If you are a candidate for a total hip replacement (THR), then you likely have severe osteoarthritis, rheumatoid arthritis, or avascular necrosis. The primary goal of THR is to predictably relieve pain, and to restore hip function, thus allowing you to go about your activities of daily living.
In osteoarthritis, the cartilage covering the head of the femur (thigh bone) is worn away, and bone rubbing on bone causes the severe pain. In THR surgery, the head of the femur and opposing worn cartilage are removed, and replaced with a smooth metal head gliding against a plastic liner and metal backing shell. A traditional THR technique requires an 8 to 10 inch long incision on the side of the hip, to remove the diseased joint and insert implant components.
Members of the MGH Department of Orthopaedic Surgery are pioneers in minimally invasive surgery (MIS) approaches for replacing hip or knee joints. In MIS procedures, surgery is performed through one incision 3 to 5 inches in length, or two smaller incisions; and similar implants are used. Surgeons reduce injury to soft tissues around the hip joint and patients may have less pain after surgery, and a faster recovery to full function. After MIS, many patients can leave the hospital within a day or two.
But MIS is not an easy or simple procedure. Surgeons have to be trained, and specially designed instruments and operating tables are required. Use of x-rays during surgery is sometimes necessary to confirm correct positioning of implants; and advances in computer guidance are being made to position components easily and reproducibly. Established pre-surgery and post-surgery protocols need to be followed. And the surgery itself can take longer than the standard approach, increasing the time the patient is under anesthesia.
Dr. Andrew Freiberg, Chief of the Arthroplasty Service at the Massachusetts General Hospital, Boston, MA, and an MIS pioneer, explains that MIS is not just about a small incision, rather “it represents a comprehensive approach that includes pre-operative education, a careful surgical procedure with minimal trauma, and a coordinated program of pain management and accelerated rehabilitation.” These all combine to allow early mobilization and function, so patients can go home sooner, and participate in family responsibilities. “Patients can benefit from MIS hip procedures, and in the hands of experienced, well trained surgeons, they get a predictable, excellent surgical outcome,” reminds Dr. Freiberg.
Dr. Harry Rubash, Chief of Orthopaedic Surgery at Massachusetts General Hospital, and Professor at Harvard Medical School is cautiously optimistic. “When considering MIS hip replacements, patients should also be aware of potential risks. Other institutions have published reports of increased MIS-associated complications including femur fracture, nerve injury and mis-placement of components, possibly requiring additional surgery and affecting the longevity of the hip reconstruction. A joint replacement needs to last nearly 20 years and no long-term data is currently available with MIS. Thorough comparative studies of the longevity and risks of newer approaches are required,” adds Dr. Rubash.
In selecting a THR procedure, patients should first select a surgeon with whom they have a good rapport and trust to provide them with the best result technically possible. Not all surgeons perform minimally invasive procedures. Many surgeons using the traditional, longer incision surgical exposure have adopted features of MIS techniques, and minimize trauma to surrounding muscles and soft tissues around the hip joint. Surgical incisions have also become smaller. Thus which surgical technique should you go for?
In selecting a THR procedure which can typically last you the rest of your life, “patients should not trade the cosmetics of a smaller scar in the MIS, for a reliable long-term outcome of traditional THR,” reminds Dr Rubash, who is also the Director of the Harvard Arthroplasty Course.
Your surgeon will choose the surgical technique depending on the severity of your arthritis or other disease, bone type and body size. The ultimate goal for you and the surgeon is a successful joint replacement procedure that will permit you to enjoy a wonderful quality of life without pain, for the very long term.