| Objective:To investigate the correlation between medial proximal tibial angle,lateral distal femur angle,hip-knee-ankle angle and posterior condylar angle in female patients with varus osteoarthritis of the knee.Methods:270 female patients in our hospital were measured by CT-scan of knee joint and standing lower limb full-length X-ray film from January2018 to August 2020.According to the Kellgren-Lawrence radiographic grade(K-L grade),they were divided into three groups.group A:K-L gradeⅠ,group B:K-L gradeⅡandⅢ,group C:K-L gradeⅣ.There are 70 patients in group A and 100 patients in group B and group C.Medial proximal tibial angle,(MPTA),lateral distal femur angle(LDFA),hip-knee-ankle angle(HKA)were measured by standing lower limb full-length X-ray film and posterior condylar angle(PCA)was measured by CT-scan of knee joint.The correlations between these parameters were analyzed statistically by Pearson correlation analysis and multiple linear regression.Results:1.Group A:The average age was 48.0,ranged from 29 to64.The mean MPTA was 87.39°±1.76°,ranged from 83.80°to 91.20°.The mean LDFA was 87.15°±2.48°,ranged from 82.70°to 95.60°.The mean HKA was 3.77°±1.91°ranged from 0.2°～7.8°.The mean PCA was3.30°±1.40°,ranged from 0°to 5.80°.There was a negative correlation between MPTA and PCA(r=-0.636,P<0.05).There was a weak positive correlation between HKA and PCA(r=-0.636,P<0.05).There is no correlation between LDFA and PCA;2.Group B:The average age was 57.3,ranged from 47 to69.The mean MPTA was 85.45°±1.90°,ranged from 80.50°～91.30°.The mean LDFA was 89.71°。±2.61°,ranged from 84.50°～95.30°.The mean HKA was7.77°±2.95°ranged from 1.20°～15.80°.The mean PCA was3.27°±1.29°,ranged from 0.40°to 6.30°.There was a negative correlation between MPTA and PCA(r=-0.572,P<0.05).There is no correlation between HKA、LDFA and PCA;3.Group C:The average age was 63.9,ranged from 48to 80.The mean MPTA was 84.93°±2.28°,ranged from 80.20°to 90.80°.The mean LDFA was 90.79°±3.26°,ranged from 82.80 to 98.30°.The mean HKA was 10.53°±4.44°ranged from 0.90°to 20.20°.The mean PCA was3.20°±1.46°,ranged from 0°～7.30°.There was a negative correlation between MPTA and PCA(r=-0.435,P<0.05).There is no correlation between HKA、LDFA and PCA;4.The all patients:a formulas were demonstrated for predicting the PCA:PCA=35.053-0.360×MPTA-0.307×K-L grade(R~2=0.281)Conclusions:1.The MPTA and K-L grades were negatively correlated with PCA,suggesting that the external rotation angle of the femoral prosthesis increased with the increase of the degree of proximal tibial varus in osteoarthritis patients undergoing total knee arthroplasty.2.The PCA can be predicted to some extent by measuring the MPTA and determing K-L grade by standing lower limb full-length X-ray film before operation using the form:PCA=35.053-0.360×MPTA-0.307×K-L grade(R~2=0.281).3.There is no correlation between HKA、LDFA and PCA in clinical practice. |
