Outcomes and Complications of Vertebral Body Tethering in Skeletally Immature Patients with Idiopathic Scoliosis.

BACKGROUND

Vertebral body tethering (VBT) aims to gradually correct scoliosis using patients' growth while preserving spinal motion. We report 5 to 8-year outcomes and complications in skeletally immature patients.

METHODS

This prospective single-center cohort study included 74 patients who had idiopathic scoliosis and a ≥5-year follow-up. Preoperative, first postoperative visit, 1-year, 2-year, and ≥5-year radiographs were analyzed. A ≥5° increase in the interscrew angle suggested tether breakage.

RESULTS

All 74 patients (5 male and 69 female) were skeletally immature at surgery. The mean age at surgery was 11.8 ± 1.3 years, and the mean follow-up time was 63.4 ± 8.4 months. Of the 74 patients, 68 patients were White, 4 were Black, and 2 were Middle Eastern or North African. VBT was performed on a mean of 7.4 vertebral levels. The maximum Cobb angle was 47.9° ± 9.4° preoperatively, whereas the instrumented Cobb angle measured 17.2° ± 12.3° at 2 years and 25.7° ± 14.0° at ≥5 years postoperatively. An unplanned return to the operating room occurred in 16 patients (21.6%). Forty-nine patients (66%) had a suspected broken tether at the final follow-up. The mean time of the first tether breakage was 38.1 ± 15 months. Forty-nine patients (66%) also had a curve of <40° without an unplanned return to the operating room at a minimum of 5 years postoperatively.

CONCLUSIONS

In our cohort, 66% (49 patients) had a radiographically suspected tether breakage after 5 years and 13.5% (10 patients) required posterior spinal fusion to date. VBT yielded significant correction in the coronal plane (p < 0.001) and transverse plane (p = 0.006) postoperatively, with a reoperation rate of 21.6%.

LEVEL OF EVIDENCE: Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.