The long-term effects of spinal fusion on the sacroiliac joints and ilium

Ninety-six patients who had lumbar disk excision and primary posterior fusion were studied 10 or more years after their operations. Thirty-seven per cent complained of persistent graft donor site pain. A comparison of fused patients with and without donor site pain and 36 patients who underwent simple disk excision, revealed no differences in the flexion-extension mobility of the sacroiliac joints, or degenerative changes in the sacroiliac joints. Ectopic bone formation at graft donor sites, and cluneal nerve neuromata did not influence the result. Patients with graft donor site pain had significantly greater complaints of persistent low back pain, postoperative leg pain, and lost more time from work. If the graft was taken from the same side as that of preoperative leg pain, persistent complaints were more common. It is concluded that the sacroiliac joints are not adversely affected by lumbar spine fusion, and that persistent donor site pain is more likely part of a total pain complex referred from the lumbar spine. The sacroiliac joints appear to be relatively noncontributory to problems following lumbar disk surgery.