Is Lenke Rule About Selective Thoracic Fusion Applicable for Younger Adult Idiopathic Scoliosis Under 40 Years of Age: Comparison With Adolescent Patients.

Abstract

Retrospective study. To evaluate the surgical outcomes of younger adult idiopathic scoliosis patients (YAdIS) with selective thoracic fusion by comparing them with adolescent idiopathic scoliosis (AIS). Seventy-two idiopathic scoliosis patients (36 adults and 36 adolescents) treated by posterior-only all-pedicle screw technique were retrospective reviewed and matched by fusion levels. Radiographic parameters were evaluated preoperatively, postoperatively, and at final follow-up. Operating time, blood loss, transfusion, and complications were noted. The clinical outcome was assessed by the Scoliosis Research Society-22 questionnaire (SRS-22). The major thoracic curves in YAdIS and AIS groups were 56.3° ± 9.7°, 53.3° ± 10.1° and corrected to 17.2° ± 7.3°, 14.9° ± 7.5° respectively without significant difference in correction rate (69.3% vs 72.0%). For the lumbar curve, Cobb angles in 2 groups were 35.6° ± 10.1°and 31.4 ± 9.2° preoperatively, and were spontaneously corrected to 18.5° ± 9.0° and 12.6° ± 8.2°.Correction rates were 48.0% and 59.8% (P < .05). Preoperative and postoperative coronal vertebra alignments (CVA) in the YAdIS group were 20.6 ± 9.7mm and 16.8 ± 7.9mm (P > .05), while in the AIS group was 17.8 ± 10.5mm and 9.7 ± 8.3mm (P < .05). However, sagittal parameters showed significant improvements in thoracic kyphosis in both groups (P < .05). Complication rates were 25% vs 11.1% (P = .13) with no significant difference. Preoperative SRS-22 was worse in the YAdIS group than AIS group. All the scores were significantly improved postoperatively in the YAdIS group. However, in the AIS group, only SRS scores improved significantly. YAdIS can also be treated very well with selective thoracic fusion based on the Lenke rule used for AIS.