The procedure is performed under general anesthesia on a radiolucent table with the patient supine. For the surgical procedure, we use the PerFuse and BioCUE Systems (Fig. 6.3) from Biomet (Biomet Biologics, Warsaw, Indiana). Biplanar fluoroscopy is then used to confirm we are able to obtain appropriate anterior-posterior (AP) and frog-leg lateral images preoperatively. The operative hips and both iliac crests are prepped and draped in the standard fashion.

The procedure is started by obtaining 120 cc of anticoagulated blood. This is typically drawn by anesthesia during the prepping and draping of the patient. The blood is placed into two 60 cc vials and centrifuged for 15 min in the BioCUE System (Biomet Biologics, Warsaw, Indiana). This concentration creates 12 cc of platelet-rich plasma (PRP). The bone marrow is then aspirated from both iliac crests. Over the anterior aspect of the iliac crest, a 2–3-mm incision is made, exposing the iliac crest. The PerFuse trochar (Biomet Biologics) is inserted into each iliac crest between the two tables of the ilium, and the bone marrow is aspirated into 10-mL syringes (Fig. 6.4). This marrow is then concentrated using the BioCUE System (Biomet Biologics). A vial for this system contains 57 cc of bone marrow and 3 cc of heparin. This is concentrated 10×, yielding 6 cc of bone marrow concentrate (BMC). From each crest, we typically obtain 120 cc of bone marrow, yielding 12 cc of BMC. The goal is to obtain 12 cc of BMC for injection into each hip.

During the 15 min that it takes the bone marrow and blood to be centrifuged, we perform the hip decompression. After confirming with fluoroscopy our starting point at the level of the lesser trochanter and distal to the vastus ridge, we make a 1-cm incision over the lateral aspect of the femur just above the tip of the lesser trochanter. The lateral cortex of the femur is then breached by tapping the tip of the decompression trochar into the bone or alternatively with a 3.2-mm drill; the decompression is performed by hand. The 6-mm trochar is advanced from lateral to medial, taking care to check on biplanar fluoroscopy the position of the trochar (Fig. 6.5). The trochar is advanced with gentle mallet taps until the tip is “in” the necrotic lesion which is typically accompanied by a change in pitch of the mallet strikes. The position is confirmed with biplanar fluoroscopy. It is important that the trochar is not advanced within 5 mm of subchondral bone to avoid collapse. If one cannot visualize the lesion radiographically, the preoperative MRI should be used as a guide as to where the trochar should sit for the decompression.

Once the trochar has been confirmed to be in the proper position, the inner sleeve of the trochar is removed, leaving a 6-mm trochar in the area of ON. The hip is then flexed, and the 12 cc of BMC and PRP are then mixed in a 30-cc syringe and injected into the trochar (Fig. 6.5). If there is excessive resistance, the trochar should be retracted to increase the space for the injection while confirming that the tip is in the area of ON. To prevent retrograde, backflow the trochar is removed and reinserted at a different angle to push cancellous bone into the tract. Alternatively, the surgeon can choose to retract the trochar until it is out of the lesion and inject demineralized bone matrix (DBX) to plug the tract. In that case, using the plunger that comes with the system is very helpful in order to push the DBX into a superior and medial position (Fig. 6.6).