and (iii) a drive mechanism in mechanical communication with the driving rod; (b) inserting the distal end of the pair of arms between the vertebrae from a posterior angle; (c) actuating the distractor-inserter, thereby distracting said vertebrae and inserting said implant between said vertebrae; and (d) repositioning said implant so that it occupies an anterior vertebral space. The method further comprises inserting an implant that has laterally opposing walls that are substantially curved with respect to the axis of insertion. The method can further comprise insertion of an implant from a posterior angle, where the posterior angle is generally parallel to the axial plane and sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is substantially parallel to the axial plane but which deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae.

Yet another method provided herein is a method of implanting implants into an intervertebral space comprising: (a) providing a distractor-inserter comprising (i) a pair of opposing arms, having distal ends; (ii) a driving rod extending between the pair of opposing arms; and (iii) a drive mechanism in mechanical communication with the driving rod; (b) inserting the distal end of the pair of arms between the vertebrae from a posterior angle; (c) actuating the distractor-inserter, thereby distracting said vertebrae and inserting said implant between said vertebrae; and (d) repeating steps (a)-(c) on the contralateral side of the spinous process. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The implant can be boxed-shaped. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the contralateral side of the spinous process. In some embodiments, the posterior angle is substantially parallel to the axial plane and the sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is parallel to the axial plane but which deviates about 20 to about 60 degrees with respect to the sagittal plane.

INCORPORATION BY REFERENCE

DETAILED DESCRIPTION OF THE INVENTION

The invention disclosed herein provides a tool to aid in intervertebral disc replacement and/or spinal fusion. The tool, i.e. device, allows a spinal surgeon to more easily access and position a replacement disc or graft within the vertebral space. In some embodiments, the device allows a spinal surgeon to control implantation depth of a replacement disc or graft. Additionally disclosed is a multifunctional device that permits substantially single-handed operation. Such a device reduces the number of tools required for performing multiple functions during disc replacement surgery and/or spinal fusion surgery, while freeing up an operator's other hand. In some embodiments, the tool, i.e. device, is rotatable about an axis extending between a pair of opposed arms. Such embodiments provide improved ergonomics and ease of use during the disc replacement surgery and/or spinal fusion surgery. By providing one or more of the preceding advantages, the device described herein improves the ease and speed with which disc replacement or spinal fusion surgery can be completed using an anterior lumbar angle. The terms “vertebral distractor-inserter,” “distractor-inserter,” and “device” are interchangeable as used herein.

The invention will now be further described with reference to the appended drawings, which are intended to be illustrative of certain preferred embodiments of the invention, but are not intended to limit the scope of the invention. One of skill in the art will recognize that other embodiments of the invention are possible within the scope of the invention; and no disclaimer of such additional embodiments is intended by referring to the illustrative examples.

The spinal cord is a collection of neurons that travels within the vertebral column and is an extension of the central nervous system. The spinal cord extends from the brain and is enclosed in and protected by the bony vertebral column. A body cavity5with spinal column is shown inFIG. 1A. The devices of the invention are designed to interact with the human spinal column10, as shown inFIG. 1A, which is comprises of a series of thirty-three stacked vertebrae12divided into five regions. The cervical region includes seven vertebrae, known as C1-C7. The thoracic region includes twelve vertebrae, known as T1-T12. The lumbar region contains five vertebrae, known as L1-L5. The sacral region is comprised of five fused vertebrae, known as S1-S5, while the coccygeal region contains four fused vertebrae, known as Co1-Co4.

In order to understand the configurability, adaptability, and operational aspects of the invention, it is helpful to understand the anatomical references of the body50with respect to which the position and operation of the devices and components thereof, are described. There are three anatomical planes generally used in anatomy to describe the human body and structure within the human body; the axial plane52, the sagittal plane54and the coronal plane56(seeFIG. 1B). Additionally, devices and the operation of devices are better understood with respect to the caudal60direction and/or the cephalad direction62. Devices positioned within the body can be positioned dorsally70(or posteriorly) such that the placement or operation of the device is toward the back or rear of the body. Alternatively, devices can be positioned ventrally72(or anteriorly) such that the placement or operation of the device is toward the front of the body. Various embodiments of the spinal devices and systems of the present invention may be configurable and variable with respect to a single anatomical plane or with respect to two or more anatomical planes. For example, a component may be described as lying within and having adaptability or operability in relation to a single plane. For example, a stem may be positioned in a desired location relative to an axial plane and may be moveable between a number of adaptable positions or within a range of positions. Similarly, the various components can incorporate differing sizes and/or shapes in order to accommodate differing patient sizes and/or anticipated loads. The device may be used in any individual for whom use of the device is suitable, including any animal belonging to the mammalia class, such as warm-blooded, vertebrate animals.

FIGS. 2A,2B, and2C depict external views of one currently preferred embodiment of the device168.FIG. 2Adepicts an embodiment of a vertebral distractor-inserter168comprising a housing136, a pair of opposing arms152A,152B in mechanical communication with the housing136, a driving rod126extending through at least a portion of the housing136and between the pair of opposing arms152A,152B, wherein the driving rod126comprises an axis118and a surface166with a plurality of angled ratchet teeth110on at least a portion of the surface166, and a ratchet drive mechanism in mechanical communication with the driving rod126. In some embodiments, the vertebral distractor-inserter168comprises a handle128attached to the housing136. In some embodiments, the vertebral distractor-inserter168does not comprise a housing136. In some embodiments, the housing136does not enclose the rod126. In some embodiments, the rod126is external to, but in communication with, the housing136.

FIG. 2Afurther depicts an embodiment having an activating lever102, which is in mechanical communication with the driving rod126. Movement of the activating lever102in the direction of the handle128causes the driving rod126and an implant (not shown) at the distal end of the driving rod126to move distally relative to the housing136. The mechanical communication may be effected through a number of means; in the depicted embodiment the mechanical communication is through a ratcheting drive mechanism124within the housing136. The ratcheting drive mechanism124uses ratchet teeth110to grip the driving rod126and drive the implant and the rod126distally when the activating lever102is moved toward the handle128.

The embodiment shown has an implant coupler140and an implant depth adjustor142. The implant coupler140abuts the implant and transfers force from the driving rod126to the implant, which in turn forces the lower arm152B and the upper arm152A apart, providing distracting force. The implant depth adjustor controls the depth to which an implant can be implanted when the depth stop146contacts the vertebra (not shown) during insertion. The embodiment has an arm depth guard112, which determines the maximum depth to which the arms152A,152B can be inserted between the vertebrae during distraction. In the embodiment shown inFIG. 2A, the driving rod126is fully retracted and the distal end of the arms152A,152B are ready for insertion between the vertebrae for subsequent distraction and implant insertion.

FIG. 2Bshows a similar embodiment of the device168in the fully extended position, wherein the implant coupler140, depth stop146and depth adjustor142are at their most distal position. This view shows what the device168would look like after use of the device168to distract the vertebrae and after insertion of the implant. This figure also shows an arm pivot114, about which the arms152A,152B may pivot to distract the vertebrae upon distal movement of the implant and the implant coupler140, the implant depth adjustor142, and the implant depth stop146.

FIG. 2Cdepicts a top view of an embodiment of the device168with the implant coupler140, depth stop146, and adjustor142in an intermediate position between full retraction and full extension. In this view, the housing136is shown along with the driving rod126, which extends through the housing136. Also visible is the implant depth stop146, which travels in a groove182of the arm152A. This view also shows a knob150on the proximal end of the driving rod126, discussed further below.

FIG. 3Ashows a cutaway side view of an embodiment of the device268having ratchet teeth210engaged. Further shown is a first ratchet pawl232and a first pawl spring230which work together with the activating lever202, activating lever spring206and activating lever pivot204to drive the driving rod226distally when the activating lever202is moved toward the handle228(i.e. toward a second position from a first position, shown by the double-headed arrow ofFIG. 3A). When an operator grips the handle and the activating lever202in one hand and pulls the activating lever202proximally toward the handle228, the activating lever202moves the first ratchet pawl232distally by pivoting about the activating lever pivot204. Since the first ratchet pawl232is engaged against the ratchet teeth210of the driving rod226, the distal motion of the ratchet pawl232drives the driving rod226distally. Also depicted in this view is a second ratchet pawl260and a second pawl spring258. The second ratchet pawl260cannot move distally or proximally, but the second ratchet spring258allows the second pawl to move away from the driving rod226as each angled ratchet tooth210advances distally. Once each tooth210passes the second pawl260, the pawl spring258pushes the second pawl260back toward the driving rod226, to engage the next ratchet tooth210along the driving rod226. Thus the second ratchet pawl260allows distal motion of the arm226and prevents proximal motion of the arm226. As the activating lever202is pulled again or farther toward the handle228, further distal motion is imparted to the arm226.

Thus, the second ratchet pawl260and the second pawl spring258cooperate to restrict or oppose proximal motion of the driving rod226as the activating lever202is reset away from the handle228. In the depicted embodiment, the activating lever202has a spring206which biases the lever202toward the first position. Once the operator releases the force on the lever202, the activating lever spring206moves the lever202away from the handle228toward its original position. As this occurs, the first pawl232and first pawl spring230, linked to the activating lever202, are also returned toward their original positions relative to the housing236prior to the operator pulling the lever202proximally. This occurs with no distal or proximal motion of the driving rod226since the first pawl spring230allows the first pawl232to move away and toward the driving rod226along the ratchet teeth210of the rod226as the pawl232ramps along the teeth210proximally. The second ratchet pawl260, engaged against the ratchet teeth210, opposes proximal motion of the rod226during this action. In embodiments where a gripping or other type of driving mechanism is used, the second ratcheting pawl260and spring258may be used to provide similar restricted proximal motion where the driving rod226comprises some ratchet teeth210on at least a portion of the rod226which can cooperate with the second ratchet pawl260and spring258.

