Describe the hip joint.

The hip joint is a synovial ball and socket joint, which is very stable and mobile at the same time. The two bones involved in the movement of this joint are the femur and the coxal bone. The movements possible at this joint are: flexion, extension, abduction, adduction, circumduction, medial and lateral rotation. The articulation involved in this joint is between the head of the femur and the acetabulum of the coxal bone. There is fibrocartilage surrounding the acetabular fossa of the acetabulum of the coxal bone, and this is made of fibrocartilage. This helps to deepen the socket of the hip joint, therefore providing additional stability.

The ligaments involved in the hip joint are thickenings of the external capsule. Also there are two internal ligaments. The external ligaments are the iliofemoral, which is Y shaped and attaches to the upper and lower ends of the intertrochanteric line, arising from the anterior inferior iliac spine. The pubofemoral ligament arises from the iliopectineal eminence and attaches to the femoral neck. The ischiofemoral ligaments attaches to the greater trochanter. All of these ligaments function to prevent hyperextension of this joint. Internally, there are two ligaments namely: the ligamentus teres, and the traverse acetabular ligament. The ligamentum teres arises from the fovea of the head of the femur, and attaches to the margins of the acetabular fossa. This helps limit adduction of the hip joint.

The anterior relations of the hip joint are the iliopsoas, rectus femoris and sartorius muscles and also the femoral nerve, and vessels. The posterior relations are the lateral rotator muscles, sciatic nerve and the gluteus maximus muscle. The inferior relations are the obturator externus and the superior relations are the gluteus minimus. Medially are the pelvic organs.

The hip joint receives its blood supply from two main arteries. Branches of the lateral and medial circumflex arteries arising from the profunda femoris artery, and the foveolar artery. Also other contributions include branches from the inferior and superior gluteal artery and obturator artery. Hiltons Law suggests that the nerves innervating muscles that cross a joint will also innervate that joint. Thus the hip joint is innervated by branches of the femoral nerve, obturator nerve, inferior / superior gluteal nerves, sciatic nerve.

Major Points  Type of joint. Bones involved. Movements. Articulation. Acetabular labrum  function. Ligaments (external)  function. Ligaments (internal)  function. Relations. Blood Supply, and Nerve supply.

Category: Anatomy Notes