Spinal implant system and method

A system includes a sleeve including first and second arms each including an outer ramp and an inward projection, each of the arms defining a cavity. First and second extensions are configured for disposal in the cavities. A fastener includes walls defining an implant cavity and a distal portion. The walls each include first and second end surfaces and a locking cavity. The extensions are configured for translation relative to the sleeve between a first orientation such that the extensions engage the respective ramps to fix the projections with a respective locking cavity in a configuration to capture the fastener with the sleeve and a second orientation such that the extensions move out of engagement with the respective ramps so that the projections are movable out of engagement with the locking cavities to release the fastener from the sleeve. Methods of use are disclosed.

TECHNICAL FIELD

The present disclosure generally relates to medical devices for the treatment of musculoskeletal disorders, and more particularly to a surgical system for implant delivery to a surgical site and a method for treating a spine.

BACKGROUND

Spinal pathologies and disorders such as scoliosis and other curvature abnormalities, kyphosis, degenerative disc disease, disc herniation, osteoporosis, spondylolisthesis, stenosis, tumor, and fracture may result from factors including trauma, disease and degenerative conditions caused by injury and aging. Spinal disorders typically result in symptoms including deformity, pain, nerve damage, and partial or complete loss of mobility.

Non-surgical treatments, such as medication, rehabilitation and exercise can be effective, however, may fail to relieve the symptoms associated with these disorders. Surgical treatment of these spinal disorders includes correction, fusion, fixation, discectomy, laminectomy and implantable prosthetics. As part of these surgical treatments, spinal constructs such as vertebral rods are often used to provide stability to a treated region. Rods redirect stresses away from a damaged or defective region while healing takes place to restore proper alignment and generally support the vertebral members. During surgical treatment, one or more rods and bone fasteners can be delivered to a surgical site. The rods may be attached via the fasteners to the exterior of two or more vertebral members. This disclosure describes an improvement over these prior art technologies.

SUMMARY

In one embodiment, in accordance with the principles of the present disclosure, a spinal implant system is provided including a sleeve, a first extension, a second extension and a bone fastener. The sleeve defines a longitudinal axis and extends between a first end and a second end. The sleeve includes a first arm, a second arm and an inner surface defining an interior cavity therebetween. Each of the arms include a movable tab having an outer ramp and an inward projection, each of the arms defining a longitudinal cavity. The first extension extends between a first end and a second end, and is configured for movable disposal in the longitudinal cavity of the first arm. The second extension extends between a first end and a second end, and is configured for movable disposal in the longitudinal cavity of the second arm. The bone fastener comprises a proximal portion including two spaced apart walls defining an implant cavity and a distal portion including a tissue engaging portion. The walls each include a first end surface, a second end surface and an outer surface extending therebetween defining a locking cavity. The extensions are configured for axial translation relative to the sleeve between a first orientation and a second orientation. In the first orientation, the second ends of the extensions engage the respective outer ramps to fix the projections with a respective locking cavity in a configuration to capture the bone fastener with the second end of the sleeve. In the second orientation, the second ends of the extensions move out of engagement with the respective outer ramps so that the projections are movable out of engagement the locking cavities to release the bone fastener from the second end of the sleeve.

In one embodiment, the spinal implant system includes a sleeve, a first extension, a second extension and at least one bone fastener. The sleeve defines a longitudinal axis and extends between a proximal end and a distal end. The sleeve includes an inner surface defining a first implant cavity. The sleeve includes a first arm having an arcuate wall that defines a longitudinal channel and includes a first flange having a planar face and a second flange having a planar face adjacent the distal end of the sleeve. The first arm has a tab that is movable in an outward direction and extends between the distal end of the sleeve and an intermediate portion of the sleeve. The tab includes an outer ramp and an inward circular projection. The sleeve includes a second arm having an arcuate wall defining a longitudinal channel and a first flange having a planar face and a second flange having a planar face adjacent the distal end of the sleeve. The second arm has a tab that is movable in an outward direction and extends between the distal end of the sleeve and the intermediate portion of the sleeve. The tab of the second arm includes an outer ramp and an inward circular projection. The first extension extends between a proximal end and a distal end, and is configured for slidable movement within the longitudinal channel of the first arm. The distal end of the first extension is configured for engagement with the outer ramp of the first arm. The second extension extends between a proximal end and a distal end, and is configured for slidable movement within the longitudinal channel of the second arm. The distal end of the second extension is configured for engagement with the ramp of the second arm. The bone fastener(s) comprise(s) a proximal portion including a first wall and a second wall spaced apart from the first wall. The walls define an implant cavity. The bone fastener(s) comprise(s) a distal portion including a tissue engaging portion. The first wall includes a first angled end surface configured to engage the first flange of the first arm, a second angled end surface configured to engage the second flange of the first arm and a first outer surface extending therebetween. The first outer surface includes a first locking cavity. The second wall includes a first angled end surface configured to engage the first flange of the second arm, a second angled end surface configured to engage the second flange of the second arm and a second outer surface extending therebetween. The second outer surface includes a second locking cavity. The extensions are configured for axial translation relative to the sleeve between a first orientation and a second orientation. In the first orientation, the second ends of the extensions engage the respective outer ramps to fix the projections with a respective locking cavity in a configuration to capture the bone fastener with the distal end of the sleeve. In the second orientation, the second ends of the extensions move out of engagement with the respective outer ramps so that the projections are movable out of engagement with the locking cavities to release the bone fastener from the distal end of the sleeve such that the projections are engageable with the edge surfaces so that the sleeve is axially translatable to force the projections outwardly and out of engagement with the locking cavities.