It is to be understood that the spring206may be eliminated in some embodiments and still provide substantially single handed operation. In such cases, the activating lever202will have to be moved toward the first position manually. This can be facilitated by including a closed handle (loop) similar to those common on scissors and forceps at the lower end of the activating lever202, through which an operator may place her fingers and by means of which an operator can impart force to the lever202in either the direction away from or toward the handle228with a single hand.

In another embodiment, the device comprises a holding means wherein a second ratchet pawl and second ratchet spring are not present. The holding means instead may comprise, for example, a pneumatic grip, a hook, a latch, a grabbing device, the gripping mechanism described further herein, manually holding the driving rod in its distal position, or another mechanical means of restricting proximal motion.

In other embodiments, the device comprises a driving means comprising a first ratchet pawl and a spring that engages a thread which winds around the driving rod. Ratchet teeth may be unnecessary in this embodiment. The activating lever may instead drive the driving rod and implant distally by engaging the threads in the same ratcheting manner described herein, and retraction may be achieved by rotating the driving rod such that the rod moves proximally with the ratchet pawls engaged against the threads of the rod.

In other embodiments, the device comprises a driving means comprising for example, a pneumatic grip, a hook, a latch, a grabbing device, the gripping mechanism described further herein, an element adapted and configured for manually pushing the driving rod distally, or another mechanical means of moving the rod and the implant distally to distract the arms and insert the implant. These and similar embodiments will be apparent to the person skilled in the art upon consideration of alternative embodiments described herein.

Further depicted inFIG. 2Ais an implant interface248, an implant depth stop246, an implant depth adjustor242, and an implant coupler240all of which are adapted and configured to cooperate with the arms252A,252B and the driving rod226and the implant to drive the implant distally, to distract the vertebrae, and to place the implant within the intervertebral space at a controlled depth. Also shown is the arm pivot214and the arm spring216, which allow outward motion of the arms252A,252B away from the axis218of the driving rod226as the implant and implant interface248are driven distally. Further depicted in this figure is a first rotation element234and second rotation element262, which together allow the handle228and the driving rod226to rotate relative to the arms252A,252B, the implant interface248, and the implant.

In some embodiments, the vertebral distractor-inserter268comprises a ratchet drive mechanism224, which comprises an activating lever202mounted to the housing236by an activating lever pivot204, a first ratchet pawl232coupled to the activating lever202and adapted to engage the ratchet teeth210and move the driving rod226distally relative to the housing236, and an engaging element to oppose proximal motion of the driving rod relative to the housing. The engaging element can be, for example, a gripping element470as shown inFIG. 5, a grabbing element, a hooking element, a pressurized holding element; or it can be a manual pushing or holding element.

In some embodiments the ratchet drive mechanism224comprises an activating lever spring206coupled to the activating lever202and the handle228, wherein the activating lever spring206opposes proximal movement of the lever202relative to the handle228. In some embodiments of the distractor-inserter268, the ratchet drive mechanism224comprises a first pawl spring230that opposes downward movement of the first pawl232and a second pawl spring258that opposes downward movement of the second pawl260.

In some embodiments of the distractor-inserter268, the driving rod226comprises a distal end and an implant interface248coupled to the distal end of the driving rod226. In some embodiments, the distractor-inserter268comprises an implant in contact with the implant interface248, whereby distal motion of the driving rod226imparts distal motion to the implant through the implant interface248; and distal motion of the implant in turn forces the opposing arms252A,252B apart.

In some embodiments, each opposing arm252A,252B comprises an arm pivot214. Some embodiments comprise a pair of opposing arms252A,252B comprising an arm spring216. Some embodiments comprise an opposing arm252A,252B comprising an arm depth guard212. In some embodiments, the implant interface248comprises an implant coupler240.

FIG. 3Bshows a cutaway side view of the housing236of an embodiment of the device268having ratchet teeth210engaged by the drive mechanism224wherein the activating lever202is in a first position. A first ratchet pawl232engages the ratchet teeth210of the driving rod226and a first pawl spring230opposes motion of the first pawl232away from the driving rod226(downward, in the depicted embodiment, although, it could be in any direction away from the driving rod226). Also shown is a second ratchet pawl260. A second pawl spring258opposes motion of the second pawl260away from the driving rod226(downward, in this case, although it could be in any direction away from the driving rod226). Further depicted is the activating lever pivot204about which the activating lever202pivots to drive the driving rod226and, therefore, the implant distally by engaging and moving the ratchet teeth210distally when the activating lever202is moved toward the handle228. Also depicted is the activating lever spring206, which opposes activating lever202movement toward the handle228, and which is capable of moving the activating lever202away from the handle228when the activating lever202is released.

FIG. 3Cshows a cutaway side view of the housing of an embodiment of the device having ratchet teeth210engaged by the drive mechanism224, wherein the activating lever202is in a second position toward the handle228. The drive mechanism224, the first ratchet pawl232, and the driving rod226are shown in as they appear when the activating lever202is moved toward the handle228. As can be seen, movement of the activating lever202toward the handle228causes the first ratchet pawl232, and the driving rod226, through engagement of the ratchet pawl232with the ratchet teeth210of the driving rod226, to move distally relative to the housing236.

In some embodiments, the vertebral distractor-inserter268is adapted for single-handed use. In such an embodiment, the vertebral distractor-inserter268is adapted for substantially single-handed distraction of vertebrae and insertion of a vertebral implant.

It is to be understood in regard to the phrase “single-handed,” the functions of holding the device in place and advancing the rod226and implant may in most instances be performed with a single hand. However, it is also noted that in some cases, depending upon operator preference and the vagaries of patient physiology, two hands may be used, e.g. to impart greater force to the lever202, without departing from the spirit and scope of the invention. The phrase “single-handed” thus distinguishes embodiments of the invention over distractor-inserter devices in which the device is held in place with one hand and the implant is advanced distally by twisting or striking an implant arm. It is considered that whether used with one hand or two, the device of the present invention provides force to both distract vertebrae and advance the implant with lessened torque, impact force or other physiologically disruptive forces, and thus less trauma to the patient, than is generally required with previously known devices. In currently preferred embodiments, the device of the present invention also permits the operator to hold the device in place and impart force for distraction and insertion with a single hand. In addition to the aforementioned advantages, single handed use is amenable to less invasive surgery than two-handed use.

Some embodiments of the device are adapted and configured to allow retraction of the implant interface and the driving rod relative to the arms of the device. This may be achieved in a number of ways. In the embodiment of the device368depicted inFIG. 4A, a cutaway side view of the device368is shown having ratchet teeth310disengaged for retraction of the driving rod326. The driving rod of this embodiment has a surface366comprising a substantially smooth area364and ratchet teeth310. When the knob350is turned about the axis318, preferably with knob350, such that the ratchet teeth310are no longer engaged by the ratchet pawl332, or the ratchet pawls332,360if there are two, the driving rod326is free to be moved proximally (or retracted) relative to the housing336and the arms352. Although this action is favorably carried out by the operator holding the handle328in one hand and turning the knob350with the other, this action is not to be interpreted as derogating in any way single-handed operation of the device368, as single-handed operation generally refers to simultaneously holding the handle328and imparting drive force to the driving arm326with a single hand, and that only in most cases. As the driving rod326may be easily disengaged from the pawls332,360with, for example, a single 180° twist about the axis318, it is considered that the present invention provides for easier and faster retraction of the driving arm326than is provided by previously known devices that require screwing the arm backwards.

In another embodiment, the driving rod326may comprise a threading around the driving rod instead of ratchet teeth, wherein the ratchet pawl332or ratchet pawls332,360if there are two, may engage the threads instead of ratchet teeth. To retract the rod326, rather than turning the driving rod326until the pawl(s)332,360disengages the teeth, and then pulling the rod326proximally, the rod326and, thereby, the implant interface248, may be retracted by turning the rod326around the long axis of the rod326. In this embodiment, the rod threads are not disengaged from at least the first ratchet pawl332.

Other embodiments may comprise combinations of threads, ratchet teeth310, and/or a substantially smooth area364along the driving rod surface366, and a combination of ratcheting and gripping elements to provide the controlled distal and proximal movement of the driving rod326, the implant, and implant interface248relative to the arms352A,352B, and to the housing336.

Likewise, the embodiment ofFIG. 4Bshows a cutaway side view the housing336of an embodiment of the device368having ratchet teeth310of the driving rod326disengaged from the first ratchet pawl332and second ratchet pawl360for retraction of the driving rod326. Also shown is the substantially smooth area364of the driving rod326surface366which allows proximal retraction of the driving rod326and, thereby, the implant interface248.

If needed or desired, retraction of the device368using the features and methods described herein may also allow retraction of the implant prior to insertion of the implant between the vertebrae.

In some embodiments, the ratchet teeth310extend along the driving rod326a length sufficient to allow the arms352to touch when the implant is loaded prior to distraction and to allow the implant to be inserted between the vertebrae. In some embodiments, for example, the ratchet teeth310extend along the length of the driving rod326for between about 6 and about 10 inches, for about 8 inches, for about 12 inches, for about 16 inches, for at least 3 inches, or for the entire length of the rod. In referring to the ratchet teeth length along the rod, “about” refers to variations of 0.5 inches to 1 inch, or of 1 inch to 2 inches.

In some embodiments, the surface366of the driving rod326comprises an area364that is substantially free of ratchet teeth on a contiguous longitudinal surface366of the driving rod, and the driving rod326is movable proximally relative to the housing336upon rotation of the rod326about its axis318such that the ratchet pawls332,360are in contact with the contiguous longitudinal surface364that is free of ratchet teeth. In some embodiments, the ratchet teeth310disengage from first and second ratchet pawls332,360upon rotation of the driving rod326about its axis318. In some embodiments, the driving rod326comprises a proximal end having a knob350.

