Objective Evaluation of Neurogenic Intermittent Claudication for Patients With Lumbar Spinal Stenosis Based on Plantar Pressure Analysis

Abstract

Study design: A cross-sectional study.

Objective: To quantify the severity of neurogenic intermittent claudication (NIC) for patients with lumbar spinal stenosis (LSS) based on the center of pressure trajectory.

Summary of background data: NIC is one of the typical symptoms of LSS. So far, the severity level of NIC is mainly evaluated by the subjective description of patients, which might be biased by patients' background differences and thus lead to an ineffective diagnosis or inappropriate treatment for LSS. Therefore, it remains necessary to develop a reliable clinical technique for quantitative evaluation of NIC to achieve more effective therapy for LSS.

Materials and methods: In the present study, the Footscan pressure system was used to detect the center of pressure trajectory. The real-time walking distance (rtWD) and the corresponding displacement of the medial-lateral center of pressure (ML-COP) were calculated based on the trajectory. The differences of ML-COP between LSS and control groups were analyzed using a one-way repeated measures analysis of variance. Regression and Pearson correlation analysis were used to investigate the correlation between rtWD and ML-COP, as well as the relation between the Oxford Claudication Score (OCS) and clinical evaluation indicators.

Results: The present study included 31 LSS patients and 31 healthy controls. There were no significant differences in demographic data between the two groups ( P >0.05). The results indicated that ML-COP would increase with the number of laps in the LSS group while not in the control group. Also, a linear relationship was identified between the ML-COP and rtWD for LSS patients ( R2 >0.80, P <0.05). Since the incremental rate of ML-COP for LSS patients was reflected by the regression coefficients of the linear regression analysis, thus the regression coefficients were defined as the claudication correlation coefficients (CCCs). In addition, it was indicated by the statistical analysis that there was a strong positive correlation between OCS and CCC ( r =0.96; P <0.001) and a medium negative correlation with final walking distance ( r =-0.67; P <0.001). It was also noticed that there was no significant correlation between the average ML-COP and OCS ( r =-0.03; P =0.864).

Conclusions: The ML-COP of LSS patients would increase with the patients' walking distance. This incremental rate, characterized by the CCC, would be used as an effective indicator to quantify the severity level of the NIC for potentially more accurate and reliable diagnosis, evaluation, and treatment of LSS.

Level of evidence: 3.