

ACEOMEGALY 825 



gion, with complete fusion of the bodies of the tenth and eleventh. The 

 intervertebral foramina are large. 



The Ribs. There is horizontal position of all the fixed ribs, 3 slight 

 downward slope of the floating ribs. Some ossification of the intercostal 

 muscles is seen, also deepening of the subcostal grooves. Ossification is 

 more marked at the lower than at the upper border of the ribs. The first 

 ribs are flat and thin, the second and third moderately thinned. The fifth 

 ribs show a curving downward of the posterior portion, encroaching upon 

 the sixth ribs and also upon the thoracic cavity. The length of the sixth 

 rib with its cartilage is 49 cm. The eighth and tenth ribs show a similar, 

 but less marked, curvature. 



Pelvis. The pelvis as mounted shows an increase in inclination of 25 

 to 30 degrees. There is almost complete synostosis of the right and partial 

 of the left sacro-iliac joint. The sacrum has large foramina anteriorly 

 but the posterior are small, the left second and third, and the right second 

 being obliterated. There is complete fusion of the bodies of the sacrum, 

 and the first segment of the coccyx is fused with the sacrum. The iliac 

 crests are broadened, especially anteriorly, and show irregular deposits of 

 osteophytes. The wings of the ilia are markedly thin in their middle por- 

 tions. The surfaces of the iliac fossae are comparatively smooth but the 

 gluteal surfaces have osteophytes at the seat of muscular insertions. The 

 ilio-pectineal lines are sharpened, especially on the left side. The rami of 

 the pubes are reduced in volume on account of marked deepening of the 

 obturator grooves on their under surfaces which reduces the thickness of 

 the rami to one-third of the normal. There is ossification of the obturator 

 membrane at its median insertion to the ischium and pubis with forma- 

 tion of an irregular bony septum, 1 cm. broad, which encroaches on the 

 obturator foramen. The meniscus of the symphysis pubis is narrowed, and 

 there is pronounced lipping of its articular margins. The lateral surfaces 

 of the ischial bodies and rami are 'markedly grooved, and their superior 

 and inferior margins show marked lipping. This grooving has greatly 

 reduced the thickness of the bones, especially of the rami. The ischial 

 tuberosities are greatly roughened and the spines moderately sharpened. 

 There is marked lipping of the acetabula, including the margins of the 

 cotyloid notches, and so much ossification of the cotyloid ligaments that 

 the cotyloid fossae are almost converted into separate compartments and 

 the cotyloid foramina are enormously increased in size at the expense of 

 the greatly thinned superior ischial rami. The articular surfaces of the 

 acetabula are very irregular, showing evidence of change in the overlying 

 articular cartilages. On the right side the cotyloid ligament is completely 

 ossified at its lower margin. The lipping of the articular margins is more 

 marked on the right side and extends outward into the capsule of the hip 

 joint for 0.5 1 cm. above and 2.5 cm. below. 



8 Largely artificially produced in the mounting of the skeleton. 



