Table 3 Comparison of preoperative, 1-year postoperative, and 5-year postoperative clinical and radiological outcomes

 Extension

−6.2 (10.6)

−1.6 (5.4)

− 1.78 (5.4)

0.002 ^a (Pre vs 1-year post: 0.005 ^b, pre vs 5-years post: 0.008 ^b)

 Flexion

125.9 (14.7)

115.8 (10.2)

113.5 (8.2)

< 0.0001 ^a (Pre vs 1-year post: < 0.0001 ^b, pre vs 5-years post: < 0.0001 ^b, 1-year post vs 5-years post: 0.007 ^b)

 JOA score (points)

52.3 (10.0)

84.8 (5.0)

77.5 (7.4)

< 0.0001 ^a (Pre vs 1-year post: < 0.0001 ^b, pre vs 5-years post: < 0.0001 ^b, 1-year post vs 5-years post: < 0.0001 ^b)

 Oxford knee score (points)

17.7 (4.4)

35.0 (2.3)

32.3 (3.6)

< 0.0001 ^a (Pre vs 1-year post: < 0.0001 ^b, pre vs 5-years post: < 0.0001 ^b, 1-year post vs 5-years post: < 0.0001 ^b)