270 



THE ARTICULATIONS. 



and the outer or upper of the two bands is sometimes described as a separate liga- 

 ment, under the name of the llio-trochanteric ligament. 



The Ligamentum Teres is a triangular band implanted by its apex into the 

 depression a little behind and below the centre of the head of the femur, and 

 by its broad base into the margins of the cotyloid notch, becoming blended with 

 the transverse ligament. It is formed of connective tissue, surrounded by a tubular 

 sheath of synovial membrane. Sometimes only the synovial fold exists, or the 

 ligament may be altogether absent. The ligament is made tense when the hip is 



semiflexed, and the limb then adducted and 

 rotated outward; it is, on the other hand, 

 relaxed when the limb is abducted. It has, 

 however, but little influence as a ligament, 

 though it may to a certain extent limit move- 

 ment, and would appear to be merely a modi- 



RECTUS MUSCLE. 



COTYLOID LIGAMENT 



CAPSULAR 

 LIGAMENT.' 



.LIGA- 

 MENTUM 

 TERES. 



FIG. 180. Hip-joint, showing the ilio-femoral 

 ligament. (After Bigelow.) 



FIG. 181. Vertical section through hip-joint. (Henle.) 



fication of the folds which in other joints fringe the margins of reflection of 

 synovial membranes (see page 218). 



The Cotyloid Ligament is a h'bro-cartilaginous rim attached to the margin of 

 the acetabulum, the cavity of which deepens ; at the same time it protects the 

 edges of the bone and fills up the inequalities on its surface. It bridges over the 

 notch as the transverse ligament, and thus forms a complete circle, which closely 

 surrounds the head of the femur, and assists in holding it in its place, acting as a 

 sort of valve. It is prismoid on section, its base being attached to the mar- 

 gin of the acetabulum, and its opposite edge being free and sharp ; whilst its 

 two surfaces are invested by synovial membrane, the external one being in 

 contact with the capsular ligament, the internal one being inclined inward, so 

 as to narrow the acetabulum and embrace the cartilaginous surface of the head of 

 the femur. It is much thicker above and behind than below and in front, and 

 consists of close, compact fibres, which arise from different points of the circum- 

 ference of the acetabulum and interlace with each other at very acute angles. 



The Transverse Ligament is in reality a portion of the cotyloid ligament, 

 though differing from it in having no cartilage-cells amongst its fibres. It con- 

 sis.ts of strong, flattened fibres, which cross the notch at the lower part of the 

 acetabulum and convert it into a foramen. Thus an interval is left beneath the 

 ligament for the passage of nutrient vessels to the joint. 



