Table 2 Univariate analyses of risk factors associated with SSI after ORIF of closed tibial plateau fracture

Gender (male)

20 (80.0)

677 (62.5)

0.074

Diabetes mellitus

2 (8.0)

150 (13.8)

0.401

Hypertension

2 (8.0)

197 (18.2)

0.189

Cerebrovascular disease

1 (4.0)

18 (1.7)

0.373

Chronic heart disease

1 (4.0)

51 (4.7)

0.868

History of any surgery

1 (4.0)

118 (10.9)

0.271

Allergy to any medications

3 (12.0)

138 (12.7)

0.912

Living area

0.827

 Rural

15 (60.0)

673 (62.1)

 Urban

10 (40.0)

410 (37.9)

Preoperative duration (days)

0.000*

 1–7

8 (32.0)

723 (66.8)

 >7

17 (68.0)

360 (33.2)

Anesthesia (general)

10 (40.0)

450 (41.6)

0.876

Number of fracture

0.057

 1

11 (44.0)

679 (62.7)

 ≥2

14 (56.0)

404 (37.3)

Mechanism (high-energy)

17 (68.0)

676 (62.4)

0.569

Current smoking

4 (16.0)

147 (13.6)

0.727

Alcohol consumption

2 (8.0)

101 (9.3)

0.821

Bone grafting (yes)

13 (52.0)

225 (20.8)

0.000*

Bone graft type

0.000*

 Autograft

8 (32.0)

113 (10.4)

 Allograft

5 (20.0)

112 (10.3)

Operative duration (minutes)

0.001*

 1–120

3 (12.0)

505 (46.6)

 >120

22 (88.0)

578 (53.4)

Intraoperative blood loss (ml)

0.000*

 1–400

15 (60.0)

931 (86.0)

 >400

10 (40.0)

152 (14.0)

ASA class

0.942

 I

3 (12.0)

155 (14.3)

 II

18 (72.0)

768 (70.9)

 III or above

4 (16.0)

160 (14.8)

Prophylactic antibiotics use

22 (88.0)

1038 (95.8)

0.057

Postoperative antibiotics use

22 (88.0)

1005 (92.8)

0.362

Fixation type

0.774

 Plate and screws

23 (92.0)

1012 (93.4)

 Screws only

2 (8.0)

71 (6.6)

Intraoperative blood transfusion

6 (24.0)

106 (9.8)

0.020*

Fracture type (Schartzker)

0.000*

 I–IV

6 (24.0)

835 (77.1)

 V–VI

19 (76.0)

248 (22.9)

Age (years)

0.461

 18–44

15 (60.0)

514 (47.5)

 45–64

8 (32.0)

462 (42.7)

 ≥65

2 (8.0)

107 (9.9)

BMI (kg/m²)

0.361

 18.5–23.9

9 (36.0)

473 (43.7)

 <18.5

1 (4.0)

11 (1.0)

 24–27.9

8 (32.0)

383 (35.4)

 ≥28.0

7 (28.0)

216 (19.9)

TP (<60 g/L)

11 (44.0)

285 (26.3)

0.048*

ALB (<35 g/L)

12 (48.0)

224 (20.7)

0.001*

GLOB (<20 g/L)

4 (16.0)

157 (14.5)

0.833

A/G values

0.009*

 1.2–2.4

18 (72.0)

970 (89.6)

 <1.2

6 (24.0)

81 (7.5)

 >2.4

1 (4.0)

32 (3.0)

ALT (>40 U/L)

12 (48.0)

199 (18.4)

0.000*

AST (>40 U/L)

11 (44.0)

140 (12.9)

0.000*

TBIL (>21 μmol/L)

4 (16.0)

91 (8.4)

0.180

DBIL (>6 μmol/L)

9 (36)

302 (27.9)

0.372

IBIL (>14 μmol/L)

6 (24)

162 (15.0)

0.213

ALP (>100 U/L)

3 (12.0)

50 (4.6)

0.087

GGT (>60 U/L)

7 (28.0)

183 (16.9)

0.145

CHE (>12 kU/L)

1 (4.0)

27 (2.5)

0.635

TBA (>10 μmol/L)

2 (8.0)

65 (6.0)

0.679

HCRP (>8 mg/L)

17 (68.0)

732 (67.6)

