Diagnosis and Standardized Treatment Strategy for Sacroiliac Joint Dysfunction

Sacroiliac joint (SIJ) dysfunction is a common but frequently underrecognized source of chronic low back and buttock pain. The SIJ plays a critical biomechanical role in transferring loads between the spine and lower extremities while stabilizing the pelvic ring. Although physiological motion is limited, mechanical, degenerative, inflammatory, and post-traumatic disorders of the joint can result in substantial pain and functional impairment. Accurate diagnosis of SIJ dysfunction is challenging because symptoms often overlap with lumbar spine and hip disorders. Patients typically present with pain localized around the posterior superior iliac spine (PSIS), sometimes radiating to the groin or posterior thigh. Diagnosis requires a comprehensive approach integrating clinical history, structured physical examination, provocation tests, and imaging studies to exclude alternative conditions. Diagnostic accuracy is improved by the sacroiliac joint score ≧4 points and by positive findings on at least three provocation tests. Definitive confirmation is obtained with peri-articular or intra-articular SIJ blocks, with at least 70% pain relief considered diagnostic. Conservative treatment is the first-line strategy and includes patient education, activity modification, pelvic stabilization exercises, manual therapy, pelvic belts, pharmacologic treatment, and image-guided injections. SIJ fusion surgery is performed for patients with persistent, function-limiting pain despite at least six months of adequate conservative treatment.