ABNORMALITIES AND VARIATIONS OF THE SACRUM
- VernacularTitle:骶骨的畸形变异
- Author:
Shihfu KUO
- Publication Type:Journal Article
- From:
Acta Anatomica Sinica
1953;0(01):-
- CountryChina
- Language:Chinese
-
Abstract:
A study of the abnormalities and variations of the sacrum was made on 400 gross sacral specimens and 800 X-ray films.It consisted of segments,spina bifida occulta,flotting spinous process....etc. The composition of sacrum varied a great deal,the segments ranged from 4 to 9.In the series of gross specimens,with normal 5 segments:285 cases(71.2%); Co became incorporated in sacrum:62 cases(15.5%);sacralisation of L_5:22 cases (5.5%);lumbarisation of S_1:13 cases(3.3%);others:18 cases(4.5%);spina bifida occulta located in S_1 and S_2:115 cases(28.7%);sacral canal entirely opened:12 cases(3%).While in X-ray film series,with normal 5 segments;640 cases(80%); Co became incorporated in sacrum:70 cases(8.75%);sacralisation of L_5:67 cases (8.37%);lumbarisation of S_1:7 cases(0.87%);spina bifida occulta located in S_1 and S_2:153 cases(19.1%);sacral canal entirely opened:41 cases(5.1%);flot- ting spinous process:86 cases(10.7%). The size of sacral biatus was measured,the mean width of the base being 18.22mm,the average length between the apex and the base 26.7 mm,the A-P diameter of the canal at the level of apex 5.45mm.The apex was most common- ly located at the level of S_4 or S_5. Examination of articular surface of upper articular process showed that they inclined obliquely in most cases,but could also be coronal or sagittal.Both arti- cular surfaces were symmetrical in 65%,asymmetrical in 21.7%,markedly asym- metrical in 13.3%. The articular surface was extending from upper 2-3(1/2)segments,they were found symmetrical in 86.7%, asymmetrical in 13.3%. In the gross specimens,the curve of the sacrum was also studied,straight. superiorly and flexed inferiorly:17.2%,gently flexed:54%,markedly flexed:11.8%, flat and straight:11%,hyperextended superiorly and flexed inferiorly:6%.In the X-ray film series,“horizontal sacrum”was found in 4.5%. The spinous process of the sacrum remained rudimentary,leaving only the tubercle.Its number was studied. 2 cases with marked anomaly were reported.One girl aged 1,with rudi- mentary sacrum,only 2 segments,the coccyx wanting,L_2-L_5 sacralized.A boy aged 6,had V-shaped defect in the sacrum.Both cases presented remarkable clinical disturbances. The clinical significance relating the abnormalities and variations of the sacrum was briefly discussed.
