2.2. Paley–Brown Rotationplasty

Step 1: For the Paley–Brown, split the apophysis. For the Paley type there is no need to split the apophysis.

Step 2: Elevate the periosteum off of the medial and lateral walls of the ilium down to the sciatic notch. Laterally elevate the periosteum off the anterior aspect of the notch to reach the ischium.

Step 3: Return to the adductor muscles and resect them from their origins. This requires dissection down to the pubic rami. The adductor muscles are completely resected in the Paley–Brown since they get in the way of medializing the femur. They also have no role since the new hip joint is a knee joint with no ability to abduct or adduct. Also resect the sartorius muscle taking care not to injure the femoral nerve. For the Paley type resect only some of the adductors but leave some.

Step 4: Enucleate the femoral head for the Paley–Brown.

Step 5: Expose the ramus of the ischium for both Paley and Paley–Brown. The biceps origin must be released from the ischium. Resect a generous portion of the ischial ramus using a saw. This allows the sciatic nerve to move medially into this space and avoid becoming entrapped by the femoral remnant when it is fused to the ilium or the femoral head. This step is essential in the Paley–Brown and is also preferred for the Paley type too. It is not necessary for the Brown type since the femur stays lateral.

Step 6: Insert a frontal plane guide wire parallel to the line going across the tops of the iliac crests. Make the Chiari osteotomy parallel to this line using a saw.

Step 7: Displace the acetabular segment medially to hook onto the inside of the ilium.

Step 8: Insert a guide wire into the femur perpendicular to the long axis of the tibia. Cut the femur along this wire. Depending on the length of the distal femur remnant, shorten the femur sufficiently to keep the knee joint as proximal as possible so that it is as close as possible to the anatomic hip joint level.

Step 9: With the femur rotated 180°, fix the distal femur with guide wires: one retrograde from the medial femoral condyle (lateral side) and one antegrade from inside the pelvis into the lateral femoral condyle (medial side). Make sure both of these cross the distal femoral growth plate to create an epiphysiodeses (this prevents the new hip joint from growing away from the pelvis). Add a third transverse wire to fix to the acetabulum proximal to the triradiate.

Step 10: Drill over each guide wire and insert three 5.5mm fully threaded screws.