Influence of posture on gait parameters in severe symptomatic lumbar stenosis before and after decompression surgery.

BACKGROUND: We searched to quantify the influence of sagittal vertical axis (SVA) on the improvement of spatiotemporal gait parameters using a gait motion analysis (GMA) before and after decompression surgery in patients suffering from lumbar stenosis (LSS).

METHODS: Thirty-nine patients with severe LSS planned for lumbar decompression underwent a full body biplanar radiographs (EOS®) to quantify the SVA, and have benefited from a three-dimensional GMA one month before surgery (M0) and 6 month (M6) after surgery. The first step of this study was to confirm the validation of three dimensional SVA (3D SVA) for posture analysis. An analysis of modification of the 3D SVA and spatio-temporal gait parameters was then carried out in order to identify any correlation.

RESULTS: Decompression surgery did not significantly improve 3D SVA between M0 and M6 (respectively 49.1 (50.3) versus 49.84 (19.02), p=0.42). Concerning spatio-temporal parameters, we found significant difference for all parameters between M0 and M6. A strong correlation (R2 >0.65) between static SVA (EOS®) and 3D SVA was demonstrated using a statistical regression equation. There was also a statistically significant correlation between SVA (static and 3D) and improvement in spatiotemporal gait parameters after decompression surgery.

CONCLUSION: This study analyses the relationship between postural change (SVA) and improvement in gait parameters measured during GMA before and after decompression surgery for lumbar spinal stenosis. This specific analysis of gait parameters may represent a prognostic assessment tool for the recovery of patients undergoing surgery for a lumbar spinal stenosis.