| Anatomy |
|
The hip is a ball and socket type joint. The socket is the “acetabulum” which is formed from the pelvis bone, and the ball is the “femoral head” which is the upper end of the thigh bone (“femur”). Surrounding the hip is a dense group of ligaments that forms its “capsule” and provides stability to the joint. The interior surface of the capsule is lined by “synovium”. This is a vascular membrane that produces “synovial fluid”. This fluid provides nutrition and lubrication for the joint. The surfaces of the femoral head and acetabulum are covered by “articular cartilage” which is like a thick Teflon coating that allows smooth, frictionless motion of the joint. Damage to the articular cartilage, whether from injury or disease, represents the beginning of arthritis. This type of injury cannot be completely reversed, but proper management can sometimes reduce the associated discomfort and slow further deterioration. The “labrum” is another type of cartilage that forms a rim around the acetabulum, deepening the socket. The size and shape of the labrum is variable. It is susceptible to tearing, but can also deteriorate with age or arthritis. This type of tear can be one of the easiest problems to treat with arthroscopic surgery. However, labral tears are usually not that simple; most times there is some associated damage to the articular cartilage. The surface of the acetabulum has a horseshoe shape with a large recess in its central bottom portion called the “acetabular fossa”. Within this fossa resides a layer of fatty tissue lined by synovium. This tissue can become inflamed with disease, creating a source of pain that can respond successfully to arthroscopic resection. At the bottom of the fossa, resides the ligamentum teres, a loose ligament that has a serpentine course from its attachment in the acetabular fossa to a central point on the femoral head called the “fovea capitis”. In childhood, it carries a nutrient vessel through its center that provides blood supply to the femoral head. Its function in adulthood is less clear. It does not provide stability to the joint, but may have other functions. This ligament can rupture and become a source of severe hip pain. Arthroscopic debridement has been remarkably successful in the majority of cases. |
