The Effect Of Correcting Of Varus Knee Deformity On Clinical Outcomes After TKA

Background: total knee replacement surgery(TKA)in the treatment of knee osteoarthritis,prosthesis selection,in patients with perioperative management,the design of the implant,and technical factors to affect the postoperative clinical curative effect of TKA surgery,and select appropriate implant size,joint line reconstruction,the recovery of soft tissue balance and physical lines of force,is especially important in the operation.Knee varus is a common joint angulation deformity.In the event of varus deformity of the knee,imaging studies showed a proximal tibia or distal femur deformity,narrow medial joint space(or widened lateral joint space),and lower limb mechanical axis < 180 degrees.When the varus Angle > is 20 degrees,the knee deformity may be accompanied by joint dislocation,and more complex reconstruction surgery is required clinically to restore the lower limb line and the motor function of the knee.At present,the investigation of clinical efficacy after TKA shows that the satisfaction of patients after TKA is only 70-89%,66% of patients feel good after TKA,33-54% of patients still have residual preoperative symptoms and joint dysfunction,and the correction of the knee valgus Angle(5-7 degrees)or the recovery of the lower limb line after TKA.It may directly affect the clinical effect of knee TKA surgery.Objectives: This project is to study the influence of the correction of the varus Angle of the knee after TKA on the postoperative clinical outcome of the knee in the surgical treatment of knee osteoarthritis,and to clarify the correlation between the axial Angle of the femur and the tibia before and after the operation(FTA)and the patient's BMI and the postoperative efficacy of TKA.To provide theoretical basis for improve the clinical effect of surgical treatment of knee osteoarthritis.Methods and patients:A total of 129 patients,including 18 males and 111 females,were enrolled in this study.Their mean age was 67.07 years old and their mean body mass index(BMI)was26.65.Inclusion criteria: patients with rheumatoid arthritis or osteoarthritis of the knee,with varus deformity of the knee;Exclusion criteria: post-traumatic knee deformity and preoperative knee valgus deformity.Preoperative data,including gender,age and body mass index(BMI),were collected.TKA was performed by the same surgeon in 129 patients.All surgical approaches were medial parapatellar approach,and femoral and tibial osteotomy was guided by conventional intramedullary positioning.P150 knee surface replacement system(Johnson & Johnson,USA)was used as prosthesis in TKA surgery.Imaging examinations before and after surgery were performed by experienced orthopedic radiologists.The femoral and tibial Angle(FTA),anatomical distal femoral Angle(a LDFA),anatomical proximal tibial Angle(a MPTA),and hip-knee-ankle HKA)axis was measured by AGFA IMPAX PACS software system.The imaging criteria of varus deformity of the knee joint were: FTA at +3 ? +8 was neutral,FTA?+2 was varus,FTA?9 was valgus.Also classified based on postoperative tibial part alignment measured as the a MPTA: neutral(?88,?92),varus(<88),and valgus(>92).A total of 129 patients were divided into three groups: preoperative varus-postoperative normal group,preoperative varus-postoperative varus group,preoperative varus-postoperative valgus group;Follow-up time after TKA: 3-12 months;KOOS score,KSS-KS knee score,KSS-FS and KOOS JR score were used to evaluate the clinical efficacy of knee joint after TKA surgery.The weight criteria of 129 patients were as follows: healthy(BMI 18.5-24.5),overweight(BMI 25-29.5),obese(BMI?30);Graph Pad Prism 8 software was used to display statistical data in the form of mean ± standard deviation.Non-parametric Kruskal-Wallis test and Wilcoxon Matched-pairs signed rank test were used.P <0.05 was considered statistically significant.Results: In this study,129 patients with knee osteoarthritis complicated with varus deformity(female 111,male 18)were studied.The average age was 67.1±7.3 years,the average BMI was 26.7±3.7 kg/m2,and the average hospital stay was 9.1±4.0 days.FTA mean values were-4.7±5.2(preoperative)and 4.5±2.9(postoperative),a LDFA mean values were 83.9±5.1(preoperative)and 84.2±3.3(postoperative),and a MPTA mean values were 84.8±3.1(preoperative)and 89.4±2.7(postoperative).There were significant differences in preoperative FTA among the three groups(P <0.05),while there was no significant difference between preoperative a LDFA and preoperative a MPTA among the three groups(P > 0.05).There was no statistically significant difference in preoperative KSS-FS scores among the three groups(P =0.29),but there were statistically significant differences in preoperative pain,function and daily life(FDL)among the three groups(P =0.14,P=0.29),and there were statistically significant differences in preoperative KOOS-SS scores among the groups(P =0.001).There was no significant difference in preoperative KOOS-Qo L scores between groups(P =0.49).According to the results of postoperative FTA measurement,the results shows a statistically significant difference on KSS-KS,KSS-FS,KOOS SS,KOOS Pain,KOOS FDL,and KOOS Qo L scores between three groups(P <0.05).According to the results of postoperative a MPTA measurement,there was no statistically significant difference in postoperative KSS-KS scores among the three groups(P =0.75),and there was no statistically significant difference in postoperative KSS-FS scores among the three groups(P =0.47).Postoperative KOOS scores,including pain,\function,daily life(FDL)and KOOS-SS scores,showed no statistically significant differences among the three groups(P =0.19,P =0.72,P =0.77).Patients with varus correction to neutral position and varus correction to varus had better quality of life than those with varus correction to valgus.Clinical efficacy of 129 patients: KSS-KS,KOOS-SS,KOOS-pain,KOOS FDL and KOOS JR scores were all excellent or good,while KSS-FS and KOOS Qo L scores were all moderate.Postoperative clinical efficacy evaluation showed that: KSS-KS score was86.9±7.6,KSS-FS score was 67.7±22.9,KOOS-SS score was 91.1±7.74,KOOS-pain score was 96.3±5.9,KOOS-FDL score was 90.1±10.1,KOOS-Qo L score was 69.9±20.4,KOOS JR score was 90.7±8.9;In this study,there was no statistically significant difference in mean age and BMI among the three groups(P =0.34,P =0.079).Conclusions:In the surgical treatment of knee osteoarthritis with varus deformity,the clinical outcomes were better when the postoperative FTA of the knee was between +3° to +8°,and the postoperative FTA,a LDFA,and a MPTA of the knee were closely related to the postoperative clinical outcomes of TKA.