In one embodiment, the spinal implant system includes a sleeve, a first extension, a second extension, an actuator and at least one bone fastener. The sleeve defines a longitudinal axis and extends between a proximal end and a distal end. The sleeve includes an inner surface defining a first implant cavity. The proximal end includes a first lateral opening and a second lateral opening. The sleeve includes a first arm having an arcuate wall that defines a longitudinal channel and includes a first flange having a planar face and a second flange having a planar face adjacent the distal end of the sleeve. The first arm has a tab that is movable in an outward direction and extends between the distal end of the sleeve and an intermediate portion of the sleeve. The tab includes an outer ramp and an inward circular projection having a chamfer surface. The sleeve includes a second arm having an arcuate wall defining a longitudinal channel and a first flange having a planar face and a second flange having a planar face adjacent the second end of the sleeve. The second arm has a tab that is movable in an outward direction and extends between the second end of the sleeve and the intermediate portion of the sleeve. The tab of the second arm includes an outer ramp and an inward circular projection having a chamfer surface. The first extension extends between a proximal end and a distal end, and is configured for slidable movement within the longitudinal channel of the first arm. The distal end of the first extension is configured for engagement with the outer ramp of the first arm. The second extension extends between a proximal end and a distal end, and is configured for slidable movement within the longitudinal channel of the second arm. The distal end of the second extension is configured for engagement with the outer ramp of the second arm. The actuator includes a handle configured to effect axial translation of the extensions relative to the sleeve. The actuator further includes a resiliently biased depressible member rotatable relative to the sleeve and configured for disposal in the first lateral opening in a first orientation and in the second lateral opening in a second orientation. The bone fastener(s) comprise(s) a proximal portion including a first wall and a second wall spaced apart from the first wall. The walls define an implant cavity. The bone fastener(s) comprise(s) a distal portion including a tissue engaging portion. The first wall includes a first angled end surface configured to engage the first flange of the first arm, a second angled end surface configured to engage the second flange of the first arm and a first outer surface extending therebetween. The first outer surface includes an edge surface that defines a first locking cavity. The second wall includes a first angled end surface configured to engage the first flange of the second arm, a second angled end surface configured to engage the second flange of the second arm and a second outer surface extending therebetween. The second outer surface includes an edge that defines a second locking cavity. The handle is manipulable to cause axial translation of the extensions relative to the sleeve between the first orientation and a second orientation. In the first orientation, the second ends of the extensions engage the respective outer ramps to fix the projections with a respective locking cavity in a configuration to capture a bone fastener with the distal end of the sleeve such that the flanges engage the end surfaces to prevent disengagement of the arms from the bone fastener. In the second orientation, the second ends of the extensions move out of engagement with the respective outer ramps so that the projections are movable out of engagement with the locking cavities to release the bone fastener from the distal end of the sleeve such that the projections are engageable with the edge surfaces so that the sleeve is axially translatable to force the projections outwardly and out of engagement with the locking cavities.

Like reference numerals indicate similar parts throughout the figures.

DETAILED DESCRIPTION

The exemplary embodiments of the surgical system and related methods of use disclosed are discussed in terms of medical devices for the treatment of musculoskeletal disorders and more particularly, in terms of a surgical system for implant delivery to a surgical site and a method for treating a spine. It is envisioned that the surgical implant system can include a bone fastener having a head with angled surfaces that prevent medial/lateral disengagement of an insertion device, such as, for example, an extender. It is further envisioned that the surgical implant system can include an extender that clicks into engagement with a bone fastener by pushing the extender onto the bone fastener.

It is envisioned that the system may include instruments that are connected or attached to an extender(s) such as, for example, a lateral translation handle or derotaton instruments. It is further envisioned that the system may have an extender with a quick release mechanism to allow the extender to slide in and out of engagement with an implant. It is contemplated that the system can include an extender having features that prevent an implant from rotating. In one embodiment, one or all of the components of the surgical system are disposable, peel-pack, pre-packed sterile devices used with an implant. One or all of the components of the surgical system may be reusable. The surgical system may be configured as a kit with multiple sized and configured components.

