Reasons for Hip Replacement Surgery

The primary indication for hip replacement surgery is pain due to a diseased hip joint. Hip disease can be very debilitating not only causing pain, but also limiting ability to perform normal activities. Fortunately, hip replacement surgery can give patients a new lease on life minimizing or eliminating pain and improving mobility.

Causes of Hip Pain

Osteoarthritis, or “wear and tear” arthritis, as it is commonly referred to, may be the most common reason that patients need hip replacement surgery. There are many conditions that can result in degeneration of the hip joint. Also, another common medical name for this problem is degenerative joint disease. The cartilage of the joint simply degenerates, breaks down and sloughs off the underlying bone. Osteoarthritis occurs with no previous history of injury to the hip – the hip simply “wears out.”

This pelvis x-ray depicts a normal hip on the right side and a severely arthritic hip on the left side. Notice the head of the femur on the side of the osteoarthritis has been notched and has migrated upward. The cartilage in this area has been destroyed.

Post-traumatic arthritis is very similar to osteoarthritis in symptoms, how it looks on x-ray and under the microscope. The only difference is that this disease is caused by trauma or injury. The trauma can come in the form of a fracture or dislocation of the hip. The trauma alters the mechanics of the hip and over time the joint begins to break down. Usually the arthritic changes are seen years after the actual traumatic event.

Rheumatoid arthritis is an autoimmune disorder. That is, the patients own body attacks the cartilage. The body mounts an aggressive inflammatory response against the cartilage of the hip. This causes joint destruction, pain and swelling.

Avascular necrosis (AVN) is also a cause of hip pain that may lead to hip replacement surgery. Avascular necrosis, also called aseptic necrosis or osteonecrosis, refers to the condition in which the femoral head loses part of its blood supply and actually dies. Although this process can occur without a reason, patients who have had a fracture or a dislocation around the hip are at risk to develop this condition. Patients who have been on steroids or who have a history of heavy alcohol use are at risk for AVN. There are several stages of AVN. Early stages have little or no x-ray findings while advanced stages show joint destruction very similar to those seen in osteoarthritis. However, all stages can be very painful despite what is seen on x-rays.

Symptoms of Hip Arthritis This pelvis x-ray depicts a normal hip on the right side and a severely arthritic hip on the left side. Notice the head of the femur on the side of the osteoarthritis has been notched and has migrated upward. The cartilage in this area has been destroyed.
Symptoms of Hip Arthritis  

The classic sign of arthritis is joint pain. Arthritis of the hip is characterized by a dull, aching pain in the groin, outer thigh or buttocks. Sometimes pain may radiate to the front of the knee. Pain from degenerative joint disease such as osteoarthritis or traumatic arthritis tends to be more pronounced with activity and less with rest. In contrast to an inflammatory arthritis like rheumatoid, pain is usually worse in the morning and lessens with activity; however, vigorous activity can result in increased pain and stiffness.

Also, hip arthritis can cause limping. With time, gait abnormalities and limitation of motion can cause muscle atrophy and weakness. Finally, because of the joint destruction, a patient can experience a leg length discrepancy with the affected leg shorter than the other side. ***

See also:
“Arthritis of the Hip.” American Academy of Orthopaedic Surgeons. 2 April, 2003.