Source: https://patents.google.com/patent/US8864785B2/en
Timestamp: 2019-04-24 18:10:02+00:00

Document:
A surgical access system for accessing a surgical target site within a spine includes a retractor and an elongated element. The retractor has a closed configuration defining a lumen with an internal circumference, and an open configuration in which the internal circumference, at least at the distal end of the retractor, is enlarged relative to said closed configuration. The open configuration creates and maintains an operative corridor to said target site. The elongated element is releasably coupled to an interior wall of the retractor and has an extension extending distal of the distal end of the retractor into the surgical target site. When coupled to the retractor, the elongated element covers a body structure at the target site without blocking access to the operative corridor.
This application is a continuation of U.S. application Ser. No. 10/941,697, filed Sep. 15, 2004, which is a continuation of U.S. application Ser. No. 10/280,489, filed Oct. 25, 2002, now U.S. Pat. No. 7,056,321, which is a continuation-in-part of U.S. application Ser. No. 09/630,077, filed Aug. 1, 2000, now U.S. Pat. No. 6,530,926. The entire disclosure of U.S. Pat. No. 6,530,926 and U.S. Pat. No. 7,056,321 is considered a part of the disclosure of this application and is hereby incorporated by reference herein.
In accordance with the present invention, a method of fixing first and second vertebrae of a patient together at a surgical site includes the following steps: inserting a first cannula into the body of the patient; moving a fusion device through the cannula and inserting the fusion device between the first and second vertebrae; moving a first fastener through the cannula and securing the first fastener to the first vertebra; moving a second fastener through the cannula and securing the second fastener to the second vertebra; moving a first fixation element through the cannula; and fixing the first fixation element to the first and second fasteners.
FIG. 38 is a perspective view of yet another embodiment of the cannula or expandable conduit in an enlarged configuration in accordance with the present invention.
FIG. 96 is a reduced scale view in partial section illustrating yet another stage in the procedure in accordance with the present invention.
The present invention is directed to a method for fixing the vertebrae of a patient at a surgical site. The method involves the use of a cannula or expandable conduit, an adjustable support for the cannula, and the inserting of surgical instruments, a viewing device, a spinal implant or fusion device, and a vertebral fixation assembly through the cannula to the surgical site.
FIGS. 1 5 illustrate one suitable cannula or expandable conduit 10 constructed for use in a method in accordance with the present invention. The cannula 10 is a tubular structure 12 centered on an axis 14. The tubular structure 12 defines a passage 16 through the cannula 10. Surgical instruments are inserted into the body during surgery through the passage 16.
The second tubular portion 40 of the tubular structure 12 is expandable from a contracted condition shown in FIG. 2 to an expanded condition shown in FIG. 1. In the contracted condition, the guide pin 90 is located in the first terminal end 82 of the arcuate slot 80 in the second tubular portion 40 and the second passage portion 74 defined by the second tubular portion is cylindrical in shape. The second passage 74 has a generally constant diameter D2 (FIGS. 2 and 3) that is approximately equal to the diameter D1 of the first tubular portion 20. Thus, the cross-sectional area of the second passage portion 74 at the second end 62 of the second tubular portion 40, which is function of the diameter D2, is approximately the same as the cross-sectional area at the first end 60 of the second tubular portion and is approximately the same as the cross-sectional area of the first passage portion 30 in the first tubular portion 20.
In the expanded condition, the guide pin 90 is located in the second terminal end 84 of the arcuate slot 80 in the second tubular portion 40 and the second tubular portion has a conical configuration. At the second end 62 of the second tubular portion 40, the second passage portion 74 has a diameter D3 (FIG. 3) that is larger than the diameter D2 of the second passage portion at the first end 60. Preferably, the diameter D3 of the second passage portion 74 at the second end 62 of the second tubular portion is 40% to 80% greater than the diameter D1 of the second passage portion at the first end 60. Thus, in the expanded condition, the cross-sectional area of the second passage portion 74 at the second end 62 of the second tubular portion 40, which is function of the diameter D3, is 16% to 64% greater than the cross-sectional area of the second passage portion at the first end 60 of the second tubular portion. In the expanded condition, the cross-sectional area of the second passage portion 74 at the second end 62 of the second tubular portion 40 is large enough to overlie a major portion of at least two adjacent vertebrae.
In addition, a loop of polyester string 104 for tearing the heat shrunk tubing 102 is wrapped around the heat shrunk tubing so that it extends both underneath and on top of the tubing. An outer end 106 of the string 104 extends beyond the tubing 102.
During an endoscopic surgical procedure, the cannula 10 is inserted into the body of a patient in the contracted condition. The outer end 106 of the string 104 is then manually pulled on by the surgeon. Pulling on the string 104 tears the heat shrunk tubing 102 most of the way along the heat shrunk tubing, which frees the second tubular portion 40 for expansion. The heat shrunk tubing 102, in its torn condition, remains attached or secured to the first tubular portion 20.
Next, the expansion tool 112 is inserted into the passage 16 in the cannula 10 until the frustoconical end section 114 is located at the second end 62 of the second tubular portion 40. The legs 114 of the expansion tool 112 are manually separated, causing the frustoconical halves 118 to separate also. As the halves 118 separate, a radially outward directed force is exerted on the inner surface 70 of the second tubular portion 40 by the halves 118, causing the second tubular portion to expand toward the expanded condition. Under the force of the expanding expansion tool 112, the guide pin 90 slides from the first terminal end 82 of the arcuate slot 80 to the second terminal end 84 of the arcuate slot to permit the expansion of the second tubular portion 40. The expansion tool 112 can be rotated about the axis 14 to ensure that the second tubular portion 40 of the cannula 10 is completely expanded to the expanded condition. The expansion tool 112 is then collapsed and removed so that one or more surgical instruments (indicated schematically at 21 in FIG. 5) and a viewing element can be received through the cannula 10 and inserted into a patient's body 130. The expandable second tubular portion 40 of the cannula 10 provides a significantly larger working area for the surgeon inside the body 130 within the confines of the cannula.
FIGS. 6 23 illustrate one suitable support apparatus for use in a method in accordance with the present invention. The support apparatus 110 includes a first support 120, a second support 140, a first adjustment mechanism 160, a second adjustment mechanism 180, and a third adjustment mechanism 900.
When the gripper mechanism 164 is either gripping the cannula 10 or released from the cannula 10 and the knob 166 is rotated, the disk 124 and parts attached to the disk 124 will move along the axis 14 of the cannula 10 relative to the cannula 10. After the support apparatus 110 is initially lined up with the cannula 10, the viewing device 200 may be positioned on the support apparatus 110 and adjusted along the axis 14 by rotation of knob 166.
The second adjustment mechanism 180 provides axial adjustment of the first and second supports 120, 140 relative to each other along the axis 14. The second adjustment mechanism 180 includes a second toothed rack member 182 connected to the first support 120, a second manually adjustable, rotatable knob 186 rotatably carried by the body 142 of the second support 140, and a second toothed gear member 185 (FIG. 13) rotatable by the second knob 186 and in meshing engagement with the teeth 183 of the second rack member 182. The second support 140, and in particular, the body 142, rotatably carries the second gear member 185 (FIG. 13).
As viewed in FIGS. 20 22, the gripper's arms 172, 174 are a part of the support arm 300 for attaching the support apparatus 110 to a mechanical robotic arm 301. The support arm 300 includes an arm portion 302 that is formed integrally with the arms 172, 174. The arms 172, 174 are integrally constructed with the arm portion 302.
As viewed in FIG. 23, the support apparatus 110 may include a second support with a fourth adjustment mechanism 500 for rotating the viewing device 200 about an axis 501 (FIG. 15) defined by the ball plungers 400 of the extension arms 151, 152 when set screw 148 is not clamping the viewing device 200 to the body 142. The axis 501 is offset from the axis 14 of the cannula 10 and perpendicular to the axis 14 of the cannula 10. Rotation of the viewing device 200 about axis 501 causes the endoscope 200 and the rod and lens assembly 203 to move perpendicular to the axis 14 of the cannula 10. This rotation will result in radial adjustment of the position of the rod and lens assembly 203 in a radial direction transverse to the axis 14. The spring-loaded connections of the spherical detent members 420 of the ball plungers 400 and the hemispherical recesses of the endoscope 202 allow rotation about the axis 501 when the set screw 148 is released from clamping engagement of the viewing device 200.
The method of securing two vertebrae 601, 602 together in accordance with the present invention may include the insertion of a vertebral fixation assembly 620 through the cannula 10 and attachment of the vertebral fixation assembly 620 to two vertebrae (such as the L4 and L5 vertebrae), as viewed in FIGS. 24 29. The fixation assembly 620 may be of any suitable construction and is shown in FIG. 26 as including four identical attachment devices 622. Each attachment device 622 includes a threaded fastener 624 or pedicle screw, placed in a vertebra 601 or 602, as viewed in FIGS. 25 & 28. The fastener 624, has a first threaded portion 626 with a first threaded diameter that threads into the vertebrae 601, 602 by screwing the fastener 624 into the vertebrae. The fastener 624 further includes a second threaded portion 628 with a second threaded diameter that may be less than the first threaded diameter. The second threaded portion 628 extends away from the vertebrae 601, 602.
The first fixation washer 640 further includes spikes 644, typically three, extending away from the vertebrae 601, 602. The spikes 644 of the first fixation washer 640 engage a lower knurled surface 652 of a vertebral fixation element 650 that in FIGS. 24 26 is a spine plate.