The following discussion includes a description of a surgical system and related methods of employing the surgical system in accordance with the principles of the present disclosure. Alternate embodiments are also disclosed. Reference will now be made in detail to the exemplary embodiments of the present disclosure, which are illustrated in the accompanying figures. Turning now toFIGS. 1-15, there is illustrated components of a surgical system, such as, for example, a spinal implant system in accordance with the principles of the present disclosure.

The spinal implant system is employed, for example, with a minimally invasive procedure, including percutaneous techniques, mini-open and open surgical techniques to deliver and introduce an implant, such as, for example, a bone fastener, at a surgical site within a body of a patient, for example, a section of a spine. It is contemplated that the spinal implant system and method may be employed with treatments using minimally invasive and percutaneous techniques.

The spinal implant system includes a sleeve30, a first extension32, a second extension34, an actuator36and at least one bone fastener38. Sleeve30defines a longitudinal axis a and extends between a first end, such as, for example, a proximal end40and a second end, such as, for example, a distal end42. Sleeve30includes a concavely curved inner surface44defining an inner cavity, such as, for example, a first implant cavity46and a convexly curved outer surface48. Implant cavity46is configured to facilitate positioning of a spinal construct, such as a vertebral rod, relative to bone fastener38. It is envisioned that all or only a portion of surface44, surface48and/or implant cavity46may be variously configured and dimensioned, such as, for example, planar, concave, convex, polygonal, irregular, uniform, non-uniform, staggered, tapered, consistent or variable, depending on the requirements of a particular application.

Proximal end40has a substantially square cross-section, which includes rounded corners (FIG. 3) configured to slidably engage actuator36. Proximal end40of sleeve30includes a first lateral opening50and a second lateral opening52. Opening52is positioned proximal to opening50. Each of openings50,52are configured for disposal of at least a portion of actuator36to prevent translation of extensions32,34relative to sleeve30. Openings50,52each extend transverse to longitudinal axis a through surfaces44,48to form a passageway through sleeve30. It is envisioned that openings50,52may each extend through surface48without extending through surface44so as to form at least one cavity in sleeve30. It is further envisioned that openings50,52may extend through surface48and/or surface44at alternate orientations relative to longitudinal axis a, such as, for example, transverse, perpendicular and/or other angular orientations such as acute or obtuse and/or may be offset or staggered. It is contemplated that sleeve30may include one or a plurality of lateral openings. Openings50,52each have a substantially rectangular configuration. It is envisioned that openings50,52may be variously configured and dimensioned, such as, for example, round, oval, oblong, square, rectangular, polygonal, irregular, uniform, non-uniform, offset, staggered, tapered, consistent or variable, depending on the requirements of a particular application.

Proximal end40includes at least one transverse groove54extending transverse to longitudinal axis a into surface48without extending through surface44. Groove54is configured to allow for the attachment of other instruments, such as, for example, drivers and rod reduction instruments with sleeve30. This feature allows the spinal implant system to be used in other surgical procedures. Groove54is aligned with opening52such that opening52extends through groove54. It is envisioned that groove54may be positioned out of alignment with opening52, such as, for example, either proximal or distal of opening52. It is contemplated that sleeve30may include one or a plurality of transverse grooves. It is envisioned that groove54may have alternate surface configurations to enhance fixation with an instrument such as, for example, rough, arcuate, undulating, mesh, porous, semi-porous, dimpled and/or textured according to the requirements of a particular application. It is further envisioned that groove54may extend into surface48at alternate orientations relative to longitudinal axis a, such as, for example, transverse, perpendicular and/or other angular orientations such as acute or obtuse and/or may be offset or staggered.

Sleeve30includes a first arm56having an arcuate wall58that defines a longitudinal channel60. Channel60extends parallel to longitudinal axis a and is configured for disposal of extension32such that extension32can translate axially therein. Channel60is defined by a planar bottom surface extending between planar side surfaces that are perpendicular to the planar bottom surface so as to form a channel having a substantially U-shaped cross-section. It is envisioned that channel60may have other cross-sectional configurations, including, for example, a cut similar to a rack and pinion, V-shaped, W-shaped, polygonal, or tapered according to the requirements of a particular application. It is further envisioned that wall58may be variously configured and dimensioned, such as, for example, planar, concave, convex, polygonal, irregular, uniform, non-uniform, staggered, tapered, consistent or variable, depending on the requirements of a particular application.

Arm56includes an enlarged portion61disposed adjacent a proximal end thereof. Portion61is configured to retain extension32in channel60. Channel60extends parallel to longitudinal axis a through portion61of to form a passageway through portion61. It is contemplated that portion61may extend the entire length of channel60. It is further contemplated that channel60may extend at various orientations relative to longitudinal axis a, such as, for example, parallel, transverse, perpendicular and/or other angular orientations such as acute or obtuse and/or may be offset or staggered.

