Hip resurfacing: Fewer risks, more benefits.
ARTHRITIS of the hip joint is a common problem in India. It occurs due to damage to the joint from various conditions such as Osteoarthritis (wear and tear arthritis), avascular necrosis (death of the bone due to lack of blood supply), trauma or injury (previous hip fractures), infection, rheumatoid arthritis, ankylosing spondylitis and other diseases. It causes severe pain, stiffness, deformity, decreased mobility and severe disability. In India, hip joint arthritis affects even young people leading to disruption of family and social life, inability to work and difficulty in movement.
Traditionally, Total Hip Replacement (THR) has been the only treatment for people suffering with hip arthritis for the past 40 years. The surgery is conducted when the symptoms or the arthritis cannot be controlled with medication.
THR is a good procedure in elderly or sedentary people, but it cannot restore the mobility desired by younger and middle aged patients. Also, it can sometimes dislocate or slip out of joint, loosen faster in younger people (and vital bone is lost as the prosthesis loosens) and patients often face restrictions in terms of their lifestyle and mobility. However, all this is possible now, courtesy the revolutionary surgery for hip arthritis known as Hip Resurfacing.
Over the last decade, the need for a better option to THR was felt more than ever before due to increase in hip arthritis incidents among young people. Subsequent medical and technological advancements led to the development of Hip Resurfacing surgery. Dr. Derek Mc Minn of Birmingham, the U.K., pioneered this procedure.
In this procedure only the diseased portion of the hip socket is cleaned and shaved instead of being removed completely. Further, two metal pieces (made of cobalt chrome) are fixed — one over the ball of the femur, and the other into the pelvic socket called acetabulum. In short, the articular surfaces of the femur and acetabulum (socket) are replaced and the femoral head is reshaped instead of removed.
At first, an incision is made to reveal the layer of muscles. This is lifted, detached from the bone and held in place to enable easy access to the femur and pelvic region. With the knee flexed at 90 degrees, the femoral head is dislocated. Once easily visible, the measurements of the femoral head and neck are taken before the actual surgery begins. The femoral head is reshaped with specialised instruments that remove only the damaged bone. The prosthetic head rests on the femoral ball. To ensure that all stays in place, the prosthetic is glued to the bone.
The surgery then moves onto the acetabular (hip socket) base. Here a hemispherical cavity removing only damaged socket bone is formed so that it allows the prosthesis to rotate freely and yet maintains a snug and stable fit. The metal cup or acetabular component is then lowered into the hollow to obtain a press-fit. The surgery is completed with the fitting together of the femoral head and the acetabular component. Unlike THR, this surgery preserves the body’s vital bone, which is essential for faster recovery. Patients can start walking within two days and can be discharged in five to six days after this one and a half-hour surgery. The marginal increase in cost is more than offset by the multiple benefits experienced by the patient.
Patients who undergo Hip Resurfacing recover faster than usual. They start walking the day after surgery without support and can go home within five days. Patients are able to walk as much as five miles a day, as early as six weeks after the operation. Unlike in THR, they can jog, swim, dance, run and even play high-impact sports, squat, sit cross-legged and even use the Indian toilet with minimum risk of dislocation. This is a procedure that is suited to Indian conditions.
Hip Resurfacing is a bone conserving and minimally invasive surgery. The natural feeling of the joint (Proprioception) is preserved. Since the femoral prosthesis size is anatomical, dislocation of the joint is rare. Unlike in THR, polyethelene is not used as a bearing material. So problems like loosening of prosthesis and early failure related to polyethelene particles are eliminated. Since early loosening is not seen in Hip resurfacing, it is expected to last much longer than THR. If another surgery is required it is much easier to perform because the bone mass has been preserved.
The ball used during surgery is similar to the natural one, which confers biomechanical advantages to the hip.
Hardly any chance of dislocation.
Improved durability, since the prosthesis does not wear out easily.
Allows improved functions and quick recovery.
Patient can sit, squat and even can participate in sports.
Allows normal range of hip movements.
Does not change length of the leg.Duplicates or restores normal structure of hip joint. The writer is a Consultant Orthopaedic and Joint Replacement Surgeon, Sri Ramakrishna Hospital, Coimbatore.
Surgeon : Dr. G. Balasubramanian