Ponte osteotomies to treat major thoracic adolescent idiopathic scoliosis curves allow more effective corrective maneuvers.

Abstract

There is controversy regarding the effect of the Ponte osteotomies in the improvement of coronal correction, its maintenance during follow-up, and the restoration of thoracic kyphosis in adolescent idiopathic scoliosis (AIS). Seventy-three AIS patients with Lenke type 1-4 curves were included. A prospective description of 43 consecutive patients who underwent apical Ponte osteotomies and sublaminar wires with hybrid instrumentation was retrospectively compared to a historical cohort of 30 patients without "Ponte osteotomies". The surgical details and complications were recorded. We evaluated the radiological measurements and SRS-22 Questionnaire scores over a 2-year follow-up. The Ponte group achieved better postoperative (70 vs 57 %) and final (62 vs 50 %) main curve correction P < 0.001, with no significant loss of correction (4.2° vs 2.5°) P = 0.2 at the final follow-up (48 vs 106 months). We did not find a difference in thoracic (T5-T12) postoperative (22° vs 24°) and final (25° vs 26°) mean kyphosis angle. However, the "Ponte osteotomies" helped to achieve a normal sagittal profile, increasing preoperative hypokyphotic curves (<10°) from 6° to 17° (control: 9°-12°; P = 0.01); and preoperative hyperkyphotic curves (>40°) from 52° to 26° (control: 46°-39°; P = 0.01). The length of surgery was similar (4.3 vs 4.6 h), as were the SRS-22 scores. No major complications were found. Ponte osteotomies in major thoracic AIS curves treated by sublaminar wires allowed more effective corrective maneuvers, which improved coronal correction without a significant loss during follow-up. The sagittal profile appears to be determined by other variables; however, "Ponte osteotomies" facilitate the contouring of the desired kyphosis.