Range of Motion According to the Fusion Level after Lumbar Spine Fusion: A Retrospective Study

Abstract

Objective: The purpose of this study was to compare the range of motion (ROM) after spinal fusion according to the levels of lumbar spinal fusion (L4/5 and/or L5/S1). Methods: One hundred fifty-six patients were included in this study after undergoing thoracolumbar or lumbar fusion from April 2010 to December 2016. All patients had a numerical rating scale less than 4. We categorized the patients according to the fusion level for statistical purposes: 86 patients in group I with L4/5 or L3/4/5 fusion, 24 in group II with only L5/S1 fusion, 34 in group III with L4/5/S1 or L3/4/5/S1 fusion, and 12 in group IV with T10-S1 fusion for lesions. The ROM was evaluated by physicians of the rehabilitation medicine department using a blinded method, and the result was compared between each group. The student t-test was used in the statistical analysis. Results: The ROM of lumbar flexion was not different between each group, except for groups I and IV (p=0.038). The ROM of lumbar extension was statistically affected by fusion at the L4/5 or L5/S1 level. The ROM of lumbar lateral flexion had a tendency of being affected by fusion at the L4/5 or L5/S1 level. The ROM of lumbar lateral rotation was not affected by fusion at the L4/5 or L5/S1 level. Conclusion: The results suggest that the lower lumbar segments (L4/5 and especially L5/S1) contribute to spinal ROM (extension and lateral flexion), but these segments alone do not play significant roles in spinal flexion movements