Alternatively, instead of using two cannulae and two endoscopes simultaneously so that both sides of adjacent vertebrae may be worked on by the surgeon at the same time, only one side of the adjacent vertebrae may be worked on and then the other side of the adjacent vertebrae may be worked on. In this case, only one endoscope, one endoscope support 110, and one monitor is required. Two cannulae would most probably be used, one for each side of the vertebrae. The second procedure includes accessing the vertebrae 601, 602 through the cannulae 10; drilling four insertion openings, one in each side of each vertebra 601, 602 utilizing suitable instruments extending through the cannula 10; inserting fasteners 624 through each cannulae and screwing one fastener into each insertion opening thereby securing each fastener 624 to a vertebra; checking the position of the vertebrae to ensure that the vertebrae have maintained the proper position and, if necessary, repositioning the vertebrae; moving eight fixation washers 640, 660, four locking nuts 670, and two fixation elements 650 through the cannulae; placing four fixation washers 640 and the fixation elements on the fasteners, each fastener extending through one fixation washer and one slot in each fixation element; placing the additional fixation washers 660 on the fasteners; and threading the locking nuts onto each fastener thereby fixing the fixation elements to the vertebrae and securing the vertebrae together in a natural and permanent position within the body. Also, bone graft may be moved through the cannula 10 and placed in and around the fixation element 650 and fasteners 624 to permit a posterior fusion across the bony elements of the vertebrae 601, 602.
If necessary, the disc between the vertebrae 601, 602 may be removed through the cannula; the area between the vertebrae cleaned and the vertebrae prepared for receiving a fusion cage or cages and/or disc replacement material. This would be done before inserting the fasteners 624 or attaching the fixation elements 650. The method may also include inserting, through the cannulae 10, one or more appropriately sized fusion cages and positioning the fusion cage(s) appropriately relative to the vertebrae 601, 602; and inserting bone graft tissue through the cannulae 10 and positioning the tissue in and around the fusion cage(s).
The method described above may, and most probably does, involve removal of tissue from the surgical site through the cannula 10. Muscle, fat, and bone may be removed through the cannula 10 to provide a proper view of the vertebrae 601, 602 at the location to receive the fixation assembly 620. Different tools may be used in the process of removing tissue. These tools may include a burr and/or tissue cutting blades that are inserted through the cannula 10.
A preferred tissue cutting blade device 710 is shown in FIGS. 30 31. The device 710 has an axis 712 and includes inner and outer cutting tubes 740, 750. Each of the inner and outer tubes 740, 750 has openings 741, 751 into their interiors. Cutting teeth 745, 755 are located on opposite sides of each opening 741, 751.
It is contemplated that viewing of the surgical site may be performed without using an endoscope. A microscope or glasses that magnify the site may be used. In fact, any suitable viewing device may be used. Also, the procedure discussed above mentions drilling the vertebrae. Any suitable alternative to drilling may be used such as using an awl or other instrument to form an opening to receive a fastener.
An exemplary arrangement for performing a procedure in accordance with the invention is illustrated in FIG. 32. The patient P is typically placed in the prone position on operating table T, taking care that the abdomen is not compressed and physiological lordosis is preserved, as is known in the art. The physician D is able to access the surgical site and perform the surgical procedure with the components of a system 1010, which will be described in greater detail herein. The system 1010 may be supported, in part, by a mechanical support arm A, such as the type generally disclosed in U.S. Pat. No. 4,863,133, which is incorporated by reference in its entirety herein. The mechanical arm of this type is manufactured by Leonard Medical, Inc., 1464 Holcomb Road, Huntington Valley, Pa., 19006. The physician D is able to view the procedure by reference to a monitor M, which displays the images captured by an endoscope and camera which will be described in greater detail herein. Alternatively, the physician D may view the surgical site though an eyepiece of the endoscope, or she may directly view the surgical site with loupes, microscope, or with the unaided eye.
The procedure described below is a two level posterolateral fixation of the spine involving the L4, L5 and S1 vertebrae. (In the drawings, the vertebrae will generally be denoted by reference letter V.) The usefulness of the inventive procedure is neither restricted to the posterolateral approach nor to the L4, L5 and S1 vertebrae, but it may be used in other anatomical approaches and other vertebrae within the cervical, thoracic and lumbar spine. The inventive procedure may be directed toward surgery involving one or more vertebral levels. It is also useful for anterior and lateral procedures. Moreover, it is believed that the invention is also particularly useful where any body structures must be accessed beneath the skin and muscle tissue of the patient, and where it desirable to provide sufficient space and visibility in order to manipulate surgical instrumentation and treat the underlying body structures. For example, certain features or instrumentation described herein are particularly useful for a minimally invasive, e.g., arthroscopic procedures, in which the expandable distal portion of the expandable conduit prevents the instrument from dislodging or popping out of the operative site.
The system 1010 includes another cannula or expandable conduit which provides an internal passage for surgical instrumentation to be inserted through the skin and muscle tissue of the patient P to the surgical site. The expandable conduit has a wall portion defining reduced profile configuration for initial percutaneous insertion into the patient. This wall portion may have a generally tubular configuration that may be passed over a dilator that has been inserted into the patient to atraumatically enlarge an opening sufficiently large to receive the expandable conduit therein.
The wall portion of the expandable conduit is subsequently expanded to an enlarged configuration, by moving against the surrounding muscle tissue to at least partially define an enlarged surgical space in which the surgical procedures will be performed. In a sense, it acts as its own dilator. Typically, but not by way of limitation, the distal portion expands to a greater extent than the proximal portion, since the surgical procedures are to be performed at the surgical site adjacent the distal portion thereof.
While in the reduced profile configuration, the expandable conduit defines a first unexpanded configuration. Thereafter, the expandable conduit enlarges the surgical space defined thereby by engaging the tissue surrounding the conduit and displacing the tissue radially outwardly as the conduit expands. The expandable conduit may be sufficiently rigid to displace such tissue during the expansion thereof. The expandable conduit may be resiliently biased to expand from the reduced profile configuration to the enlarged configuration. In addition, the conduit may also be manually expanded with surgical instrumentation inserted therein, as will be described below. The surgical site is at least partially defined by the expanded conduit itself. During expansion, the conduit moves from the first overlapping configuration to a second overlapping configuration.
In addition to enlargement, the distal end portion of the expandable conduit may be configured for relative movement with respect to the proximal end portion in order to allow the physician to precisely position the distal portion at the desired location. This relative movement also provides the advantage that the proximal portion of the expandable conduit nearest the physician D may remain substantially stable during such distal movement. In an exemplary embodiment, the distal portion is a separate component which is pivotably or movably attached relative to the proximal portion. Alternatively, the distal portion is flexible or resilient in order to permit such relative movement.
Another embodiment of the cannula or expandable conduit for use in a method in accordance with the present invention is illustrated in FIGS. 33 37 and is designated by reference number 1020. The expandable conduit 1020 includes a proximal wall portion 1022, which has a tubular configuration, and a distal wall portion, which is an expandable skirt portion 1024. The skirt portion 1024 is expandable from a reduced profile configuration having an initial dimension 1026 and corresponding cross-sectional area (illustrated in FIG. 33), to an enlarged configuration having a dimension 1028 and corresponding cross-sectional area (illustrated in FIG. 35). The skirt portion 1024 may be attached to the proximal cylindrical tube portion 1022 with a rivet 1030, pin, or similar connecting device to permit movement of the skirt portion 1024 relative to the proximal cylindrical tube portion 1022.
The skirt portion 1024 is manufactured from a resilient material, such as stainless steel. The skirt 1024 is manufactured so that it normally assumes an expanded configuration illustrated in FIG. 35. As illustrated in FIG. 34, the skirt portion 1024 may assume an intermediate dimension 1034 and corresponding cross-sectional area, which is greater than dimension 1026 of the reduced profile configuration of FIG. 33, and smaller than dimension 1028 of FIG. 35. Skirt portion 1024 may assume the configuration of FIG. 34 when deployed in the patient in response to the force of the tissue acting on the skirt portion. The actual dimension 1034 will depend upon several factors, including the rigidity of the skirt portion 1024, the surrounding tissue, and whether such surrounding tissue has relaxed or tightened during the course of the procedure. An outer plastic sleeve 1032 (illustrated in dashed line in FIG. 33) may be provided which surrounds the expandable conduit 1020 and maintains the skirt 1024 in the reduced profile configuration. The plastic sleeve 1032 may have a braided polyester suture embedded within it (not shown), aligned substantially along the longitudinal axis thereof; such that when the suture is withdrawn, the sleeve 1032 is torn, which allows the expandable conduit 1020 to resiliently expand from the reduced profile configuration of FIG. 32 to the expanded configurations of FIGS. 34 35. While in the reduced profile configuration of FIG. 33, the skirt portion 1024 defines a first overlapping configuration 1033, as illustrated by the dashed line. As the skirt portion 1024 resiliently expands, the skirt portion assumes the second configuration 1035, as illustrated in FIGS. 34 35.
The skirt portion 1024 is sufficiently rigid that it is capable of displacing the tissue surrounding the skirt portion as it expands. Depending upon the resistance exerted by surrounding tissue, the skirt portion 1024 is sufficiently rigid to provide some resistance against the tissue to remain in the configurations of FIGS. 34 35. Moreover, the expanded configuration of the skirt portion 1024 is at least partially supported by the body tissue of the patient. The rigidity of the skirt portion 1024 and the greater expansion at the distal portion creates a stable configuration that is at least temporarily stationary in the patient, which frees the physician from the need to actively support the conduit 1020 until the endoscope mount platform 1300 and support arm 1400 are subsequently added (see FIGS. 52 53).
The skirt portion 1024 of expandable conduit 1020 is illustrated in an initial flattened configuration in FIG. 36. The skirt portion 1024 may be manufactured from a sheet of stainless steel having a thickness of about 0.007 inches for skirt portions having a fully expanded dimension 1028 of about 65 mm in its unrestricted circular shape. The skirt portion 1024 may also take on an oval shape having a longer dimension of about 85 mm. An increased thickness, e.g., about 0.010 inches, may be used in connection with skirt portions having a larger diameter, such as about 65 mm. Other materials, such as Nitinol or plastics having similar properties, may also be useful.
