Lumbar Vertebral Body Tethering: Single Center Outcomes and Reoperations in a Consecutive Series of 106 Patients.

ABSTRACT

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To evaluate the outcomes and reoperation rates in patients with adolescent idiopathic scoliosis (AIS) undergoing lumbar anterior vertebral body tethering (AVBT). SUMMARY OF BACKGROUND DATA Anterior vertebral body tethering (AVBT) is a viable option in growing children. The benefit of motion preservation must be balanced by a higher reoperation rate. A paucity of reports has addressed lumbar AVBT. METHODS: A single-center retrospective study was conducted to identify all patients who underwent lumbar AVBT (lowest instrumented vertebra L3 or L4) with a minimum 2 years of follow-up. Clinical and radiographic parameters, including complications and reoperations, were also collected. Statistical analysis was performed using Student's t-test for qualitative variables. RESULTS: From a dataset of 551 patients, we identified 106 patients (89% female) who underwent a lumbar AVBT (33 lumbar only, 73 bilateral thoracic/lumbar) with mean follow-up of 4.1±1.6 years at which point 85% (90/106) had reached skeletal maturity. Preoperatively, these patients were skeletally immature (age 12.8±1.3 y, Sanders 3.3±0.8, R=0.6±0.9) with a lumbar coronal curve angle of 49.6°±11.2 which corrected to 19.9°±11.2 (P <0.0001) at most recent follow-up. At the latest follow-up, 76.4% (81/106) of the patients harbored a coronal curve angle of < 30°. Twenty patients (18.9%) underwent 23 reoperations, with overcorrection being the most common (10/23, 43%). Broken tethers led to reoperation in 3 instances (3/23, 13%). Six patients in the cohort needed a posterior spinal fusion (6/106, 5.4%). CONCLUSIONS: Vertebral body tethering is a viable treatment option for skeletally immature patients with idiopathic scoliosis. This report is the largest to date for lumbar AVBT, highlighting that 84% of patients harbored a curve < 35° at the latest follow-up but with an 18.9% reoperation rate. LEVEL OF EVIDENCE 3.