FIG. 5Ashows a non-ratcheting embodiment of the device468. The device468has a pair of opposing arms452A,452B and two gripping elements470,474, wherein the first gripping element470is adapted and configured to grip and drive the driving rod426distally when the activating lever402is moved toward the handle428. The second gripping element474allows distal movement of the driving rod426, but opposes proximal motion of the driving rod426when the activating lever402is released and allowed to move away from the handle428, for example, to its original resting (first) position. The first gripping element470also releases its grip on the driving rod426when the lever402is moved away from the handle428, for example, to its original resting position. The first gripping spring472moves the first gripping element470proximally when the activating lever402is released. The first gripping element470is adapted and configured to only grip the driving rod426upon driving rod distal motion. Similarly, in the embodiment ofFIG. 5, the second gripping element474is adapted and configured to only grip the driving rod426upon driving rod proximal motion.

FIG. 5Bshows a cutaway side view of the housing436of a non-ratcheting embodiment of the device468. The first gripping spring472opposes the distal motion of the first gripping element470and the driving rod426that an operator causes by moving the activating lever402toward the handle428. A second gripping spring476opposes proximal motion of the driving rod426when the lever402moves away from the handle428. Movement of the lever402away from the handle428may be manually forced, or may be the result of an activating lever spring206within the handle428and attached to the activating lever pivot204which opposes movement of the lever402toward the handle428. Also depicted is a gripping release lever478, which is adapted to permit release the second gripping member474to allow the driving rod426to be retracted.

Some embodiments comprise a drive mechanism424comprising at least one gripping element470which opposes proximal motion of the drive mechanism412. Activating the lever402drives the implant distally by moving the driving rod426. As the activating lever402returns to its original position, the first gripping element470releases the driving rod, however the second gripping element474opposes proximal motion of the driving rod426and the implant. The drive mechanism may comprise a gripping spring,472, or476, or two gripping springs472and476.

In some embodiments of the distractor-inserter468, the drive mechanism424comprises a gripping element474and a ratcheting drive mechanism as described previously. Some embodiments comprise other means for driving implant distally. These means can be other mechanical mechanisms capable of allowing unidirectional movement, along with a release mechanism for reversing such unidirectional movement. Some embodiments comprise other means for distracting the arms. The means for distracting may be other tools altogether through which the distractor-inserter may be placed and used to place the implant.

FIGS. 6A & 6Bdepict views of an embodiment of the device568showing relative rotation of the arms552A,552B and the handle528. Also shown in these views are at least one arm depth guard512and the activating lever502. In use, the patient is stationary, and thus the arms552A,552B of the device568and the implant must remain in a fixed position relative to the patient during distraction and insertion for patient safety and for optimal implantation results. However, the user of the device568may need to be at a variety of angles relative to the patient; thus, the device is adapted to allow distraction and insertion in a more ergonomic manner for the user and, thus, a safer manner for the patient. This is achieved by allowing at least one degree of freedom of rotation in the device568. That is, the device568is adapted to allow rotation of the handle528, activating lever502, and housing536relative to the arms552A,552B and the implant, about the axis218of the driving rod226. This is achieved by providing at least one rotation element234(not shown inFIG. 6, shown inFIG. 3A) that allows free rotation of these elements relative to each other.

FIG. 6Ashows the axial view of the device568looking from the distal end to the proximal end of the device568. In this view, the arms552A,552B are in a neutral position relative to the housing536. InFIG. 6B, also an axial view of the device568looking from the distal end to the proximal end of the device568, the arms552A,552B are rotated relative to the housing536about the driving rod axis218. While it may appear that the arms552A,552B are rotated, in use the rotation is relative, and the user will more likely rotate the housing536and the activating lever502relative to the arms552A,552B, keeping the arms552A,552B and implant aligned appropriately with the vertebral anatomy of the patient.

In some embodiments, a vertebral distractor-inserter568comprises a pair of opposing arms552A,552B, a housing536in mechanical communication with the pair of opposing arms552A,552B and rotatable about an axis218extending between the opposing arms552A,552B, and a driving rod226extending through at least a portion of the housing536and between the pair of opposing arms552A,552B. Some embodiments comprise a distal end having an implant interface248, wherein the housing536and at least a portion of the driving rod226are rotatable relative to the pair of opposing arms552A,552B and the implant interface248. Some embodiments further comprise an implant interface248comprising an interface rotation element262, whereby the interface rotation element allows rod226rotation relative to the pair of opposing arms552A,552B. Some embodiments further comprise a housing536comprising a housing rotation element234, whereby the housing rotation element234allows housing536and rod226rotation relative to the pair of opposing arms552A,552B.

In some embodiments, a vertebral distractor-inserter568comprises a pair of opposing arms552A,552B, a housing536in mechanical communication with the pair of opposing arms552A,552B and rotatable about an axis218extending between the opposing arms552A,552B, a driving rod226extending through at least a portion of the housing536and between the pair of opposing arms552A,552B, and a drive mechanism224adapted to move the driving rod226distally relative to the housing536.

In some embodiments of a rotatable vertebral distractor-inserter536, the vertebral distractor-inserter comprises a drive mechanism224. Embodiments of the drive mechanism are described herein.

FIGS. 7A & 7Bdepict views of an embodiment of the device668having an implant depth adjustment feature.FIG. 7Ashows a depth adjustor642at its distal-most setting, which results in the implant moving beyond the distal end of the arms652A,652B the least distance. When the implant depth adjustor642is moved proximally, moving the depth stop646distally relative to the implant or the implant coupler640, or both, an implant at the distal end of the implant interface648can move farther distally into the space between the vertebrae because the depth stop646is more proximal than when the adjustor642is at its distal-most setting.FIG. 7Bshows an intermediate setting for the implant depth adjustor642, wherein the implant can move more distally relative to the distal end of the arms652A,652B than the implant can when the adjustor642is at its distal-most setting, as is depicted inFIG. 7A. The implant depth adjustor642can be threaded proximally and distally to move the implant depth stop646and control, thereby, the distal depth achievable by the implant using the device668. Other mechanisms for adjusting this depth are possible including, for example, a ratchet, a peg, a clamp, and a grip. In some embodiments, the implant depth stop646will be adjusted before placing the distal ends of the arms452A,452B into the intervertebral space and will remain in the same position throughout the procedure. The operator may pre-determine the implant depth in any art-recognized means, e.g. by measuring the depth with various imaging techniques or, after the vertebrae have been accessed, by in situ measurement methods. Since adjustment of the implant depth generally occurs before the device is inserted into the patient, such adjustment does not derogate the single-handed use of the device, as explained with reference to other steps ancillary to distraction and insertion, above.

In some embodiments, the invention provides a vertebral distractor-inserter668comprising a housing136, a pair of opposing arms652A,652B in mechanical communication with the housing136, a driving rod626extending through at least a portion of the housing136and between the pair of opposing arms652A,652B, a drive mechanism224adapted to move the driving rod626distally relative to the housing136, and an implant depth adjustor642that is adjustable to a plurality of implant depth settings and is adapted to push the distractor-inserter668proximally upon insertion of an implant to a selected implant depth setting. The implant depth adjustor642may optionally comprise an implant depth stop646. Example drive mechanisms are previously described herein. This vertebral distractor-inserter668may be ratcheting, gripping, a combination of these, or of another type altogether. Any distractor-inserter described herein may be adapted for single-handed use. It may also or alternatively comprise an implant interface648as described herein. It may also be adapted such that the housing136and at least a portion of the driving rod626are rotatable about an axis118extending between the opposing arms652A,652B, as described herein.

FIG. 8depicts a view of an embodiment of the device768in use showing distraction of adjacent vertebrae780. Shown is the distal end of a device768having opposing arms752A,752B, arm depth guards712, a driving rod726having an implant interface748having an implant depth adjustor742and an implant depth stop746at the driving rod726distal end. Also shown is an implant738at the distal end of the implant interface748which has distracted the arms752A,752B and is positioned between the vertebrae780. As the driving rod726is moved distally relative to the arms752A,752B, the arms752A,752B will be urged proximally out of the space between the vertebrae780; but the implant738will remain between the vertebrae780.FIG. 9depicts a view of an embodiment of the device868in use showing insertion of an implant838between distracted vertebrae880wherein the arms852A,852B and the arm depth guards812of the arms852A,852B have been urged proximally out of the space between the vertebrae880, and the implant838is in direct contact with and sits between the vertebrae880. The implant880cannot move distally when the implant depth stop846abuts the vertebra880.

Multiple elements may be combined in the devices contemplated herein. Additionally, in some embodiments, the invention provides a method for distracting adjacent vertebrae880and inserting an implant838between the distracted vertebrae880. The method comprises mounting the implant838to a driving rod826of a vertebral distractor-inserter device868described herein. The device868may having a housing136, a pair of opposing arms152A,152B in mechanical communication with the housing136having a distal end, and a drive mechanism224in mechanical communication with the driving rod826. The driving rod826extends through at least a portion of the housing136and between the pair of opposing arms852A,852B. The method may further comprise positioning the distal end of the pair of arms852A,852B between the vertebrae880, distracting the vertebrae880by single-handed operation of the vertebral distractor-inserter868, inserting the implant838between the distracted vertebrae880by single-handed operation of the vertebral distractor-inserter868, and retracting the pair of opposing arms852A,852B from between the vertebrae880.

In some embodiments, the invention provides a method for distracting adjacent vertebrae880and inserting an implant838between the distracted vertebrae880, wherein the distracting step comprises activating the drive mechanism224using one hand. The step of activating moves the implant880distally and distracts the pair of opposing arms852A,852B. In some embodiments of the method, the inserting comprises advancing the implant880into the distracted space between the vertebrae880. In some embodiments of the method, advancing the implant comprises activating the drive mechanism224using one hand and extending the implant880beyond the distal end of the pair of opposing arms852A,852B. In some embodiments, the method comprises the additional step of releasing the implant880from the distractor-inserter868.

