Sacroiliac Dysfunction

Sacroiliac joint (SIJ) pain — any age.

Causes

• Mechanical disorders (hypo- or hypermobility)
• Post-traumatic
• Childbirth (postnatal period)
• Inflammation (sacroiliitis — think spondyloarthropathy)
• Degenerative change
• Osteitis condensans ilii
• Infection (rare)

History

Dull ache in the buttock, may refer to the groin or posterior thigh — can mimic lumbosacral spine or hip pain. Unilateral or bilateral. Worse on loading: walking, running, squatting, rising from low chairs. No neurological symptoms.

Examination

The joint is difficult to palpate (especially in larger patients). Provocation tests:

• Direct pressure over the joint.
• Compression tests — patient supine, press down on both iliac crests to compress the SIJs.
• Patrick (FABER) test — supine, foot of the affected side on the opposite knee (hip flexed, abducted, externally rotated); pressing the knee and the opposite ASIS down together provokes buttock/low-back pain from the SIJ (also stresses the hip).

Investigations

None usually needed; ultrasound can show fluid/inflammation in the joint. (If inflammatory features — consider spondyloarthropathy workup and MRI.)

Management

• Traumatic or hypo/hypermobility disorders: physiotherapy + NSAIDs (if not contraindicated); most resolve in 1–3 weeks.
• Inflammatory or degenerative causes: SIJ corticosteroid injection if the above fails.