Comparative Study Of Three Rotational Positioning Methods Of Tibial Prosthesis During TKA

ObjectivesThe purpose of this study was to follow up and CT measurements of patients with tibial prosthesis rotation position determined by medial 1/3 of tibial tubercles,Akagi line and ROM technique during total knee arthroplasty,In order to find out the accurate localization method of tibial prosthesis and guide the clinical work.MethodsA total of 129 cases of total knee arthroplasty for knee osteoarthritis in our department from July 2020 to April 2021 were analyzed.According to the positioning method of tibial prosthesis randomly selected preoperatively,the patients were divided into three groups.There were 40 cases in medial 1/3 of tibial tubercles group(Insall group),including 9 males and 31 females,10 cases of left knee and 30 cases of right knee,with average age of 66.30±6.07 years and average BMI of 26.65±3.67 kg/m~2.There were51 cases in Akagi group,including 16 males and 35 females,26 cases in left knee and 25cases in right knee,with average age of 65.25±6.12 years and average BMI of 27.80±4.53 kg/m~2.There were 38 cases in ROM technology group,including 6 males and 32females,25 cases in left knee and 13 cases in right knee,with an average age of5.53±6.09 years and an average BMI of 28.83±3.88 kg/m~2.The main research contents included:1.Preoperative evaluation of age,BMI,gender,KSS and WOMAC score,knee range of motion,VAS score,etc.2.Tibial prosthesis was placed intraoperatively according to the previously randomly selected tibial positioning method.3.KSS and WOMAC scores,knee range of motion and VAS scores were followed up.4.On the CT three-dimensional images of the tibial and knee prosthesis after operation,we measured the included angle of the tibial prosthesis axis and the connecting line from the geometric center of the tibial prosthesis platform to the medial edge of the tibial tubercle,from the geometric center of the tibial prosthesis platform to the medial 1/3 point of the tibial tubercle,and the femoral prosthesis axis.5.Statistical methods:Measurement data were described as mean±standard deviation,and independent sample analysis of variance was used for comparison between groups.Counting data were described as the number of cases.Chi-square test was used for comparison between groups,and the test direction was bilateral.P<0.05 was statistically significant.SPSS 25.0 was used to analyze the data.ResultsThe follow-up time was 9-18 months,with an average of 12.65 months.1.There were no statistically significant differences in preoperative age,BMI,gender,KSS and WOMAC scores,knee range of motion and VAS scores among the three groups,indicating that the three groups were comparable.2.The clinical KSS score and functional KSS score in the three groups increased with time.At 6 weeks after surgery,the clinical KSS score and functional KSS score in the Insall group were significantly lower than those in the Akagi group and the ROM group(P<0.05),but there was no statistical difference between the three groups at the last follow-up(P>0.05).3.WOMAC pain,WOMAC stiffness,WOMAC difficulty of daily activities score and VAS score in 3 groups decreased with time,and knee motion increased with the extension of postoperative time,with no statistical difference between groups(P>0.05).4.Relative to the line from the geometric center of the tibial prosthesis platform to the medial edge of the tibial tuberosity,the average external rotation of the tibial prosthesis axis in the Insall group was 5.85°±1.87,the average internal rotation in the Akagi group was 0.07°±1.70,and the average internal rotation in the ROM group was1.27°±6.01.Compared with the line from the geometric center of the tibial prosthesis platform to the middle 1/3 point of the tibial tuberosity,the average internal rotation of the tibial prosthesis axis in Insall group was 1.60°±1.37,the average internal rotation in Akagi group was 6.69°±1.55,and the average internal rotation in ROM group was7.99°±6.18.Compared with the axis of the femoral prosthesis,the mean external rotation of the tibial prosthesis in the Insall group was 3.37°±2.12,the mean internal rotation in the Akagi group was 0.35°±2.54,and the mean internal rotation in the ROM group was1.45°±3.25.The measurement Angle of Insall group was statistically different from that of Akagi group and ROM group(P<0.05),while the measurement results of Akagi group and ROM group were not statistically different(P>0.05).ConclusionThe medial 1/3 of tibial tubercles can easily lead to tibial prosthesis external rotation placement,which may lead to temporary dysfunction in the short term after surgery,but has no effect on long-term prognosis.Akagi line can be used to obtain more accurate prosthesis alignment and good clinical efficacy.Better alignment can also be obtained using ROM technique,but accurate placement of the femoral component and proper soft tissue release are preconditions and internal rotation is prevented.