Do ponte osteotomies enhance correction in adolescent idiopathic scoliosis? an analysis of 191 lenke 1A and 1B curves

Study Design Retrospective review of a prospectively collected multicenter database of patients with adolescent idiopathic scoliosis (AIS). Objective To determine if Ponte osteotomies improve correction in Lenke 1A and 1B AIS curves treated with pedicle screws. Summary of Background Data There is little data studying the risks and benefits of Ponte osteotomies in AIS. Methods We identified patients with Lenke 1A and 1B curve types treated with pedicle screw constructs and a 2-year follow-up. They were grouped based on whether they did (PO) or did not (NoPO) have Ponte osteotomies. Demographic, surgical, and radiographic data collected preoperatively and at 2 years were statistically analyzed using unpaired Student t test and Fisher exact test. Results One hundred ninety-one patients met the inclusion criteria (mean age of 14.7 ± 2.2 years), and among those, 125 patients (65.4%) had Ponte osteotomies (average of 4.3 ± 1.5 Pontes per patient). The patients treated with Ponte osteotomies had similar clinical and radiographic parameters (major Cobb: PO = 51.5°, NoPO = 50.8°, p =.6) to the patients who did not have Ponte osteotomies except that they had stiffer and more lordotic curves (Flexibility Index: PO = 47.3%, NoPO = 54.5%, p =.04; T5-T12 kyphosis: PO = 18.7°, NoPO = 23.2°, p =.02). At 2 years, the patients treated with Ponte osteotomies had significantly better thoracic Cobb angle correction (Correction Index: PO = 67.1%, NoPO = 61.8%, p =.01) and an increase in T5-T12 kyphosis (PO = +3.0°, NoPO = -0.4°, p =.045). The Ponte group demonstrated greater rib prominence correction (PO = 53.2%, NoPO = 38.4%, p =.02). There were no neurologic events in this cohort. Conclusions Although the use of Ponte osteotomies was not randomized, these data suggest that greater deformity correction in all 3 planes may be possible when Ponte osteotomies are performed for the stiffer and more lordotic Lenke 1A and 1B curves. The clinical significance of these overall small statistical differences remains to be determined. Level of Evidence III.