The Approach

Following a natural plane between muscles and without detachment of muscle or tendons from the bone, the hip is exposed. The femoral neck is cut and the arthritic femoral head and neck are then removed. Next, the arthritic acetabulum undergoes a procedure called reaming. Reamers of gradually increasing diameter accurately shape the bone of the acetabulum to accept the acetabular prosthesis. An acetabular prostheis slightly larger in diameter than the prepared acetabular cavity is inserted with a press fit that produces initial stability. During insertion, x-ray is used to position the prosthesis accurately. One or more screws may also be used to enhance stability. Following insertion of the acetabular shell , the bearing surface is then inserted. Preparing the femur requires that the table rotate the leg externally, extend the hip, and drop the foot toward the floor to allow for access through this small approach. A special broach is inserted into the femoral canal. Progressively larger broaches are inserted with the size being limited by the outer cortical bone.

Following insertion of the final broach, the driving handle is then removed. The broach is temporarily left in as a “trial” femoral prosthesis and its upper end is capped with a trial femoral head. The table repositions the leg to its normal position and the trial head is “reduced” into the acetabulum. X-ray is now used for sizing. Side by side television monitors compare the x-ray image of the patient’s opposite hip to the operated hip. This comparison gives immediate information regarding equality of length and femoral offset (horizontal distance of the femur from the pelvis). The leg and hip are moved by the table to check for stability. If the initial trial shows undesirable length, offset, or stability, adjustments are made.

The femoral prosthesis can be secured with cement, or by press-fit with subsequent bone on-growth. Whether cement is used or not, a femoral prosthesis of specific size is accurately inserted to reproduce the fit, length, and offset indicated by trial.

The final result is achieved by reducing the hip resulting in the femoral head being placed into the acetabulum. The wound is then washed with antibiotic solution and closed.