Arm56includes a first angled flange62having a planar face64that is parallel with longitudinal axis a. Arm56includes a second angled flange66having a planar face68that is parallel with longitudinal axis a. Flanges62,66are disposed adjacent distal end42. Face64is configured to engage a planar first angled end surface70of bone fastener38and face68is configured to engage a planar second angled end surface72of bone fastener38. Faces64,68engage surfaces70,72to facilitate engagement of sleeve30with bone fastener38and prevent disengagement of arm56from bone fastener38.

Faces64,68and surfaces70,72each have a surface which is smooth and continuous, uninterrupted by any gaps or protrusions. It is envisioned that faces64,68may extend at various orientations relative to longitudinal axis a, such as, for example, parallel, transverse, perpendicular and/or other angular orientations such as acute or obtuse and/or may be offset or staggered. It is further envisioned that faces64,68and/or surfaces70,72may be variously configured and dimensioned, such as, for example, planar, concave, convex, polygonal, irregular, uniform, non-uniform, staggered, tapered, consistent or variable, depending on the requirements of a particular application. It is contemplated that all or a portion of faces64,68and/or surfaces70,72may have alternate surface fixation configurations, such as, for example, rough, undulating, porous, semi-porous, dimpled, polished and/or textured according to the requirements of a particular application. It is further contemplated that sleeve30may engage bone fastener38and prevent sleeve30from rotating relative to bone fastener38about longitudinal axis a in alternate fixation configurations, such as, for example, friction fit, pressure fit, locking protrusion/recess, locking keyway and/or adhesive.

Arm56includes a movable tab74extending between distal end42and an intermediate portion76of sleeve30. Tab74includes a proximal portion78defined by a pair of parallel planar sidewalls80and a distal portion82, which is non-uniform. It is envisioned that all or a portion of tab74may be variously configured and dimensioned, such as, for example, planar, concave, convex, polygonal, irregular, uniform, non-uniform, staggered, tapered, consistent or variable, depending on the requirements of a particular application. It is further envisioned that all or a portion of tab74may be radially flexible to facilitate connection to and removal from bone fastener38. It is contemplated that tab74may be resilient to maintain the connection between tab74and bone fastener38.

Inner surface44includes a curved first transverse wall45and a curved second transverse wall47. Walls45,47each have a curvature, which is continuous with surface44. Wall45defines a first ridge49and wall47defines a second ridge51. Ridges49,51each define a planar face. Ridges49,51are configured to engage at least a portion of bone fastener38to prevent movement of bone fastener38relative to sleeve30in an axial direction.

An inner surface of portion78defines a ledge79that is coplanar with ridge49and has a curvature that is continuous with wall45. Ridge49and ledge79define a U-shaped wall configured to engage at least a portion of bone fastener38to prevent movement of bone fastener38relative to arm56in an axial direction.

Tab74includes an outer ramp84extending from outer surface48along longitudinal axis a. Ramp84is tapered between a first end86having a width w and a second end88having a width w1. Width w1is greater than width w (FIG. 7). Ramp84is planar between end86and end88and is configured to engage extension32so that an inward circular projection92of tab74is movable out of engagement with a locking cavity90in bone fastener38to release bone fastener38from end42, as will be discussed.

Locking cavity90is substantially circular and defined by an edge surface91and a planar wall surface of bone fastener38. It is envisioned that all or a portion of the surface of locking cavity90may be, for example, planar, concave, convex, polygonal, irregular, uniform, non-uniform, staggered, tapered, consistent or variable, depending on the requirements of a particular application. It is further envisioned that locking cavity90may be variously configured, such as, for example, round, oval, oblong, square, rectangular, polygonal, irregular, uniform, non-uniform, offset, staggered, tapered, consistent or variable, depending on the requirements of a particular application. Edge surface91has a radial band configuration disposed about locking cavity90and extends a wall thickness to the planar wall surface of bone fastener38. Surface91is engageable with projection92to move projection92out of engagement with locking cavity90to release bone fastener38from end42, as will be discussed.

Tab74is configured to move through a range of motion sufficient to allow engagement and disengagement of bone fastener38. Chamfer95engages surface91as arm56translates axially relative to bone fastener38to force projection92outwardly and out of engagement with locking cavity90to release bone fastener38from end42. It is envisioned that projection92may extend from inner surface44at various orientations relative to longitudinal axis a, such as, for example, parallel, transverse, perpendicular and/or other angular orientations such as acute or obtuse and/or may be offset or staggered. It is further envisioned that projection92may be variously configured and dimensioned, such as, for example, round, oval, oblong, square, rectangular, polygonal, irregular, uniform, non-uniform, offset, staggered, tapered, consistent or variable, depending on the requirements of a particular application. It is contemplated that bone fastener38may be captured with distal end42in alternate fixation configurations, such as, for example, friction fit, pressure fit, locking protrusion/recess, locking keyway and/or adhesive.

