Temporary internal distraction for severe scoliosis: two-year minimum follow-up

Purpose Temporary internal distraction (TID) is a surgical technique used to correct severe scoliosis. We sought to evaluate the long-term outcomes associated with temporary internal distraction (TID) for severe scoliosis. Methods Scoliosis patients who underwent TID from 2006 to 2019 at a single institution were identified. Patients with coronal Cobb angles >= 90 degrees or congenital scoliosis, and >= 2-year follow-up were included. Clinical and imaging data were reviewed for patient and operative characteristics and complications. Patient-reported outcomes were also analyzed. Results 51 patients (37 female) were included. Mean age at surgery was 14.3 +/- 3.5 years. Mean follow-up was 5.8 +/- 3.0 years. Eighteen (35%) curves were idiopathic, 24 (47%) were cerebral palsy (CP) related, and 9 (18%) were congenital. Mean Cobb angle was 103 degrees preoperatively and 20 degrees at final follow-up, with an intermediate angle of 55o in staged procedures. Intraoperative neuromonitoring changes occurred in 13 (25.4%) cases, but all returned to baseline with immediate lessening of distraction. Overall, three (5.8%) cases of wound dehiscence, five (9.7%) cases of deep infections, one (2%) case of screw protrusion, and one (2%) case of delayed extremity weakness occurred. Patient-reported outcomes significantly improved at final follow-up. Conclusion Our findings suggest that TID is a valuable adjunct for correcting severe scoliosis. The mean Cobb reduction achieved (81%) was higher than that reported for halo-traction and was sustained over long-term follow-up. TID also allowed a shorter a hospital stay. While intraoperative neuromonitoring changes were not uncommon, they were reversible. However, care must always be exercised as major corrections may rarely result in delayed neurologic deficits despite intact neuromonitoring.