Neuromonitoring Changes Are Common and Reversible With Temporary Internal Distraction for Severe Scoliosis

Retrospective review of consecutive cases.

To examine the neurologic implications of applying intraoperative distraction to large curves.

Temporary rods provide internal distraction during correction of severe scoliosis and may be an alternative to prolonged halo traction or vertebral column resection.

A single surgeon's consecutive experience with posterior-only spinal fusion with temporary distraction rods was reviewed retrospectively. Inclusion criteria were long posterior-only spinal fusion (10 or more levels) for severe scoliosis (major Cobb angle 80° or greater), treated with temporary internal distraction. Records were reviewed for age, gender, diagnosis, intraoperative course, and complications. Radiographs were reviewed for Cobb angles, T1-S1 length, and space available for each lung.

Twenty-two patients with a mean age of 14 years and a mean of 15 levels fused (range, 10-18 levels) were included. The mean preoperative coronal Cobb angle was 113° (range, 83°-144°), and a mean correction of 62° (54%) was achieved. There was a mean T1-S1 increase of 8.4 cm (range, 2.4-14 cm). Nine patients had 2-stage procedures separated by a mean of 7 days. Thirteen patients had a single procedure. Of 22 patients, 9 (41%) had intraoperative neuromonitoring changes. All neuromonitoring changes were reversed after releasing distraction on the temporary rod, except in 1 case. No patient had a clinical neurologic deficit.

Use of temporary distraction rods for severe scoliosis produces curve correction while providing a mean increase in T1-S1 height of 8 cm. Most steps in this surgery are reversible. Neuromonitoring changes are common, but they are reversible with release of some distraction. Neuromonitoring changes did not affect the final magnitude of correction, and there were no clinical neurologic deficits. We recommend that this procedure be performed only with good neuromonitoring.