Utilization of Offset Iliac Connectors as Anchoring Sites in Severe Rigid Scoliosis: New Technique

Abstract

Study Design: This was a prospective cohort study. Objectives: To introduce the iliac connectors as fixation options in spinal constructs used for correction of severe scoliosis at locations other than the lumbopelvic region. Methods: Nine patients with severe rigid scoliosis undergoing surgical release and posterior instrumentation in the period between January 2013 and January 2015 were included in this prospective cohort study. Mean age was 18.4 years; 8 had triple structural curves, and the remaining patient had double structural curves. Cobb angles of the primary and compensatory curves were compared with the immediate, 1-year, and 2-year postoperative measurements using the F test, with P value ≤.05 indicating statistical significance. Screw densities of the final constructs were calculated and compared with the screw densities when the offset iliac connectors were not used. Results: One to 4 offset iliac connectors were used in all 9 patients, increasing screw density by a mean of 6.24 ( P < .001). The mean Cobb angle of the major curve was corrected from 98.44° to 58.2° ( P < .001), that of the first compensatory curve, from 56.55° to 38.33° ( P < .001), and that of the second compensatory curve, from 40.75° to 26.63° ( P < .001). There were no intraoperative neurological complications. After a mean follow-up of 30.6 months, the construct remained stable in all patients with no loss of correction. Conclusion: Offset iliac connectors can be a valuable tool to increase screw density in correction of severe scoliosis, thus increasing overall biomechanical strength of the final construct.