The hip joint is located where the thigh bone (femur) meets the pelvic bone. It is a "ball and socket joint". The upper end of the femur is formed into a round ball (the "head" of the femur).
A cavity in the pelvic bone forms the socket (acetabulum). The head of the femur is covered with a layer of smooth cartilage which is a fairly soft, white substance about 1/8 inch thick. The socket is also lined with cartilage(also about 1/8 inch thick).
An x-ray of the hip joint usually shows a "space" between the ball and socket because the cartilage does not show up on x-rays.
Keeping Fit with an Arthritic Hip
A recent study suggests that people with hip arthritis may fare better if they force themselves to remain as active as possible, even if the exercise cause some pain. Take pain medicine as necessary before exercising.
There is no evidence that being active will cause a more rapid deterioration of your arthrtic hip. Being active is important for your general health and mental well being.
Remain as active as your pain allow you to be until you decide to proceed with surgery.
Walking a treadmill or jogging will usually aggravate hip pain. The best all around exercise for you is swimming. Bicycling(stationary or mobile) is also well tolerated.
Diseases of Hip Joint
Any number of conditions which can cause arthritis of the hip. The term "Arthritis" literally means inflammation of a joint. Osteoarthritis mainly damages the joint cartilage, but there is often some inflammation as well. The cause of hip osteoarthritis is not known.It is thought to be simply a process of "wear and tear" in most cases. Rheumatoid Arthritis (R.A.) starts in the synovium and is mainly "inflammatory". It eventually destroys the joint cartilage. Bone next to the cartilage is also damaged, making it very soft.
Symptoms of Hip Diseases
The most prominent symptom of hip arthritis is pain. Hip pain is most commonly experienced in the groin The pain can radiate down the front of the thigh for a few inches as well. Occasionally it goes all the way down the thigh to the knee ("referred pain").
Most patients with significant hip disease have a limp and one leg may feel shorter than the other. Bone-on-bone contact occasionally causes the patient to feel or hear the heap creaking during walking.
As the disease progresses, the hip becomes stiff and less movement is posibble. This may make it difficult for you to clip your toe nails or to tie your shoe laces.
Total Hip Replacement Surgery
The modern total hip replacement was invented in 1962 by Sir John Charnley, an orthopedic surgeon working in a small country hospital in England. The arthritic femoral head is removed. It is replaced with a metal ball which is attached to a metal stem.
The stem is cemented in to the hollow marrow space of the femur. The worn out hip socket is lined with a plastic socket, which is also cemented in place. The painful parts of the arthritic hip are thereby completely replaced with metal and plastic surfaces.
The plastic socket has a very low frictional resistance, and a very low wear rate against the metal ball. The operation has become fairly routine and is successful around 98% of the
time.
Young patients (under 60) are usually advised to have cementless replacements in the belief that they will ultimately outlast cemented ones.
Other Surgical Treatment Alternatives
Hip Fusion (Arthrodesis) Arthrodesis fuses the femur to the pelvis. It is usually only offered to very young people whose work involves heavy manual labor.
An osteotomy of the thigh bone is another possible alternative. In this procedure the femur is cut and realigned to change the direction of forces across the arthritic hip.
Femoral Hemiarthroplasty ("half a hip replacement") The socket is not replaced. The femur component is similar to that of a total hip replacement, But its ball is large and fills the normal socket, bearing directly against the cartilage. However, the cartilage all too frequently wears out (causing pain) and a second operation is then needed to install a socket component.
Pseudoarthrosis (Girdlestone) involves the removal of the femoral head and leaving the hip without any replacement. It leaves the patient with a short leg and an unstable hip and the need to use two crutches permanently.
Core Biopsy for avascular necrosis (AVN) involves using a coring device to remove a core of bone about one quarter inch in diameter from the femoral head. It is used mainly in the earliest stage of osteonecrosis.
When should you consider Hip Replacement Surgery ?
Hip arthritis is not a life-threatening condition : the procedure is "elective". The decision to have the operation is a highly personal matter, and only you can make that decision. If you are confined to a wheelchair and in constant pain, it is a decision that will be quite easy for you to make. If your arthritis is responding to conservative measures, and you can still walk long distances without a cane, you don't need a hip replacement.
Here are some facts to help you make your decision :
- Once you have hip arthritis it will never get better. It won't even stay the same. It will generally progress as time goes by.
- There are no exercise, diets, vitamins or minerals (including calcium) which will make any difference.
- The rate of further deterioration varies greatly from person to person.
- More than 96% of patients who have had a hip replacement operation have no major complications.
- If your pain and disability are not responding to conservative measures, why put it off for another year or two when you could have spent that time enjoying your life free of pain!
