178 



THE ARTICULATIONS OF THE PELVIS. 



lower border of the transverse process of the last lumbar vertebra obliquely down- 

 wards to the lateral part of the base of the sacrum ; its fibres diverge as they 

 descend, and some of them join the anterior sacro-iliac ligament. 



The ilio-lumbar ligament is a strong band passing outwards and some- 

 what backwards from the summit of the transverse process of the last lumbar 

 vertebra to the iliac crest of the hip-bone ; it is inserted into the latter above the 

 back part of the iliac fossa, where its fibres expand somewhat, so as to give it a 

 triangular form. 



The lateral lumbo-sacral ligament represents an anterior superior costo-transverse ligament : 

 the ilio-lumbar ligament is a thickening of the anterior layer of the fascia lumborum. 



ARTICULATIONS OF THE SACRUM AND COCCYX, AND OF THE PIECES OF THE 

 COCCYX. The sacrum and the coccyx are united by an intervertebral disc ; by an 

 anterior ligament, a thin layer of fibres forming a continuation of the anterior 



Fig. 205. LIGAMENTS OP THE 



PELVIS AND HIP-JOINT SEEN 

 FROM BEHIND, FROM A FEMALK 



SUBJECT. (Allen Thomson. ) 



1, ilio-lumbar ligament ; 2, 

 posterior sacro-iliac ligaments, the 

 short and the oblique ; 3, great 

 sacro-sciatic ligament ; 4, small 

 sacro -sciatic ligament ; 5, obtu- 

 rator membrane ; 6, posterior 

 ligament of symphysis pubis ; 



7, 7, continuation of supraspinous 

 ligament from the lower lumbar 

 vertebrae over the sacral spines ; 



8, transverse process of last lum- 

 bar vertebra, from which the 

 lateral lumbo-sacral ligament is 

 seen descending ; 9, capsular liga- 

 ment of the hip-joint ; the figure 

 is placed on the ischio-capsular 

 band. 



common ligament of the 

 vertebras ; by a posterior 

 ligament, more strongly 



developed, which descends from the margin of the inferior orifice of the sacral 

 canal to the back of the coccyx ; by inter articular ligaments between the cornua 

 of the two bones ; and by lateral ligaments, passing on each side from the lower 

 lateral angle of the sacrum to the transverse process of the first piece of the coccyx. 

 The pieces of the coccyx, so long as they remain separate, are connected by fibro- 

 cartilaginous discs and prolongations of the above-mentioned anterior and posterior 

 ligaments. 



A distinct cavity is stated by Cruveilhier to be present in the centre of the disc between 

 the sacrum and coccyx in those cases in which the coccyx is freely moveable. This is in con- 

 formity with the observations of Luschka on the other intervertebral discs. After middle 

 life, the union between the pieces of the coccyx is usually ossific ; and the coccyx may then 

 also become united to the sacrum. The union of the coccyx is less frequent in the female 

 than in the male ; and the mobility of the coccyx seems to increase during pregnancy. 



From the tip of the coccyx a fibrous band passes to the integument, which is often, 

 especially in the infant, marked by a depression (foveola coccygea) at this spot. 



The SACRO-ILIAC ARTICULATION is formed between the auricular surfaces of 

 the sacrum and ilium, which are covered each with a layer of cartilage, that on the 

 sacrum being the thicker, and closely applied together, but are not usually directly 



