Abstract: ObjectiveTo find out the reason of sacro-iliac articulation malposition misdiagnosed as single prolapse of lumbar intervertebral disc, define the essential point of diagnosing sacro-iliac articulation malposition, and choose the best treatment.MethodsChanges such as X-ray photos of lumbosacral portion and pelvis, CT photos, physiological curvature, pyramid space, joint space, pubic symphysis, and wing of ilium showed in MRI photos, and symptoms, signs of 29 patients with sacro-iliac articulation malposition were analyzed and compared with distribution of nerve in the same part.Results29 patients with sacro-iliac articulation malposition all had bulge of lumbar intervertebral disc showed by CT and MRI photos, 26 had retrograde affection of spinal column, 17 had spinal column sequence changes showed by X-ray photos. After 3-10 times treatment on the basis of sacro-iliac articulation malposition, 19 healed, 8 were effective, and 2 had been better.ConclusionCurative method of sacro-iliac articulation malposition is different with prolapse of lumbar intervertebral disc, although there being many same symptoms and signs, only need conservative treatment.

Key words: sacro-iliac articulation malposition, prolapse of lumbar intervertebral disc, misdiagnose, stress, mechanics