Labral tears can be classified according to location, etiology, and type: Location:Īlthough anterior and anterosuperior tears appear to be the most common.Īnterior labral tears are also common in patients with degenerative hip disease or acetabular dysplasia. An older person with a history of hip and/or acetabular dysplasia, or the result of repeated pivoting and twisting.Īcetabular labral tears represent the most common cause for mechanical hip symptoms – in a recent study, they were found to be the cause of groin pain in more than 20% of athletes presenting with groin pain.A young person with a twisting injury to the hip, usually an external rotation force in a hyperextended position.Two common types of mechanisms have been recognized: Acetabular Labral Anatomy Mechanism of Injury In the presence of a labral tear, this latter function is lost and may lead to increased contact pressure, which is thought to have a role in the development of degenerative disease of the hip. The labrum functions to increase the stability of the hip joint and to seal the hip joint and prevent escape of fluid. The periphery of the labrum is more vascularized than the articular region. The acetabular labrum is a fibrocartilaginous structure that surrounds the periphery of the acetabulum and inserts on the transverse acetabular ligament.īlood supply to the acetabulum is primarily through the obturator artery, superior gluteal artery, and inferior gluteal artery. See Also: Hip Joint Anatomy Acetabular Labral Anatomy However, a large percentage of labral tears are not associated with any known specific event or cause.

Direct trauma, sporting activities, and certain movements of the hip including torsional or twisting movements have been cited to cause labral tears. Researchers have attributed the labral injury to a variety of causes. Its Incidence is highest in patients with acetabular dysplasia. Many bursae have stalk of synovial membrane to bind it.Acetabular Labral Tear of the hip are more common than previously thought.Form numerous bursae that allow muscles crossing the hip to slide freely.Weakest of 3 ligaments, is drawn tighter in flexion of hip, but doesn’t restrict.Origin from ischium, radiates toward intertrochanteric line.Abduction of the hip joint is restricted by this ligament.Function: as extend hip joint, it becomes tight- holds the head of femur into acetabulum.As approach femur, it splits into 2 parts, thus called Y ligament (of Bigelow).Called the strongest ligament in the body.Ofrom ilium and extends anteriorly across hip joint.Has thickened portions called ligaments:.Most of the limit of extension is due to fibrous capsule.Extension of the hip joint is limited whereas knee has greater mobility.as increase stability, sacrifice mobility (shoulder is mobile/unstable).Fibrous capsule surrounds entire joint.Around rim of acetabulum, have labrum of fibrocartilage that helps to deepen the socket.Most blood for femur head / neck is from medial / lateral femoral circumflex.Contains a small artery = artery of the head of the femur (not enough to supply head of femur on its own) is a branch of obturator artery.Deep in acetabulum, have another region that is not articular with small fat pad and synovial membrane fold that extends to similar area on head of femur.Has gap in inferior limit where a nonarticular region is filled by transverse acetabular ligament.Has fairly large articular surface (smooth) in a horseshoe shape.Innervation: femoral nerve, obturator nerve, sciatic nerve, superior gluteus nerve.

Vessels: Branches of superior & inferior gluteal, Obturator artery, Circumflex femoris arteries, Interna Pudendal artery, External Iliac artery, Femoralis artery, Profunda femoris artery & Perforating branches.Movements: flexion and extension, abduction and adduction, rotation.Ischiofemoral ligament (restricts adduction and internal rotation).

Pubofemoral ligament (reduces abduction and external rotation).

Iliofemoral ligament (strongest ligament in the body terminates extension in the joint).

Joint capsule: attached to the edges of the acetabulum & neck of femur.

Special features of the acetabular fossa: acetabular labrum, fat pad, transverse acetabular ligament.

Joint surfaces: Part of the femoral head with articular cartilage & acetabulum (only lunate surface).

Complete anatomy of hip joint