Sleeve30includes a second arm94, similar to arm56, including an arcuate wall96that defines a longitudinal channel98. Channel98extends parallel to longitudinal axis a and is configured for disposal of extension34such that extension34can translate axially therein. Channel98is defined by a planar bottom surface extending between planar side surfaces that are perpendicular to the planar bottom surface so as to form a channel having a substantially U-shaped cross-section. Arm94includes an enlarged portion99disposed adjacent a proximal end thereof. Portion99is configured to retain extension34in channel98. Channel98extends parallel to longitudinal axis a through portion99of to form a passageway through portion99.

Arm94includes a first angled flange100having a planar face102that is parallel with longitudinal axis a. Arm94includes a second angled flange104having a planar face106that is parallel with longitudinal axis a. Flanges62,66are disposed adjacent distal end42. Face102is configured to engage a planar first angled end surface108of bone fastener38and face106is configured to engage a planar second angled end surface110of bone fastener38. Faces102,106engage surfaces108,110to facilitate engagement of sleeve30with bone fastener38and prevent disengagement of arm94from bone fastener38. Planar faces102,104and surfaces108,110each have a surface that is smooth and continuous, uninterrupted by any gaps or protrusions.

Arm94includes a movable tab112extending between distal end42and intermediate portion76. Tab112includes a proximal portion114defined by a pair of parallel planar sidewalls116and a distal portion118, which is non-uniform. An inner surface of portion114defines a ledge115that is coplanar with ridge51and has a curvature that is continuous with wall47. Ridge51and ledge115define a U-shaped wall configured to engage at least a portion of bone fastener38to prevent movement of bone fastener38relative to arm94in an axial direction.

Tab112includes an outer ramp120extending from surface48along longitudinal axis a. Ramp120is tapered between a first end122having a width w and a second end124having a width w1. Width w1is greater than width w. Ramp120is planar between end122and end124and is configured to engage extension34so that an inward circular projection128of tab112is movable out of engagement with a locking cavity126in bone fastener38to release bone fastener38from end42, similar to cavity90and projection92.

Projection128extends transverse to longitudinal axis a from surface44. Projection128includes a planar face129and is configured for fixation with locking cavity126to capture bone fastener38with end42. Projection128includes a circumferential chamfer135adjacent face129such that projection128is tapered. Chamfer135engages surface127to securely retain projection128within locking cavity126when projection128is aligned with locking cavity126. Chamfer135also engages surface127as arm94translates axially relative to bone fastener38to move projection128in and out of engagement with locking cavity126, as will be discussed.

Extension32extends between a first end, such as, for example, a proximal end130and a second end, such as, for example, a distal end132. Extension32is configured for slidable movement within longitudinal channel60. Extension32includes a planar first surface134configured to slidably engage the planar bottom surface of longitudinal channel60and an arcuate second surface136, opposite surface134. Extension32includes planar side surfaces138extending between surfaces134,136. Surfaces138engage the planar side surfaces of longitudinal channel60when extension32is disposed within longitudinal channel60to maintain extension32within longitudinal channel60during axial translation of first extension32relative to sleeve30along longitudinal axis a. Extension32has a height between surfaces134,136which is approximately equal to a depth of longitudinal channel60. Surface136has a curvature that is similar to that of arcuate wall58such that first surface136and arcuate wall58form a convexly curved wall having a continuous curvature when first extension32is disposed within longitudinal channel60.

End130includes a flange portion140configured for disposal in a first aperture142of actuator36to fix extension32with actuator36. Aperture142is substantially rectangular. Portion140is securely retained within aperture142. Aperture142is in communication with a longitudinal channel143extending along longitudinal axis a. Channel143extends through a portion of actuator36and is configured for disposal of end130when portion140is disposed in aperture142. Surface134includes a tapered portion144at end132configured for engagement with ramp84. Portion144extends through surface134at an angle which is approximately equivalent to the angle in which ramp84extends from surface48such that surface48is aligned with surface136at end82when portion144engages ramp84. In one embodiment, end130has an opening extending through surfaces134,136; a pin may extend through the opening in end130and into a portion of actuator36to fix extension32with actuator36. It is envisioned that extension32may be fixed with actuator36in alternate fixation configurations, such as, for example, friction fit, pressure fit, locking protrusion/recess, locking keyway and/or adhesive.

Extension34extends between a first end, such as, for example, a proximal end146and a second end, such as, for example, a distal end148. Extension34is configured for slidable movement within longitudinal channel98. Extension34includes a planar first surface150configured to slidably engage the planar bottom surface of longitudinal channel98and an arcuate second surface152, opposite surface150. Extension34includes planar side surfaces154extending between surfaces150,152.

End146includes a flange portion156configured for disposal in a second aperture158in actuator36to fix extension34with actuator36. Aperture158is substantially rectangular. Portion156is substantially rectangular such that portion156is securely retained within aperture158. Aperture158is in communication with a longitudinal channel159extending along longitudinal axis a. Aperture158extends through a portion of actuator36and is configured for disposal of end146when portion156is disposed in aperture158. Surface154includes a tapered portion160at end148configured for engagement with ramp120. In one embodiment, end146has an opening extending through surfaces150,152; a pin may extend through the opening in end146and into a portion of actuator36to fix extension34with actuator36.

