Abstract: Devices and methods for performing percutaneous spinal surgery under direct visualization and through a single cannula are shown. A device (10) is provided which includes an elongated cannula (20) having a first inner diameter (D.sub.I) and an outer diameter (D.sub.O) sized for percutaneous introduction into a patient. The cannula (20) defines a working channel (25) between its ends (21, 22) which has a second diameter (D.sub.2) equal to the diameter (D.sub.I) of the cannula sized for receiving a tool therethrough. An elongated viewing element (50) is engageable to the cannula (20) adjacent the working channel (25), preferably by a fixture (30). The fixture (30) includes a housing (31) attachable to the proximal end (22) of the cannula (20) that defines a working channel opening (35) which is in communication with the working channel (25). The housing (31) also defines an optics bore (60) adjacent the working channel opening (35).

Abstract: Presented is a method and instrumentation for removal of a pair of rectangular blocks of vertebral bone tissue of predetermined and precise dimensions to provide an intervertebral recess, with guarded depth for safety, achieving and maintaining the desired intervertebral space, as well as obtaining and injecting into the intervertebral recess a well-fitted bone plug of the same dimension as the recess that receives it. Two cooperating instruments are utilized in the invention, one being an intervertebral mortising cutter and the other a precision guide and spacer. The guide and spacer functions dually to retain the associated adjacent vertebrae at a precise selected and predetermined spacing and to guide penetration of the mortising cutter. Following advancement of the mortising cutter into the bone tissue of the two adjacent vertebrae, the instruments, along with the blocks of bone tissue, are removed from the site to produce a precisely configured recess.

Abstract: One embodiment of a spinal implant 10 includes a body 11 sized and configured for engagement between adjacent vertebrae V. The body 11 includes two opposite faces 12, 14 and an outer surface 13 between the two faces 12, 14. The body 11 includes a porous biocompatible material for permitting tissue ingrowth therethrough. A sleeve 15 is disposed around the outer surface 13 of the body 11. The sleeve 15 is composed of a second material which is relatively stronger under compressive loads than the biocompatible material of the body 11. Also provided is a plurality of apertures 16 through the sleeve 15 in communication with the outer surface 13 of the body 11 for bone ingrowth. Means for attaching the sleeve to the endplates of adjoining vertebral bodies are also provided.

Abstract: A new top-loading transverse connector of the present invention for bridging between longitudinal members of a spinal fixation system implant. The transverse connector is loaded and clamped to the longitudinal member from the top permitting easy access and adjustment and may clamp at the same location along the rod as a vertebral fixation element. The transverse connector comprises an elongate body and an engagement portion on each opposing end of the elongate body. The engagement portion includes downward legs each with a surface to engage the longitudinal member. The downward legs are displaced from each other to define a space therebetween. The engagement portion includes an upper surface defining an opening therethrough. The opening intersects the space defined between the downward legs. Together, the space and opening are configured to receive the clamp assembly carried on the longitudinal member. Another object of the invention, is to provide an improved system including the transverse connector.

Abstract: A method and apparatus for minimally invasive tissue removal contemplates a system including a tissue cutting tool having a motor driven cutting blade reciprocating within a percutaneously introducable cannula. In accordance with one method of the invention, the frequency of reciprocation of the cutting blade is tuned to a characteristic frequency of the target tissue to be excised, which frequency is a function of certain properties of the target tissue and the surrounding tissue. Cutting at the characteristic frequency of the target tissue not only enhances the speed and efficiency of the tissue excision, but also minimizes the risk of cutting surrounding tissue. Another aspect of the system includes feedback control of both aspiration and irrigation circuits of the system. With the feedback control, coupled with user settable inputs, the surgeon can control the system to "tease" tissue into the cutting opening to provide more manageable bite sizes of the excised tissue.

Abstract: A system and method for anterior fixation of the spine utilizes a cylindrical implant engaged in the intradiscal space at the cephalad and caudal ends of the construct. The implants are cylindrical fusion devices (10) filled with bone material to promote bone ingrowth and fusion of the disc space. An attachment member (40) is connected to each of the fusion devices (10) and bone screws (30) having similar attachment members (33) are engaged in the vertebral bodies of the intermediate vertebrae. A spinal rod (50) is connected to each of the attachment members using an eyebolt assembly (53, 54, 55). In a further inventive method, a revision of the construct is achieved by removing the fusion devices. Each fusion device is engaged by an elongated guide member (62) over which a cylindrical trephine (70) is advanced. The trephine (70) has an inner diameter larger than the diameter of the fusion implant and includes cutting teeth (72) for extracting a core (84) of bone material around the fusion implant.

