An Implanted Prosthesis Can Restore Walking

rthopaedic surgeon Steven Lietman, M.D., points to an X-ray of a 61-year-old man whose renal cell cancer has spread into the deep socket in his pelvis that holds the head of his thigh bone. The tumor has eroded the socket so badly that the simple act of moving has become unbearable for this man.

Typically patients like these, Lietman explains, have been treated with total hip replacement or removing the femoral ball to prevent it from grinding against the deteriorating pelvic bone. The surgery allows patients to walk, but not well, and they face a strong likelihood of complications. What’s more, in total hip replacement, the plastic cone that holds the ball of the femur wears out over time, requiring another surgery.

Now, Lietman is improving these results by using a technique that’s little known in this country—implanting an apparatus called the partial pelvis replacement prosthesis. For many patients with pelvic tumors and with failed total hip replacements the approach is providing a new lease on life. The prosthesis includes a stainless steel cap fixed to the pelvis with screws and bone cement, and durable steel prongs that help anchor the cap and allow surgeons to bypass the diseased pelvic bone.

Lietman learned about the prosthesis at a medical conference in Australia and became adept at implanting it. The procedure, however, is complicated, requiring the surgeon to delicately dissect around major arteries and extremely vascular tumors to avoid bleeding, so only a few top centers offer it. For patients the results have been dramatic. People who came in on crutches or in a wheelchair walked with little or no pain six to 12 weeks after surgery. “And many of them,” Lietman notes, “had been told, ‘Forget it, you’ll never walk again.’”

—- GL