After exposure of the hip, detach the vastus lateralis subperiosteally from the lateral aspect of the femur distal to the vastus tubercle.

With a power saw or osteotome ( Figure 4-2 , A ), begin the osteotomy just distal to the vastus tubercle and direct it proximally ( B ). If a Gigli saw is used, before making the osteotomy use a finger to ensure that the saw is sufficiently anterior and that the sciatic nerve is not trapped between the saw and the bone ( C ).

Once the trochanter has been cut, retract it proximally and release the short external rotators from the trochanteric fragment. Alternatively, if a posterior approach to the hip is used, detach the external rotators before the osteotomy is performed.

Make the skin incision parallel to the posterior border of the greater trochanter.

Incise the fascia in-line with the skin incision.

Isolate the gluteus medius and minimus muscles anteriorly and posteriorly.

Elevate the vastus lateralis subperiosteally from the femoral shaft and retract it anteriorly. Preserve its origin at the vastus tubercle.

Begin the osteotomy just medial to the tendinous insertions of the gluteus medius and minimus into the greater trochanter. The osteotomy exits distal to the vastus ridge so that the origin of the lateralis is preserved in continuity with the bony wafer ( Figure 4-3 ).

Divide the external rotators close to their insertion, preserving them for reattachment. Alternatively, if a posterior approach to the hip is used, detach the external rotators before the osteotomy is performed.

Retract the osteotomized trochanter with its muscular sleeve anteriorly and hold it with a self-retaining retractor.