Abstract: An interbody fusion device in one embodiment includes a tapered body defining a hollow interior for receiving bone graft or bone substitute material, The body defines exterior threads which are interrupted over portions of the outer surface of the device. The fusion device defines truncated side walls so that on end view the body takes on a cylindrical form. The side walls are provided with vascularization openings, and the body wall device includes opposite bone ingrowth slots extending through the interrupted thread portion of the body. In another embodiment, the tapered body is solid and formed of a porous biocompatible material having sufficient structural integrity to maintain the intradiscal space and normal curvature. The material is preferably a porous tantalum having fully interconnected pores to facilitate complete bone tissue ingrowth into the implant.

Abstract: A method and apparatus minimally invasive tissue removal contemplates a system including a tissue cutting tool having a motor driven cutting blade reciprocating within a percutaneously introducable cannula. In accordance with one method of the invention, the frequency of reciprocation of the cutting blade is tuned to a characteristic frequency of the target tissue to be excised, which frequency is a function of certain properties of the target tissue and the surrounding tissue. Cutting at the characteristic frequency of the target tissue not only enhances the speed and efficiency of the tissue excision, but also minimizes the risk of cutting surrounding tissue. Another aspect of the system includes feedback control of both aspiration and irrigation circuits of the system. With the feedback control, coupled with user settable inputs, the surgeon can control the system to "tease" tissue into the cutting opening to provide more manageable bite sizes of the excised tissue.

Abstract: A spinal implant system includes a pair of spinal rods arranged on opposite sides of the spinous processes of a patient. An transverse connector assembly in accordance with the invention includes a plate having a central portion which spans between the spinal rods. At each end of the central portion is an integral body portion having an elongated slot formed therein. An eyebolt extending through the slot and has an opening to receive the spinal rod therethrough to clamp the spinal rod to a respective one of the body portions. At the end of each body portion distal from the central portion is an enlarged end piece having an end face oriented generally perpendicular to the longitudinal axis of the slot in the plate body. A threaded post extends from the end face and is used together with a nut to clamp the yoke portion of the vertebral fixation element to the plate. In another embodiment, an eyebolt assembly is used to mount a vertebral fixation element to an endpiece bar extending from the plate.

Abstract: Surgical procedures for stabilizing a spine include exposing a portion of each of adjacent vertebrae requiring fusion and placing an osteoinductive material within an area between the portions of the adjacent vertebrae in contact with the cortical bone of the portions. In another aspect, surgical procedures for stabilizing a spine are provided which include exposing a portion of each of adjacent vertebrae requiring fusion, adding an osteoinductive cytokine to a carrier material and placing the carrier material between the portions of the adjacent vertebrae in contact with the cortical bone of the portions.

Abstract: One embodiment of the invention a spinal fixation system includes an elongated spinal element (11) configured to extend adjacent the spine, and a plurality of fixation elements (15) each engagable to the spine and to the elongated spinal element (11). The embodiment further includes an extension member (28) having a head portion (30) defining a variable angle surface and an elongated portion (29) extending from the head portion, and a clamping member (31) for clamping the extension member (28) to the elongated spinal element (11). The clamping member (31) defines a mating surface configured for mating engagement with the variable angle surface of the extension member (28) to permit orientation of the elongated portion (29) of the extension member (28) at a plurality of angles relative to the elongated spinal element (11).

Abstract: A template assembly is provided for marking locations on the disc annulus for the implantation of an interbody fusion device or the introduction of a working instrument. The template assembly includes a tubular body sized for percutaneous introduction into a patient and advancement to an affected intervertebral disc. An elongated shaft slidably extends through the tubular body and is threadedly engaged to the tubular body at its proximal end so that rotation of the shaft relative to the tubular body advances the shaft through the body. A guide foot is pivotably connected to the distal end of the tubular body to be pivoted from a first position aligned with the tubular body to a second deployed position oriented substantially perpendicular to the tubular body. The guide body is pivoted from the first position to the second position by advancement of the elongated shaft through the tubular body.

Abstract: An iliac screw includes a smooth distal shank (35), a threaded proximal shank (37) and a proximal head portion (38). The smooth distal shank (35) is configured to penetrate the cancellous bone of the iliac wings, while the threaded shank (37) carries bone threads configured for engagement with the cortical or the cancellous bone. The head portion (38) is configured for engagement with an elongated fixation member, such as a spinal rod.

Abstract: A method and apparatus for minimally invasive tissue removal contemplates a system including a tissue cutting tool having a motor driven cutting blade reciprocating within a percutaneously introducable cannula. In accordance with one method of the invention, the frequency of reciprocation of the cutting blade is tuned to a characteristic frequency of the target tissue to be excised, which frequency is a function of certain properties of the target tissue and the surrounding tissue. Cutting at the characteristic frequency of the target tissue not only enhances the speed and efficiency of the tissue excision, but also minimizes the risk of cutting surrounding tissue. Another aspect of the system includes feedback control of both aspiration and irrigation circuits of the system. With the feedback control, coupled with user settable inputs, the surgeon can control the system to "tease" tissue into the cutting opening to provide more manageable bite sizes of the excised tissue.

