Abstract: A dual-radius glenoid component of a shoulder joint prosthesis for use in total shoulder arthroplasty has two radii of curvature. At substantially the center of the articulating surface a first non-conforming radius of curvature is provided, while a second conforming radius of curvature, smaller than that of the first radius of curvature and more closely conforming to the curvature of the humeral component, is disposed about the periphery of the articulating surface. The central non-conforming radius of curvature provides reduced constraint of the humeral component. In contrast, the conforming peripheral radius of curvature provides maximum constraint of the humeral component. When the humeral component is substantially centered on the articulating surface reduced constraint is placed on the prosthesis and less load is transferred to the bone-implant interface. As the humeral component translates towards the periphery, constraint on the prosthesis increases to prevent dislocation.

Abstract: An instrument is provided for use in shaping a femur preparatory to implantation of a knee prosthesis. A gap checking device is fixed to the distal end of the patient's femur and referenced to the epicondyles of the femur. The gap checking device includes slots through which a cutting instrument can be passed to shape the femur so that it can receive the femoral component of the prosthesis. One of the slots enables the distal femoral cut to be made. The thickness of the gap checking device is selected so that the distance between the distal femoral cut and the distal surface of the gap checking device plus the thickness of a shim resting on the cut proximal tibia surface is equal to the combined thickness of the tibial and femoral components of the prosthesis. This enables balancing of the ligaments to be checked before the femoral cuts are made, but while the gap checking device is secured to the femur.

Abstract: A pelvic positioning device for stabilizing a patient while lying on their side in a lateral decubitus position. The device includes an anterior pelvic support mechanism including anterior support pads for contacting both pubic tubercles and the ASIS on one or both sides of the patient's body. In a preferred embodiment, the anterior pelvic support mechanism includes two ASIS pads. To provide additional stabilization an upper torso pad may be included proximate the sternum of the patient's rib cage. In addition, the device includes a posterior pelvic support mechanism including a telescopic vertical member and a crescent shaped posterior support pad. The posterior support pad is mounted by a collar to a free end of the telescopic vertical member so as to be freely rotatable in a horizontal plane parallel with the operating table.

Abstract: A patella resection and replacement device comprising a pliers-like clamp for gripping and holding the patella, the clamp having a spring biased hinge bolt. A specially designed drill guide may be snapped into place and removed from the hinge bolt without releasing the patella during surgery. Similarly, a specially designed patella button presser may be snapped into place and removed from the hinge bolt. Without the necessity of releasing, re-gripping and re-orienting the patella during the process, the time for the operation is greatly reduced.