How is Hip Arthritis Diagnosed?

Hip arthritis can be diagnosed with a history of progressively increasing pain, first occurring with activities and eventually occurring at rest. Loss of motion in the hip also may be an indication of hip arthritis. Progressive limp and limb length inequality may be present as well. Hip arthritis should be clearly differentiated from other conditions that result in increasing pain such as hernias, aneurysms, and urologic and gynecologic problems.

Physical examination
The physician will check:

• The patient's gait to determine limb length inequality and the presence of Trendelenburg gait.
• Limb length assessment both in the standing and supine (prone) position may reveal that one leg is shorter than the other due to hip arthritis.
• Range of motion of the hip that shows a loss of internal rotation is a common sign of hip arthritis.

Difficulty in lifting the leg to the side may be present in severe cases. The hallmark of hip arthritis is pain with hip flexion and internal and external rotation. Another common symptom of hip arthritis is pain in the groin and on the outside thigh.

It is important to examine the lumbar spine for signs of herniated discs or radioulopathy since these conditions have symptoms similar to those of hip arthritis. Weakness in the leg, loss of sensation, reflex uneveness, pain with lumbar motion, or tenderness over the sacroiliac joint may all be signs that the hip complaints come from a condition in the back.

Diagnostic tests
Routine X-rays showing a standing front and rear view of the pelvis, and a "frogleg" lateral view will reveal arthritis signs such as:

• narrowing of the joint space.
• flattening of the subchondral (beneath the cartilage) bone.
• bone spur formation.
• limb length inequality.

Occasionally, oblique views of the pelvis are necessary to determine subtle dysplasia (abnormal tilt in the acetabulum) or abnormal formation of the acetabulum. MRI scanning and bone scanning may be used to detect other conditions such as the early stages of osteonecrosis of the femoral head.