Study On The Relationship Between Lumbar Pelvic Sagittal Plane Parameters And Prosthesis Impingement In Patients Who Have Undergone Lumbar Fusion

Objective: Total hip arthroplasty is an intervention with a high success rate for the advanced stage of various severe hip diseases,which fundamentally solves the problem of hip pain and dysfunction in patients.Prosthesis dislocation is one of the most common reasons for revision after THA.The dislocation of the prosthesis can cause severe pain,limited mobility and repeated dislocation of the patient’s hip joint,which brings great physical and mental pain and economic burden to the patient.It is clinically found that the incidence of prosthesis dislocation after total hip arthroplasty in patients with a history of lumbar fusion is significantly higher than that in patients without a history of lumbar fusion,increased rate of prosthesis dislocationis associated with impingement,however,there is still much debate about the impact of different fusion segments on the risk of impingement.In this study,the sagittal plane parameters of the lumbar vertebra and pelvis of patients with different fusion segments were compared with those of normal people.The impact of different fusion segments on impact was explored from the perspectives of balance and mobility,and the reasons for the increased impact risk were explored.Methods: A total of 80 patients who met the inclusion and exclusion criteria were selected from the Department of Spine Surgery of the Second Affiliated Hospital of Inner Mongolia Medical University from August to November 2021.Group A:Lumbar fusion involving the sacrum(n=13);Group B: Single-level fusion not involving the sacrum(n=20);Group C: Multi-level fusion not involving the sacrum(n=24);Group D : Normal group without lumbar fusion(n=23).Sagittal X-ray films of the lumbar pelvis in standing and sitting positions were taken,and their parameters(balance parameters: LL,SS,AA,PFA;mobility parameters: ΔLL,ΔSS,ΔAA,ΔPFA)were measured.The sagittal balance parameters and mobility parameters of the lumbar vertebra and pelvis between the groups were compared respectively,and statistical analysis was performed to analyze the differences(P<0.05).Result:(1)LL is positively correlated with SS,and negatively correlated with AA and PFA;ΔPFA is negatively correlated with ΔLL,ΔSS,ΔAA,while ΔLL,ΔSS,ΔAA is positively correlated;(2)Compared with the D group,the three fusion groups all had a higher impact risk,and there was a significant difference(P<0.05);(3)The standing LL of group A was smaller than that of other groups,and was significantly different from that of group D and group B(P<0.05);Group C standing LL < group B standing LL < group D standing LL,but the difference was not statistically significant(P>0.05);(4)The ΔLL,ΔSS and ΔAA of the three fusion groups were significantly smaller than the ΔLL,ΔSS and ΔAA of the D group,and theΔPFA of the three fusion groups were significantly greater than the D group ΔPFA,with statistical significance(P<0.05);There was no significant difference in ΔSS,ΔAA,and ΔPFA among the three fusion groups(P>0.05),while only ΔLL in group C and ΔLL in group A had significant differences among the three groups(P<0.05).Further research is required.Conclusion:(1)Compared with the D group,the three fusion groups had significantly higher impact risk;(2)From the analysis of mobility,the increased risk of impingement was related to the decreased mobility of the lumbar pelvis and the increased mobility of the femur.The mobility of the three fusion groups was significantly lower than that of the D group,but the differences in mobility among the three fusion groups were not obvious;(3)From the perspective of balance,the smaller the LL,the backward tilt of the pelvis,the vertical acetabulum,the greater the extension of the femur,and the higher the risk of impingement.The impact risks of the three groups were compared with each other,group A > group C > group B.