The Correlation Study Between Measurement Of HKA In Early Phase And Knee Stretch Activity After TKA

Introduction:TKA is the final treatment for knee osteoarthritis.The purpose of this study was to investigate the patients with TKA in our hospital.Taking the LLR before discharge,measureing the HKA,and analying the correlation between HKA in early phase and knee stretch activity.Understanding whether the knee joint is not fully extended will affect the measurement of HKA.It provides reference for clinical review.Methods:A retrospective study was performed on 102 patients who underwent primary replacement of knee joint in the joint surgery department from January 2017 to March 2018.Age,sex,hospitalization,preoperative and postoperative straightening were recorded.HKA Angle was measured and recorded by using LLR before and after surgery.The data obtained were calculated and compared by means of two double-blind measurements.Patients were divided into three groups according to their early postoperative knee straightening:A(fully extended,31 cases)?B(strech activity between 1 to 3,41 cases)?C(strech activity over 3,30 cases).The difference of HKA Angle between each group was compared.The correlation between postoperative straightening and HKA Angle of each group was analyzed.In addition,102 patients were randomly sampled.Fifty patients were taken out to inform them by telephone to return for review,LLR and HKA Angle were measured and recorded by the same method.The difference of HKA Angle between preoperative,postoperative and follow-up was compared.Correlation analysis was conducted between postoperative straightening to postoperative HKA Angle and ? HKA(difference between postoperative and follow-up HKA Angle),Finally,proper statistical methods were used to compare the relationship between the ?HKA angle and each index.Multivariate linear regression analysis was carried out for ?HKA angle and influencing factors.Results:?A total of 102 patients with KOA were collected.25 males(knee)and 77 females(knee).Average age:68.00 ±6.60 years?the average length of stay was 13.55 ± 3.55 days.the average preoperative HKA angle was 7.70 ±4.28 degrees?the mean preoperative straightening was 5.53 ± 5.77 degrees.the average postoperative HKA angle was 4.08 ± 2.86 degrees?The mean postoperative straightening was 2.31 ± 2.04.There were no statistically significant differences in gender,age,length of stay,preoperative straightening and preoperative HKA angle between the three groups(p>0.05);?The difference of HKA angle and straight degree between the three groups was statistically significant.Postoperative HKA angle increased with the straightening.There was a high positive correlation between postoperative HKA angle and postoperative straightening of group B and C and with the increase of straightening,the correlation increased(the correlation coefficients r were 0.948 and 0.967,respectively,all p values were<0.05)?50 patients were followed up(8 males,42 females).Average age of 67.74 ± 7.20?the average length of stay was 14.00 ±3.00 days.the average preoperative HKA angle was 7.00 ± 4.70 degrees?the mean preoperative straightening was 5.70±5.60 degrees?the average postoperative HKA angle was 3.20 ± 2.50 degrees?the mean postoperative straightening was 1.90± 1.60 degrees?the mean follow-up HKA angle was 1.50 ±1.30 degrees?mean ? HKA Angle 2.02 ± 1.89 degrees?the average time of LLR review was 5.20 ± 2.42 months?the anova of repeated measurement of HKA angle before,after and during follow-up showed statistically significant difference in time principal effect.Further pairwise comparison revealed differences between HKA angle and preoperative and postoperative HKA angle.Follow-up HKA angle was significantly lower than preoperative and postoperative HKA angle.?After follow-up,there was-a high positive correlation between postoperative straightening and postoperative HKA angle and ?HKA angle in 50 patients.(the correlation coefficient r is 0.969 and 0.858 respectively,and the p value is all<0.05).There was no correlation between ?HKA angle and age,hospitalization time,preoperative HKA and other indicators,and the difference was not statistically significant.Multiple linear regression analysis showed that:the degree of postoperative straight to delta HKA changes have influence,influence factors for its independence,were positively correlated,and that the greater the degree of postoperative unbend,delta HKA is bigger(adjusted R2=0.874,F=57.615,P<0.001).Conclusion:1,After TKA,early HKA Angle was highly positively correlated with postoperative knee straightening;2,The higher the degree of Limited degree of knee extension after surgery,the greater the HKA angle in the early postoperative period;3,Patients after TKA surgery should not take LLR too early.It can reduce both medical costs and radiation exposure.