Hip impingement is a disorder caused by a lack of room, or clearance, between the head and neck of the femur (thigh bone) and the rim of the acetabulum. Due to this lack of clearance, when the hip is flexed, as in many common activities like running, sitting or bending over, the femur and the rim of the acetabulum rub together, causing significant pain in the joint. As a result of extensive contact between the femur and acetabulum, the labrum (layer of cartilage) may suffer damage, slowly degenerate, and may even cause arthritis in the hip over time.
Hip impingement is more common in athletic men, and any athletic or strenuous activity may further aggravate pain in the groin area caused by impingement. Remaining in a stationary seated position for long periods of time may also aggravate the condition. If conservative treatments are unable to relieve the pain you feel from hip impingement, your doctor may recommend arthroscopic surgery.
The labrum is a layer of fibrous cartilage that lines the rim of the socket in which the ball of the femur sits. This cartilage provides cushioning for the joint and keeps the femur in place. A tear in the labrum can result either from injury or from degeneration due to impingement or other joint conditions.
In some cases, labral tears are not significant enough to cause symptoms and therefore don't require surgical treatment. But occasionally they can cause symptoms such as locking or "catching" in the joint and pain in the hip or groin area.
Since labral tears are often difficult to detect during a physical examination, your doctor may use magnetic resonance imaging (MRI) with a dye injection to confirm the diagnosis. Once the diagnosis is confirmed, arthroscopic hip surgery may be recommended.
Articular Cartilage Injuries
Articular cartilage is a layer of material in the hip joint that covers the surface of the femoral head and acetabulum (a cavity at the base of the pelvis), cushioning them and allowing them to move against each other without causing damage. This cartilage sometimes tears or becomes damaged, either from high impact sports like running or jumping, as a result of friction caused by hip impingement, or from basic wear and tear.
When articular cartilage is damaged, the torn fragment often protrudes into the joint, causing pain when the hip is flexed. Also, the bone material beneath the surface no longer has protection from joint friction, which may eventually result in arthritis if left untreated. Articular cartilage injuries often occur in conjunction with other hip injuries, and like labral tears, may require an MRI with a dye injection to confirm the diagnosis. After confirming the diagnosis, your surgeon may recommend arthroscopic surgery.
Removal of loose bodies is a common reason surgeons perform arthroscopic hip surgery. These loose bodies are often the result of trauma, such as a fall, a car or motorbike accident, or a sports-related injury, or they may result from degenerative disease. When a torn labrum rubs continuously against cartilage in the joint, this may also cause fragments to break free and enter the joint. Loose bodies can cause a "catching" in the joint.
Unlike some hip conditions, loose bodies are relatively easy to detect with modern X-ray techniques. Once diagnosed, the removal of loose bodies through hip arthroscopy usually results in a reduction in hip pain.