|Beitragstitel||Clinical Improvement after Decompression Surgery Reflects Improved Gait Symmetry During a Six Minute Walking Test in Patients with Symptomatic Lumbar Spinal Stenosis|
Symptomatic lumbar spinal stenosis (sLSS) is the most common reason for spinal surgery in patients older than 65 years and leads to functional limitations such as reduced walking and standing ability. However, objective measurements of gait and gait asymmetry during prolonged walking are limited. The objective of this study was whether expected postoperative improvements in clinical scores are related to improvements in gait symmetry during a 6-min walk test (6MWT).
Twenty patients with sLSS (9 female; age, 72.0±6.4 years; body mass index, 28.5±5.2 kg/m2) scheduled for decompression and, if required, fusion surgery of the symptomatic level were included after providing informed consent. Patients completed the Oswestry Low Back Pain Disability Index 2.1 (ODI) on the day prior to surgery and 10±3 weeks postoperatively and performed a 6MWT. Gait patterns and asymmetry were recorded with inertial sensors (RehaGait, Hasomed GmbH, Magdeburg, Germany) during the first and last minute. Spatiotemporal parameters (e.g. stride length, stance phase) and sagittal ankle, knee and hip kinematics were calculated by the RehaGait. Gait asymmetry was defined as 100*|right-left|/(0.5*(|right+left|)) for spatiotemporal parameters and as |right-left| for maximum joint angles. Differences between pre- and postoperative data were detected using paired t-tests (α<.05). Relationships between changes in ODI and gait asymmetry in minute 6 were detected using a multiple linear regression model.
The ODI score improved from 31±18 to 17±17 postoperatively (P=.001), while the walking distance (346±111m; P=.617) did not change significantly. Patients with greater improvement in the ODI score had greater postoperative improvement in gait symmetry of foot angles at push off in minute 6 of the 6MWT (R=.550; P=.012).
There was a large heterogeneity in gait asymmetry, ODI score and walking distance during the 6MWT. While overall patients had better ODI scores after surgery as one would expect, those with greater improvements in the clinical ODI score also had greater improvement in gait symmetry indicating improved gait stability. Improved gait symmetry after surgery may not only improve the ability to perform daily activities but may also prevent altered loads in some joints due to asymmetric gait.