In some embodiments of the method for distracting adjacent vertebrae880and inserting an implant838between the distracted vertebrae880the positioning step comprises urging the pair of arms852A,852B between the vertebrae880up to the position where a depth guard812of the arms852A,852B contacts the vertebrae880. In some embodiments, the positioning step comprises urging the pair of arms852A,852B between the vertebrae880up to a distal depth of at most 75 mm, or at least about 25 mm, or between about 35 mm and 55 mm. When referring to distal depth herein, “about” refers to variations in depth of between 1 mm and 2 mm, or between 2 mm and 5 mm. In some embodiments, the distal depth is the distance from the depth guard812to the distal end of the pair of opposing arms852A,852B. In some embodiments, the arms852A,852B are inserted between the vertebrae880up to a distal depth such that the depth guard812is proximal to, but not abutting, the proximal side of the vertebrae880. In some embodiments, the depth guard812is proximal to and abutting, or contacting, the proximal side of the vertebrae880.

In some embodiments, mounting the implant comprises the step of adjusting the implant depth adjustor642to control the maximum distal implant depth achievable during the inserting step. In a related embodiment, the implant depth achievable is a maximum of about 25 mm, a minimum of about 0 mm, or between about 3 mm and 8 mm. When referring to implant herein, “about” refers to variations in depth of between 1 mm and 2 mm, or between 2 mm and 5 mm. The implant depth is measured from the distal end of the depth stop646to the distal end of the implant interface648.

In some embodiments, insertion of the implant comprises the step of retracting the pair of opposing arms852A,852B from between the vertebrae880by abutting the implant depth adjustor642against a proximal side of the vertebrae880and activating the drive mechanism224using one hand.

In some embodiments, the invention provides a method comprising activating the drive mechanism224wherein the activating comprises the step of ratcheting the driving rod826distally, wherein the driving rod826comprises an axis218and a surface366with a plurality of angled ratchet teeth210on at least a portion of the surface366. In such an embodiment, the drive mechanism224may comprise an activating lever202capable of movement between a first position and a second position and mounted to the housing236by an activating lever pivot204. The drive mechanism may further comprise a first ratchet pawl232coupled to the activating lever202and adapted to engage the ratchet teeth210. The first ratchet pawl may move the driving rod826distally relative to the housing236as described herein. The drive mechanism may further comprise a second ratchet pawl260adapted to engage the ratchet teeth210and oppose proximal motion of the driving rod826relative to the housing236as described herein.

In some embodiments, the invention provides a method comprising gripping the rod424and moving the driving rod424distally wherein the distractor-inserter is an embodiment as described herein. In some embodiments, the step of ratcheting comprises the step of applying a force to the activating lever402to move the lever402toward the second position. In some embodiments of the method, the step of ratcheting further comprises the steps of releasing the force on the activating lever402and allowing the activating lever spring206to move the activating lever402toward the first position.

In some embodiments, the invention provides a method comprising rotating the housing236and at least a portion of the driving rod226relative to the pair of opposing arms252A,252B and to the implant838.

In some embodiments, the housing236is rotatable about an axis218extending between the opposing arms252A,252B relative to the arms252A,252B and to the implant838, and wherein at least a portion of the driving rod226is rotatable about the axis218extending between the opposing arms252A,252B relative to the pair of opposing arms252A,252B and to the implant838. This method may further comprise activating a drive mechanism224wherein the activating step moves the implant distally and distracts the pair of opposing arms252A,252B. In some embodiments, inserting the implant comprises advancing the implant838into the distracted space between the vertebrae880. In some embodiments, the advancing the implant comprises activating the drive mechanism224and extending the implant838beyond the distal end of the pair of opposing arms252A,252B.

In some embodiments, the invention provides a method comprising mounting the implant838to a driving rod826of a vertebral distractor-inserter868having a housing136, a pair of opposing arms852A,852B, and a ratchet drive mechanism224in mechanical communication with the driving rod826. The method further comprises positioning the distal end of the pair of arms852A,852B between the vertebrae880, and distracting the vertebrae880. Distracting the vertebrae880may further comprise activating the ratchet drive mechanism224and inserting the implant838between the distracted vertebrae880. Inserting the implant838may comprise advancing the implant838into the distracted space between the vertebrae880, wherein the step of advancing comprises activating the ratchet drive mechanism224and retracting the pair of opposing arms852A,852B from between the vertebrae880.

In some embodiments of the method, the step of activating moves the implant838distally and distracts the pair of opposing arms852A,852B. In some embodiments, the distraction is caused by the distal motion of the implant838having a depth that is greater than the distance between the arms852A,852B at the distal end of the device868. As the implant838moves distally, the implant838contacts the arms852A,852B and forces them apart, outwardly from the axis of the driving rod826. When the arms852A,852B are forced apart, if the distal ends of the arms852A,852B are between the vertebrae880, the distal motion of the implant838also distracts, i.e. opens, the space between the vertebrae880.

Alternatively, in another embodiment, the implant interface848contacts the arms852A,852B, distracts the arms852A,852B, and thus distracts the vertebrae880as the interface848is moved distally. In some embodiments, the step of advancing comprises extending the implant838beyond the distal end of the pair of opposing arms852A,852B. In some embodiments, the activating the ratchet drive mechanism224comprises ratcheting the driving rod826distally, wherein the driving rod826comprises an axis218and a surface366with a plurality of angled ratchet teeth210on at least a portion of the surface366, and wherein the ratchet drive mechanism224comprises an activating lever202capable of movement between a first position and a second position and mounted to the housing136by an activating lever pivot204, a first ratchet pawl232coupled to the activating lever202and adapted to engage the ratchet teeth210and move the driving rod826distally relative to the housing136, and a second ratchet pawl260adapted to engage the ratchet teeth210and oppose proximal motion of the driving rod826relative to the housing136.

In some embodiments, the invention provides a method for ratcheting comprising the step of applying a force to the activating lever202to move the lever202toward the second position. In some embodiments the drive mechanism224comprises a handle228attached to the housing136and an activating lever spring206coupled to the activating lever202and the handle228, wherein the activating lever spring206opposes proximal movement of the lever202relative to the handle228, and wherein the step of ratcheting further comprises the steps of releasing the force on the activating lever202and allowing the activating lever spring206to move the activating lever202toward the first position. In some embodiments, the method comprises releasing the implant838from the distractor-inserter868, wherein the implant838was coupled to the distractor-inserter868.

In some embodiments, the invention provides a method comprising mounting the implant838to a driving rod826of a vertebral distractor-inserter868having a pair of opposing arms852A,852B having a distal end, a housing136in mechanical communication with the pair of opposing arms852A,852B which is rotatable about an axis118extending between the opposing arms852A,852B relative to the arms852A,852B and to the implant838, and a drive mechanism224in mechanical communication with the driving rod826, wherein the driving rod826extends through at least a portion of the housing136and between the pair of opposing arms852A,852B and wherein at least a portion of the driving rod826is rotatable about the axis118extending between the opposing arms852A,852B relative to the pair of opposing arms852A,852B and to the implant838, positioning the distal end of the pair of arms838between the vertebrae880, rotating the housing136and at least a portion of the driving rod826relative to the pair of opposing arms852A,852B and to the implant838, distracting the vertebrae880, inserting the implant838between the distracted vertebrae880, and retracting the pair of opposing arms852A,852B from between the vertebrae880. The distracting may further comprise activating the drive mechanism224, wherein the activating moves the implant838distally and distracts the pair of opposing arms852A,852B. The inserting may comprise advancing the implant838into the distracted space between the vertebrae880. The advancing may comprise activating the drive mechanism224and extending the implant838beyond the distal end of the pair of opposing arms852A,852B.

The method may further comprise ratcheting the driving rod826distally, wherein the driving rod826comprises an axis118and a surface366with a plurality of angled ratchet teeth110on at least a portion of the surface366, and wherein the drive mechanism224comprises an activating lever102capable of movement between a first position and a second position and mounted to the housing136by an activating lever pivot204, a first ratchet pawl232coupled to the activating lever102and adapted to engage the ratchet teeth110and move the driving rod826distally relative to the housing136, and a second ratchet pawl260adapted to engage the ratchet teeth110and oppose proximal motion of the driving rod826relative to the housing136. The ratcheting can comprise actions previously described herein.

The positioning can further comprise using a depth adjustor642to control the implantation depth between the vertebrae880. Some embodiments of the method comprise mounting the implant838to a driving rod826of a vertebral distractor-inserter868having a pair of opposing arms852A,852B having a distal end and a depth guard812, an implant depth adjustor642that is adjustable to a plurality of implant depth settings, a housing136in mechanical communication with the pair of opposing arms852A,852B, and a drive mechanism224in mechanical communication with the driving rod826, wherein the driving rod826extends through at least a portion of the housing136and between the pair of opposing arms852A,852B, and wherein the mounting comprises the step of adjusting the implant depth adjustor642to control the maximum distal implant depth achievable during the inserting step, positioning the distal end of the pair of arms852A,852B between the vertebrae880, wherein the positioning comprises urging the pair of arms852A,852B between the vertebrae880up to the position where the depth guard812contacts the vertebrae880, distracting the vertebrae880, inserting the implant838between the distracted vertebrae880, and retracting the pair of opposing arms852A,852B from between the vertebrae880.

In some embodiments, the invention provides a method for implanting an implant838between distracted vertebrae880comprising urging wherein the step of urging moves a pair of arms852A,852B between the vertebrae880up to a distal depth of at most about 75 mm, or at least about 25 mm, or between about 35 mm and 55 mm, wherein distal depth is the distance from a depth guard812to the distal end of the pair of opposing arms852A,852B. In some embodiments, the implant depth achievable is a maximum of about 25 mm, a minimum of about 0 mm, or between about 3 mm and 8 mm. The implant depth is measured from the distal end of the depth stop846to the distal end of the implant interface848. In some embodiments, the distractor-inserter868is adapted to push the housing136proximally relative to the implant838upon insertion of the implant838to a selected implant depth setting, and the inserting comprises the step of retracting the pair of opposing arms852A,852B from between the vertebrae880by abutting the arm depth guard812against a proximal side of the vertebrae880and activating the drive mechanism224.

