Use of a novel corrective device for correction of deformities in adolescent idiopathic scoliosis

Background Adolescent idiopathic scoliosis (AIS), with an incidence of 3%, is a common deformity. Correction of severe curvature of the deformity has attracted much investigation to achieve safe, reproducible results. We present our experience with a novel device for the correction of deformities across a spectrum of curve types, the rod link reducer. This system allows direct visualization of a mass derotation to achieve deformity correction. Methods Prospective cohort study of patients with severe AIS treated in our institution during 2017 with major TL/L curves. Pre- and postoperative Cobb angles and coronal balance; operative time; and estimated blood loss, fusion levels, and screw density were recorded. Our results were split between those with a Lenke A/B classification and Lenke C, with a goal of correction of curve in the former and achieving good coronal balance with a preservation of distal motion segments in the latter. Results There were 31 patients enrolled in our series. Within the Lenke A/B group, there were 18 patients, achieving a mean correction of 56% (SD 10%) and a correction of a mean coronal balance of 14.5 mm (SD 12.5 mm) of C7 from the CSVL to 10.9 mm (SD 10.6 mm). Our screw density was 1.3 screws (SD 0.1) per vertebrae fused. Our operative time was 185 min (SD 38 min). Average recorded blood loss was 721 ml (SD 289). In our Lenke C cohort, preoperative and postoperative mean Cobb angles (SD) were 73.3 (13.4) and 33.8 (11.9), respectively, with an average correction of 54% (SD 11%). The mean (SD) operative time was 03:35 (SD 00:35). Fusion levels were over a mean of 12.1 (SD 1.7) vertebrae, with a screw density of 1.3 (SD 0.1) per level. Mean intraoperative blood loss was 829 ml (SD 355). No patient received an allogenic blood transfusion. There were no adverse neurological events in this patient cohort. Conclusions The link rod system allows for excellent correction of spinal deformity and a short operative time.