Actuator36includes a handle162configured to effect axial translation of extensions32,34relative to sleeve30. Handle162includes an inner surface164defining a substantially square passageway166having rounded corners (FIG. 4) configured for disposal of end40such that end40can translate axially within passageway166along longitudinal axis a. Handle162includes an outer surface168disposed opposite to surface162. Apertures142,158each extend through surface164and surface168. Longitudinal channels143,159extend through surface164without extending through surface168.

Actuator36includes a first cylindrical channel170extending transverse to longitudinal axis a through surface164. An outer surface168and longitudinal channel143are configured for disposal of a cylindrical pin171. A second cylindrical channel172extends transverse to longitudinal axis a through surface164. Surface168and longitudinal channel159are configured for disposal of a cylindrical pin173. It is envisioned that cylindrical channels170,172may be disposed in an orientation relative to longitudinal axis a, for example, perpendicular and/or selected angular orientations such as acute or obtuse, perpendicular and/or parallel.

Actuator36includes a first resiliently biased depressible member174and a second resiliently biased depressible member176. Members174,176are rotatable relative to sleeve30. Member174includes a tip178configured for disposal in opening50in a first orientation when extensions32,34are in a first orientation and in lateral opening52when extensions32,34are in a second orientation. Member176includes a tip180configured for disposal in opening50when extensions32,34are in the first orientation and in opening52when extensions32,34are in the second orientation.

Member174includes a button182and a cylindrical opening184extending transverse to longitudinal axis a through member174. Opening184is configured for disposal of pin171such that member174is rotatable relative to sleeve30about pin171. Member174includes a first biasing member, such as, for example, a spring175disposed between sleeve30and tip178to bias tip178inwardly for disposal in opening50when extensions32,34are in the first orientation or opening52when extensions32,34are in the second orientation. Member176includes a button186and a cylindrical opening188extending transverse to longitudinal axis a through member176. Opening188is configured for disposal of pin173such that member176is rotatable relative to sleeve30about pin173. Member176includes a second biasing member, such as, for example, a spring177disposed between sleeve30and tip180to bias tip180inwardly for disposal in opening50when extensions32,34are in the first orientation or opening52when extensions32,34are in the second orientation.

Bone fastener38includes a proximal portion, such as, for example, a receiver190having a first wall192and a second wall194spaced apart from first wall192. Walls192,194extend parallel to longitudinal axis a. Walls192,194define an implant cavity196. Bone fastener38includes a distal tissue engaging portion, such as, for example, a shaft198. It is envisioned that the tissue engaging portion of bone fastener38may be configured to penetrate tissue. It is further envisioned that the tissue engaging portion of bone fastener38may comprise a screw, a hook, a clamp, or other mechanism configured to engage bone or other tissue.

Wall192includes first and second end surfaces that define surfaces70,72, which each extend parallel to longitudinal axis a. Wall192includes a planar face200extending between surfaces70,72. Face200is configured to engage the U-shaped wall defined by ridge49and ledge79to prevent movement of bone fastener38relative to arm56in an axial direction (FIG. 14). Locking cavity90extends transverse to longitudinal axis a through the first outer surface of bone fastener38. Wall194includes first and second end surfaces that define surfaces108,110, which each extend parallel to longitudinal axis a. Wall194includes a planar face202extending between surfaces108,110. Face202is configured to engage the U-shaped wall defined by ridge51and ledge115to prevent movement of bone fastener38relative to arm94in an axial direction (FIG. 14). Locking cavity126extends transverse to longitudinal axis a through the second outer surface of bone fastener38. It is contemplated that walls192,194, surfaces70,72and/or surfaces108,110may be disposed at alternate orientations, relative to longitudinal axis, such as, for example, transverse, perpendicular and/or other angular orientations such as acute or obtuse, co-axial and/or may be offset or staggered.

At least a portion of an inner surface of receiver190is threaded and engageable with a coupling member, such as, for example, a setscrew. It is envisioned that the inner surface of receiver190can include a thread form located adjacent wall192and a thread form located adjacent wall194each configured for engagement with a setscrew. It is envisioned that the inner surface of receiver190may be disposed with the setscrew in alternate fixation configurations, such as, for example, friction fit, pressure fit, locking protrusion/recess, locking keyway and/or adhesive. It is contemplated that all or only a portion of the inner surface of receiver190may have alternate surface configurations to enhance fixation with the setscrew such as, for example, rough, arcuate, undulating, mesh, porous, semi-porous, dimpled and/or textured according to the requirements of a particular application.