In some embodiments, the invention provides a vertebral distractor-inserter, comprising a housing, a pair of opposing arms in mechanical communication with the housing, and a driving means for driving a rod and an implant at the distal end of the rod distally, wherein the driving means comprises an activating lever and a driving mechanism activated by the activating lever. The driving means may comprise a gripping means for gripping the rod while the activating lever drives the rod distally relative to the housing. Such means is described below and shown inFIGS. 5A & 5B. The driving means may comprise a ratcheting means for incrementally ratcheting the rod distally as the activating lever is pulled proximally relative to the housing. Examples of such ratcheting means are described herein and some example embodiments are shown inFIGS. 2,3, and4. The vertebral distractor-inserter may comprise a holding means for opposing proximal motion of the rod while resetting the lever after lever activation. Examples of such holding means are described herein. The vertebral distractor-inserter may comprise a rotating means for allowing operator rotation of the housing relative to the pair of opposing arms about an axis extending between the opposing arms. Examples of such rotating means are described herein, and examples are shown inFIGS. 2 and 6. The vertebral distractor-inserter may comprise a depth-controlling means for adjusting and controlling the depth to which an implant may be inserted by an operator between adjacent vertebrae. Examples of such depth-controlling means are described herein, and examples are shown inFIGS. 2,3,7,8, and9.

FIGS. 10A,10B,10C, and10D depict external views of one currently preferred embodiment of the device168where the device is used to place the implant between two vertebrae from a posterior or a posterior-lateral angle. Introducing the device from a posterior or posterior-lateral angle comprises introducing the device into the intervertebral space from the dorsal side of the patient, where the posterior angle is parallel to the axial plane52(seeFIG. 1B). In some embodiments, the posterior angle is approximately parallel to the axial plane52and the sagittal plane54of the patient. Alternatively, the device can be introduced to the spinal column parallel to the axial plane52but at an angle with respect to the sagittal plane54.

FIG. 10Ais a side view of one embodiment of a vertebral distractor-inserter168comprising a housing136, a pair of opposing arms152A,152B in mechanical communication with the housing136, a driving rod126extending through at least a portion of the housing136and between the pair of opposing arms152A,152B, wherein the driving rod126comprises an axis118and a surface166. In some embodiments, the driving rod can comprise a plurality of angled ratchet teeth110on at least a portion of the surface166of the driving rod126. The device168can further comprises a ratchet drive mechanism124in mechanical communication with the plurality of angled ratchet teeth on the driving rod126as shown inFIG. 10A. The arms152A,152B of the device168further comprise a depth guard112on each arm. The depth guards112limit the extent to which the arms152A,152B can be inserted into the intervertebral space. In some embodiments, the vertebral distractor-inserter168comprises a handle128attached to the housing136. In some embodiments, the vertebral distractor-inserter168does not comprise a housing136. In some embodiments, the housing136does not enclose the rod126. In some embodiments, the rod126is external to, but in communication with, the housing136.

FIG. 10Afurther depicts an embodiment having an activating lever102, which is in mechanical communication with the driving rod126. The activating lever102is mounted to the housing136by an activating lever pivot104. Movement of the activating lever102in the direction of the handle128, designated by the arrow in the figure, causes the driving rod126and an implant (not shown) coupled to an implant coupler140at the distal end of the driving rod126to move distally relative to the housing136. The mechanical communication between the driving rod and the activating lever may be effected through a number of means. In the depicted embodiment the mechanical communication is through a ratcheting drive mechanism124within the housing136. The ratcheting mechanism described above can be included with the device. The ratcheting drive mechanism124uses at least one ratchet pawl to grip the ratchet teeth110of the driving rod126and to drive the implant and the rod126distally when the activating lever102is moved toward the handle128. The ratchet pawl, or in some embodiments, ratchet pawls, of the ratchet drive mechanism124further locks the driving rod126in place thereby preventing movement in a proximal direction. In some embodiments, the drive mechanism can be advanced manually. In some embodiments, the drive mechanism is a screw-type drive mechanism where the screw drive mechanism interacts with threads located on the driving rod. In some embodiments, the device further comprises a gripping member or other suitable holding means for restricting proximal motion of the driving rod. Activating the lever102drives the implant distally by moving the driving rod126. As the activating lever102returns to its original position, the gripping element opposes proximal motion of the driving rod and the implant. In some embodiments at least one gripping member is present. In some embodiments, more than one gripping member is present. The gripping member may comprise, for example, a pneumatic grip, a hook, a latch, a grabbing device, or any other suitable element for restricting proximal motion.

In some embodiments, the vertebral distractor-inserter168is adapted for single-handed use. In such an embodiment, the vertebral distractor-inserter168is adapted for substantially single-handed distraction of vertebrae and insertion of a vertebral implant. It is to be understood in regard to the phrase “single-handed,” the functions of holding the device in place and advancing the rod126and implant may in most instances be performed with a single hand. However, it is also noted that in some cases, depending upon operator preference and the vagaries of patient physiology, two hands may be used, e.g. to impart greater force to the lever102, without departing from the spirit and scope of the invention. The phrase “single-handed” thus distinguishes embodiments of the invention over distractor-inserter devices in which the device is held in place with one hand and the implant is advanced distally by twisting or striking an implant arm. It is considered that whether used with one hand or two, the device of the present invention provides force to both distract vertebrae and advance the implant with lessened torque, impact force or other physiologically disruptive forces, and thus less trauma to the patient, than is generally required with previously known devices. In currently preferred embodiments, the device of the present invention also permits the operator to hold the device in place and impart force for distraction and insertion with a single hand. In addition to the aforementioned advantages, single handed use is amenable to less invasive surgery than two-handed use.

Some embodiments of the device are adapted and configured to allow retraction of the implant interface and the driving rod relative to the arms of the device. This may be achieved in a number of ways. In the embodiment shown inFIG. 10A, the device comprises a knob150. The knob150can be used to facilitate retraction of the driving rod. The driving rod of this embodiment has a surface166comprising a substantially smooth area164and ratchet teeth110. When the knob150is turned about the axis118of the driving rod126, preferably with knob150, such that the ratchet teeth110are no longer engaged by the ratchet pawl, or the ratchet pawls, if there are two, the driving rod126is free to be moved proximally (or retracted) relative to the housing136and the arms152A,152B. Although this action is favorably carried out by the operator holding the handle128in one hand and turning the knob150with the other, this action is not to be interpreted as derogating in any way single-handed operation of the device168, as single-handed operation generally refers to simultaneously holding the handle128and imparting drive force to the driving arm126with a single hand. As the driving rod126may be easily disengaged from the pawls with, for example, a single 180° twist about the axis118, it is considered that the present invention provides for easier and faster retraction of the driving arm126than is provided by previously known devices that require screwing the arm backwards.

In another embodiment, the driving rod126may comprise a threading around the driving rod instead of ratchet teeth, wherein the ratchet pawl or ratchet pawls if there are two pawls, of the ratchet drive mechanism may engage the threads instead of ratchet teeth on the driving rod. To retract the rod126, rather than turning the driving rod126until the pawl(s) disengages the teeth, and then pulling the rod126proximally, the rod126and, thereby, the implant coupler140, may be retracted by turning the rod126around the long axis118of the driving rod126. In this embodiment, the rod threads are not disengaged from at least the first ratchet pawl132.

Other embodiments may comprise combinations of threads, ratchet teeth110, and/or a substantially smooth area along the driving rod surface166, and a combination of ratcheting and gripping elements to provide the controlled distal and proximal movement of the driving rod126, the implant, and implant coupler140relative to the arms152A,152B, and to the housing136.

If needed or desired, retraction of the device168using the features and methods described herein may also allow retraction of the implant prior to insertion of the implant between the vertebrae.

In some embodiments, the ratchet teeth110extend along the driving rod126a length sufficient to allow the arms152A,152B to touch when the implant is loaded prior to distraction and to allow the implant to be inserted between the vertebrae. In some embodiments, for example, the ratchet teeth110extend along the length of the driving rod126for between about 6 and about 10 inches, for about 8 inches, for about 12 inches, for about 16 inches, for at least 3 inches, or for the entire length of the rod. In referring to the ratchet teeth length along the rod, “about” refers to variations of 0.5 inches to 1 inch, or of 1 inch to 2 inches.

In some embodiments of the distractor-inserter168, the drive mechanism124comprises a gripping element and a ratcheting drive mechanism as described previously. Some embodiments comprise other means for driving implant distally. These means can be other mechanical mechanisms capable of allowing unidirectional movement, along with a release mechanism for reversing such unidirectional movement. Some embodiments comprise other means for distracting the arms. The means for distracting may be other tools altogether through which the distractor-inserter may be placed and used to place the implant.

FIG. 10Billustrates a similar embodiment of the device168as viewed from the proximal end with a driving rod126and the implant coupler140in the fully extended position. The arms152A,152B of the device168are in a closed configuration when the driving rod126is in the fully extended position.FIG. 10Balso illustrates the resting position of the device168after the implant has been inserted.

FIG. 10Cdepicts a top view of an embodiment of the device168with the driving rod and the implant coupler140in a fully retracted position as indicated by the arms152A,152B touching each other. In this view, the housing136is shown along with the driving rod126, which extends through the housing136. This view also shows a knob150on the proximal end of the driving rod126.

