[The effect of children's gluteal muscle contracture on skeleton development].
OBJECTIVE
To explore the effect of children's gluteal muscle contracture (GMC) on skeleton development.


METHODS
The pelvic plain films of 368 GMC cases confirmed by operation from May 1995 to June 2005 and those of 200 individuals as control were analyzed for this research project. The pelvic CT scans were performed in 30 GMC cases and 25 controls. The data of both groups were used to comparison, analysis and statistics treatment in pelvic plain X-ray film, hip joint, acetabular index, neck shaft angle, centre-edge (CE) angle, the form of pelvic obturator foramen, the existence or nonexistence of the iliac hyperdense line.


RESULTS
There were 68 cases with pelvis obliquity in the case group but no one in the control group. The iliac hyperdense lines at the side of sacroiliac joints were found on the pelvic plain films of 321 of 368 cases with GMC and 5 of 200 controls. In 368 cases with GMC, the iliac hyperdense lines were detected in 306 of 314 patients beyond 7-year-old, and 313 of 336 appeared mostly the contracture of gluteus maximus muscle, which showed to be significant in statistics. In GMC group, the oblique plane became steeper and almost oriented posteroanteriorly, while in control group,the pelvic CT showed that the outer codex of posterior ilium at the level of sacroiliac joint appeared as an oblique plane, oriented from posteromedial to anterolateral side. The data were processed with statistics software, found that compared with the control group, the results of pre-operation group's examines such as CE angle, neck shaft angle, longitudinal diameter, cross diameter, and the iliac hyperdense line had significant differences (P < 0.01), the results of post-operation group's those examines showed no significant differences (P > 0.01), and the acetabular index appeared no significant differences (P > 0.01).


CONCLUSIONS
The children's gluteal muscle contracture has the significant effect on skeleton development, which could lead to pelvis obliquity, coxa valga, leg length pseudoinequality, CE angle increasing, etc. The iliac hyperdense line on the pelvic plain film is probably a characteristic change of GMC.
Ni
Bing
B
Department of Orthopaedics, Affiliated Hospital of Children of Chongqing University of Medical Science, Chongqing 400016, China.
Li
Ming
M
D000293:Adolescent; D000328:Adult; D001846:Bone Development; D002081:Buttocks; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D003286:Contracture / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000473:pathology*; D014057:Tomography, X-Ray Computed; D055815:Young Adult