As discussed above, the skirt portion 1024 is attached to the proximal cylindrical portion 1022 with a pivotable connection, such as rivet 1030. A pair of rivet holes 1036 are provided in the skirt portion 1024 to receive the rivet 1030. The two free ends 1038 and 1040 of the skirt portion 1024 are secured by a slidable connection, such as second rivet 1044 (not shown in FIG. 36, illustrated in FIGS. 33 35). A pair of complementary slots 1046 and 1048 are defined in the skirt portion 1024 adjacent the end portions 1038 and 1040. The rivet 1044 is permitted to move freely within the slots 1046 and 1048. This slot and rivet configuration allows the skirt portion 1024 to move between the reduced profile configuration of FIG. 33 and the expanded configuration of FIGS. 34 35. The use of a pair of slots 1046 and 1048 reduces the risk of the “button-holing” of the rivet, i.e., a situation in which the opening of the slot becomes distorted and enlarged such that the rivet may slide out of the slot, and cause failure of the device. However, the likelihood of such occurrence is reduced in skirt portion 1024 since each of the slots 1046 and 1048 in the double slot configuration has a relatively shorter length than a single slot configuration, which thereby limits the ability of the respective slots 1046 and 1048 to be distorted to the extent in which a rivet may slide out of position. In addition, the configuration of rivet 1044 and slots 1046 and 1048 permits a smooth operation of enlarging and reducing the skirt portion 1024, and allows the skirt 1024 to expand to span as many as three vertebrae, e.g., L4, L5, and S1, to perform a multi-level fixation.
As illustrated in FIG. 35, the skirt 1024 may be expanded to a substantially conical configuration having a substantially circular or elliptical profile. Alternatively, features may be provided on the skirt which facilitate the bending of the skirt at several locations to provide a pre-formed enlarged configuration. For example, in another embodiment of the cannula or expandable conduit 1070, illustrated in FIGS. 38 40, skirt portion 1074 may have four sections 1076 a, 1076 b, 1076 c, 1076 d having a reduced thickness. For a skirt portion 1074 having a thickness 1078 of about 0.007 inches thick, reduced thickness sections 1076 a, 1076 b, 1076 c, 1076 d may have a thickness 1080 of about 0.002 0.004 inches (FIG. 39). The width of the reduced thickness sections 1076 a, 1076 b, 1076 c, 1076 d may be about 1 5 mm. The thickness 1078 of the skirt portion 1074 may be reduced by milling or grinding, as is known in the art. Thus when the skirt 1074 is opened, it moves toward a substantially rectangular configuration, subject to the resisting forces of the body tissue (FIG. 40). Alternatively, another embodiment of the skirt (not shown) may be provided with two reduced thickness sections (rather than the four reduced thickness sections of skirt 1074) which would produce a substantially “football”-shaped access area.
In another embodiment of the cannula or expandable conduit 1080, the skirt portion 1084 is provided with a plurality of perforations 1086, in order to increase flexibility at the desired locations (FIGS. 41 43). The size and number of perforations 1086 may vary depending upon the desired flexibility and durability. Alternatively, the skirt may be scored or otherwise provided with a groove or rib in order to facilitate the bending of the skirt at the desired location.
According to still further embodiments, the cannula or expandable conduit may be provided with one slot. As illustrated in FIG. 44, skirt portion 1094 is provided with slot 1096 and aperture 1098. A rivet (not shown) is stationary with respect to aperture 1098 and slides within slot 1096. Similarly, skirt 1104 is provided with an aperture 1108 which receives a rivet (not shown) which slides within elongated slot 1106 (FIG. 45).
An early stage in the process is to determine the access point in the skin of the patient to insert the access conduit. In the exemplary embodiment, the access point corresponds to the posterior-lateral aspects of the spine. Manual palpation and Anterior-Posterior (AP) fluoroscopy may be used to determine the optimal incision locations. For the exemplary procedure, placement of the cannula or expandable conduit 1020 is preferably midway (in the ceph-caud direction) between the L4 through S1 vertebrae, centrally about 4 7 cm from the midline.
An incision is made at the above-determined location. A guide wire (not shown) is introduced under fluoroscopic guidance through the skin, fascia, and muscle to the approximate surgical site. A series of dilators is used to sequentially expand the incision to the desired width, about 23 mm for the exemplary procedure, without damaging the structure of surrounding tissue and muscles. A first dilator is placed over the guide wire, which expands the opening. The guide wire is then subsequently removed. A second dilator that is slightly larger than the first dilator is placed over the first dilator, which expands the opening further. Once the second dilator is in place, the first dilator is subsequently removed.
As illustrated in FIG. 46, following placement of the largest dilator 1120, the expandable conduit 1020, in its reduced profile configuration, is introduced and positioned in a surrounding relationship over the dilator 1120. Dilator 1120 is subsequently removed from the patient, and the expandable conduit 1020 is allowed to remain in position.
Once the expandable conduit 1020 is positioned in the patient, it may be enlarged to provide a passage for the insertion of various surgical instrumentation and an enlarged space for performing the procedures described herein. As described above, the expandable conduit may accommodate the enlargement in several ways. In one embodiment, a distal portion of the cannula may be enlarged, and a proximal portion may maintain a constant diameter. The relative lengths of the proximal portion 1022 and the skirt portion 1024 may be adjusted to vary the overall expansion of the conduit 1020. Alternatively, such expansion may extend along the entire length of the expandable conduit. In the exemplary procedure, the expandable conduit 1020 may be expanded by removing suture 1035 and tearing sleeve 1032 surrounding the expandable conduit 1020, and subsequently allowing the skirt portion 1024 to resiliently expand towards its fully expanded configuration as (illustrated in FIG. 35) to create an enlarged surgical space from the L4 to the S1 vertebrae. The resisting force exerted on the skirt portion may result in the skirt portion 1024 assuming the intermediate configuration illustrated in FIG. 34. Under many circumstances, the space created by the skirt portion 1024 in the intermediate configuration is a sufficiently large working space to perform the procedure described herein. Once the skirt portion 1024 has expanded, the rigidity and resilient characteristics of the skirt portion 1024 allow the conduit 1020 to resist closing to the reduced profile configuration of FIG. 33 and to at least temporarily resist being expelled from the incision. These characteristics create a stable configuration for the conduit 1020 to remain in position in the body, supported by the surrounding tissue. It is understood that additional support may be needed, especially when an endoscope 1500 is added.
According to the exemplary embodiment, the expandable conduit 1020 may be further enlarged at its distal end portion using an expander apparatus to create a surgical access space. An expander apparatus useful for enlarging the expandable conduit has a reduced profile configuration and an enlarged configuration. The expander apparatus is inserted into the expandable conduit in the reduced profile configuration, and subsequently expanded to the enlarged configuration. The expansion of the expander apparatus also causes the expandable conduit to be expanded to the enlarged configuration. In some embodiments, the expander apparatus may increase the diameter of the expandable conduit along substantially its entire length in a conical configuration. In other embodiments, the expander apparatus expands only a distal portion of the expandable conduit, allowing a proximal portion to maintain a constant diameter.
In addition to expanding the expandable conduit, the expander apparatus may also be used to position the distal portion of the expandable conduit at the desired location for the surgical procedure. The expander engages the interior wall of the expandable conduit, and moves the cannula to the proper location. For the embodiments in which the distal portion of the expandable conduit is relatively movable with respect to the proximal portion, the expander apparatus is useful to position the distal portion without substantially disturbing the proximal portion.
In the exemplary embodiment, an expander apparatus may be used to further expand the skirt portion 1024 towards the fully expanded configuration (illustrated in FIG. 35). The expander apparatus is inserted into the expandable conduit, and typically has two or more members which are movable to engage the interior wall of the skirt portion 1024 and apply a force sufficient to further expand the skirt portion. An exemplary expander apparatus, expander apparatus 1200, is illustrated in FIGS. 47 and 48, and is constructed of two components 1202 and 1204 defining a tongs-like configuration, and which are pivotable about a pin 1206. The components 1202 and 1204 are typically constructed of steel having a thickness of about 9.7 mm. Each of the components 1202 and 1204 has a proximal handle portion 1208 and a distal expander portion 1210. Each proximal handle portion 1208 has a finger grip 1212 that may extend transversely from the longitudinal axis 1214 of the apparatus 1200. The proximal handle portion 1208 may further include a stop element, such as flange 1216, that extends transversely from the longitudinal axis 1214, and which is dimensioned to provide a visual and tactile indication of the proper depth for inserting the expander apparatus 1200 by engaging the proximal portion 1025 of the expandable conduit 1020 when the apparatus 1200 is inserted a predetermined depth. In the exemplary embodiment, the dimension 1218 from the flange 1216 to the distal tip 1220 is about 106 mm. The dimension 1218 is determined by the typical depth of the body structures beneath the skin surface at which the surgical procedure is being performed. The distal portions 1210 are each provided with a frusto-conical outer surface 1222 for engaging the inside wall of the skirt portion 1024. As illustrated in FIG. 47, the unexpanded distal width 1224 of the apparatus 1200 at the distal tip 1220 is about 18.5 mm.
In use, the finger grips 1212 are approximated towards one another (arrow A), which causes the distal portions 1210 to move to the enlarged configuration (arrows B), illustrated in FIG. 48. The components 1202 and 1204 are also provided with a cooperating tab 1226 and shoulder portion 1228 which are configured for mutual engagement when the distal portions 1210 are in the expanded configuration. In the exemplary embodiment, the expanded distal width 1230 of the distal portions 1210 is about 65 mm to about as large as 83 mm. The tab 1226 and shoulder configuration 1228 limits the expansion of the apparatus 1200 in order to prevent expanding the skirt portion 1024 of the expandable conduit 1020 beyond its designed dimension, and to minimize trauma to the underlying tissue. Further details of the expander apparatus are described in U.S. patent application Ser. No. 09/906,463 filed Jul. 16, 2001, which is incorporated by reference in its entirety herein.
When the expandable conduit 1020 is inserted into the patient and sleeve 1032 is removed, the skirt portion 1024 expands to a point where the outward resilient expansion of the skirt portion is balanced by the force of the surrounding tissue. The surgical space defined by the conduit may be sufficient to perform the surgical procedures. However, if it is desired to expand the expandable conduit 1020 further, the expander apparatus 1200 may be inserted into the expandable conduit 1020 in the reduced profile configuration until the shoulder portions 1216 are in approximation with the proximal lip 1025 of the cylindrical portion 1024 of the expandable conduit 1020 (FIG. 49).