FIG. 10Ddepicts an embodiment of the device as viewed from the distal end. The housing136is shown along with the driving rod126, which extends through the housing136. The implant coupler140abuts the implant and transfers force from the driving rod126to the implant, which in turn forces the first arm152B and the second arm152A apart, thereby providing distracting force to the vertebrae. The embodiment has an arm depth guard112, which determines the maximum depth to which the arms152A,152B can be inserted between the vertebrae during distraction. As the activating lever102is moved toward the handle128, the driving rod advances forward. As the implant is advanced into the intervertebral space, the forward motion of the driving rod126causing the arms152A,152B to retract from the vertebrae180A,180B.

FIG. 11Ais a view of the device168in use as viewed from the underside of the device168. As shown inFIG. 11A, the device uses a posterior-lateral angle to interact with the vertebra180A,180B. The arms152A,152B are inserted into the intervertebral space up to the location of the arm depth guard112parallel to the axial plane52and the sagittal plane54. The user or surgeon then moves the activating lever102in the direction of the handle128multiple times. A ratcheting mechanism located within the housing136engages the ratcheting teeth110on the driving rod126. Each movement of the activating lever advances the driving rod forward, thereby advancing the implant coupler140and the implant138. As the implant138is advanced forward, the arms152A,152B are forced apart thereby distracting the vertebrae180A,180B, as shown inFIG. 11A. The user can continue to advance the implant forward, the implant thereby passing through the arms and thereby entering the intervertebral space.

FIG. 11Bis a close-up view of the device in use showing distraction of adjacent vertebrae180A,180B from the posterior side of the vertebral column. Shown is the distal end170of a device168shown inFIG. 11Ahaving opposing arms152A,152B, arm depth guards112, a driving rod126having an implant coupler140at the driving rod126distal end. Also shown is an implant138at the distal end of the implant coupler140, which has distracted the arms152A,152B of the device168, and is positioned between the vertebrae180A,180B. As the driving rod126continues to moves distally relative to the arms152A,152B, the arms152A,152B will be urged proximally out of the space between the vertebrae180A,180B. However, the implant138remains between the vertebrae180A,180B.

A suitable implant can be used with the device described herein. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion, as seen inFIG. 12A.FIG. 12Ais one embodiment of an implant138have sides substantially parallel to the axis of insertion as viewed from the side.FIG. 12Bis a view of the implant138ofFIG. 12Aas viewed from the top.FIG. 12Cis a perspective view of the implant138shown inFIG. 12A. In some embodiments, an implant can be inserted on one side of the spinous process using at an angle parallel to the axial plane52and the sagittal plane54. Additionally, more than one implant can be inserted into the intervertebral space. For example, a second implant can be inserted on the side contralateral to the first implant. In some embodiments, more than one implant can be inserted into the intervertebral space simultaneously. The implant can have a box-like structure, e.g., a square box or cube structure. Alternatively, the implant can be a prism, such as a rectangular prism, or a polygonal prism. The implant can have any suitable 3-dimensional configuration. The implant can have a length running in the proximal-distal direction, a width, and a height. In some embodiments, the length, width, and height are the same. Alternatively, the length, width, and height are different. The length can be longer than the width and the height. In some embodiments, the implant is a disc-like structure having a radius. The disc-like structure can also have a height. The disc-like structure can comprise a substantially circular base, a translated copy of the base, and a side joining the base and translated base. The disc can also comprise side segments joining the base and translated base. In some embodiments, the disc-like structure comprises a circular base with a radius that is the same at every location. Alternatively, the disc-like structure comprises an oval base. In some embodiment, the implant138can comprise a serrated edge152, as shown inFIGS. 11A and 11B. The serrated edge of the implant138can interact with the surface of the vertebrae. The serrated edge152of the implant138facilitates the placement of the implant138as well as helps to ensure the immobility of the implant138. A serrated edge152can be located on one side of the implant. In some embodiments, both edges of the implant138can comprise a serrated edge152.

In some embodiments, the implant can comprise laterally opposing walls that are substantially curved. One embodiment of an implant138with curved laterally opposing walls is shown inFIG. 12D.FIG. 12Eis a view of the implant138ofFIG. 12Das viewed from the top. A perspective view of an implant138with curved walls is illustrated inFIG. 12F. In some embodiments, the implant has one laterally opposing wall that is substantially parallel to the axis of insertion and one laterally opposing wall that is substantially curved. The curved wall can facilitate the placement of the implant in the intervertebral space. The implant can be inserted into the intervertebral space and then adjusted until positioned in a desired location. The implant can be inserted into the intervertebral space and repositioned such that the implant is positioned in the anterior intervertebral space. In some embodiments, the implant can be positioned such that substantially half of the implant is positioned on one side of the spinous process and substantially half of the implant is positioned on the other side of the spinous process. The implant can be positioned such that a majority of the implant is positioned on one side of the spinous process. The implant can comprise a curved wall that is insertable around the spinal column. In some embodiments more than one implant with curved laterally opposing walls can be inserted into the intervertebral space. The implant can comprise a serrated edge152which interacts with the surface of the vertebrae. The serrated edge152facilitates the placement of the implant138as well as helps to ensure the immobility of the implant138. A serrated edge152can be located on one side of the implant. In some embodiments, both edges of the implant can comprise a serrated edge152, as shown inFIGS. 11A and 11B.

FIG. 13Ais a view of the device168in use with an alternative embodiment of an implant138as viewed from the underside of the device. As shown inFIG. 13A, the device interacts with the vertebrae180A,180B using a posterior or posterior-lateral angle. The device can approach the posterior of the vertebral column parallel to the axial plane52and the sagittal plane54and can be inserted into the intervertebral space from either side of the spinous process.FIG. 13A, illustrates a device that can be used to insert an implant into the intervertebral space contralateral to the side illustrated inFIG. 11A. The arms152A,152B are inserted into the intervertebral space up to the location of the arm depth guard112. The user or surgeon then moves the activating lever102in the direction of the handle128multiple times. A ratcheting mechanism located within the housing136engages the ratcheting teeth110on the driving rod126. Each movement of the activating lever advances the driving rod forward, thereby advancing the implant coupler140and the implant138. As the implant138is advanced forward, the arms152A,152B are forced apart thereby distracting the vertebrae180A,180B, as shown inFIG. 13A. The implant advances forward and enters the intervertebral space.

FIG. 13Bis a close-up view of the device168in use showing distraction of adjacent vertebrae180A,180B using a posterior approach, wherein the device is introduced parallel to the axial plane52and the sagittal plane54. Shown is the distal end170of a device168having opposing arms152A,152B, arm depth guards112, and a driving rod126having an implant interface148at the driving rod126distal end. Also shown is an implant138at the distal end of the implant interface148, which has distracted the arms152A,152B of the device168, and which accesses the intervertebral space from the posterior side of the vertebral column. As the driving rod126continues to moves distally relative to the arms152A,152B, the arms152A,152B are distracted and the implant138passes through the arms152A,152B into the intervertebral space. As the driving rod126is further advanced distally relative to the arms152A,152B, the arms152A,152B will be urged proximally out of the space between the vertebrae180A,180B. The implant138remains between the vertebrae180A,180B.

A suitable implant can be used with the device described herein. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion, as seen inFIG. 14A.FIG. 14Ais one embodiment of an implant138have sides substantially parallel to the axis of insertion as viewed from the side. In some embodiments, the implant can have solid sides. Alternatively, the implant138can have cut outs in the sides as shown inFIG. 14A.FIG. 14Bis a view of the implant138ofFIG. 14Aas viewed from the top.FIG. 14Cis a perspective view of the implant138shown inFIG. 14A. In some embodiments, an implant can be inserted on one side of the spinous process using a posterior angle. Additionally, more than one implant can be inserted into the intervertebral space. For example, a second implant can be inserted on the other side of the spinous process. In some embodiments, more than one implant can be inserted into the intervertebral space simultaneously. The implant can have a box-like structure, e.g., a square box or cube structure. Alternatively, the implant can be a prism, such as a rectangular prism, or a polygonal prism. The implant can have any suitable 3-dimensional configuration. The implant can have a length, width, and height. In some embodiments, the length, width, and height are the same. Alternatively, the length, width, and height are different. In some embodiments, the implant is a disc-like structure having a radius. The disc-like structure can also have a height. The disc-like structure can comprise a substantially circular base, a translated copy of the base, and a side joining the base and translated base. The disc can also comprise side segments joining the base and translated base. In some embodiments, the disc-like structure comprises a circular base with a radius that is the same at every location. Alternatively, the disc-like structure comprises an oval base. In some embodiment, the implant138can comprise a serrated edge152, as shown inFIGS. 13A and 13B. The serrated edge of the implant138can interact with the surface of the vertebrae. The serrated edge152of the implant138facilitates the placement of the implant138as well as helps to ensure the immobility of the implant138. A serrated edge152can be located on one side of the implant. In some embodiments, both edges of the implant138can comprise a serrated edge152, as shown inFIGS. 13A and 13B.

In some embodiments, the implant can comprise laterally opposing walls that are substantially curved. One embodiment of an implant138with curved laterally opposing walls is shown inFIG. 14D.FIG. 14Dis a side view of the implant. In some embodiments, the implant can have solid sides. Alternatively, the implant138can have cut outs in the sides as shown inFIG. 14D.FIG. 14Eis a view of the implant138ofFIG. 14Das viewed from the top. A perspective view of an implant138with curved walls is illustrated inFIG. 14F. In some embodiments, the implant has one laterally opposing wall that is substantially parallel to the axis of insertion and one laterally opposing wall that is substantially curved. The curved wall can facilitate the placement of the implant in the intervertebral space. The implant can be inserted into the intervertebral space and then adjusted until positioned in a desired location. In some embodiments, the implant can be positioned such that substantially half of the implant is positioned on one side of the spinous process and substantially half of the implant is positioned on the other side of the spinous process. The implant can be positioned such that a majority of the implant is positioned on one side of the spinous process. The implant can comprise a curved wall that is insertable around the spinal column. In some embodiments more than one implant with curved laterally opposing walls can be inserted into the intervertebral space. The implant can comprise a serrated edge152which interacts with the surface of the vertebrae. The serrated edge152facilitates the placement of the implant138as well as helps to ensure the immobility of the implant138. A serrated edge152can be located on one side of the implant. In some embodiments, both edges of the implant can comprise a serrated edge152, as shown inFIGS. 13A and 13B.