0.965

LDH (>250 U/L)

10 (40.0)

244 (22.5)

0.040*

HBDH (>182 U/L)

5 (20.0)

183 (16.9)

0.683

TC (>5.2 mmol/L)

1 (4.0)

127 (11.7)

0.232

TG (>1.7 mmol/L)

3 (12.0)

186 (17.2)

0.496

HDL-C (<1.1 mmol/L)

12 (48.0)

435 (40.2)

0.430

LDL-C (>3.37 mmol/L)

2 (8.0)

148 (13.7)

0.413

VLDL (>0.78 mmol/L)

2 (8.0)

181 (16.7)

0.246

Na+ (<135 mmol/L)

13 (52.0)

320 (29.5)

0.015*

K+ (mmol/L)

0.772

 3.5–5.5

24 (96.0)

1002 (92.5)

 <3.5

1 (4.0)

70 (6.5)

 >5.5

0 (0.0)

11 (1.0)

CL- (mmol/L)

0.151

 99–110

18 (72.0)

929 (85.8)

 <99

6 (24.0)

135 (12.5)

 >110

1 (4.0)

19 (1.8)

TCO2 (mmol/L)

0.475

 20–30

25 (100.0)

1022 (94.4)

 <20

0 (0.0)

17 (1.6)

 >30

0 (0.0)

44 (4.1)

GLU (>6.1 mmol/L)

9 (36.0)

373 (34.4)

0.871

UREA (>8 mmol/L)

0 (0.0)

74 (6.8)

0.176

UA (>upper limit)

1 (4.0)

85 (7.8)

0.477

WBC (>10*10⁹/L)

15 (60.0)

344 (31.8)

0.003*

NEUT (1.8–6.3*10⁹/L)

0.281

 1.8–6.3

9 (36.0)

556 (51.3)

 <1.8

0 (0.0)

6 (0.6)

 >6.3

16 (64.0)

521 (48.1)

LYM (<1.1*10⁹/L)

5 (20.0)

303 (28.0)

0.379

MON (>0.6*10⁹/L)

15 (60.0)

658 (60.8)

0.939

RBC <lower limit

17 (68.0)

436 (40.3)

0.005*

HGB <lower limit

21 (84.0)

587 (54.2)

0.003*

HCT <lower limit

22 (88.0)

675 (62.3)

0.009*

MCV (fL)

0.365

 82–100

25 (100.0)

1002 (92.5)

 <82

0 (0.0)

40 (3.7)

 >100

0 (0.0)

41 (3.8)

MCH (pg)

0.564

 27–34

24 (96.0)

990 (91.4)

 <27

0 (0.0)

47 (4.3)

 >34

1 (4.0)

46 (4.2)

MCHC (g/L)

0.423

 316-354

23 (92.0)

1008 (93.1)

 <316

0 (0.0)

32 (3.0)

 >354

2 (8.0)

43 (4.0)

PDW (%)

0.557

 12–18.1

21 (84.0)

945 (87.3)

 <12

4 (16.0)

116 (10.7)

 >18.1

0 (0.0)

22 (2.0)

D-Dimer (>0.5 mg/L)

20 (80.0)

650 (60.0)

0.043*

AG (mmol/L)

0.024*

 8–16

16 (64.0)

854 (78.9)

 <8

7 (28.0)

212 (19.6)

 >16

2 (8.0)

17 (1.6)

OSM < 260 mOsm/L

6 (24.0)

104 (9.6)

0.017*

CA (mmol/L)

0.480

 2.11–2.52

17 (68.0)

822 (75.9)

 <2.11

8 (32.0)

246 (22.7)

 >2.52

0 (0.0)

15 (1.4)

P (mmol/L)

0.027*

 0.85–1.51

17 (68.0)

932 (86.1)

 <0.85

2 (8.0)

53 (4.9)

 >1.51

6 (24.0)

98 (9.0)

Mg (mmol/L)

0.008*

 0.75–1.02

18 (72.0)

941 (86.9)

 <0.75

6 (24.0)

79 (7.3)

 >1.02

1 (4.0)

63 (5.8)

PLT (10*10⁹/L)

0.905

 125–350

20 (80.0)

901 (83.2)

 <125

1 (4.0)

41 (3.8)

 >350

4 (16.0)

141 (13.0)