Table 1 Preoperative data between groups and between the first and second knees

Gender (F/M)

 Female (n, %)

47 (87.04)

80 (83.33)

64 (85.33)

33 (80.49)

0.831

 Male (n, %)

7 (12.96)

16 (16.67)

11 (14.67)

8 (19.51)

Age (year)

67.85 ± 8.31

68.90 ± 7.80

70.43 ± 7.25

68.42 ± 7.68

0.266

BMI (kg/m²)

 1st knee

26.74 ± 4.04

26.22 ± 5.00

26.81 ± 4.75

27.33 ± 5.80

0.654

 2nd knee

27.03 ± 4.04

26.35 ± 5.02

26.97 ± 4.82

27.15 ± 5.71

0.745

 P value

0.701

0.858

0.837

0.890

CCI

2.57 ± 1.24

2.33 ± 1.38

2.52 ± 1.35

2.29 ± 1.40

0.600

The TKA types

 MP (n, %)

32 (59.26)

62 (64.58)

40 (53.33)

24 (58.54)

0.531

 PS (n, %)

22 (40.74)

34 (35.42)

35 (46.67)

17 (41.46)

KSS-knee

 1st knee

36.80 ± 11.22

38.26 ± 10.74

37.87 ± 11.49

38.88 ± 13.08

0.827

 2nd knee

38.22 ± 10.55

39.79 ± 9.80

42.91 ± 7.79

44.37 ± 7.30

0.002

 P value

0.498

0.303

0.002

0.022

KSS-function

 1st knee

38.33 ± 13.21

40.47 ± 13.67

39.20 ± 13.15

40.12 ± 14.25

0.802

 2nd knee

39.54 ± 12.41

41.88 ± 12.74

42.27 ± 10.50

45.24 ± 10.66

0.140

 P value

0.627

0.462

0.117

0.069

WOMAC-pain

 1st knee

17.96 ± 4.47

16.80 ± 3.82

17.39 ± 3.82

16.85 ± 4.29

0.345

 2nd knee

17.13 ± 4.46

16.41 ± 3.71

16.79 ± 3.51

15.12 ± 3.47

0.063

 P value

0.334

0.467

0.318

0.048

WOMAC-stiffness

 1st knee

6.94 ± 1.84

7.28 ± 2.11

7.15 ± 2.06

6.83 ± 2.04

0.605

 2nd knee

6.39 ± 1.72

6.63 ± 1.88

6.47 ± 1.72

5.95 ± 1.63

0.239

 P value

0.108

0.024

0.030

0.034

WOMAC-physical function

 1st knee

57.48 ± 13.64

55.69 ± 14.25

57.24 ± 13.87

56.49 ± 13.61

0.852

 2nd knee

56.11 ± 13.32

54.34 ± 14.18

54.45 ± 12.56

52.66 ± 13.01

0.666

 P value

0.598

0.513

0.199

0.197