The device described herein can be used to distract the vertebrae of the spinal column by approaching the spinal column from the posterior side of the vertebral column, or by using a posterior approach. In some embodiments, the device can approach the posterior side of the vertebral column so that the device is inserted from directly behind the vertebral column. In other words, the device168can be inserted into the intervertebral space after entering the intervertebral space from a posterior-lateral angle. The device can enter the intervertebral space parallel to the axial plane and at an angle with respect to the sagittal plane, as shown inFIG. 15. As shown inFIG. 15, the device enters the intervertebral space from the side at an angle as opposed to from directly behind or parallel to the axial52and sagittal plane54. The device can be inserted into the intervertebral space from any suitable angle. As shown inFIG. 15, the device interacts with the vertebrae180A,180B from the posterior side of the vertebral column. The device can approach the posterior of the vertebral column and be inserted into the intervertebral space from either side of the spinous process. The device168can be inserted into the intervertebral space parallel to the axial plane52and the sagittal plane54. Alternatively, the device can be inserted into the intervertebral space parallel to the axial plane52but at an angle with respect to sagittal plane as shown inFIG. 15. In some embodiments, the device is introduced to the spinal column using a posterior angle where the device is introduced at an angle that deviates from the sagittal plane by between about 20 degrees to about 60 degrees with respect to the sagittal plane. In some embodiments, the device is introduced to the spinal column using a posterior angle where the device is introduced at an angle that deviates from the sagittal plane by between about 20 degrees to about 30 degrees with respect to the sagittal plane. In some embodiments, the device is introduced to the spinal column using a posterior angle where the device is introduced at an angle that deviates from the sagittal plane by between about 30 degrees to about 40 degrees with respect to the sagittal plane. In some embodiments, the device is introduced to the spinal column using a posterior angle where the device is introduced at an angle that deviates from the sagittal plane by between about 40 degrees to about 50 degrees with respect to the sagittal plane. In some embodiments, the device is introduced to the spinal column using a posterior angle where the device is introduced at an angle that deviates from the sagittal plane by between about 50 degrees to about 60 degrees with respect to the sagittal plane.

As previously described, the arms152A,152B are inserted into the intervertebral space up to the location of the arm depth guard112. The user or surgeon then moves the activating lever in the direction of the handle multiple times. A ratcheting mechanism located within the housing136engages the ratcheting teeth on the driving rod126. Each movement of the activating lever advances the driving rod forward, thereby advancing the implant coupler140and the implant138. As the implant138is advanced forward, the arms152A,152B are forced apart thereby distracting the vertebrae180A,180B. The user then continues to advance the implant forward and the implant enters the intervertebral space.

Multiple elements may be combined in the devices contemplated herein. A variety of methods are also contemplated. One method includes a method of inserting a spinal implant between two vertebrae, comprising: (a) placing an intervertebral implant between a pair of opposing arms of a vertebral distractor-inserter, the distractor-inserted comprising: (i) the pair of opposing arms, having distal ends; (ii) a driving rod extending between the pair of opposing arms, wherein the driving rod comprises an axis and a surface with a plurality of angled ratchet teeth on at least a portion of the surface; and (iii) a drive mechanism in mechanical communication with the driving rod; (b) inserting said distal ends of the pair of opposing arms between a pair of vertebrae from a posterior angle; and (c) actuating said distractor-inserter, thereby distracting said vertebrae and inserting said implant between said vertebrae. In some embodiments, the method further provides for a device wherein the driving rod comprises an axis and a surface having a plurality of angled ratchet teeth on at least a portion of the surface. The method can further comprise a ratchet drive mechanism in communication with the angled ratchet teeth. Alternatively, the method can comprise the use of a device comprising a screw drive mechanism. The device can be introduced between the pair of vertebrae from a posterior angle, where the posterior angle is generally parallel to the axial plane and sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is substantially parallel to the axial plane but deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the other side of the spinous process. In some embodiments, the implant has laterally opposing walls that are substantially curved. In some embodiments of the method, one of the opposing walls is substantially parallel to the axis of insertion and the other opposing wall is substantially curved. In some embodiments of the method, the actuating step can further comprise inserting an implant having laterally opposing walls in the intervertebral space wherein the inserting of the implant comprises repositioning the implant in the intervertebral space by following the curvature of the implant. The method can further comprise the use of a distractor-inserter in which the distractor-inserter comprises a housing in mechanical communication with the pair of opposing arms, wherein the driving rod extends through at least a portion of the housing. The distractor-inserter can comprise a handle attached to the housing. Additionally, the method for inserting a spinal implant between two vertebrae can comprise the use of a ratchet drive mechanism, wherein the ratchet drive mechanism of the distractor-inserter comprises: (a) an activating lever mounted to the housing by an activating lever pivot; (b) a first ratchet pawl coupled to the activating lever and adapted to engage the ratchet teeth and move the driving rod distally relative to the housing; and (c) a second ratchet pawl adapted to engage the ratchet teeth and oppose proximal motion of the driving rod relative to the housing. Furthermore, the method can comprise the use of a distractor-inserter can comprise a handle attached to the housing and the ratchet drive mechanism comprises an activating lever spring coupled to the activating lever and the handle, wherein the activating lever spring opposes proximal movement of the lever relative to the handle. In some embodiments of the method, the ratchet-drive mechanism comprises: (a) a first pawl spring that opposes downward movement of the first pawl; and (b) a second pawl spring that opposes downward movement of the second pawl. The surface of the driving rod comprises an area that is substantially free of ratchet teeth on a contiguous longitudinal surface of the driving rod, and wherein the driving rod is movable proximally relative to the housing upon rotation of the rod about its axis such that the ratchet pawls are in contact with the contiguous longitudinal surface that is free of ratchet teeth. The ratchet teeth can disengage from the first and second ratchet pawls upon rotation of the driving rod about its axis.

Additionally provided herein is a method of inserting a spinal implant between two vertebrae, comprising: (a) placing an intervertebral implant between a pair of opposing arms of a vertebral distractor-inserter, the distractor-inserted comprising: (i) a pair of opposing arms having distal ends; (ii) a housing in mechanical communication with the pair of opposing arms and rotatable about an axis extending between the opposing arms; and (iii) a driving rod extending through at least a portion of the housing and between the pair of opposing arms; (b) inserting said distal ends of the pair of opposing arms between a pair of vertebrae from a posterior angle; and (c) actuating said distractor-inserter, thereby distracting said vertebrae and inserting said implant between said vertebrae. The method can further provide for the use of a distractor-inserter wherein the driving rod comprises a distal end having an implant interface, wherein the housing and at least a portion of the driving rod are rotatable relative to the pair of opposing arms and the implant interface. The implant interface can additionally comprises an interface rotation element, whereby the interface rotation element allows rod rotation relative to the pair of opposing arms. The housing can comprises a housing rotation element, whereby the housing rotation element allows housing and rod rotation relative to the pair of opposing arms. In some embodiments, the distractor-inserter is adapted for single-handed use. The method can further provide for a device that can be introduced between the pair of vertebrae from a posterior angle, where the posterior angle is generally parallel to the axial plane and sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is substantially parallel with respect to the axial plane but deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the other side of the spinous process. In some embodiments of the method, the implant has laterally opposing walls that are substantially curved. In some embodiments, one of the opposing walls is substantially parallel to the axis of insertion and the other opposing wall is substantially curved. In some embodiments of the method, the actuating step can further comprise inserting an implant having laterally opposing walls in the intervertebral space wherein the inserting of the implant comprises repositioning the implant in the intervertebral space by following the curvature of the implant.

Further provided herein is a method of inserting an implant between vertebrae, comprising: (a) placing a vertebral implant between a pair of opposing arms of a vertebral distractor-inserter, said distractor-inserter comprising: (i) a housing; (ii) a pair of opposing arms in mechanical communication with the housing; (iii) a driving rod extending through at least a portion of the housing and between the pair of opposing arms; and (iv) a drive mechanism in mechanical communication with the driving rod, wherein the drive mechanism is adapted to move the driving rod distally relative to the housing, and wherein the distractor-inserter is adapted for single-handed distraction of vertebrae and insertion of a vertebral implant; (b) inserting said distal ends of the pair of opposing arms between a pair of vertebrae from a posterior angle; and actuating said distractor-inserter, thereby distracting said vertebrae and inserting said implant between said vertebrae. The method can further provide for a device that can be introduced between the pair of vertebrae from a posterior angle, where the posterior angle is generally parallel to the axial plane and sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the device is introduced at a posterior angle that is substantially parallel to the axial plane but which deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the other side of the spinous process. In some embodiments, the implant has laterally opposing walls that are substantially curved. In some embodiments, one of the opposing walls is substantially parallel to the axis of insertion and the other opposing wall is substantially curved. In some embodiments of the method, the actuating step can further comprise inserting an implant having laterally opposing walls in the intervertebral space wherein the inserting of the implant comprises repositioning the implant in the intervertebral space by following the curvature of the implant.

