Summary: Spinal range of motion is limited in all three planes of motion following a spine fusion and instrumentation in adolescents with idiopathic scoliosis.
Introduction: The spinal range of motion (ROM) of adolescents with idiopathic scoliosis (AIS) is affected by instrumentation and fusion. No universally accepted guidelines exist for deciding on the level of instrumentation. This study measures the changes in spinal ROM pre and post instrumentation and fusion and compares them to age‐group matched controls.
Methods: This is a prospective study of 26 patients with AIS (18 F, 8M, mean age 14.5 ± 2.2y; Cobb angle > 50 degrees) who underwent spinal instrumentation and fusion. 16 subjects returned for a post operative assessment. Trunk ROM was assessed with a 3‐Dimensional Motion Capture system (VICON; Oxford, UK). While standing the subjects were instructed to move their trunk maximally in all three planes (transverse, coronal and sagittal). The max values were statistically compared within the Scoliosis Group (left side to right side) and to a “Control Group” of age matched typically developing adolescents (p<0.05). Further analysis was done to compare those subjects in the Scoliosis Post‐Op Group that had the fusion at L2 or above (L2+) to those that had a fusion at L3 or below (L3‐).
Results: Within the Scoliosis Pre‐Op Group there was significantly greater rotation and side‐bending to the left versus the right. The Scoliosis Group had less trunk rotation and side‐bending to the right along with less forward bending flexibility (Table 1) compared to the Control Group. Post operatively the Scoliosis Group lost greater than 46% ROM in the transverse plane, greater than 44% ROM in the coronal plane, 50% ROM bending forward and 15% bending back.
Conclusion: AIS have less ROM in all three planes and move asymmetrically compared to Controls. One year following spinal fusion and instrumentation further loss of ROM was measured in all three planes with the most motion lost in subjects fused at L3 or below.
Significance: These results provide a comparison for spinal motion prior to surgical instrumentation and fusion and also provide realistic expectations for spinal flexibility.