One of the most exciting and beneficial recent advances in orthopaedic surgery has been the use of arthroscopy to repair injuries of the hip joint. These techniques have gained significant exposure as prominent athletes such as Alex Rodriguez, Kurt Warner, and Greg Norman have undergone the procedure. Many recreational athletes and non-athletes have also experienced relief from their hip pain with arthroscopic hip procedures. In addition, it is thought that the procedure may delay or prevent the need for hip replacement.
When orthopedic surgeons refer to the 'hip' joint, they are referring to the ball-and-socket joint formed by the top of the thigh bone(or femur) and the hip socket (or acetabulum.) The top of the femur is a large ball covered by smooth articular cartilage. This 'femoral head' is connected at an angle to the main shaft of the femur by the 'neck' of the femur. The acetabulum is a deep socket formed by the bones of the pelvis. Most of the socket is covered by articular cartilage. The labrum is a rim of rubber-like tissue that is attached circumferentially along much of the rim of the socket. It acts like a washer or gasket, providing stability to the hip joint and distributing stress. Its function is similar to the meniscus in the knee and the labrum in the shoulder. Other important hip joint structures include the ligamentum teres that connects the femoral head to the acetabulum, the hip joint capsule that surrounds the entire joint, and the hip muscles which are some of the most powerful muscles in the body.
The normally-functioning hip joint is very stable by virtue of its deep socket, and it absorbs high forces as we walk, run, and exercise. Because the muscles of the hip are so powerful, simply standing on one leg can cause the hip to experience forces three times the weight of your body. Activities such as running, weight lifting, dancing, swinging a club, or kicking a ball place even greater stress on the hip. And over time these stresses can cause the normal structures of the hip to be injured. Acute injuries-- including tears of the labrum, injury to the articular cartilage, tendinitis, stretching of the capsule, and tendon or ligament tears--can also occur.
The shape of the femur and acetabulum are also implicated in causing injury to the hip through a mechanism termed "impingement." This "femoro-acetabular impingment" (or FAI) is abnormal contact between the rim of the socket and the neck of the femur. Repeated contact in these areas can be painful as the labrum gets pinched, and tears in the labrum and articular cartilage can develop. In some cases the patient may have a hip socket that is excessively deep or rotated to the back. A femoral head and neck that is more cam-shaped, rather than round, can also predispose to impingement. Occasionally a patient will have a combination of both types of impingement.
The location of pain from FAI and labrum tears is usually in the groin and/or the side of the hip. The symptoms usually worsen with activity and are alleviated by rest. A catching or popping sensation in the hip is often reported, especially when arising from a seated position, getting in to or out of a car, or other activities that flex and rotate the hip.
An orthopedic surgeon who is an expert in the diagnosis and treatment of hip problems is the best person to evaluate for femoroacetabular impingement and labrum tears. This evaluation will include a comprehensive history and physical examination as well as x-rays of the hip. X-rays can help determine if the hip has too much arthritis, indicating that a patient would be better suited for hip replacement. MRI scans are very sensitive at detecting injuries such as labrum tears, although occasionally an MRI scan will overlook these injuries. CT scans and hip injections can also be used to aid in diagnosis and surgical planning.
Within the last several years, the ability to treat these hip conditions arthroscopically has been developed. Arthroscopic surgery is a minimally invasive technique. This means that labrum tears, articular cartilage injuries, hip instability, and bone malformations in many cases can be corrected through two or three small incisions using a small camera called the arthroscope. This is similar to arthroscopic surgeries on other joints such as shoulder labrum repairs and knee meniscus trimming. As this procedure has gained popularity amongst orthopedic surgeons, specific surgical techniques and instruments have been developed to address the unique challenges of hip arthroscopy. For example, hip labrum tears can be repaired using small anchors inserted in the bone around the rim of the acetabulum. The surgeon passes the suture attached to these anchors around the labrum. The anchors act like tent stakes, holding the labrum in place against the bone until the body can heal it in place.An essential part of any hip arthroscopic surgery is addressing bone abnormalities such as the "cam"-shaped femoral neck and the excessively deep socket. These conditions are often present in addition to labrum tears, and indeed contribute to the labrum tears developing. During the arthroscopic surgery, these bones can be reshaped to alleviate the femoroacetabular impingement. Clinical studies have shown that these surgical techniques provide excellent pain relief in most patients. The benefits of doing the surgery arthroscopically include smaller incisions, quicker recovery, less pain, and no overnight hospital stay is required.
Physical therapy begins the day after surgery. Depending on the extent of the surgery, crutches may be used for two to six weeks, and full recovery is expected within four to twelve months.
Many patients endure the challenges of living with painful hip conditions that have been undiagnosed or experience little improvement with non-surgical treatment. State-of-the-art diagnostic and surgical techniques for femoroacetabular impingement and related conditions relieve pain that has previously been difficult to treat. These arthroscopic techniques allow most patients to resume a high level of activity after surgery and may delay or prevent the need for hip replacement.