Arthritis hip
If the surface cartilage is badly damaged or if the joint surfaces are not aligned properly
(example, in a shallow hip) then the cartilage will wear out much more quickly than the
normal wear and tear and as a result the bone under the cartilage layer is exposed. The
exposed bone starts to rub against each other and the process of osteoarthritis (wear
and tear) is established. Osteoarthritis is therefore the result of mechanical wear and tear on a joint. The main
feature is a loss of surface cartilage with bone rubbing on bone. This process produces
pain. The body tries to relieve this pain by increasing the amount of fluid in the joint.
This is why joints are sometimes swollen. The formation of bone spurs and cysts around
the joint is another hallmark of osteoarthritis. The classic sign of arthritis is joint pain. Inflammatory arthritis, like osteoarthritis, may affect the hip and cause pain characterized by a dull, aching pain in the groin, outer thigh, or buttocks. Pain is usually worse in the morning and lessens with activity; however, vigorous activity can result in increased pain and stiffness. The pain may limit your movements or make walking difficult. In an arthritic hip • The cartilage lining is thinner than normal or completely absent. The degree of
cartilage damage and inflammation varies with the type and stage of arthritis. The diagnosis of arthritis is made on history, physical examination and x-rays. Treatment of hip arthritis involves many different modalities including anti-inflammatory medicines, physical therapy, steroid injection, and surgery.
Anti-inflammatory medications often need to be adjusted and monitored to suit the individual patient. Depending on the type of arthritis, disease-modifying anti-rheumatic drugs may need to be instituted. Severe inflammatory types of arthritis such as rheumatoid disease often will require the initiation of biologic therapy. Consultation with a competent rheumatologist is imperative.
Viscosupplement (lubricant) injections are sometimes useful.
The most common surgical procedures performed for arthritis of the hip include: • Total hip replacement provides pain relief and improves motion. After reaming is complete, the artificial socket is inserted. There are two types of sockets,
(a) a cemented socket or (b) an uncemented socket. A cemented socket is cemented into
the bone and an uncemented socket allows bone to grow into it. The surgeon will advise
the patient which is the most appropriate socket. An uncemented socket has the ability to accept a socket lining which is either polyethylene (special plastic), ceramic or metal. The liner is inserted into the socket. Ceramic and metal articulating joint surfaces have lower wear rates than plastic sockets and therefore tend to be used in younger patients. The newer plastics last a lot longer than the older ones and are appropriately used in older patients. After preparation of the socket, the femoral bone is prepared with various instruments to
accept either a cemented or an uncemented femoral component. Once the canal is prepared the femoral stem is inserted with or without cement. A trial femoral head is placed on the stem and the hip is reduced. During the trial reduction the hip is tensioned appropriately and put through a range of motion. At the same time leg lengths and stability are examined. Following the trial reduction the appropriate head is then placed on the stem and the hip is reduced. Occasionally leg lengths may not be entirely equal in order to tension the hip appropriately and thereby prevent dislocation. Following insertion of the components the wound is closed usually with absorbable sutures and a drain is inserted.
New ceramic-on-ceramic joint replacements are expected to meet greater demands
of younger, more active patients and be in service longer than ever before. To meet these demands and reduce the potential for early failure due to osteolysis, alternate bearing surfaces have been developed to minimize the amount of wear in total hip replacements. Traditional hip replacement surgery typically involves a procedure leaving patients with a 12-18 inch scar and a hospital stay of up to 3-5 days. However, a patient may be a candidate for minimally invasive hip replacement surgery. This technique uses the same implants as traditional hip replacement surgery, but allows surgeons to avoid disturbing as much muscle and tendon tissue. This technique may also provide potential benefits to patients such as: • Smaller incisions.
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