Study On The Change Of Lumbar Spinal Canal Volume After Total Knee Arthroplasty

Objective The purpose of this study is to compare the cross-sectional area,lumbar spinal canal volume,lumbar lordosis angle(lumbarlordosis,LL),sacral inclination angle(sacralslope,SS)and lumbar JOA score of patients undergoing total knee arthroplasty(totalkneearthroplasty,TKA)before and after total knee arthroplasty(TKA).The purpose of this study is to explore the influence of TKA on lumbar sagittal balance parameters and spinal canal volume,and to explore the reasons for the occurrence or aggravation of lumbar symptoms after TKA.Methods A total of 32 patients who met the inclusion and exclusion criteria were selected from our hospital from November 2020 to November 2022.The patients were divided into three groups according to knee flexion angle(Knee flexion angle,KA): group A: KA < 15 °,group B: 15 °≤ KA < 30 °,group C: KA≥30°.The thin CT data of lumbar vertebrae before and after operation were taken,and the measurement parameters were collected(objective parameters: lumbar canal volume,cross-sectional area of spinal canal,lumbar lordosis angle,sacral inclination angle;subjective parameters: lumbar JOA score).The subjective and objective parameters of each group were compared and statistically analyzed,and the differences were analyzed(P < 0.05).Results(1)The volume of lumbar spinal canal after TKA in group B and group C decreased by(0.94 ±1.70)cm3 and(3.40 ±2.18)cm3 respectively,(2)The LL in group C was higher than that before operation,but there was no significant difference in LL between group B and C before and after operation.The SS of group A was larger than that of group A,and there was no significant difference between group B and C in SS before and after operation.(3)The LL of group A was higher than that of group B and C,and there was no significant difference between group B and group C.The SS of group A was higher than that of group B,and there was no significant difference between AC and BC groups.(4)There was no difference in cross-sectional area of lumbar spinal canal among groups A,B and C.Conclusion(1)Patients with knee flexion contracture angle ≥ 15 °will have a decrease in lumbar spinal canal volume after TKA for more than 6 months,which may be the cause of lumbar symptoms after TKA and need to be further studied.(2)Knee flexion deformities are corrected in a short time after TKA,and new compensatory changes will occur in the lumbar spine and pelvis in order to ensure sagittal balance,and LL and SS will increase.(3)The greater the knee flexion angle,the smaller the LL and SS in patients with knee osteoarthritis,in order to maintain the sagittal balance of the body.