Abstract: A flexible trephine includes a flexible section that is formed of a spring member. The trephine is tubular and includes a central passage so that the trephine can coaxially fit over a longitudinal implant while force is applied to the trephine. The trephine has an annular cutting head for removing bone that surrounds the implant, so that the implant can be removed. The trephine is urged in the longitudinal direction of the implant while fitted coaxially on the implant so that the implant can be separated from the bone. The flexible section of the trephine allows the trephine to conform to and follow a bowed implant. The cutting head can include multiple teeth or a single osteotome.

Abstract: A device for indicating the location of the anteroposterior femoral axis has a spike or needle that engages the anterior-most point in the intercondylar notch and a rounded or spherical surface is placed on the trochlear groove of the femur and urged in a posterior direction. That is, the rounded surface or ball is urged toward the bottom of the trochlear groove. This causes the rounded surface or ball to self-locate into the deepest point of the trochlear groove. The anterior-most point in the intercondylar notch and the deepest part of the trochlear groove anteriorly are points that accurately determine the anteroposterior femoral axis, and the device includes a marking device or guide member that is fixed perpendicular to this axis. A surgeon, therefore, has an accurate indication of the correct femoral component rotation for proper implant position in a knee replacement or other surgical procedure.