Age-related differences in the human sacroiliac joint: a histological study; - implications for therapy.

Sacroiliac joint dysfunction often is implicated in the etiology of low back pain. Few data exist on age differences in sacroiliac tissues. The purpose of this study was to identify by light microscopy the differences that exist between age decades. Joints from 36 fetuses and 15 adult cadavers were excised and prepared in the routine manner. In fetal joints, complete cavitation was not observed before 34 weeks of age; the iliac surface was predominantly fibrous or fibrocartilage. Fibrous bands connected joint surfaces even in term specimens. All adult specimens showed degenerative changes which included incomplete fibrous (N = 9) or chondroid (N = 5) ankylosis and incompletely healed, presumed fractures of the joint surface (N = 6). On the average, sacral cartilage was 1.7 times thicker than the iliac "cartilage." The potential for the older sacroiliac joint to be affected by techniques of manual therapy is questionable given the degenerative features observed. J Orthop Sports Phys Ther 1986;7(6):325-334.