Hip resurfacing surgery- who needs it?
Are you suffering from hip arthritis? Has your surgeon advised you a hip replacement?Hang on! If you need a hip replacement, please read the following information on facts about the operation and a more advanced bone preserving option called hip resurfacing.
What is the hip joint? Watch video on hip joint anatomy and hip replacement operation
The hip joint is a ball and socket joint which connects the torso to your legs. It is formed by the upper end of the thigh bone ( femur) and the socket of your pelvic bone ( acetabulum). A natural shock absorber tissue called “articular cartilage” lines the ends of the bones and allows painless smooth movements.
What are the symptoms of hip arthritis?
The patient complains of pain and restriction of movement. Pain may often be felt in the knee alone with no hip symptoms. Occasionally the pain may be felt more in the buttock area rather than in front of the groin. Gradually you will loose your ability to retain a active life style through exercise and sports.
Your doctor may advise x rays on which hip arthrosis is seen as a loss of joint space or narrowing of the gap. Loss of this lining shock absorber articular cartilage results in pain while you walk.
Initially your doctor may prescribe you pain killers and suggest you to perform exercises to retain flexibility of your joints.
When you have run out of non operative options like pain killers, physical therapy your orthopedic surgeon might advise you to seek a hip replacement.
The hip joint may need to be replaced with an artificial joint when it is irreversibly damaged and cannot be salvaged by alternate surgery. The patient complains of pain and restriction of movement.
Who needs a hip replacement?
In India, many young patients with rheumatoid arthritis, ankylosing spondylitis, avascular necrosis, post septic arthritis, post traumatic arthritis, are advised a hip replacement for disabling pain.
Thus many hip replacement operations are performed in younger patients. The surgery should cater to the enhanced demands on an artificial joint by younger and more active patients. Hip replacement is a successful operation for patients above 60 years
What is a total hip replacement?
In this operation the ball shaped upper end of the thigh bone (femur) and the socket (acetabulum) are replaced. The ball is replaced with a long metal stem that is fixed into the upper end if the thigh bone. Its upper spherical end articulates with a cup shaped polyethylene socket that is cemented into the pelvis.
Conventional hip replacements sacrifice a great deal of normal bone as the head, neck, and upper part of the thigh bone is removed for implantation of the prosthesis. Moreover wear debris from the polythetheylene liner lead to osteolysis and bone loss. When this first hip is to be changed or revised after its lifespan more bone loss occurs. Conventional hips have a small ball to reduce friction and wear, but the ill effect of this is an increased risk of dislocation. An average dislocation rate of 3- 4 % has been reported. These implants do not last very longer than 20 years and revision rates of 50% at 20 years have been reported. Survival rates are less satisfactory for the relatively younger active patients. Thus a total hip replacement is not an ideal implant for younger patients less than fifty years old who need a new hip. It is however the best option in elderly people.
Problems with conventional total hip replacement:
A total hip replacement is an excellent & time tested operation in the elderly. However in the young problems may arise. These are
(1) Excessive bone sacrifice and loss
(2) Increased risk of dislocation
(3) Patients cannot squat or sit cross legged on the floor with out the risk of dislocation.
(4) Range of movement is less
(5) Patients cannot involve in sports
(6) Poor survival in young and active patients they require earlier revision.
(7) Revision surgery is difficult
(8) The hip feels less like a normal hip
(9) The cup wears with time and plastic from it harms bone
(10) Change in length of the leg after surgery leading to leg length discrepancy.
Why remove normal bone when only the surface of the ball is bad?
Video shows comparison of Hip replacement and hip resurfacing
This is the logic behind hip resurfacing. This bone preserving hip resurfacing involves replacing only the diseased bony surfaces of the head of femur and acetabulum. This involves sculpting the head of the femur and covering it with a metal cap and fixing an uncemented socket into the acetabulum to receive the head.
What is Hip Resurfacing?
It is a bone preserving hip operation. In this operation only the worn out surface at the top of the femur bone is scraped and shaped into a cylindrical form from a spherical form. A metal spherical cap is glued or cemented over the cylindrical stump like a tooth crown over an old stump.
This restores the normal shape & size to the upper end of the thigh bone. Next the socket in the hip bone is scraped into a hemisphere. A metal cup is impacted after complete cartilage removal. This cup will integrate with the body’s bone on the back side as it has a layer of the same material as bone. The hip shape is thus restored to normal. Bone is preserved in the head of the thigh bone. If a hip resurfacing were to fail for some reason, it would be still possible to change this to a conventional hip replacement later on.
Preservation of bone and less stress shielding makes it easy to revise this hip if needed. The large head size provides a very stable joint and recreates the sensation of a normal hip joint. Patients have gone back to playing Judo and Squash after this operation. Advances metallurgy makes the metal on metal articulation likely to survive longer in the young and active patient. With less metal inside the bone and less invasion of the medullary cavity of the femur, the risk of infection is reduced. Rehabilitation is faster and better.
Advantages of hip resurfacing:
(1) Allows the patient to squat and sit cross legged on the floor safely
(2) Allows a normal range of movement.
(3) Sacrifices only the surface diseased bone and preserves normal bone
(4) Imparts a more normal sensation
(5) The joint is likely to last longer even in younger and active patients.
(6) Earlier and faster rehabilitation
(7) Less risk of dislocation
(8) Easier to revise if needed
So in conclusion although total hip replacements remain an excellent option in a specific elderly age group, Hip replacement alternatives like Hip surfacing should be strongly considered in young and middle aged patients ( less than 60 years) requiring a hip replacement in India.
Dr.A.K.Venkatachalam is a consultant Orthopaedic surgeon in Chennai.View Patient stories here-