Removal of old prosthesis
A determination should be made as to whether the cemented femoral component and cement can be removed through the proximally exposed portion of the femur or whether a more extensive approach (i.e., an extended trochanteric osteotomy) is warranted. In general, most first and second generation cemented stems without a roughened or pre-coated surface are easily removed with a variety of extraction devices. If the component is mono-block, a looped extraction device with a slap-hammer easily performs the extraction.
If the component is modular, the femoral head should be
disimpacted and a modular stem extractor, such as the
Biomet Bohn™ or possibly a vicegrip, should be used
on the Morse taper.
Removal of cement
Once the femoral component itself has been removed, the cement mantle should be removed from the top of the femur without sacrificing proximal bone stock. This can be accomplished with cement removal hand tools. The cement should be removed in piecemeal fashion from the proximal femur. Care should always be taken to preserve the distal diaphyseal portion of the femur. If perforations in the proximal femur begin to occur because of fixed cement, it may be appropriate to convert exposure to an extended trochanteric osteotomy and directly visualize the bone cement interface. A well-fixed cement plug may be removed by using ultrasonic cement removal instrumentation. Small windows for removing distal cement should be avoided with the use of a distally fixed stem.