Hip Disorders and Injuries

The hip is a complex joint formed by the articulation of several bones surrounded by muscular attachments and ligaments to form what is known as a ball and socket joint. The complexity provides for tremendous strength but lends to disease susceptibility especially in the event of mechanical stress that may result in debilitating injury. Given the musculoskeletal and supporting structural relations any assortment of disorders is possible. In general, the most common disorders plaguing the hip joint can be classified and further differentiated based on the age of onset, supporting tissue origin of the disorder, bony fracture involvement, and/or the arthritic components of the ailment. Discussion of the basic principles, functional terminology and anatomical relations will provide the foundation for the overview to follow.

The hip forms the essential connection between the lower limb and the bony structures of the pelvic girdle. The hip represents a ball and socket joint, providing a strong and stable foundation, which allows movement to occur in a number of axes. With the femoral head representing the ball and the acetabulum the socket, the round head of the femur articulates with the cup like acetabulum of the hipbone. Most of the head of the femur is covered with articlar cartilage, which is thickest over weight bearing areas. The acetabulum, a semicircular depression in the lateral portion of the hipbone is formed by the fusion of three bony contributions, the ileum, ischium and pubis. The hip is designed for stability over a wide range of movements essential for daily function and ambulation. Functional necessity is evidenced by the fact that during a standing position the entire weight of the upper body is transmitted through the hipbones down into the head and neck of the communicating femurs. Injury and disorders account for extreme impairment in functioning.