The association of sacroiliac joint bridging with other enthesopathies in the human body

STUDY DESIGN. A descriptive study of the association between sacroiliac joint (extra-articular) bridging and other enthesopathies. OBJECTIVES. To examine the relationship between sacroiliac joint bridging with other entheseal reaction sites in the skeleton, and its prognostic value in spinal diseases. SUMMARY OF BACKGROUND DATA. Sacroiliac joint bridging is considered a hallmark of spinal diseases (e.g., ankylosing spondylitis). Nevertheless, its association with other enthesopathies has never been quantified and analyzed. METHODS. A total of 289 human male skeletons with sacroiliac joint bridging and 127 without (of similar demographic structure) were evaluated for the presence of entheseal ossification, cartilaginous calcification, and other axial skeleton joint fusion (a total of 18 anatomic sites). The presence of diffuse idiopathic skeletal hyperostosis and spondyloarthropathy was also recorded. RESULTS. Sacroiliac joint bridging was strongly associated with entheseal reactions in other parts of the body. Of the sacroiliac joint bridging group, 24.91% had diffuse idiopathic skeletal hyperostosis, and 8.05% had spondyloarthropathy. CONCLUSIONS. The presence of sacroiliac joint bridging indicates an intensive general entheseal process in the skeleton.