Another method provided herein is a method for distracting adjacent vertebrae and inserting an implant between the distracted vertebrae from a posterior angle, comprising: (a) mounting the implant to a driving rod of a vertebral distractor-inserter having a pair of opposing arms, a distal end, and a drive mechanism in mechanical communication with the driving rod, wherein the driving rod extends between the pair of opposing arms; (b) positioning the distal end of the pair of arms between the vertebrae from a posterior angle; (c) distracting the vertebrae by single-handed operation of the vertebral distractor-inserter; (d) inserting the implant between the distracted vertebrae by single-handed operation of the vertebral distractor-inserter; and (e) retracting the pair of opposing arms from between the vertebrae. The distracting step can further comprise activating the drive mechanism using one hand, wherein the activating moves the implant distally and distracts the pair of opposing arms. In some embodiments of the method, the vertebral distractor-inserter has a housing in mechanical communication with the pair of opposing arms, wherein the driving rod extends through at least a portion of the housing. Additionally, the inserting step of the method for distracting adjacent vertebrae can further comprise advancing the implant into the distracted space between the vertebrae. The advancing step can comprise activating the drive mechanism using one hand and extending the implant beyond the distal end of the pair of opposing arms. In some embodiments, the method further comprises the additional step of releasing the implant from the distractor-inserter. The method provided can include the use of a distractor-inserter comprising a the pair of opposing arms comprising a depth guard, and wherein the positioning step comprises urging the pair of arms between the vertebrae up to the position where the depth guard contacts the vertebrae. In some embodiments of the method, the vertebral distractor-inserter has a housing in mechanical communication with the pair of opposing arms, wherein the driving rod extends through at least a portion of the housing, and wherein the activating the drive mechanism comprises the step of ratcheting the driving rod distally, wherein the driving rod comprises: (a) an axis and (b) a surface with a plurality of angled ratchet teeth on at least a portion of the surface, and wherein the drive mechanism comprises: (i) an activating lever capable of movement between a first position and a second position and mounted to the housing by an activating lever pivot, (ii) a first ratchet pawl coupled to the activating lever and adapted to engage the ratchet teeth and move the driving rod distally relative to the housing, and (iii) a second ratchet pawl adapted to engage the ratchet teeth and oppose proximal motion of the driving rod relative to the housing. The method can further provide for a device that can be introduced between the pair of vertebrae from a posterior angle, where the posterior angle is generally parallel to the axial and sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is substantially parallel to the axial plane but deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the other side of the spinous process. In some embodiments, the implant has laterally opposing walls that are substantially curved. In some embodiments, one of the opposing walls is substantially parallel to the axis of insertion and the other opposing wall is substantially curved. In some embodiments of the method, the actuating step can further comprise inserting an implant having laterally opposing walls in the intervertebral space wherein the inserting of the implant comprises repositioning the implant in the intervertebral space by following the curvature of the implant.

In some embodiments, further provided is a method for distracting adjacent vertebrae and inserting an implant between the distracted vertebrae from a posterior angle, comprising the steps of: (a) mounting the implant to a driving rod of a vertebral distractor-inserter having a pair of opposing arms, and a ratchet drive mechanism in mechanical communication with the driving rod, wherein the driving rod extends between the pair of opposing arms; (b) positioning the distal end of the pair of arms between the vertebrae from a posterior angle; (c) distracting the vertebrae, wherein the distracting comprises activating the ratchet drive mechanism; (d) inserting the implant between the distracted vertebrae, wherein the inserting comprises advancing the implant into the distracted space between the vertebrae, and wherein the advancing comprises activating the ratchet drive mechanism; and (e) retracting the pair of opposing arms from between the vertebrae. The activating step can further comprise moving the implant distally and distracting the pair of opposing arms. The step of activating the ratchet drive mechanism, in some embodiments, can further comprise the step of ratcheting the driving rod distally, wherein the driving rod comprises: (a) an axis; and (b) a surface with a plurality of angled ratchet teeth on at least a portion of the surface, and wherein the ratchet drive mechanism comprises: (i) an activating lever capable of movement between a first position and a second position and mounted to the housing by an activating lever pivot, (ii) a first ratchet pawl coupled to the activating lever and adapted to engage the ratchet teeth and move the driving rod distally relative to the housing, and (iii) a second ratchet pawl adapted to engage the ratchet teeth and oppose proximal motion of the driving rod relative to the housing. The device can be introduced between the pair of vertebrae from a posterior angle, where the posterior angle is generally parallel to the axial and sagittal planes. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is substantially parallel with respect to the axial plane but which deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the other side of the spinous process. In some embodiments, the implant has laterally opposing walls that are substantially curved. In some embodiments, one of the opposing walls is substantially parallel to the axis of insertion and the other opposing wall is substantially curved. In some embodiments of the method, the actuating step can further comprise inserting an implant having laterally opposing walls in the intervertebral space wherein the inserting of the implant comprises repositioning the implant in the intervertebral space by following the curvature of the implant.

Yet another embodiment of the method provided herein includes a method for distracting adjacent vertebrae and inserting an implant between the distracted vertebrae from a posterior angle, comprising the steps of: (a) mounting the implant to a driving rod of a vertebral distractor-inserter having: (i) a pair of opposing arms having a distal end, (ii) a housing in mechanical communication with the pair of opposing arms which is rotatable about an axis extending between the opposing arms relative to the arms and to the implant, and (iii) a drive mechanism in mechanical communication with the driving rod, wherein the driving rod extends through at least a portion of the housing and between the pair of opposing arms and wherein at least a portion of the driving rod is rotatable about the axis extending between the opposing arms relative to the pair of opposing arms and to the implant; (b) positioning the distal end of the pair of arms between the vertebrae from a posterior angle; (c) rotating the housing and at least a portion of the driving rod relative to the pair of opposing arms and to the implant; (d) distracting the vertebrae; (e) inserting the implant between the distracted vertebrae; and (f) retracting the pair of opposing arms from between the vertebrae. The distracting step can further comprise activating the drive mechanism, wherein the activating moves the implant distally and distracts the pair of opposing arms. Additionally, the inserting step of the method can further comprise advancing the implant into the distracted space between the vertebrae. The device can be introduced between the pair of vertebrae from a posterior angle, where the posterior angle is generally parallel to the axial plane and sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is substantially parallel to the axial plane but deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the other side of the spinous process. In some embodiments, the implant has laterally opposing walls that are substantially curved. In some embodiments, one of the opposing walls is substantially parallel to the axis of insertion and the other opposing wall is substantially curved. In some embodiments of the method, the actuating step can further comprise inserting an implant having laterally opposing walls in the intervertebral space wherein the inserting of the implant comprises repositioning the implant in the intervertebral space by following the curvature of the implant.

Another embodiment of the method provided herein comprises a method for distracting adjacent vertebrae and inserting an implant between the distracted vertebrae from a posterior angle, comprising the steps of: (a) mounting the implant to a driving rod of a vertebral distractor-inserter having (i) a pair of opposing arms having a distal end and a depth guard, (ii) an implant depth adjustor that is adjustable to a plurality of implant depth settings, (iii) a housing in mechanical communication with the pair of opposing arms, and (iv) a drive mechanism in mechanical communication with the driving rod, wherein the driving rod extends through at least a portion of the housing and between the pair of opposing arms, wherein the mounting comprises the step of adjusting the implant depth adjustor to control the maximum distal implant depth achievable during the inserting step; (b) positioning the distal end of the pair of arms between the vertebrae, wherein the positioning comprises urging the pair of arms between the vertebrae up to the position where the depth guard contacts the vertebrae; (c) distracting the vertebrae; (d) inserting the implant between the distracted vertebrae from a posterior angle; and (e) retracting the pair of opposing arms from between the vertebrae. The device can be introduced between the pair of vertebrae from a posterior angle, where the posterior angle is generally parallel to the axial plane and sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is substantially parallel to the axial plane but deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the other side of the spinous process. In some embodiments, the implant has laterally opposing walls that are substantially curved. In some embodiments, one of the opposing walls is substantially parallel to the axis of insertion and the other opposing wall is substantially curved. In some embodiments of the method, the actuating step can further comprise inserting an implant having laterally opposing walls in the intervertebral space wherein the inserting of the implant comprises repositioning the implant in the intervertebral space by following the curvature of the implant.

Further provided herein is a method of implanting an implant in an intervertebral space comprising: (a) providing a distractor-inserter comprising (i) a pair of opposing arms, having distal ends; (ii) a driving rod extending between the pair of opposing arms; and (iii) a drive mechanism in mechanical communication with the driving rod; (b) inserting the distal end of the pair of arms between the vertebrae from a posterior angle; (c) actuating the distractor-inserter, thereby distracting said vertebrae and inserting said implant between said vertebrae; and (d) repositioning said implant so that it occupies an anterior vertebral space. The method further comprises inserting an implant that has laterally opposing walls that are substantially curved with respect to the axis of insertion. The method can further comprises a posterior angle, where the posterior angle is generally parallel to the axial plane and sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is substantially parallel to the axial plane but which deviates about 20 to about 60 degrees with respect to the sagittal plane. The method further comprises the use of a distractor-inserter for inserting a spinal implant between the vertebrae.

Yet another method provided herein is a method of implanting implants into an intervertebral space comprising: (a) providing a distractor-inserter comprising (i) a pair of opposing arms, having distal ends; (ii) a driving rod extending between the pair of opposing arms; and (iii) a drive mechanism in mechanical communication with the driving rod; (b) inserting the distal end of the pair of arms between the vertebrae from a posterior angle; (c) actuating the distractor-inserter, thereby distracting said vertebrae and inserting said implant between said vertebrae; and (d) repeating steps (a)-(c) on the contralateral side of the spinous process. In some embodiments, the implant has laterally opposing walls that are substantially parallel to the axis of insertion. The implant can be boxed-shaped. The method can further comprise inserting at least two implants into the intervertebral space. One implant can be inserted on one side of the spinous process and another implant can be inserted on the contralateral side of the spinous process. In some embodiments, the posterior angle is substantially parallel to the axial plane and the sagittal plane. In some embodiments of the method, the device can be introduced between the pair of vertebrae from a posterior angle where the posterior angle is parallel to the axial plane but which deviates about 20 to about 60 degrees with respect to the sagittal plane.