As illustrated in FIG. 49, the expander apparatus 1200 is inserted in the access conduit 1020 in the reduced profiled configuration. Expansion of apparatus 1200 is achieved by approximating the handle portions 1212 (not shown in FIG. 50), which causes the distal portions 1210 of the expander apparatus 1200 to move to a spaced apart configuration. As the distal portions 1210 move apart and contact the inner wall of the skirt portion 1024, it is expanded by allowing the floating rivet 1044 to slide within the two slots 1046 and 1048 of the skirt portion 1024. When the distal portions 1210 reach the maximum expansion of the skirt portion 1024 (illustrated by a dashed line), the shoulder 1228 and tab portion 1226 of the expander apparatus 1200 come into engagement to prevent further expansion of the tong portions (as illustrated in FIG. 48). The conduit 1020 may be alternatively further expanded with a balloon or similar device.
A subsequent, optional step in the procedure is to adjust the location of the distal portion of the expandable conduit relative to the body structures to be operated on. For example, the expander apparatus 1200 may also be used to engage the inner wall of the skirt portion 1024 of the expandable conduit 1020 in order to move the skirt portion 1024 of the expandable conduit 1020 to the desired location. For an embodiment in which the skirt portion 1024 of the expandable conduit 1020 is relatively movable relative to the proximal portion, e.g. by use of the rivet 1030, the expander apparatus 1200 is useful to position the skirt portion 1024 without substantially disturbing the proximal portion 1022 or the tissues closer to the skin surface of the patient. As will be described below, the ability to move the distal end portion, e.g., the skirt portion, without disturbing the proximal portion is especially beneficial when additional apparatus, as described below, is mounted relative to the proximal portion of the expandable conduit.
An endoscope mount platform 1300 and indexing arm 1400 provide securement of an endoscope 1500 on the proximal portion 1025 of access conduit 1020 for remotely viewing the surgical procedure, as illustrated in FIGS. 51 54. The endoscope mount platform 1300 also provides several functions during the surgical procedure. The endoscope mount platform 1300 includes a base 1302 that extends laterally from a central opening 1304 in a general ring-shaped configuration. For the physician who is primarily viewing the procedure by observing a monitor, the base 1302 provides an aid for the physician when inserting surgical instruments into the central opening 1304. For example, the size of the base 1302 provides visual assistance (as it may be observable in the physician's peripheral vision) as well as provides tactile feedback as the instruments are lowered towards the central opening 1304 and into the expandable conduit 1020.
The endoscope mount platform 1300 further provides a guide portion 1306, which extends substantially parallel to the longitudinal axis 1308 away from the central opening 1304. The base 1302 is typically molded as one piece with the guide portion 1306. The base 1302 and guide portion 1306 may be constructed as a suitable polymer such as polyetheretherketone (PEEK). The guide portion 1306 includes a first upright member 1310 extending upward from the base 1302, and a second upright member 1312 extending upward from the base 1302. The upright members 1310 and 1312 each have a respective vertical grooves 1314 and 1315 for slidably receiving an endoscopic mount assembly 1318.
The endoscope 1500 (not shown in FIG. 51) is movably mounted to the endoscope mount platform 1300 by the endoscope mount assembly 1318 including endoscope mount 1320 and a saddle unit 1322. The saddle unit 1322 is slidably mounted within the grooves 1314 and 1315 in the upright members 1310 and 1312. The endoscope mount 1320 receives the endoscope 1500 through a bore 1326 which passes through the endoscope mount 1320. Part of the endoscope 1500 may extend through the expandable conduit 1020 substantially parallel to central axis 1308 into the patient's body 1130.
The endoscope mount 1320 is removably positioned in a recess 1328 defined in the substantially “U”-shaped saddle unit 1322, which is selectively movable in a direction parallel to the longitudinal axis 1308 in order to position the endoscope 1500 at the desired height within the expandable conduit 1020 to provide a zoom feature to physician's view of the surgical procedure.
A screw mechanism 1340 is positioned on the base 1302 and between the upright members 1310 and 1312, and is used to selectively move the saddle unit 1322 with the endoscope mount 1320 and the endoscope 1500. The screw mechanism 1340 comprises a thumb wheel 1342 and a spindle 1344. The thumb wheel 1342 is rotatably mounted in a bore in the base 1302. The thumbwheel has an external thread 1346 received in a cooperating thread in the base 1302. The spindle 1344 is mounted for movement substantially parallel to the central axis 1308. The spindle 1344 has a first end received in a rectangular opening in the saddle unit 1322, which inhibits rotational movement of the spindle unit 1344. The second end of the spindle 1344 has an external thread which cooperates with an internal thread formed in a bore within the thumbwheel 1342. Rotation of the thumb wheel 1342 relative to the spindle 1344, causes relative axial movement of the spindle unit 1344 along with the saddle unit 1322. Further details of the endoscope mount platform are described in U.S. patent application Ser. No. 09/491,808, filed Jan. 28, 2000, application Ser. No. 09/821,297, filed Mar. 29, 2001, and application Ser. No. 09/940,402, filed Aug. 27, 2001, which are incorporated by reference in their entirety herein.
As illustrated in FIGS. 52 54, the endoscope mount platform 1300 is mounted to the support arm 1400. The support arm 1400, in turn, is mounted to mechanical support, such as mechanical support arm A, which is incorporated by reference in its entirety herein. The support arm 1400 rests on the proximal portion 1025 of the expandable conduit 1020. The support arm 1400 includes an indexing collar 1420, which is received in the central opening 1304 of the base 1302 of endoscope mount platform 1300. The indexing collar 1420 is substantially torroidal in section and has an outer peripheral wall 1422 and inner wall 1424 and a wall thickness 1426. The indexing collar further includes a flange 1428, which supports the indexing collar 1420 on the support arm 1400.
In order to support cannula or conduits 1020 of different dimensions, a plurality of indexing collars 1420 may be provided to accommodate each respective conduit size while using a single endoscope mount platform 1300. The central opening 1304 of the endoscope mount platform 1300 has constant dimension, e.g., a diameter of about 32.6 mm. An appropriate indexing collar 1420 is selected to support the respective conduit 1020. Thus the outer wall 1422 and the outer diameter 1430 are unchanged between different indexing collars 1420, although the inner wall 1424 and the inner diameter 1432 vary to accommodate differently sized conduits 1020.
The indexing collar 1420 is mounted to the proximal portion of the expandable conduit 1020 and allows angular movement of the endoscope mount platform 1300 with respect thereto about the central axis 1308 (as indicated by arrow C in FIG. 52). The outer wall 1422 of the index collar 1420 includes a plurality of hemispherical recesses 1450 for receiving one or more ball plungers 1350 on the endoscope mount platform 1300 (indicated in dashed line.) This mount configuration permits the endoscope mount platform 1300, along with the endoscope 1500 to be fixed in a plurality of discrete angular positions. Further details of the support arm and indexing collar are described in U.S. patent application Ser. No. 09/491,808, filed Jan. 28, 2000, application Ser. No. 09/821,297, filed Mar. 29, 2001, and application Ser. No. 09/940,402, filed Aug. 27, 2001.
The endoscope, such as endoscope 1500 (FIG. 55), has an elongated configuration that extends into the expandable conduit 1020 in order to view the surgical site. In particular, endoscope 1500 has an elongated rod portion 1502 and a body portion 1504 which is substantially perpendicular thereto. In the exemplary embodiment, rod portion 1502 of endoscope 1500 has a diameter of about 4 mm and a length of about 106 mm. Body portion 1504 may define a tubular portion 1506 which is configured to be slidably received in the bore 1326 of endoscope mount 1320 as indicated by arrow D. The slidable mount of the endoscope 1500 on the endoscope mount 1300 permits the endoscope 1500 to adjust to configurations that incorporate different conduit diameters. Additional mobility of the endoscope 1500 in viewing the surgical site may be provided by rotating the endoscope mount platform 1300 about the central axis 1308 (as indicated by arrow C in FIG. 52).
The rod portion 1502 supports an optical portion (not shown) at a distal end 1508 thereof, which may define a field of view of about 105 degrees and a direction of view 1511 of about 25 30 degrees. An eyepiece 1512 is positioned at an end portion of the body portion 1504. The camera (not shown) is attached to the endoscope 1500 adjacent the eyepiece 1512 with a standard coupler unit. A light post 1510 supplies illumination to the surgical site at the distal end portion 1508. A preferred camera for use in the system and procedures described herein is a three chip unit that provides greater resolution to the viewed image than a single chip device.
A subsequent stage in the procedure is the placement of the support arm 1400 and the endoscope mount platform 1300 on the proximal portion 1025 of the expandable conduit 1020 (FIG. 53), and mounting of the endoscope 1500 on the endoscope mount platform 1300. A next step is insertion of surgical instrumentation into the expandable conduit to perform the surgical procedure on the body structures at least partially within the operative space defined by the expanded portion of the expandable conduit. In the exemplary method, skirt portion 1024 of expandable conduit 1020 at least partially defines operative space 1090 in which the surgical procedures described herein may be performed (FIG. 56). Depending upon the overlap of the skirt portion, the skirt portion may define a surface which is continuous about the circumference or which is discontinuous having one or more gaps where the material of the skirt portion does not overlap. For illustrative purposes, the surgical instrumentation described herein is useful to perform a two-level spinal fixation. Surgical instrumentation inserted into the expandable conduit is used for debridement and decortication. In particular, the soft tissue, such as fat and muscle, covering the vertebrae are removed in order to allow the physician to visually identify the various “landmarks,” or vertebral structures, which enable the physician to locate the location for attaching the fasteners 4600 or other procedures, as will be described herein. Allowing visual identification of the vertebral structures enables the physician to perform the procedure while viewing the surgical area through the endoscope, microscope, loupes, etc., or in a conventional, open manner.
Tissue debridement and decortication of bone are completed using one or more debrider blades, bipolar sheath, high speed burr, and additional conventional manual instruments. The debrider blades are used to excise, remove and aspirate the soft tissue. The bipolar sheath is used to achieve hemostasis through spot and bulk tissue coagulation. The debrider blades and bipolar sheath are described in greater detail in U.S. Pat. No. 6,193,715, assigned to Medical Scientific, Inc., which is incorporated by reference in its entirety herein. The high speed burr and conventional manual instruments are also used to continue to expose the structure of the vertebrae.
