Table 4 Subgroup analysis with matched pairs (matching Sanders type, age, and Böhler’s angle postoperative in normal range); comparison of postoperative data and complications between C-Nail and plate osteosynthesis

Age (years)

44.3 ± 9.7

44.8 ± 10.3

43.8 ± 9.3

Sanders IV

48 (73%)

24 (73%)

24 (73%)

Böhler’s angle in normal range

62 (94%)

31 (94%)

31 (94%)

 Type of fracture (open)

3 (5%)

1 (3%)

2 (6%)

0.56

 Böhler’s angle preoperative

16.2 ± 10.5

16.9 ± 9.9

15.6 ± 11.2

0.39

 Duration of operation (min)

106.6 ± 28.8

97.2 ± 22.5

116.0 ± 31.4

0.015

 Böhler’s angle postoperative

27.9 ± 5.4

28.7 ± 5.8

27.1 ± 5.1

0.27

 Böhler’s angle difference post-preop.

11.6 ± 9.9

11.8 ± 9.1

11.5 ± 10.8

0.60

 Time duration of follow-up (months)

15.9 ± 13.5

14.3 ± 9.4

17.5 ± 16.6

0.99

 Bone healing achieved

60 (91%)

30 (91%)

30 (91%)

1.00

 Time duration to bone healing (weeks)

14.0 ± 8.0

10.6 ± 4.4

17.4 ± 9.3

< 0.001

 Full weight-bearing achieved (n)

61 (92%)

31 (94%)

30 (91%)

0.64

 Time duration to full weight-bearing (weeks)

12.9 ± 5.4

10.7 ± 4.8

15.2 ± 5.2

< 0.001

 Subtalar arthrosis

17 (30%)

5 (17%)

12 (43%)

0.04

 Subtalar arthrodesis

4 (7%)

2 (7%)

2 (7%)

1.00

 AOFAS

81 ± 15.4

80 ± 17

81 ± 13.8

0.91

 Total number of complications

21 (32%)

7 (21%)

14 (42%)

0.06

 Further operations

12 (18%)

6 (18%)

6 (18%)

1.00

 Malposition of screws

4 (6%)

3 (9%)

1 (3%)

0.34

 Wound edge necrosis

13 (20%)

2 (6%)

11 (33%)

0.005

 Superficial wound infection

8 (12%)

2 (6%)

6 (18%)

0.13

 Osteomyelitis

4 (6%)

1 (3%)

3 (9%)

0.30

 Infection with one/multiple pathogens

1 (2%)/4 (6%)

0 (0%)/1 (3%)

1 (3%)/3 (9%)

0.34

 Non-union

2 (3%)

0 (0%)

2 (7%)

0.16