Shaft198is threaded along a length thereof and has a cylindrical cross section configuration. Shaft198includes an outer surface having an external thread form. It is contemplated that the thread form may include a single thread turn or a plurality of discrete threads. It is further contemplated that other engaging structures may be located on shaft198, such as, for example, a nail configuration, barbs, expanding elements, raised elements and/or spikes to facilitate engagement of shaft198with tissue, such as, for example, vertebrae and/or iliac bone. It is envisioned that all or only a portion of shaft198may have alternate cross section configurations, such as, for example, oval, oblong, triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, undulating, arcuate, variable and/or tapered. It is contemplated that the outer surface of shaft198may include one or a plurality of openings. It is further contemplated that all or only a portion of the outer surface of shaft198may have alternate surface configurations to enhance fixation with tissue such as, for example, rough, arcuate, undulating, mesh, porous, semi-porous, dimpled and/or textured according to the requirements of a particular application. It is envisioned that all or only a portion of shaft198may be disposed at various orientations, relative to longitudinal axis a, such as, for example, transverse, perpendicular and/or other angular orientations such as acute or obtuse and/or may be offset or staggered. It is further envisioned that all or only a portion of shaft198may be cannulated.

Distal end42may be advanced distally along longitudinal axis a over bone fastener38such that faces64,68engage surfaces70,72and faces102,106engage surfaces108,110to retain sleeve30with bone fastener38in a first orientation, prevent rotation of sleeve30relative to bone fastener38about longitudinal axis a and prevent sleeve30from moving from bone fastener38perpendicular to longitudinal axis a. The U-shaped wall defined by ridge49and ledge79engages face200and the U-shaped wall defined by ridge51and ledge115engages face202. Projections92,128are aligned with locking cavities90,126and chamfers95,135slide along surfaces91,127such that projections92,128move into locking cavities90,126to retain sleeve30with bone fastener38.

Handle162is manipulable to cause axial translation of extensions32,34relative to sleeve30. To provisionally capture bone fastener38, button182is pressed to overcome the force of spring175and button186is pressed simultaneously to overcome the force of spring177to permit actuator36to advance distally along longitudinal axis a. As actuator36is advanced distally, portion144is advanced from end86to end88and portion160is advanced from end122to end124such that distal ends132,148engage ramps84,120such that projections92,128are not dis-engageable, removable and/or movable out from locking cavities90,126(FIG. 14). In the first orientation, projections92,128are fixed within locking cavities90,126. Buttons182,186may be released such that springs175,177each apply a force to insert tips178,180into lateral openings50.

To move extensions32,34to the second orientation, button182is pressed to overcome the force of spring175and button186is pressed simultaneously to overcome the force of spring177to withdraw tips178,180from lateral openings50so as to permit actuator36to advance proximally along longitudinal axis a and allow tabs74,112to move out of engagement with locking cavities90,126to release bone fastener38from sleeve30. Actuator36may be advanced proximally along longitudinal axis a until tips178,180are aligned with openings52. As actuator36is advanced proximally, portion144is advanced from end88to end86and portion160is advanced from end124to end122such that ends132,148disengage ramps84,120. This configuration allows projections92,128to disengage from locking cavities90,126.

As sleeve30is advanced proximally, chamfers95,135engage and slide along surfaces91,127forcing projections92,128out of engagement with locking cavities90,126(FIG. 13). Actuator36may be advanced proximally along longitudinal axis a until tips178,180are aligned with openings52. Buttons182,186may be released such that springs175,177each apply a force to insert tips178,180into openings52.

In use, as shown inFIG. 15, to treat the affected section of vertebrae V, a medical practitioner obtains access to a surgical site including vertebrae V1, V2in any appropriate manner, such as through incision and refraction of tissues. It is envisioned that the spinal implant system may be used in any existing surgical method or technique including open surgery, mini-open surgery, minimally invasive surgery, and percutaneous surgical implantation, whereby vertebrae is accessed through a micro-incision, or sleeve that provides a protected passageway to the area. Once access to the surgical site is obtained, the particular surgical procedure is performed for treating the spinal disorder. The spinal implant system is then employed to augment the surgical treatment. The spinal implant system can be delivered or implanted as a pre-assembled device or can be assembled in situ. The components of the spinal implant system may be completely or partially revised, removed or replaced during or after the surgical procedure.

Pilot holes or the like are made in vertebrae V1, V2for receiving shaft198of bone fastener38. The spinal implant system is disposed adjacent vertebrae V at a surgical site and the components of spinal implant system are manipulable to drive, torque, insert or otherwise connect bone fastener38to vertebrae, according to the particular requirements of the surgical treatment.

Initially, extensions32,34are disposed in the second orientation, described above, such that projections92,128are not disposed in locking cavities90,126(FIG. 13) and tips178,180are disposed in lateral openings52. Distal end42is distally into alignment with bone fastener38such that faces64,68engage surfaces70,72and faces102,106engage surfaces108,110to retain sleeve30with bone fastener38in a first orientation, as described above.

