Neural complications in the surgical treatment of adolescent idiopathic scoliosis

Study Design. Multicenter, prospective, consecutive clinical series. Objective. To report on neural complications in a prospective cohort study of 1301 children undergoing spinal fusion and instrumentation for adolescent idiopathic scoliosis (AIS). Summary of Background Data. The incidence of neural complications for spinal deformity surgery has been reported to be 0.26% to 17%. However, most studies have relied on retrospective voluntary reporting of nonconsecutive cases. Methods. A review of 1301 consecutive surgical cases was conducted using the Prospective Pediatric Scoliosis Study database, which is maintained by the Spinal Deformity Study Group. Results. There were 9 neural complications. There were 3 thecal penetrations, none of which required repair, and none of which demonstrated intraoperative neural monitoring changes or postoperative clinical sequelae. There were 2 nerve root injuries. In 1 nerve root injury, a positional compression femoral neurapraxia resolved over 6 months. The other was an L4 neurapraxia despite lowest instrumented vertebra L1, and resolved spontaneously by 3 months' follow-up. There were 4 spinal cord injuries. One required removal of implants and fusion in situ, 1 required relaxation of correction and in situ fusion with instrumentation, while the other 2 were observed after fusion and instrumentation with reduction. All resolved spontaneously within 3 months after operation. Conclusion. The neural complication rate was 0.69%. Two thecal penetrations were due to medial placement of pedicle screws, and 1 was due to dissection during spine exposure. If these are eliminated, as they imply intraspinal entry but not direct neural injury, together with 1 positional neurapraxia, which is remote from the surgical field, our complication rate is 0.38%. This is consistent with other studies in the North American Literature, including multiple reports from the Scoliosis Research Society. Common themes are significant curve correction producing neural stretch and the use of sublaminar wires. None of the neural injuries was permanent. These results reaffirm that surgical treatment of adolescent idiopathic scoliosis has a low but real neural complication rate.