Hip resurfacing is a surgical alternative designed to address severe hip arthritis and joint pain, often resulting from conditions like osteoarthritis. Unlike traditional total hip replacement, this procedure treats the damaged surfaces of the hip joint to alleviate discomfort and restore function when non-surgical treatments are no longer effective. It is a distinct orthopedic option for those seeking to regain an active lifestyle.
Defining Hip Resurfacing
Hip resurfacing is a bone-conserving procedure that involves capping the damaged femoral head instead of removing it entirely. The surgeon first shaves down the top of the femur’s ball-shaped head to reshape it, preparing it to receive a custom-fitted implant. This prepared bone is then covered with a smooth, hollow metal cap, which is often made from a cobalt-chrome alloy.
The procedure also involves preparing the hip socket, or acetabulum, by removing damaged cartilage and implanting a matching metal shell. This metal-on-metal articulation creates the new bearing surface of the hip joint. The primary goal is to preserve the maximum amount of the patient’s natural bone structure, which helps replicate the hip’s natural biomechanics and function post-operatively.
Key Distinctions from Total Hip Replacement
The most significant difference between hip resurfacing (HR) and total hip replacement (THR) lies in the amount of bone removed from the femur. In THR, the entire femoral head and a portion of the neck are cut away, and a long, stemmed component is inserted deep into the thigh bone’s marrow cavity. Conversely, HR only involves trimming the head of the femur to fit the cap, leaving the femoral neck and the rest of the upper thigh bone intact.
Component size represents another major distinction, as hip resurfacing utilizes a much larger ball size, closely matching the diameter of the patient’s natural femoral head. This larger ball size can provide greater inherent stability to the joint, which may translate to a reduced risk of dislocation compared to the smaller ball typically used in a standard total hip replacement. Furthermore, the preserved bone stock simplifies conversion to a standard total hip replacement if the resurfacing implant eventually wears out or fails.
Patient Selection Criteria
Hip resurfacing is generally reserved for active patients due to the biomechanical demands placed on the implant and the preserved bone. Ideal candidates are typically younger than 65, maintain a physically active lifestyle, and expect a high level of function following the surgery. A fundamental requirement is good overall bone density, as the remaining femoral neck and head must be strong enough to support the metal cap and withstand activity.
Patients with severe osteoporosis, large cysts, or significant deformity of the femoral head are usually excluded because the procedure relies on the structural integrity of the existing bone. Historically, males have shown a lower rate of revision surgery and are often considered the best candidates, partly due to having larger natural femoral head sizes and generally higher bone density compared to females. Women, particularly those who are post-menopausal, are evaluated more cautiously because of a greater risk of a femoral neck fracture in the early post-operative period.
The Surgical Process and Post-Operative Expectations
The hip resurfacing procedure typically lasts between one and a half to three hours and is performed under either general or regional anesthesia. The surgeon makes an incision to access the hip joint, dislocates the femoral head, and then uses specialized instruments to carefully trim and reshape the head. Once the head is prepared, the metal cap is securely cemented or pressed onto the bone, and the acetabulum is reamed to accept the metal socket component.
Following the procedure, immediate post-operative care focuses on managing pain and encouraging early mobilization, often beginning on the first day after surgery. Patients are monitored in a recovery room and typically spend one to four days in the hospital before discharge. Pain management involves a combination of medications, and patients begin walking with the aid of crutches or a walker, with weight-bearing usually permitted immediately or soon after the operation.
Long-term rehabilitation begins with physical therapy soon after the surgery. The initial focus is on gentle exercises to restore range of motion and prevent blood clots, gradually progressing to strengthening exercises. Most patients can transition from using two crutches to one or a cane within three weeks and may be able to resume driving (if the surgery was on the left hip). Full recovery and a return to daily activities often take about six weeks, but a complete return to high-impact sports usually requires three to six months and must be cleared by the orthopedic surgeon.