Comparison of Clinical and Radiologic Outcome of Adolescent Idiopathic Scoliosis Treated with Hybrid Hook-Screw Instrumentation versus Universal Clamp System

Background. In surgical treatment of adolescent idiopathic scoliosis (AIS), hybrid universal clamp system has been used by some authors. We aimed to compare the clinical and radiologic outcome of hybrid universal clamp with hybrid thoracic hook lumbar screw. Methods. A prospective study was performed on 56 consecutive patients with AIS, who had alternatively undergone a posterior spinal fusion and instrumentation with hybrid thoracic hook lumbar screw system (28 patients: group A) and hybrid universal clamp system (28 patients: group B) between June 2006 and January 2014 at Imam Reza University Hospital and had been followed up for more than two years. The comparison was according to radiographic changes, operative time, intraoperative blood loss, complications, and Scoliosis Research Society (SRS-22) outcome scores. Results. The preoperative mean curve Cobb angle was 58° ± 7° (42°-74°) in group A and 60° ± 9° (46°-75°) in group B. The mean final coronal curve correction was 60.4% and 75.5% in groups A and B, respectively (P = 0.001). Postoperative SRS outcome scores were also comparable. Conclusion. Universal clamp instrumentation had a significantly better curve correction and lower complication rate compared with hybrid thoracic hook lumbar screw. Both instrumentation methods had similar operative time, intraoperative blood loss, and postoperative SRS outcome scores.