Posterior spinal fusion with multilevel posterolateral convex disc releases for the treatment of severe thoracolumbar scoliosis

Background: Severe, rigid thoracolumbar scoliosis presents a surgical challenge to achieve 3-dimensional correction, maximize distal motion segments, and avoid operative morbidity conferred by combined anterior-posterior approaches or 3-column osteotomies. We present a new approach for releasing these curves, using multilevel posterolateral convex disc release (PCDR) and posterior instrumented fusion. Methods: There were 3 adults and 1 adolescent (mean age, 31.8 years; 2 females) with severe progressive thoracic and transforaminal lumbar (major) idiopathic scoliosis (IS) who were treated with 3-level PCDR, multiple posterior column osteotomies, and posterior instrumented thoracolumbar fusion with all-pedicle screw constructs. Results: Restoration of global coronal and sagittal alignment was achieved for all patients (minimum 2-year follow-up). Lowest instrumented vertebra (LIV) was L4 in 2 patients and L3 in the remaining 2. All except 1 were fused to the lower end vertebra. Postoperatively, mean thoracolumbar curve was reduced from 77.38 (range, 698-918) to 21.88 (72%D), LIV tilt decreased from 26.88 to 8.38, and LIV translation improved (2.5-1.2 cm; 58%D), whereas lumbar lordosis remained unchanged. Average central sacral vertical line shift measured via C7 sagittal vertical axis changed from 1.4 to 0.7 cm. There were no complications except for dysesthesias in the lower extremity on the side of the PCDR in 1 patient, which resolved after 3 months. Conclusions: Severe thoracolumbar IS presents a surgical challenge to achieve 3-dimensional correction, minimize fusion levels, and avoid procedural morbidity. PCDR is a novel technique that may facilitate this correction with minimal procedure-related morbidity.