FIGS. 57 61 illustrate an embodiment of a fusion device or spinal implant 2010 that is inserted between the adjacent vertebrae. The spinal implant 2010 is placed between adjacent vertebrae to provide sufficient support to allow fusion of the adjacent vertebrae, as shown in FIGS. 67 and 78. The spinal implants 2010 are preferably made from an allograft material.
The spinal implant 2010 (FIGS. 57 61) has a first end 2020 for insertion between the adjacent vertebrae V. The first end 2020 has a tapered surface 2022 to facilitate insertion of the implant between the adjacent vertebrae V. The surface 2022 defines an angle X of approximately 45.degree. as shown in FIG. 60.
The spinal implant 2010 (FIGS. 57 and 58) has a second end 2030 that is engageable with a tool 2032 (FIG. 70) for inserting the implant between the adjacent vertebrae V. The tool 2032 has a pair of projections 2034, one of which is shown in FIG. 70, that extend into recesses 2036 and 2038 in the end 2030 of the implant 2010. The recesses 2036 and 2038 (FIGS. 57 and 58) extend from the second end 2030 toward the first end 2020. The recess 2036 (FIG. 60) is, defined by an upper surface 2040 and a lower surface 2042 extending generally parallel to the upper surface 2040. The recess 2038 (FIG. 58) has a lower surface 2046 and an upper surface 2048 extending generally parallel to the lower surface 2046.
The recesses 2036 and 2038 define a gripping portion 2052. The projections 2034 on the tool 2032 extend into the recesses 2036 and 2038 and grip the gripping portion 2052. The projections 2034 engage the upper and lower surfaces 2040 and 2042 of the recess 2036 and the upper and lower surfaces 2046 and 2048 of the recess 2038. Accordingly, the tool 2032 grips the implant 2010 for inserting the implant between the adjacent vertebrae V.
The implant 2010 (FIGS. 57 60) has an upper surface 2060, as viewed in FIGS. 57 60, for engaging the upper vertebra V. The implant 2010 has a lower surface 2062, as viewed in FIGS. 57 60, for engaging the lower vertebra V. The upper and lower surfaces 2060 and 2062 extend from the first end 2020 to the second end 2030 of the implant 2010 and parallel to the upper and lower surfaces 2040, 2042, 2046, and 2048 of the recesses 2036 and 2038. The upper surface 2060 has teeth 2064 for engaging the upper vertebra V. The lower surface 2062 has teeth 2066 for engaging the lower vertebra V. Although FIGS. 57 and 58 show four teeth 2064 and four teeth 2066, it is contemplated that any number of teeth could be used.
A first side surface 2070 and a second side surface 2072 extend between the upper and lower surfaces 2060 and 2062. The first side surface 2070 extends along a first arc from the first end 2022 of the implant 2010 to the second end 2030. The second side surface 2072 extends along a second arc from the first end 2022 to the second end 2030. The first and second side surfaces 2070 and 2072 are concentric and define portions of concentric circles. The teeth 2064 and 2066 parallel to each other and extend between the side surfaces 2070 and 2072 and along secant lines of the concentric circles defined by the side surfaces.
The implant 2010 is formed by harvesting allograft material from a femur, as known in the art. The femur is axially cut to form cylindrical pieces of allograft material. The cylindrical pieces are then cut in half to form semi-cylindrical pieces of allograft material. The semi-cylindrical pieces of allograft material are machined into the spinal implants 2010.
A pair of spinal implants 2010 may be placed bilaterally between the adjacent vertebrae V. The cannula or expandable conduit 1020 is inserted into the patient's body adjacent the vertebrae V. The skirt portion 1024 of the cannula 1020 is radially expanded to provide a working space adjacent the vertebrae V. Disc material between the vertebrae V is removed using instruments such as kerrisons, rongeurs, or curettes. A microdebrider may also be utilized to remove the disc material. An osteotome, curettes, and scrapers are used to prepare end plates of the vertebrae V for fusion. Preferably, an annulus of the disc is left between the vertebrae V.
Distracters are used to sequentially distract the disc space until the desired distance between the vertebrae V is achieved. The fusion device or implant 2010 is placed between the vertebrae V using the tool 2032. The first end 2020 of the implant 2010 is inserted first between the vertebrae V. The implant 2010 is pushed between the vertebrae V until the end 2030 of the implant is between the vertebrae. A second spinal implant 2010 is inserted on the ipsilateral side using the same procedure.
A shield apparatus 3100 with an elongated portion 3102 may be used to facilitate insertion of the implants 2010 between the vertebrae V. A distal portion 3110 of the apparatus 3100 may be placed in an annulotomy. The implant 2010 is inserted with the side surface 2170 facing the elongated portion 3102 so that the apparatus 3100 can act as a “shoe horn” to facilitate or guide insertion of the implants 2010 between the vertebrae.
The implants 2010 may be inserted between the vertebrae V with the first ends 2020 located adjacent each other and the second ends 2030 spaced apart from each other, as shown in FIG. 67. The implants 2010 may also be inserted between the vertebrae V with the first ends 2020 of the implants 2010 spaced apart approximately the same distance that the second ends 2030 are spaced apart. It is contemplated that the implants 2010 may be inserted in any desired position between the vertebrae V. It is also contemplated that only one implant 2010 may be inserted between the vertebrae V. Furthermore, it is contemplated that the implants 2010 may be inserted between vertebrae using an open procedure.
Another embodiment of a fusion device or spinal implant 2110 is illustrated in FIGS. 62 66. The spinal implant 2110 is substantially similar to the embodiment disclosed in FIGS. 57 61. The implant 2110 is placed between the adjacent vertebrae V to provide sufficient support to allow fusion of the adjacent vertebrae, as shown in FIG. 69. The spinal implant 2110 is preferably made from an allograft material.
The spinal implant 2110 (FIGS. 62 66) has a first end 2120 for insertion between the adjacent vertebrae V. The first end 2120 has a tapered surface 2122 to facilitate insertion of the implant between the adjacent vertebrae V. The surface 2122 defines an angle Y of approximately 45.degree. as shown in FIG. 66.
The spinal implant 2110 (FIGS. 62 and 63) has a second end 2130 that is engageable with the projections 2034 on the tool 2032 for inserting the implant between the adjacent vertebrae V. The projections 2034 extend into recesses 2136 and 2138 in the end 2130 of the implant 2110. The recesses 2136 and 2138 extend from the second end 2130 toward the first end 2120. The recess 2136 (FIGS. 62 and 65) is defined by an upper surface 2140 and a lower surface 2142 extending generally parallel to the upper surface 2140. The recess 2138 (FIG. 63) has a lower surface 2146 and an upper surface 2148 extending generally parallel to the lower surface 2146.
The recesses 2136 and 2138 define a gripping portion 2152. The projections 2034 on the tool 2032 extend into the recesses 2136 and 2138 and grip the gripping portion 2152. The projections 2034 engage the upper and lower surfaces 2140 and 2142 of the recess 2136 and the upper and lower surfaces 2146 and 2148 of the recess 2138. Accordingly, the tool 2032 grips the implant 2110 for inserting the implant between the adjacent vertebrae V.
The implant 2110 (FIGS. 62 65) has an upper surface 2160, as viewed in FIGS. 62 65, for engaging the upper vertebra V. The implant 2110 has a lower surface 2162, as viewed in FIGS. 62 65, for engaging the lower vertebra V. The upper and lower surfaces 2160 and 2162 extend from the first end 2120 to the second end 2130 of the implant 2110 and parallel to the upper and lower surfaces 2140, 2142, 2146, and 2148 of the recesses 2136 and 2138. The upper surface 2160 has teeth 2164 for engaging the upper vertebra V. The lower surface 2162 has teeth 2166 for engaging the lower vertebra V. Although FIG. 63 shows four teeth 2164 and four teeth 2166, it is contemplated that any number of teeth could be used.
A first side surface 2170 and a second side surface 2172 extend between the upper and lower surfaces 2160 and 2162. The first side surface 2170 extends along a first arc from the first end 2122 of the implant 2110 to the second end 2130. The second side surface 2172 extends along a second arc from the first end 2120 to the second end 2130. The first and second side surfaces 2170 and 2172 are concentric and define portions of concentric circles. The teeth 2164 and 2166 extend parallel to each other and between the side surfaces 2170 and 2172 along secant lines of the concentric circles defined by the side surfaces.
The implant 2110 is formed by harvesting allograft material from a femur, as is known in the art. The femur is axially cut to form cylindrical pieces of allograft material. The cylindrical pieces are then cut in half to form semi-cylindrical pieces of allograft material. The semi-cylindrical pieces of allograft material are machined into the spinal implants 2110.
A spinal implant 2110 is placed unilaterally between the adjacent vertebrae V. The cannula 1020 is inserted into the patient's body adjacent the vertebrae V. The skirt portion 1024 of the cannula 1020 is radially expanded to provide a working space adjacent the vertebrae V. Disc material between the vertebrae V is removed using instruments such as kerrisons, rongeurs, or curettes. A microdebrider may also be utilized to remove the disc material. An osteotome, curettes, and scrapers are used to prepare end plates of the vertebrae V for fusion. Preferably, an annulus of the disc is left between the vertebrae V.
Distracters are used to sequentially distract the disc space until the desired distance between the vertebrae V is achieved. The implant 2110 is placed between the vertebrae V using the tool 2032. It is contemplated that the apparatus 3100 could be used also. The first end 2120 of the implant 2110 is inserted first between the vertebrae V. The implant 2110 is pushed between the vertebrae V until the end 2130 of the implant is between the vertebrae. It is contemplated that the implant 2110 may be inserted in any desired position between the vertebrae V. It is also contemplated that more than one implant 2110 may be inserted between the vertebrae.
