Acetabulum Health Dictionary

The thigh bone, which is the longest and strongest bone in the body. As the upper end is set at an angle of about 120 degrees to the rest of the bone, and since the weight of the body is entirely borne by the two femora, fracture of one of these bones close to its upper end is a common accident in old people, whose bones are often weakened by osteoporosis (see under BONE, DISORDERS OF). The femur ?ts, at its upper end, into the acetabulum of the pelvis, forming the hip-joint, and, at its lower end, meets the tibia and patella in the knee-joint.... femur

The joint formed by the head of the thigh bone and the deep, cup-shaped hollow on the side of the pelvis which receives it (acetabulum). The joint is of the ball-and-socket variety, is dislocated only by very great violence, and is correspondingly di?cult to reduce to its natural state after dislocation. It is enclosed by a capsule of ?brous tissue, strengthened by several bands, of which the principal is the ilio-femoral or Y-shaped ligament placed in front of the joint. A round ligament also unites the head of the thigh bone to the margin of the acetabulum.

For hip-joint disease, see under JOINTS, DISEASES OF.... hip-joint

The joint between the pelvis and the upper end of the femur. The hip is a ball-and-socket joint; the smooth, rounded head of the femur fits securely into

the acetabulum, a cup-like cavity in the pelvis. Tough ligaments attach the femur to the pelvis, further stabilizing the joint and providing it with the necessary strength to support the weight of the body and take the strain of leg movements. The structure of the hip allows a considerable range of leg movement. hip, clicking A fairly common condition in adults in which a characteristic clicking is heard and felt during certain movements of the hip joint. Clicking hip is caused by a tendon slipping over the bony prominence on the outside of the femur, and does not indicate disease. Clicking of the hip that can be heard during examination of newborn babies indicates possible dislocation of the hip (see developmenal hip displasia).... hip

(CDH) an abnormality present at birth in which the head of the femur is displaced or easily displaceable from the acetabulum (socket) of the ilium, which is poorly developed; it frequently affects both hip joints. CDH occurs in about 1.5 per 1000 live births, being more common in first-born girls, in breech deliveries, and if there is a family history of the condition. The leg is shortened and has a reduced range of movement, and the skin creases may be asymmetrical. All babies are routinely screened for CDH at birth and at developmental check-ups by gentle manipulation of the hip causing it to be reduced and dislocated with a clunk (see Barlow manoeuvre; Ortolani manoeuvre). The diagnosis is confirmed by X-ray or ultrasound scan. Treatment is with a special harness holding the hip in the correct position. If this is unsuccessful, the hip is reduced under anaesthetic and held with a plaster of Paris cast or the defect is corrected by surgery. Successful treatment of an infant can give a normal hip; if the dislocation is not detected, the hip does not develop normally and osteoarthritis develops at a young age.... congenital dislocation of the hip

see acetabulum.... cotyloid cavity

(innominate bone) a bone formed by the fusion of the ilium, ischium, and pubis. It articulates with the femur by the acetabulum of the ilium, a deep socket into which the head of the femur fits (see hip joint). Between the pubis and ischium, below and slightly in front of the acetabulum, is a large opening – the obturator foramen. The right and left hip bones form part of the *pelvis.... hip bone

the ball-and-socket joint (see enarthrosis) between the head of the femur and the acetabulum (socket) of the ilium (see hip bone). It is a common site of osteoarthritis and rheumatoid arthritis, which is often treated surgically (by *hip replacement). See also congenital dislocation of the hip.... hip joint

n. (pl. labra) a lip or liplike structure; occurring, for example, around the margins of the articulating socket (acetabulum) of the hip bone.... labrum

a large opening in the *hip bone, below and slightly in front of the acetabulum. See also pelvis.... obturator foramen