Vertebral coplanar alignment technique: a surgical option for correction of adult thoracic idiopathic scoliosis.

ABSTRACT

PURPOSE: Previous studies have demonstrated vertebral coplanar alignment (VCA) as an effective surgical option for adolescent idiopathic scoliosis (AIS). The purpose of this study is to analyze the outcome of VCA for the surgical correction of adult idiopathic scoliosis (AdIS). METHODS: 35 AdIS patients (mean age 24.2 years) undergoing VCA-instrumentation were reviewed. The main thoracic curve and thoracic kyphosis (TK, T5-T12) were evaluated preoperatively, immediate postoperatively, and at the final follow-up (>1 year). All patients were stratified by the TK modifier before surgery "+" (TK, >40°), "-" (TK, <10°), and "N" (TK, 10°-40°) for normal. The apical vertebral body-to-rib ratio (AVB-R), rib hump (RH), and rotational angle to sacrum (RAsac) were measured to assess the correction of rotational deformity. Quality of life was evaluated with SRS-20 questionnaires. RESULTS: The main thoracic curve (59.1° vs. 19.3°, P < 0.001) and rotational deformity (AVB-R 2.4 vs. 1.7 %, P < 0.001, RH 34.9 vs. 19.1 mm, P < 0.001, RAsac 19.6° vs. 11.9°, P < 0.001) were significantly reduced with surgery. Sagittal deformity improved significantly in group "+" (51.4° vs. 31.6°, P < 0.001) and group "-" (6.2° vs. 20.1°, P < 0.001), while no significant postoperative change in TK was observed in group "N" (23.5° vs. 26.3°, P = 0.270). Patients were followed for an average of 18.7 months with no significant loss of correction. SRS scores improved greatly from 57.7 preoperatively to 71.6 at the final follow-up. CONCLUSIONS: VCA can be effectively used for the correction of the coronal and rotational deformity, with better sagittal profile restoration in adult thoracic idiopathic scoliosis with sagittal malalignment.