The hip joint is formed between the 'ball' of the femoral head and the 'socket' of the acetabulum and a cartilaginous labrum. Strong supporting muscles, the fibrous joint capsule and ischiofemoral ligament make this a stable joint.
Hip dislocations are either congenital or traumatic. Congenital dislocation of the hip is caused by dysplasia of the femoral head or acetabulum and is covered in the separate article Developmental Dysplasia of the Hip.
This remainder of this article deals with traumatic dislocation.
Traumatic hip dislocation is an orthopaedic emergency. Large forces are required to cause hip dislocation (except in prosthetic hips) and this means that such injury may be associated with other life-threatening injuries and other fractures. The condition is extremely painful. Accurate and swift diagnosis means appropriate management can reduce morbidity.