Surgical Approaches in Complex Hip Reconstruction

Stem cells are osteoprogenitor or osteopotent cells that can convert into osteoblasts, osteoclasts, or chondroblasts. For hip cartilage damage, we clean the damaged islands of cartilage with hip arthroscopy and inject stem cells; over time, review MRIs show the cartilage growing back, like grass growing, with less damage and fewer symptoms after about 6 months — though it does take time. In orthopaedics we harvest stem cells from the iliac crest, using a Jamshidi needle, taking around 120 ml of blood from the marrow (posterior or anterior, near the spine). This is then put into a centrifuge machine for about 45 minutes to 1 hour to concentrate the stem cells before injection.

Earlier, international companies like Johnson, Stryker and Zimmer supplied all the revision and complex hip replacement implants, but they have since withdrawn much of their hardware because of government policies and duties. Luckily we now have two or three Indian companies that have come up very well and collaborated to produce cost-effective implants. Earlier a hip replacement used to cost around $10,000–$12,000; now that has come down to between $7,000 and $8,000. Where there are problems, I also try to reduce my own surgical fees to help the patient.

It depends on the pathology and on the activity — for example, Andy Murray, the tennis player, had a hip replacement and could carry on with most of his activities, though one cannot guarantee 100%. If someone has had a total hip replacement, high-impact sports of that kind are generally not advisable — but they can change to a different sport. If the condition is femoroacetabular impingement (FAI) rather than arthritis, we do hip arthroscopy to remove the impingement, clean the cartilage, and inject stem cell therapy; the hip regenerates over about 6 months and results on repeat MRI are often excellent. Most sport-related damage is to ligaments or cartilage, not true hip arthritis — hip arthritis itself means the cartilage is gone and the anatomy is deformed, which is a different issue, and after that kind of hip replacement patients feel great satisfaction just resuming daily activities.

We look at the X-ray to see whether the hip joint space is maintained. If pain has started but mobility is still there and the joint space and cartilage are maintained, we don't straight away advise hip replacement — we have other options, such as the arthroscopic method, where we clean up osteochondral extra bone formation or damaged cartilage and repair it with stem cell therapy. That is a good option instead of hip replacement. Once the cartilage is completely damaged on CT or MRI, with no blood flow to the femoral head, then the only answer is hip replacement.

For sickle cell disease in children, bone marrow transplant is the standard treatment, with the best results when done early while the patient is still a child — my colleague Dr. Dharma Choudhary's centre specialises in this. As for hip arthroplasty itself, it is not recommended below 17–18 years of age because the hip does not develop enough. Below that age we instead use arthroscopy to clean up damage, or osteotomies — we change the weight-bearing surface of the hip with procedures like valgus or varus osteotomy — based on where the MRI shows the main damage, which relieves pain much better.

The posterior approach to the hip, using the Kocher-Langenbeck or Southern technique, is generally preferred for complex hip arthroplasty that requires acetabular reconstruction, because it gives wide visibility of the acetabulum and allows the sciatic nerve to be identified early.

Straightforward primary hip replacement can be performed through an anterior approach, such as the Smith-Petersen approach, or an anterolateral approach such as the Hardinge approach, both of which work well for standard cases that do not require acetabular reconstruction.

The interval between the two heads of the gluteus muscle is identified, using the piriformis tendon as a guide. The tendon is released from its origin, followed by the rest of the short external rotators, and this sequence allows the sciatic nerve to be defined early and protected throughout the procedure.

The sciatic nerve runs close to the greater and lesser sciatic notches and must never be caught by retractors or instruments placed in this area, the superior gluteal vessels supplying the abductor muscles must be preserved, and the obturator canal, where the obturator nerve, artery and vein run, must be avoided entirely.