The apparatus or shield 3100 for use in placing the fusion devices or spinal implants between the vertebrae is illustrated in FIGS. 71 75. The apparatus 3100 includes an elongated body portion 3102, which protects the nerve root or dura, and a mounting portion 3104, which allows for the surgeon to releasably mount the apparatus 3100 to the cannula 1020. Consequently, the surgeon is able to perform the surgical procedures without requiring the surgeon or an assistant to continue to support the apparatus 3100 throughout the procedure, and without reducing the field of view.
The apparatus 3100 may be manufactured from a biocompatible material such as, but not limited to, stainless steel. In the exemplary embodiment, apparatus 3100 is manufactured from stainless steel having a thickness of about 0.02 inches to about 0.036 inches. The elongated body portion 3102 has dimensions which correspond to the depth in the body in which the procedure is being performed, and to the size of the body structure which is to be shielded by elongated body portion 3102. In the exemplary embodiment, the elongated body portion 3102 has a width 3106 of about 0.346 inches and a length of about 5.06 inches (FIG. 72), although other dimensions would be appropriate for spinal surgical procedures performed at different locations, or for surgical procedures involving different body structures. The distal tip portion 3110 of the apparatus 3100 may have a slightly curved “bell mouth” configuration which allows for atraumatic contact with a body structure, such as a nerve. It is contemplated that the elongated body portion may have any desired shape.
The mounting portion 3104 allows the apparatus 3100 to be secured to a support structure in any number of ways. In the exemplary embodiment, mounting portion 3104 may include a ring portion. As seen in FIGS. 72, 73 and 75, ring portion 3120 has a substantially ring-shaped configuration with an opening 3124, which defines an angle 3126 of about 90 degrees of the total circumference of the ring portion 3120. As will be described in greater detail below, the angle 3126 is a nominal value, because the ring portion 3104 is resilient, which permits the opening 3124 to change size during the mounting process.
In the exemplary embodiment, the mounting portion 3104 has a substantially cylindrical configuration in order to be mounted within the interior lumen of the cannula 1020, as will be described below. The ring portion 3104 has an exterior dimension 3130 of about 0.79 inches, and an interior dimension 3132 of about 0.76 inches. It is understood that the dimensions of the ring portion 3104 would be different if the expandable conduit 1020 has a different interior dimension. Moreover, the cylindrical shape of the ring portion 3104 would change if the apparatus 3100 is used with a support member having a differently shaped internal lumen.
Finger grip portions 3122 extend from the mounting portion 3104 and allow the surgeon to apply an inwardly directed force (as indicated by arrows A) to the ring portion 3120. The resilient characteristics of the ring portion 3120 allow the material to deflect thereby reducing the exterior dimension 3130 and reducing the spacing 3124. Releasing the finger grip portions 3122 allows the ring portion to move towards its undeflected condition, thereby engaging the interior wall of the expandable conduit 1020.
The elongated body portion 3102 and the mounting portion 3104 may be manufactured from a single component, such as a sheet of stainless steel, and then the mounting portion 3104 may be subsequently formed into a substantially cylindrical shape. In another embodiment, the mounting portion 3104 may be manufactured as a separate component and attached to the elongated body portion, by techniques such as, but not limited to welding and securement by fasteners, such as rivets.
The expandable conduit 1020 serves as a stable mounting structure for apparatus 3100. In particular, mounting portion 3104 is releasably mounted to the interior wall of proximal wall portion 1022 of expandable conduit 1020. Elongated body portion 3102 extends distally into the operative site to protect the desired body structure, such as the nerve, as will be described below.
To install the apparatus 3100 within the interior passage of the proximal wall portion 1022, the surgeon may apply an inwardly directed force on the ring portion 3120, thereby causing the ring portion to resiliently deform, as illustrated by dashed line and arrows B in FIGS. 77 78. The surgeon subsequently inserts the apparatus 3100 into the interior lumen of the proximal wall portion 1022 (as indicated by arrow C) to the position of ring portion 3104 illustrated in solid line in FIGS. 77 78. When the surgeon releases the finger grip portions 3122, the ring portion 3120 resiliently moves towards its undeflected configuration, thereby engaging the interior lumen of the proximal wall portion 1022. The mounting portion 3104 described herein has the advantage that it is easily removed and/or moved with respect to the conduit 1020 without disturbing the position of the conduit 1020 or any other instrumentation.
As illustrated in FIGS. 76 and 78, the configuration of the mounting portion 3104 and the elongated body portion 3102 allow the elongated body portion to occupy a small space along the periphery of the proximal wall portion 3122. This allows the apparatus to protect the desired body structure without blocking access for the insertion of other surgical instrumentation, and without blocking visibility by the surgeon during the procedure.
The mounting portion 3104 is one exemplary configuration for mounting the apparatus 3100 to the support structure. It is contemplated that the apparatus 3100 may be mounted within the cannula in another manner.
When in position, the distal end portion 3110 covers the exiting nerve root R, while exposing the disc annulus A (See FIG. 76). As discussed above, the debridement and decortication of tissue covering the vertebrae, as well as a facetecomy and/or laminectomy if indicated, are performed prior to the insertion of apparatus 3100 into the surgical space. Thus, there is no need to displace or retract tissue, and apparatus 3100 merely covers the nerve root and does not substantially displace the nerve root or any other body tissue. It is understood that term “cover” as used herein refers to apparatus 3100 being a small distance adjacent to the body structure, or in contact with the body structure without applying significant tension or displacement force to the body structure.
Additional surgical instrumentation S may be inserted into the expandable conduit to perform procedures on the surrounding tissue. For example, an annulotomy may be performed using a long handled knife and kerrisons. A discectomy may be completed by using curettes and rongeurs. Removal of osteophytes which may have accumulated between the vertebrae may be performed using osteotomes and chisels.
As illustrated in FIG. 79, the elongated body portion 3102 is rotated to protect the spinal cord, or dura D, during the above procedures. The surgeon may change the position of the apparatus 3100 by approximating the finger grips 3122 to release the ring portion from engagement with the inner wall of the proximal wall portion 1020, and then re-position the apparatus 3100 without disturbing the expandable conduit 1020 (as shown in FIG. 77).
During certain surgical procedures, it may be useful to introduce crushed bone fragments or the fusion devices 2010 or 2110 to promote bone fusion. As illustrated in FIGS. 80 80 a, apparatus 3100 is useful to direct the implants into the space I between adjacent vertebrae V. As shown in the figures, the distal portion 3110 of the elongated body portion 3102 is partially inserted into the space I. The distal end portion 3110, is positioned between adjacent vertebrae V, and creates a partially enclosed space for receiving the implants or other material therein.
Another embodiment of the apparatus or shield is illustrated in FIGS. 81 82, and designated apparatus 3200. Apparatus 3200 is substantially identical to apparatus 3100, described above, with the following differences noted herein. In particular, distal end portion 3210 includes a pair of surfaces 3240 and 3242. Surface 3240 is an extension of elongated shield portion 3202, and surface 3242 extends at an angle with respect to surface 3240. In the exemplary embodiment, surfaces 3240 and 3242 defined an angle of about 90 degrees between them. Alternatively another angle between surfaces 3240 and 3242 may be defined as indicated by the body structures to be protected.
As illustrated in FIGS. 83 84, distal end portion 3210 allows the apparatus to provide simultaneous shielding of both the dura D and the nerve root R. In FIGS. 83 84, surface 3242 shields the dura D, and surface 3240 shields the nerve root R. It is understood that surfaces 3240 and 3242 may be interchanged with respect to which tissue they protect during the surgical procedure.
After the spinal implants 2010 or 2110 are inserted between the vertebrae V, the fasteners 4600 are attached to the vertebrae. Prior to attachment of the fasteners, the location of the fastener attachment is confirmed. In the exemplary embodiment, the pedicle entry point of the L5 vertebra is located using visual landmarks as well as lateral and A/P fluoroscopy, as is known in the art. With reference to FIG. 56, the entry point 4092 is prepared with an awl 4550. The pedicle hole 4092 is completed using instruments known in the art such as a straight bone probe, a tap, and a sounder. The sounder, as is known in the art, determines whether the hole that is made is surrounded by bone on all sides, and that there has been no perforation of the pedicle wall.
After hole 4092 in the pedicle is provided (or at any point during the procedure), an optional step is to adjust the location of the distal portion 1024 of the expandable conduit 1020. This may be performed by inserting the expander apparatus 1200 into the expandable conduit 1020, expanding the distal portions 1210, and contacting the inner wall of the skirt portion 1024 to move the skirt portion 1024 to the desired location. This step may be performed while the endoscope 1500 is positioned within the expandable conduit 1020, and without substantially disturbing the location of the proximal portion of the expandable conduit 1020 to which the endoscope mount platform 1300 may be attached.
A particularly useful fastener for use in the exemplary procedure is the fastener 4600, illustrated in FIGS. 85 86, and described in greater detail in U.S. patent application Ser. No. 10/075,668, filed Feb. 13, 2002 and application Ser. No. 10/087,489, filed Mar. 1, 2002, which are incorporated by reference in their entirety herein. Fastener 4600 includes a screw portion 4602, a housing 4604, a spacer member 4606, a biasing member 4608, and a clamping member, such as cap screw 4610. The screw portion 4602 has a distal threaded portion 4612 and a proximal, substantially spherical joint portion 4614. The threaded portion 4612 is inserted into the hole 4092 in the vertebrae, as will be described below. The substantially spherical joint portion 4614 is received in a substantially annular, part spherical recess 4616 in the housing 4604 in a ball and socket joint relationship (see also FIG. 88).
As illustrated in FIG. 86, the fastener is assembled by inserting the screw portion 4602 into a bore in a passage 4618 in the housing 4604, until the joint portion 4614 engages the annular recess 4616. The screw portion 4602 is retained in the housing 4604 by the spacer member 4606 and biasing member 4608. The biasing member 4608 provides a biasing force to drive the spacer member 4606 in frictional engagement with the joint portion 4614 of the screw member 4602 and the annular recess 4616 of the housing 4604. The biasing provided by the biasing member 4608 frictionally maintains the relative positioning of the housing 4604 with respect to the screw portion 4602. The biasing member 4608 is selected such that biasing force prevents unrestricted movement of the housing 4604 relative to the screw portion 4602. However, the biasing force is insufficient to resist the application of force by a physician to move the housing 4604 relative to the screw portion 4602. In other words, this biasing force is strong enough to maintain the housing 4604 stationary relative to the screw portion 4602, but this force may be overcome by the physician to reorient the housing 4604 with respect to the screw member 4602, as will be described below.
