Table 3 Univariate analysis of variables associated with screw cut-out in CMN group

Age at surgery

79.2

78.9

83.7

0.235

1.13

0.92–1.38

Sex

0.554

Female

40 (72.7%)

37 (92.5%)

3 (7.5%)

Male

15 (27.3%)

15 (100%)

0

BMI (kg/m ² )

22.4

22.6

19.3

0.136

0.77

0.55–1.09

Days to Surgery

3.1

3.1

2.3

0.741

0.91

0.53–1.56

Fracture classification

0.410

AO/OTA A1

35 (63.6%)

34 (97.1%)

1 (2.9%)

AO/OTA A2

15 (27.3%)

13 (86.7%)

2 (13.3%)

AO/OTA A3

5 (9.1%)

5 (100%)

0

Basicervical fracture extension

0.020

0.10

0.04–0.22

No

47 (85.5%)

47 (100%)

0

Yes

8 (14.5%)

5 (62.5%)

3 (37.5%)

Singh index

1.000

<=3

33 (60.0%)

31 (93.9%)

2 (6.1%)

>3

22 (40.0%)

21 (95.5%)

1 (4.5%)

Cleveland index

1.000

Ideal (zone 5, 8)

52 (94.5%)

49 (94.2%)

3 (5.8%)

Non-ideal (zone 4, 6, 7, 9)

3 (5.5%)

3 (100%)

0

Tip-Apex distance (mm)

16.4

16.2

19.2

0.213

1.21

0.90–1.63

Neck-shaft angle

0.208

Good (<5 degrees)

22 (40%)

22 (100%)

0

Acceptable (5–10 degrees)

23 (41.8%)

20 (87.0%)

3 (13.0%)

Poor (>10 degrees)

10 (18.2%)

10 (100%)

0

Neck-screw axis

0.440

Good (<5 degrees)

36 (65.5%)

34 (94.4%)

2 (5.6%)

Acceptable (5–10 degrees)

12 (21.8%)

12 (100%)

0

Poor (>10 degrees)

7 (12.7%)

6 (85.7%)

1 (14.3%)

Reduction quality (AP view)

0.568

Extramedullary

18 (32.7%)

18 (100%)

0

Anatomical

36 (65.5%)

33 (91.7%)

3 (8.3%)

Intramedullary

1 (1.8%)

1 (1.9%)

0

Reduction quality (Axial view)

0.330

Extramedullary

4 (7.3%)

4 (7.7%)

0

Anatomical

38 (69.1%)

37 (71.2%)

1 (33.3%)

Intramedullary

13 (23.6%)

11 (21.2%)

2 (66.7%)