Hip osteoarthritis (OA) is a common form of osteoarthritis. It affects the hip joint very much the same way it affects the knee. The hip joint is the joint that connects the pelvic bone, or pelvis to the thigh bone (femur).
The most common symptom is pain while putting weight on the affected hip, such as during walking or even sitting for prolonged periods of time. The pain is typically felt in the groin area or buttocks, or sometimes over the front of the thigh.
You may limp, which is the body's way of reducing the amount of force that the hip has to withstand. Your hip may also feel stiff, and this will cause difficulty with certain activities such as getting into or out of a low chair or a car, or using the toilet.
You may also experience difficulties with crossing over low obstacles on the ground. Finally, as the condition becomes worse, pain may be present all the time and may even keep you awake at night.
OA of the hip can be caused by a hip injury earlier in life. Changes in the alignment of the hip, e.g. after a fracture inside the hip joint or of the surrounding bones, can lead to uneven weight distribution through the hip joint.
This eventually leads to accelerated ‘wear and tear’ of the joint. Some people are born with an abnormality in the shape of the hip joint. This is known as developmental dysplasia of the hip (DDH). Severe cases of DDH are usually detected from birth or early in life, but milder forms of DDH may only begin to cause discomfort in adult life.
Avascular necrosis (AVN) is another cause of degeneration of the hip joint. In this condition, the femoral head (the ball portion of the femur, or thigh bone) loses a substantial portion of its blood supply and begins to die. The dying femoral head is unable to withstand the large forces that are transmitted through the hip joint during even normal activities like walking and climbing stairs, and becomes increasingly deformed. AVN has been linked to alcoholism, fractures and dislocations of the hip, and long-term steroid treatment for other diseases. In some cases, no cause can be identified. Early cases of AVN can usually be diagnosed using an MRI of the hip joint.
In many cases of hip OA, however, no definite cause can be identified. In such instances, the degeneration of the hip joint is probably related to the effects of ageing and ‘wear-and-tear’.
The diagnosis of hip OA starts with a complete history and physical examination by your doctor. X-rays will be required to determine the extent of the joint damage and can also help the doctor find a possible cause for it.
Other tests may be required if there is reason to believe that other conditions are contributing to the degenerative process. Magnetic resonance imaging (MRI) may be necessary to determine whether your hip condition is from problems with AVN. Blood tests may be required to rule out other forms of arthritis or infection in the hip.
Hip OA cannot be cured, but therapies are available to relieve discomfort and to control the degeneration of the joint.
Your doctor may prescribe medicine to help control your pain. Physical therapy plays a critical role in the nonsurgical management of hip OA. A primary goal is to help you learn how to control symptoms and maximise the function of your hip. You will learn ways to calm pain and symptoms, which might include the use of rest, massage and heat therapy. A walking stick or walking frame may be needed to reduce pressure on the hip when walking. Range of motion and stretching exercises will be used to improve hip motion. You will be shown strengthening exercises for the hip to steady the joint and protect it from further injury. Your therapist can suggest tips for getting your tasks done with less strain on the joint.
In severe cases and when nonsurgical treatment is ineffective, surgical treatment of OA may be appropriate.
Arthroscopy (‘Keyhole Surgery’)
Surgeons can use an arthroscope to look inside the hip joint to check its condition. An arthroscope is a miniature television camera inserted into the joint though a small incision. During the procedure, your surgeon may use several techniques to give you relief from pain. One method involves cleaning the joint by removing loose fragments of cartilage, and another method involves simply removing bits of tissue that may be irritating the hip joint. See Arthroscopy.
This procedure is sometimes helpful for temporary relief of symptoms, and is useful in some instances of early hip OA.
Artificial Hip Replacement
An artificial hip replacement is the ultimate solution for advanced hip OA. This is the definitive treatment for severe hip OA, and is both safe and very effective. With advances in the design of artificial hips and also improvements in surgical technique, hip replacement can now be performed in both young and old patients, and can often be reasonably expected to last the lifetime of the patient. More advanced procedures, such as hip resurfacing, have the potential to off er even better function to younger patients with very physically demanding lifestyles, whether in terms of work or play. However, even with conventional total hip replacement, most patients will be able to return to a normal lifestyle within 2 to 3 months of the surgery.