In the exemplary embodiment, the biasing member 4608 is a resilient ring having a gap 4620, which permits the biasing member 4608 to radially contract and expand. The biasing member 4608 has an arched shape, when viewed end-on (FIG. 86 a). The arch shape of the spring member 4608 provides the biasing force, as will be described below. The spacer member 4606 and the biasing member 4608 are inserted into the housing 4604 by radially compressing the biasing member into an annular groove 4622 in the spacer member 4606. The spacer member 4606 and the biasing member 4608 are slid into the passage 4618 until the distal surface of the spacer member 4606 engages the joint portion 4614 of the screw portion 4602, and the biasing member 4608 expands radially into the annular groove 4620 in the housing 4604. The annular groove 4620 in the housing 4604 has a dimension 4623 which is smaller than the uncompressed height of the arched shape of the biasing member 4608. When the biasing member 4608 is inserted in the annular groove 4620, the biasing member 4608 is flattened against its normal bias, thereby exerting the biasing force to the spacer member 4606. It is understood that similar biasing members, such as coiled springs, belleville washers, or the like may be used to supply the biasing force described herein.
The spacer member 4606 is provided with a longitudinal bore 4626, which provides access to a hexagonal recess 4628 in the proximal end of the joint portion 4614 of the screw member 4602. The proximal portion of the housing 4604 includes a pair of upright members 4630 and 4631 that are separated by substantially “U”-shaped grooves 4632. A recess for receiving elongated member 4650 is defined by the pair of grooves 4632 between upright members 4630 and 4631. Elongated member 4650 is to be placed distally into the housing 4604 in an orientation substantially transverse to the longitudinal axis of the housing 4604, as will be described below. The inner walls of the upright members 4630 and 4631 are provided with threads 4634 for attachment of the cap screw 4610 by threads 4613 therein.
The fastener 4600 is inserted into the expandable conduit 1020 and guided to the prepared hole 4092 in the vertebrae as a further stage of the procedure. The fastener 4600 must be simultaneously supported and rotated in order to be secured in hole 4092. In the exemplary embodiment, the fastener 4600 is supported and attached to the bone by an endoscopic screwdriver apparatus 4660, illustrated in FIGS. 87 88. Screwdriver 4660 includes a proximal handle portion 4662 (illustrated in dashed line), an elongated body portion 4664, and a distal tool portion 4666.
The distal tool portion 4666, as illustrated in greater detail in FIG. 88 includes a substantially hexagonal outer periphery which is received in the substantially hexagonal recess 4628 in the joint portion 4614 of the screw member 4602. A spring member at the distal tool portion 4666 releasably engages the hexagonal recess 4628 of the screw member 4602 to support the fastener 4600 during insertion and tightening. In the exemplary embodiment, a spring member 4672 is configured to engage the side wall of the recess 4628. More particularly, a channel/groove is provided in the tip portion 4666 for receiving the spring member 4672. The channel/groove includes a medial longitudinal notch portion 4676, a proximal, angled channel portion 4678, and a distal substantially transverse channel portion 4680. The spring member 4672 is preferably manufactured from stainless steel and has a medial portion 4682 which is partially received in the longitudinal notch portion 4676, an angled proximal portion 4684 which is fixedly received in the angled channel portion 4678, and a transverse distal portion 4686 which is slidably received in the transverse channel 4680. The medial portion 4682 of the spring member 4672 is partially exposed from the distal tip portion 4666 and normally biased in a transverse outward direction with respect to the longitudinal axis (indicated by arrow E), in order to supply bearing force against the wall of the recess 4628. Alternatively, the distal tip portion of the screw driver may be magnetized in order to hold the screw portion 4602. Similarly, the distal tip portion may include a ball bearing or similar member which is normally biased in a radially outward direction to engage the interior wall of the recess 4628 to secure the fastener 4600 to the screwdriver distal tip 4666.
The insertion of the fastener 4600 into the prepared hole 4092 may be achieved by insertion of screwdriver 4660 into conduit 1020 (indicated by arrow G). This procedure may be visualized by the use of the endoscope 1500 in conjunction with fluoroscopy. The screw portion 4602 is threaded into the prepared hole 4092 by the endoscopic screwdriver 4660 (indicated by arrow H). The endoscopic screwdriver 4660 is subsequently separated from the screw, by applying a force in the proximal direction, and thereby releasing the distal tip portion 4666 from the hexagonal recess 4628 (e.g., causing the transverse distal portion 4686 of the spring member 4672 to slide within the transverse recess 4680 against the bias, indicated by arrow F), and removing the screwdriver 4660 from the expandable conduit 1020. An alternative method may use a guide wire, which is fixed in the hole 4092, and a cannulated screw which has an internal lumen (as is known in the art) and is guided over the guide wire into the hole 4092. The screwdriver would be cannulated as well to fit over the guide wire.
In a further stage of the procedure, the housing portions 4604 of the fasteners 4600 are substantially aligned such that their upright portions 4630 and 4631 face upward, and the notches 4632 are substantially aligned to receive the fixation element or elongated member 4650 therein. The frictional mounting of the housing 4604 to the screw member 4602, described above, allows the housing 4604 to be temporarily positioned until a subsequent tightening step, described below. Positioning of the housing portions 4604 may be performed by the use of an elongated surgical instrument capable of contacting and moving the housing portion to the desired orientation. An exemplary instrument for positioning the housings 4604 is a grasper apparatus 4700, illustrated in FIG. 89. The grasper apparatus 4700 includes a proximal handle portion 4702, an elongated body portion 4704, and distal nose portion 4706. The distal nose portion 4706 includes a pair of grasping jaws 4708 a and 4708 b, which are pivotable about pin 4710 by actuation of the proximal handle portion 4702. The grasping jaws 4708 a and 4708 b are illustrated in the closed position in FIG. 89. As is known in the art, pivoting the movable handle 4714 towards stationary handle 4712 causes longitudinal movement of actuator 4716, which in turn pivots the jaw 4708 b towards an open position (illustrated in dashed line). The biasing members 4718 and 4720 are provided to return the handles 4712 and 4714 to the open position and bias the jaws 4708 a and 4708 b to the closed position.
A subsequent stage in the process is the insertion of the fixation element or elongated member 4650 into the expandable conduit 1020. The elongated member is manufactured from a biocompatible material and must be sufficiently strong to maintain the positioning of the vertebrae, or other body structures. In the exemplary embodiment, the elongated members 4650 are manufactured from Titanium 6/4 or titanium alloy. Alternatively, the elongated member may be manufactured from stainless steel or other suitable material. The radii and length of the elongated members 4650 are selected by the physician to provide the best fit for the positioning of the screw heads. Such selection may be performed by placing the elongated member 4650 on the skin of the patient overlying the location of the fasteners and viewed fluoroscopically. For example, a 70 mm preformed rod having a 3.5″ bend radius may be selected for the spinal fixation.
The elongated member 4650 is subsequently fixed to each of the fasteners 4600, and more particularly, to the housings 4604 of each fastener. The grasper apparatus 4700, described above, is also particularly useful for inserting the elongated member 4650 into the expandable conduit 1020 and positioning it with respect to each housing 4604. As illustrated in FIG. 89, the jaws 4708 a and 4708 b of the grasper apparatus 4700 each has a curved contact portion 4722 a and 4722 b for contacting and holding the outer surface of the elongated member 4650.
As illustrated in FIG. 90, the grasper apparatus 4700 may be used to insert the elongated member 4650 into the operative space 1090 defined at least partially by the skirt portion 1024 of the expandable conduit 1020. The cut-out portions 1056 and 1058 provided in the skirt portion 1024 assist in the process of installing the elongated member 4650 with respect to the housings 4604. The cut-out portions 1056 and 1058 allow an end portion 4652 of the elongated member 4650 to extend beyond the operative space without raising or repositioning the skirt portion 1024. The elongated member 4650 is positioned within the recesses in each housing 4604 defined by grooves 4632 disposed between upright members 4630 and 4631. The elongated member 4650 is positioned in an orientation substantially transverse to the longitudinal axis of each housing 4604.
Further positioning of the elongated member 4650 may be performed by guide apparatus 4800, illustrated in FIG. 91. Guide apparatus 4800 is useful in cooperation with an endoscopic screwdriver, such as endoscopic screwdriver 4660 (illustrated in FIG. 87), in order to position the elongated member 4650, and to introduce and tighten the cap screw 4610, described above and illustrated in FIG. 86. Tightening of the cap screw 4610 with respect to the housing 4604 fixes the orientation of the housing 4604 with respect to the screw portion 4602 and fixes the position of the elongated member 4650 with respect to the housing 4604.
In the exemplary embodiment, the guide apparatus 4800 has a proximal handle portion 4802, an elongated body portion 4804, and a distal tool portion 4806. The elongated body portion 4804 defines a central bore 4808 (illustrated in dashed line) along its longitudinal axis 4810. The central bore 4808 is sized and configured to receive the endoscopic screwdriver 4660 and cap screw 4610 therethrough. In the exemplary embodiment, the diameter of the central bore 4808 of the elongated body portion 4804 is about 0.384 0.388 inches in diameter, and the external diameter of the endoscopic screwdriver 4660 (FIG. 87) is about 0.25 inches. The proximal handle portion 4802 extends transverse to the longitudinal axis 4810, which allows the physician to adjust the guide apparatus 4800 without interfering with the operation of the screwdriver 4660.
The distal portion 4806 of the apparatus includes several semicircular cut out portions 4814 which assist in positioning the elongated member 4650. As illustrated in FIG. 92, the cut out portions 4814 are sized and configured to engage the surface of elongated member 4650 and move the elongated member 4650 from an initial location (illustrated in dashed line) to a desired location.
