Lumbar Vertebral Body Tethering
Alan A. Stein, Amer F. Samdani, Alexander J. Schüpper, Zan Naseer, Ronit Shah, Sabrina Zeller, Joshua M. Pahys, Solomon Praveen Samuel, Alejandro Quinonez, Steven W. Hwang
Abstract
STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To evaluate the outcomes and reoperation rates in patients with adolescent idiopathic scoliosis undergoing lumbar anterior vertebral body tethering (AVBT). BACKGROUND: AVBT is a viable option for growing children. The benefit of motion preservation must be balanced by a higher reoperation rate. A paucity of reports has addressed lumbar AVBT. MATERIALS AND 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 of 2 years of follow-up. Clinical and radiographic parameters, including complications and reoperations, were also collected. Statistical analysis was performed using the Student t test for qualitative variables. RESULTS: From a data set of 551 patients, we identified 106 patients (89% female) who underwent a lumbar AVBT (33 lumbar only, 73 bilateral thoracic/lumbar) with a 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 yr, 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.