Abstract: Apparatus and method for determining the kinematics of a large joint (e.g., a knee) undergoing arthroplasty, for comparing the kinematics of the joint undergoing surgery with the kinematics of the normal joint, and for providing the surgeon with information allowing the balancing of the ligaments of the joint upon the installation of a prosthesis replacement joint. The apparatus includes optical targets mounted on joint replacement components fitted to the resected bones of the joint. One or more video cameras are used to obtain a series of images of the various optical targets as the extremity is flexed, extended, and rotated. A computer is responsive to the images of the targets to determine the kinematics of the joint as it is flexed, extended and rotated.

Abstract: An orthopedic component for total joint replacement that comprises a metal tray (3) and polymer liner (27), the metal tray having screw holes (7a, 7b) for fixation with screws (9) to bone and a circumferential rim or wall (15) with a smooth inner surface (21). The liner (27) is provided with a flexible sealing ridge (39) around its entire periphery, the sealing ridge being positioned so that it sealingly engages the tray rim so as to form a fluid-tight seal between the liner and the tray. The liner is provided with a locking mechanism comprised of tabs at the longitudinal ends of the liner which engage grooves in the front and rear of the tray.

Abstract: An orthopedic component for total joint replacement that comprises a metal tray (3) and polymer liner (27), the metal tray having screw holes (7a, 7b) for fixation with screws (9) to bone and a circumferential rim or wall (15) with a smooth inner surface (21). The liner (27) is provided with a flexible sealing ridge (39) around its entire periphery, the sealing ridge being positioned so that it sealingly engages the tray rim so as to form a fluid-tight seal between the liner and the tray. The liner is provided with a locking mechanism comprised of tabs at the longitudinal ends of the liner which engage grooves in the front and rear of the tray.

Abstract: A surgical cable system is provided which includes a surgical cable and a passer for passing the cable around a bone to which the cable is to be secured. The cable includes a main cable having a lead cable attached to one end of the main cable and a fastener preattached to the first end of the main cable. The lead cable has an enlargement (a bead) affixed to its free end. The passer includes a curved probe and a recess or cavity is provided in the probe near its tip and a slot extends from the cavity to the tip of the probe. The cavity is sized to accept the enlargement of the lead cable and the slot is sized to receive the lead cable so that as the probe is withdrawn (pulled) from under the bone, the lead cable and the main cable are pulled under the bone so as to minimize the space required to pass the cable. The lead cable and a portion of the main cable may then be inserted in the fastener.

Abstract: An acetabular component for a hip replacement system comprises an acetabular shell, and a liner having a seal for insertion into the acetabular shell. In the preferred embodiment, the shell has a smooth tapered surface in its peripheral inner surface, and the liner has several annular ridges protruding from its outer surface. Upon insertion of the liner into the shell, the annular ridges of the liner come into sealing engagement with the smooth tapered surface of the shell. This sealing engagement substantially prevents a migration of debris along an interface of the liner with the shell. The liner is provided with several peripheral tabs for interference fit with several peripheral notches in the shell. An interlock comprising another liner ridge and a shell groove, provide a positive engagement to hold the liner in the shell as it bottoms therein.