HIP JOINT 331 



femoral extremity is implanted into the fovea capitis femoris, 

 whilst its flattened acetabular end is bifid, and is fixed to the 

 margins of the acetabular notch, and also to the transverse 

 ligament. This attachment can be defined by the removal 

 of the synovial layer and some areolar tissue. The liga- 

 mentum teres is surrounded by a prolongation of the synovial 

 layer, and a small artery runs along it to the head of the 

 femur. 



It is difficult to understand the part which the ligamentum 

 teres plays in the mechanism of the hip joint. It presents 

 very different degrees of strength in different subjects. It 

 becomes very tense when the thigh is slightly flexed and 

 then adducted. 



The Interior of the Joint and the Synovial Stratum. A 

 mass of soft fat occupies the non-articular bottom of the 

 acetabulum. Upon this the ligamentum teres is placed, and 

 blood-vessels and nerves enter it by passing through the 

 notch under cover of the transverse ligament. The vessels 

 are derived from the medial femoral circumflex and the 

 obturator arteries, and the nerves are twigs from the anterior 

 branch of the obturator nerve, from the accessory obturator, 

 when it is present, and from the nerve to the rectus femoris 

 muscle. A nerve-twig is also supplied to the posterior 

 part of the joint by the nerve to the quadratus femoris. 



The synovial stratum lines the inner surface of the fibrous 

 stratum of the capsule. From the fibrous stratum it is reflected 

 on to the neck of the femur, and it clothes the bone as far 

 as the margin of the articular cartilage which covers the head. 

 Along the line of reflection some fibres of the fibrous stratum 

 proceed proximally on the neck of the femur and raise the 

 synovial layer in the form of ridges. These fibres are termed 

 the retinacula or cervical ligaments. 



The retinacitla are of some surgical importance. In intracapsular 

 fracture of the neck of the femur they may escape rupture, and they 

 may then, to some extent, help to retain the fragments in apposition. 

 Hence examinations of this class of fracture must be conducted gently, 

 lest by rupturing this ligamentous connection the fragments be perma- 

 nently displaced. 



At the acetabular attachment of the capsule the synovial 

 membrane is reflected on to the labrum glenoidale and 

 invests both its surfaces. It also covers the articular surface 

 of the transverse ligament and the cushion of fat which 



