Table 1 Socio-demographic characteristics of patients in case and control group

Age (years)**

35.07 ± 15.16

43.03 ± 15.73

33.41 ± 14.52

< 0.001

 0 ~ 

63 (16.28)

1 (1.49)

62 (19.38)

0.263

 20 ~ 

91 (23.51)

24 (35.82)

67 (20.94)

 30 ~ 

83 (21.45)

16 (23.88)

67 (20.94)

 40 ~ 

71 (18.35)

11 (16.42)

60 (18.75)

 50 ~ 

53 (13.70)

11 (16.42)

42 (13.12)

 60 ~ 

26 (6.72)

4 (5.97)

22 (6.87)

Sex

0.777

 Male

294 (75.97)

50 (74.63)

244 (76.25)

 Female

93 (24.03)

17 (25.37)

76 (23.75)

Areas**

< 0.001

 Rural

187 (48.32)

16 (23.88)

171 (53.44)

 Urban

200 (51.68)

51 (76.12)

149 (46.56)

Occupation*

0.039

 “White-trouser” workers

183 (47.29)

24 (35.82)

159 (49.69)

 “Blue-trouser” workers

204 (52.71)

43 (64.18)

161 (50.31)

Education

0.614

 High

78 (20.16)

12 (17.91)

66 (20.63)

 Low

309 (79.84)

55 (82.09)

254 (79.37)

Smoking

42 (10.85)

4 (5.97)

38 (11.88)

0.158

Drinking

4 (1.03)

3 (4.48)

1 (0.031)

0.131

Type 2 Diabetes**

12 (3.10)

9 (13.43)

3 (0.94)

< 0.001

Hypertension

9 (2.33)

3 (4.48)

6 (1.88)

0.401

Cardiovascular disease **

10 (2.58)

9 (13.43)

1 (0.031)

< 0.001

BMI

23.36 ± 4.06

23.55 ± 4.30

23.32 ± 4.06

0.677

 Thin

34 (8.79)

8 (11.94)

26 (8.12)

0.626

 Normal

198 (51.16)

28 (41.79)

170 (53.13)

 Overweight

119 (30.75)

24 (35.82)

95 (29.69)

 Obesity

36 (9.30)

7 (10.45)

29 (9.06)

Surgery **

< 0.001

 End-to-end suture

48 (12.40)

2 (2.99)

46 (14.36)

 Neurolysis

286 (73.90)

63 (94.03)

63 (94.03)

 Nerve transfers and neurolysis

13 (3.36)

2 (2.99)

11 (3.44)

 PTTF and neurolysis

30 (7.75)

0 (0)

30 (9.37)

 Achilles tendon lengthening and neurolysis

10 (2.58)

0 (0)

10 (3.14)

Post operation

 Follow-up time (months)

15.29 ± 2.60

14.67 ± 2.81

15.37 ± 1.93

0.791

 Knee Immobilization **

122 (31.52)

6 (8.96)

(36.25)

< 0.001