Abstract: A surgical instrument for use in a computer assisted navigation system is provided. The instrument includes at least one reference element registerable in the navigational system disposed on a mounting assembly. The mounting assembly is rotatably mounted on the instrument and includes a counterweight or other anti-rotation feature whereby the reference element may be maintained in a desired orientation. A rotatable shaft may extend through the mounting assembly and have one end which is securable to a rotary driver such as a drill and a second end securable to a rotary tool such as a reamer. The second end of the shaft may utilize a collet assembly to firmly grasp the driven tool and thereby limit relative movement of the tool and the reference elements disposed on the mounting assembly.

Abstract: A system for registering an orthopedic implant in a computer assisted navigation system. The system includes a plurality of differently sized implants which may be the femoral component or hip stem of a prosthetic hip joint. A registration device is engageable with each of the implants in a predefined relative position. The registration device also includes at least one reference element registerable in the computer assisted navigation system. A second reference structure also having at least one reference element registerable in the computer assisted navigation system is detachably secured to the implant. The relative positions of the reference elements located on the registration device and second reference structure differs for each of the plurality of implants and thereby allows the navigation system to determine the nominal size of the implant. The relative position and orientation of the implant relative to the second structure can also be calibrated using the registration device.

Abstract: A connector plug gap sealer that fits smoothly within an internal cavity of a connector plug includes a first section, a second section, and a third section, the second section includes a flat section and a guiding section, the third section extending from the guiding section around the horizontal axis of symmetry. The first, second and the third sections configured into a single unitary piece to define the plug gap sealer having a flat bottom surface around the horizontal axis of symmetry of the plug gap sealer. The method associated with installing the connector plug gap sealer is also disclosed.