What it is
Placement of implants across the sacroiliac joint through a small incision at the side of the buttock, stabilizing the joint so that it fuses.
Who it is for
A deliberately narrow group: SI joint pain confirmed by image-guided diagnostic injection, after sustained non-operative treatment has failed. It is also considered for SI pain developing after a lumbar fusion ending at the sacrum. Where the diagnosis has not been confirmed by injection, the operation should not be offered.
How it works
With the patient face down, a small lateral incision is made over the joint. Under X-ray guidance, a guide pin is placed across the joint, the track is prepared, and two or three implants are inserted across it. Some designs are placed laterally across the joint, others along it; the principle is the same.
Recovery
Usually home the same day or after one night. Partial weight-bearing with crutches for a period in some protocols. Return to desk work commonly two to four weeks. Fusion consolidates over months.
Risks and alternatives
Implant malposition, nerve irritation, infection, bleeding, failure of fusion, and persistent pain where the joint was not the true source. Alternatives are continued injections, radiofrequency ablation, physical therapy, or accepting the symptoms.