Table 1 Patient demographics and risk factors

Sex

 Female

130 (62.8%)

88 (63.3%)

42 (61.8%)

 Male

77 (37.2%)

51 (36.7%)

26 (38.2%)

Age (years)

55 (± 14)

53 (± 14)

57 (± 13)

BMI

24.1 (± 3.2)

24.0 (± 3.3)

24.5 (± 2.9)

NEER classification

 Two-part

63 (30.4%)

51 (36.7%)

12 (17.6%)

 Three-part

91 (44.0%)

58 (41.7%)

33 (48.5%)

 Four-part

53 (25.6%)

30 (21.6%)

23 (33.8%)

Fracture-dislocation

 No

179 (86.5%)

122 (87.8%)

57 (83.8%)

 Yes

28 (13.5%)

17 (12.2%)

11 (16.2%)

Low BMD of proximal humerus

 No

88 (42.5%)

62 (44.6%)

26 (38.2%)

 Yes

119 (57.5%)

77 (55.4%)

42 (61.8%)

Humeral head extension

  ≥ 8 mm

112 (54.1%)

86 (61.9%)

26 (38.2%)

  < 8 mm

95 (45.9%)

53 (38.1%)

42 (61.8%)

Medial hinge comminuted

 No

174 (84.1%)

127 (91.4%)

47 (69.1%)

 Yes

33 (15.9%)

12 (8.6%)

21 (30.9%)

GT comminuted

 No

184 (88.9%)

128 (92.1%)

56 (82.4%)

 Yes

23 (11.1%)

11 (7.9%)

12 (17.6%)

Volume of the main GT fragment (mm³)

2180 (± 796)

2185 (± 841)

2169 (± 700)

Surface area of the main GT fragment (mm²)

2339 (± 689)

2334 (± 709)

2348 (± 650)

The main GT fragment separate (from humeral head)

 No

56 (27.1%)

44 (31.7%)

12 (17.6%)

 Yes

151 (72.9%)

95 (68.3%)

56 (82.4%)

Displacement of the main GT fragment (mm)

7.2 (± 7.5)

6.8 (± 7.2)

8.1 (± 7.9)

Adequate medial support

 No

44 (21.3%)

27 (19.4%)

17 (25.0%)

 Yes

163 (78.7%)

112 (80.6%)

51 (75.0%)

Residual head-shaft displacement

  ≤ 5 mm

171 (82.6%)

116 (83.5%)

55 (80.9%)

  > 5 mm

36 (17.4%)

23 (16.5%)

13 (19.1%)

Head-shaft angle

 110°–150°

182(87.9%)

120 (86.3%)

62 (91.2%)

  > 150° or < 110°

25 (12.1%)

19 (13.7%)

6 (8.8%)

Residual GT displacement

  ≤ 5 mm

154 (74.4%)

122 (87.8%)

32 (47.1%)

  > 5 mm

53 (25.6%)

17 (12.2%)

36 (52.9%)