Abstract: An attachment plate for use with a spinal rod system converts a normally side-tightening eyebolt to a top-tightenable arrangement for engaging spinal fixation elements to the spinal rod. The plate is configured for use with spinal fixation elements having a posteriorly projecting central post, one lateral surface of the post contacting the spinal rod when the rod extends through an aperture of the eyebolt. The attachment plate is generally L-shaped with a slot in one portion for receiving the posteriorly projecting threaded post of the eyebolt. The plate includes a flange portion having a surface configured to engage the lateral surface of the fixation element post opposite the spinal rod. The attachment plate includes a camming segment to provide a clamping force component directed toward the flange portion of the plate to thereby tightly clamp the spinal rod to the fixation element post when a nut is threaded onto the eyebolt threaded post.

Abstract: A transverse fixator assembly for spanning between a number of longitudinal members situated adjacent a patient's vertebrae and methods for fixation of the spine which allow variation of the distance between two or more vertebrae. The assembly includes a number of connectors configured to span the distance between and engage the longitudinal members. The connectors define a thru-hole for engaging a bone bolt which is engaged to a vertebra plus a number of spikes projecting from the connector. A locking mechanism is configured to prevent the bolt from rotating relative to the connector when the nut is being tightened. One or more of the connectors may be a dynamic connector which is slidably engaged to the longitudinal members to vary the distance between the vertebrae for compression or distraction.

Abstract: A spinal implant system for correcting spinal deformities and abnormalities includes an elongated spinal rod configured to be implanted adjacent the spinal column and spanning across several vertebral levels. A number of fixation elements, such as spinal hooks, are provided for engaging vertebrae at a number of vertebral levels. At least some of the fixation elements includes an elongated stem projecting from a vertebra engaging portion. The stems of each of the fixation elements are connected to the spinal rod by way of a rod connector having a one-piece body defining a rod channel adapted to receive the spinal rod therethrough, a stem bore adapted to receive a stem therethrough, and a threaded bore. The stem bore and rod channel intersect to permit contact between the rod and the stem of a fixation element. The threaded bore intersects either the rod channel or the stem bore so that a set screw threaded into the threaded bore bears against the spinal rod or fixation element stem.

Abstract: A system for internal fixation of bone includes a fixation plate having a number of bores therethrough, a corresponding number of screws each having an enlarged head portion and an elongated shaft portion defining bone engaging threads thereabout and a non-threaded portion between the head and threaded portions, and a corresponding number of screw anti-backout members each having a bore therethrough. The screw anti-backout members are positioned within the bores of the fixation plate and are initially sized to slidingly receive an elongated shaft therethrough. The screws are advanced through the plate bores and screw anti-backout members so that the fixation plate is secured to the underlying bone with the bores of the screw anti-backout members surrounding a non-threaded portion of the shafts. The system is thereafter heated sufficiently to shrink the bores of the screw anti-backout members, thereby trapping the non-threaded portions of the screw shafts between the fixation plate and the threaded portions.

Abstract: A cable used in spinal surgery has one crimp of a two crimp assembly crimped to one end of it. The second crimp has a ball held in a socket of the first crimp. The other end of the cable is passed around the bone or bones and any necessary orthopedic spinal device and it is then passed through an aperture in the second crimp. The cable is then tensioned by application thereto of a tensioning tool with the tool applied to the cable and to an abutment face of the second crimp, whereupon the cable is tensioned, with the ball and socket arrangement enabling swiveling of the crimps with respect to each other, thus minimizing sharp bends in the cable. Then the second crimp portion receiving the cable portion in the aperture adjacent the tensioning tool is crimped onto that cable portion to complete the attachment. Then tile tensioning tool is removed, and the free end of the cable is cut off at the abutment surface.

Abstract: A system and method for internal fixation of vertbra of the spine to facilitate graft fusion is disclosed which minimizes the degee of trauma and the amount of surgical invasion. In one aspect the system includes fixation hardware which is inserted through small incisions aligned with each pedicle to be instrumented. The hardware includes bone screws, fixation plates, engagement nuts, and linking members. In an important feature of the hardware, the fixation plates, engagement nuts and linking members are supported suprafascially but subcutaneously so that the fascia and muscle tissue are not damaged, by a bone screw which includes an elongated smooth shank intermediate bone engaging threads and machine threads that is configured to support the fixation hardware above the fascia.