Application Of Plantar Pressure Analysis In Evaluating The Preoperative And Postoperative Walking Ability In Lumbar Spinal Stenosis Patients

BackgroundLSS is a common degenerative disease in elder population.For patients with severe symptoms,current treatment option is to relieve the nerve compression in the spinal canal by surgery.Accurate assessment of surgery indications is extremely important for the effect of treatment.However,a key feature of the disease is that the patient’s NIC symptoms are prominent and the objective signs are obscure.It is difficult to diagnosis LSS through physical examination.In addition,due to the stenotic images may not be associated with clinical symptoms,it is difficult to determine the severity of the disease by measuring the dimension of the spinal canal.Currently,questionnaires such as JOA and ODI are often used as a method of assessing the severity of the disease,however,it is still a subjective judgment of patients,moreover,there is no evaluation for the typical symptom of NIC.Previous studies have confirmed that the walking ability in patients with lumbar spinal stenosis is an important index for the severity of LSS,which can also be used for evaluating the efficacy of surgery,moreover,the occurrence of NIC will damage the balance function of the patients,result in a limited walking ability.Previous studies have reported that plantar pressure analysis can objectively evaluate the walking function of the subject by measuring the dynamic trajectory of the COP,and the ML-COP is confirmed to be useful for evaluating the dynamic balance function.To our knowledge,there haven’t been any report on the characteristic of COP trajectory after the occurrence of NIC in LSS patients,the relationship between dynamic balance function and walking distance is still unknown.How to achieve an objective quantitative assessment of walking ability in patients with LSS,in addition to compare the improvement of walking ability before and after decompression and fusion surgery,accordingly evaluate the efficacy of the surgery remains to be investigated.Objective:1.The Footscan^?pressure system was used to measure the dynamic trajectory of foot COP after the occurrence of NIC in patients with LSS.The ML-COP was calculated to evaluate the balance function between LSS patients and normal control,and investigate the changes of balance function when LSS patients walk continuously after the occurrence of NIC.2.Investigate the correlation between balance function and walking function after the occurrence of NIC symptoms in patients with LSS,and develop an objective evaluation index based on COP to reflect the walking ability,in addition to verify the correlation between the index and clinical symptoms and image findings.3.Comparatively evaluate improvement of walking ability and clinical symptoms of LSS patients before and after spinal decompression and fusion surgery to objectively evaluate the efficacy of surgical treatment.Methods:1.The experiment was conducted in two groups.1)Experimental group:patients diagnosed with LSS and NIC symptoms;2)Control group:healthy adults of the similar age.The Footscan^?pressure system was used to perform a dynamic plantar pressure test,the range and velocity of ML-COP were calculated accordingly to investigate the difference in balance function between the experimental group and the control group,the trend of ML-COP range and velocity under different walking distances were investigated.2.Regression analysis was used to verify the correlation between ML-COP and walking distance.The NICI was developed to describe the trend of ML-COP.Clinical symptoms were evaluated and imaging parameters were measured in the experimental group.Spearman rank correlation analysis was conducted to verify the correlations between the NICI,claudication distance,OCS score,SSS score and DSA/SCA of the patients.3.Patients in the experimental group were treated by decompression and fusion surgery in addition to home exercise rehabilitation,and the improvement of claudication index,OCS score,and SSS score were compared before suregey,3 months and 6 months after decompression and fusion surgery.Results:1.A total of 20 LSS patients met the criteria for inclusion.（1）The ML-COP range and velocity of the experimental group increased significantly compared to the control group;（2）The ML-COP range of the experimental group increased with the walking distance,while the ML-COP range of the control group did not.2.The linear regression analysis results of ML-COP and walking distance were statistically significant.The NICI was significantly negatively correlated with the claudication distance of patients（r=-0.894,P<0.001）,significantly positively correlated with the OCS score of patients（r=0.741,P<0.001）,significantly positive correlated with the SSS_1,2 score（r=0.744,P<0.001）,and significant negative correlated with the DSA/SCA of the patient（r=-0.806,P<0.001）.3.16 LSS patients were successfully followed up after decompression and fusion surgery.（1）The NICI was not significantly improved compared with 3 months postoperative（P=0.909）,and it was significantly improved at 6 months（P<0.001）;（2）OCS score was significantly decreased 3 months postoperative（P<0.001）,it improved further at 6 months compared with 3 months（P<0.001）;（3）SSS_1,2 at 3 months postoperative was significantly lower than preoperative（P<0.001）,and 6 months postoperative was basically the same as that at 3 months（P=0.182）.The SSS₃ at 6months was significantly lower than that at 3 months after operation（P<0.001）.Conclusions:1.After the occurrence of NIC,the balance function in LSS patients is significantly damaged compared to the normal population,and as the patient’s walking distance increases,their balance function further decreases,which is linearly related to walking distance.2.The NICI calculated basing on the linear trend of balance function can objectively reflect their walking ability of LSS patients and also has strong correlation with the imaging and clinical symptom,which provides a new objective method for patients’preoperative symptom evaluation.3.Decompression and fusion surgery combined with standardized home exercise can significantly improve the walking ability and clinical symptoms of LSS patients.The claudication index can be used to objectively evaluate the efficacy of decompression and fusion surgery.In addition,the postoperative walking ability improvement in LSS patients has some deviations between subjective and objective assessment.Patients are more likely to subjectively overestimate their own walking ability.There needs more emphasis on postoperative home exercise in LSS patients.