Handle162is manipulated to cause axial translation of extensions32,34relative to sleeve30, to provisionally capture bone fastener38. Buttons182,186are engaged to permit actuator36to advance distally along longitudinal axis a. Distal ends132,148engage ramps84,120such that projections92,128are not movable out of locking cavities90,126, as shown inFIG. 14. Projections92,128are fixed within locking cavities90,126.

Sleeve30defines a cavity204configured for passage of instruments, such as, for example, a driver for applying torque and driving bone fastener38into vertebrae V1, V2and/or a rod reduction instrument such that the instrument may be passed through cavity204and into implant cavity46. Upon treatment employing the components of the spinal implant system, bone fastener38is ejected from sleeve30for fixation with vertebrae V1, V2.

To eject bone fastener38from sleeve30, the medical practitioner engages buttons182,186simultaneously. Actuator36is advanced proximally such that ends132,148disengage ramps84,120, as described above, to allow projections92,128to disengage from locking cavities90,126. Sleeve30is advanced proximally along longitudinal axis a, as described above, such that chamfers95,135engage and slide along surfaces91,127. Projections92,128are driven outwardly and out of engagement with locking cavities90,126, as shown inFIG. 13. Upon completion of the procedure, the surgical instruments and assemblies are removed from the surgical site and the incision is closed.

In one embodiment, tabs74,112comprise a resilient configuration and/or material and are biased outwardly such that projections92,128may pivot in and out of locking cavities90,126. Tabs74,112are biased outwardly such that projections92,128are spaced apart from locking cavities90,126when sleeve30is engaged with bone fastener38. To capture bone fastener38with sleeve30, actuator36may be advanced distally such that portion144is advanced from end86to end88and portion160is advanced from end122to end124such that ends132,148engage ramps84,120to fix projections92,128within locking cavities90,126to capture bone fastener38with end42. To remove sleeve30from bone fastener38, actuator36may be advanced proximally such that portion144is advanced from end88to end86and portion160is advanced from end124to end122such that ends132,148disengage ramps84,120causing resilient tabs74,112to pivot outwardly such that projections92,128pivot out of engagement with locking cavities90,126to release bone fastener38from distal end42.

Bone fastener38may be employed as a bone screw, pedicle screw, or multi-axial screw used in spinal surgery. It is contemplated that bone fastener38may be coated with an osteoconductive material such as hydroxyapatite and/or osteoinductive agent such as a bone morphogenic protein for enhanced bony fixation. Bone fastener38can be made of radiolucent materials such as polymers. Radiomarkers may be included for identification under x-ray, fluoroscopy, CT, or other imaging techniques. Metallic or ceramic radiomarkers, such as tantalum beads, tantalum pins, titanium pins, titanium endcaps, and platinum wires can be used.

It is envisioned that the spinal implant system may include one or a plurality of extenders, inserters, rod reduction instruments, bone fasteners and/or vertebral constructs, which may be alternately sized and dimensioned, and arranged as a kit, according to the requirements of a particular application.

In one embodiment, shown inFIGS. 16-20, the spinal implant system, similar to the device and methods described above with regard toFIGS. 1-15, includes a sleeve230similar to sleeve30, which defines a longitudinal axis a1and extends between a proximal end232and a distal end234. Sleeve230includes a concavely curved inner surface236defining an implant cavity238and a convexly curved outer surface240.

Sleeve230includes a first arm242including a first flange244having a planar face244extending perpendicular to longitudinal axis a1and a second flange248having a planar face250extending perpendicular to longitudinal axis a1adjacent distal end234of sleeve230. Planar faces246,250are configured to engage axial end surfaces70,72to engage sleeve230with first wall192and prevent sleeve230from rotating relative to bone fastener38about longitudinal axis a1. First arm242includes a movable tab252, which includes an inward projection254extending transverse to longitudinal axis a1from inner surface236and configured for fixation with locking cavity90to capture bone fastener38with distal end234of sleeve230.

Sleeve230includes a second arm256including a first flange258having a planar face260extending perpendicular to longitudinal axis a1and a second flange262having a planar face264extending perpendicular to longitudinal axis a1adjacent distal end234of sleeve230. Planar faces260,262are configured to engage axial end surfaces108,110to engage sleeve230with second wall194and prevent sleeve230from rotating relative to bone fastener38about longitudinal axis a1. Arm256includes a movable tab266, which includes an inward projection268extending transverse to longitudinal axis a1from inner surface236and configured for fixation with locking cavity126to capture bone fastener38with distal end234of sleeve230.

To provisionally capture bone fastener38, sleeve230is positioned relative to bone fastener38such that projections254,268are longitudinally aligned with locking cavities90,126. Sleeve230is advanced distally along longitudinal axis a2until projections254,268engage locking cavities90,126causing projections254,268to be disposed in locking cavities90,126to capture bone fastener38with distal end234.