As illustrated in FIG. 93, the guide apparatus 4800 is used in cooperation with the endoscopic screwdriver 4660 to attach the cap screw 4610. The distal end of the body portion 4804 includes a pair of elongated openings 4816, which permit the physician to endoscopically view the cap screw 4610 retained at the distal tip 4666 of the endoscopic screw driver 4660.
The guide apparatus 4800 and the endoscopic screwdriver 4660 may cooperate as follows: The guide apparatus 4800 is configured to be positioned in a surrounding configuration with the screwdriver 4600. In the exemplary embodiment, the body portion 4804 is configured for coaxial placement about the screwdriver 4660 in order to distribute the contact force of the guide apparatus 4800 on the elongated member 4650. The distal portion 4806 of the guide apparatus 4800 may bear down on the elongated member 4650 to seat the elongated member 4650 in the notches 4632 in the housing 4604. The “distributed” force of the guide apparatus 4800 may contact the elongated member 4650 on at least one or more locations. In addition, the diameter of central bore 4808 is selected to be marginally larger than the exterior diameter of cap screw 4610, such that the cap screw 4610 may freely slide down the central bore 4808, while maintaining the orientation shown in FIG. 93. This configuration allows the physician to have effective control of the placement of the cap screw 4610 into the housing 4604. The cap screw 4610 is releasably attached to the endoscopic screwdriver 4660 by means of spring member 4672 engaged to the interior wall of hexagonal recess 4611 as it is inserted within the bore 4808 of the body portion 4804 of guide apparatus 4800. The cap screw 4610 is attached to the housing 4604 by engaging the threads 4615 of the cap screw 4610 with the threads 4634 of the housing.
As illustrated in FIG. 94, tightening of the cap screw 4610 fixes the assembly of the housing 4604 with respect to the elongated member 4650. In particular, the distal surface of the cap screw 4610 provides a distal force against the elongated member 4650, which in turn drives the spacer member 4606 against the joint portion 4614 of the screw portion 4602, which is consequently fixed with respect to the housing 4604.
If locations of the vertebrae are considered acceptable by the physician, then the fixation procedure is substantially complete once the cap screws 4610 have been attached to the respective housings 4604, and tightened to provide a fixed structure as between the elongated member 4650 and the various fasteners 4600. However, if compression or distraction of the vertebrae with respect to one another is required additional apparatus would be used to shift the vertebrae prior to final tightening of all the cap screws 4610.
In the exemplary embodiment, this step is performed with a surgical instrument, such as compressor-distracter instrument 4900, illustrated in FIG. 95, which is useful to relatively position bone structures in the ceph-caud direction and to fix their position with respect to one another. Thus, the compressor-distracter instrument 4900 has the capability to engage two fasteners 4600 and to space them apart while simultaneously tightening one of the fasteners to fix the spacing between the two vertebrae, or other bone structures. Moreover, the compressor-distracter instrument 4900 may also be used to move two fasteners 4600, and the vertebrae attached thereto into closer approximation and fix the spacing there between.
The distal tool portion 4902 of the compressor-distracter instrument 4900 is illustrated in FIG. 95. (Further details of the compressor-distracter apparatus is described in co-pending U.S. application Ser. No. 10/178,875, filed Jun. 24, 2002, entitled “Surgical Instrument for Moving Vertebrae,” which is incorporated by reference in its entirety herein.) The distal tool portion 4902 includes a driver portion 4904 and a spacing member 4906. The driver portion 4904 has a distal end portion 4908 with a plurality of wrenching flats configured to engage the recess 4611 in the proximal face of the cap screw 4610, and to apply torque to the cap screw. The driver portion 4904 is rotatable about the longitudinal axis (indicated by arrow M) to rotate the cap screw 4610 relative to the fastener 4600. Accordingly, the driver portion 4904 can be rotated to loosen the cap screw 4610 on the fastener 4600 and permit movement of the elongated member 4650 connected with one of the vertebrae relative to the fastener 4600 connected with another of the vertebrae. The cap screw 4610 can also be rotated in order to tighten the cap screw 4610 and clamp the elongated member 4650 to the fastener 4600.
The distal tool portion 4902 may also include a spacing member, such as spacing member 4906, which engages an adjacent fastener 4600 b while driver member 4904 is engaged with housing 4600 a to move the fastener 4600 b with respect to fastener 4600 a. In the exemplary embodiment, spacing member 4906 is a jaw portion which is pivotably mounted to move between a first position adjacent the driver portion and a second position spaced from the driver portion, as shown in FIG. 95. The distal tip 4910 of the spacing member 4906 is movable relative to the driver portion 4904 in a direction extending transverse to the longitudinal axis.
As illustrated in FIG. 95, the spacer member 4906 can be opened with respect to the driver portion 4904 to space the vertebrae further apart (as indicated by arrow N). The distal portion 4910 of the spacer member 4906 engages the housing 4604 b of fastener 4600 b and moves fastener 4600 b further apart from fastener 4600 a to distract the vertebrae. Where the vertebrae are to be moved closer together, e.g. compressed, the spacer member 4906 is closed with respect to the driver portion 4904 (arrow P), as illustrated in FIG. 96. The distal portion 4610 of spacer member 4606 engages housing 4604 b of fastener 4600 b and moves fastener 4600 b towards fastener 4600 a. When the spacing of the vertebrae is acceptable to the physician, the cap screw 4610 a is tightened by the driver member 4904, thereby fixing the relationship of the housing 4604 a with respect to elongated member 4650, and thereby fixing the position of the vertebrae, or other bone structures, with respect to one another.
Once the elongated member or fixing element 4650 is fixed with respect to the fasteners 4600, the procedure is substantially complete. The surgical instrumentation, such as the endoscope 1500 is withdrawn from the surgical site. The expandable conduit 1020 is also withdrawn from the site. The muscle and fascia typically close as the expandable conduit 1020 is withdrawn through the dilated tissues in the reduced profile configuration. The fascia and skin incisions are closed in the typical manner, with sutures, etc. The procedure described above may be repeated for the other lateral side of the same vertebrae, if indicated.
Accordingly, the method of fixing three vertebrae V of a patient together at the surgical site includes inserting a first cannula 1020 into the body of the patient. The skirt portion 1024 of the cannula 1020 is expanded using the expander apparatus 1200. A first fusion device 2010 or 2110 is moved through the cannula 1020 and inserted between the first and second vertebrae V. A first fastener 4600 is moved through the cannula 1020 and secured to the first vertebra V. A second fastener 4600 is moved through the cannula 1020 and secured to a second vertebra V. A second fusion device 2010 or 2110 is moved through the cannula 1020 and inserted between the second and third vertebrae V. A third fastener 4600 is moved through the cannula 1020 and secured to the third vertebra V. A first fixation element 4650 is moved through the cannula 1020. The first fixation element 4650 is fixed to the first, second, and third fasteners 4600.
A second cannula 1020 is inserted into the body of the patient laterally from where the first cannula was inserted. The skirt portion 1024 of the second cannula 1020 is expanded using the expander apparatus 1200. A third fusion device 2010 or 2110 is moved through the cannula 1020 and inserted between the first and second vertebrae V. A fourth fastener 4600 is moved through the second cannula 1020 and secured to the first vertebra V. A fifth fastener 4600 is moved through the cannula 1020 and secured to the second vertebra V. A fourth fusion device 2010 or 2110 is moved through the second cannula 1020 and inserted between the second and third vertebrae V. A sixth fastener 4600 is moved through the second cannula 1020 and secured to the third vertebra V. A second fixation element 4650 is moved through the second cannula 1020. The second fixation element 4650 is fixed to the fourth, fifth, and sixth fasteners.
Although the method of securing the three vertebrae together is described as including the insertion of fusion devices between the second and third vertebrae, it is contemplated that fusion devices may only be inserted between the first and second vertebrae. Furthermore, it is contemplated that the skirt portion 1024 of the cannula 1020 could include a stop that retains the skirt portion in an expanded configuration as shown in U.S. patent application Ser. No. 09/855,358, which is incorporated by reference in its entirety herein.
an elongated element adapted to be releasably coupled to an interior wall of the retractor, the elongated element including a contiguous extension dimensioned to extend distal of the distal end of the retraction element into the surgical target site, wherein the elongated element and the extension are formed of a single, monolithic structure, wherein the elongated element is configured such that when coupled to the retractor, the elongated element covers a body structure at the target site without substantially reducing the field of view through the retractor and without blocking access to the operative corridor for insertion of additional surgical instruments through the retractor to the target site.
2. The surgical access system of claim 1, wherein the elongated element slideably engages the retractor.
3. The surgical access system of claim 1, wherein the elongated element is configured to prevent inadvertent contact with nerve roots during a surgical procedure.
4. The surgical access system of claim 1, wherein the contiguous extension of the elongated element is configured to be disposed at least partially into a space between first and second vertebrae.
5. The surgical access system of claim 1, wherein the retractor defines a fully enclosed lumen.
6. The surgical access system of claim 1, wherein the elongated element is configured to guide insertion of an implant between first and second vertebrae at the target site.
an elongated element releasably engageable to an interior wall of the retractor such that the elongated element is mounted within the lumen and a distal portion of the elongated element extends distally from the distal end of the retractor into the target site, wherein the elongated element and the distal portion are formed of a single, monolithic structure, wherein the elongated element is configured such that when mounted to the retractor, the elongated element covers a body structure at the target site without substantially reducing the field of view through the retractor and without blocking access to the operating corridor such that additional surgical instruments can be inserted through the retractor to the target site.
8. The system of claim 7, wherein the elongated element is configured to guide insertion of an implant between first and second vertebrae at the target site.
9. The system of claim 7, wherein the distal portion of the elongated element is configured to be at least partially inserted between adjacent vertebrae at the target site.
10. The system of claim 7, wherein the elongated element slideably engages the retractor.
11. The system of claim 7, wherein the elongated element is configured to prevent inadvertent contact with nerve roots during a surgical procedure.
12. The system of claim 7, wherein the retractor defines a fully enclosed lumen.
13. The surgical access system of claim 1, wherein the elongated element is configured to be coupled to the retractor in either the closed or open configuration.
14. The system of claim 7, wherein the elongated element is configured to be coupled to the retractor before or after the retractor is expanded.

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