Background
Methods
Study design and setting
Patients and eligibility criteria
Variables, data sources, and measurements
Bias
Statistical methods
Results
Participants
Descriptive data
SSI group (n = 41) | Non-SSI group (n = 246) | Total (n = 287) |
p
| |||||
---|---|---|---|---|---|---|---|---|
Mean
|
SD
|
Mean
|
SD
|
Mean
|
SD
| |||
Age | y | 52.1 | 11.1 | 50.5 | 14.2 | 50.7 | 13.8 | 0.4 |
Weight | kg | 85.0 | 18.2 | 78.1 | 18.4 | 79.2 | 18.5 |
0.03
|
BMI | kg/m² | 27.7 | 5.1 | 26.7 | 5.4 | 26.8 | 5.4 | 0.2 |
n
|
%
|
n
|
%
|
n
|
%
| |||
Sex | Male | 28 | 68.3 % | 113 | 45.9 % | 141 | 49.1 % |
0.01
|
Female | 13 | 31.7 % | 133 | 54.1 % | 146 | 50.9 % | ||
Comorbidities | None | 20 | 48.8 % | 136 | 55.3 % | 156 | 54.4 % | |
1–3 | 17 | 41.5 % | 95 | 38.6 % | 112 | 39.0 % | ||
4–5 | 3 | 7.3 % | 4 | 1.6 % | 7 | 2.4 % | ||
≥ 6 | 1 | 2.4 % | 7 | 2.9 % | 8 | 2.8 % | 0.2 | |
Diabetes mellitus | 5 | 12.2 % | 16 | 6.6 % | 21 | 7.3 % | 0.3 | |
Immunosuppression | 1 | 2.4 % | 3 | 1.2 % | 4 | 1.4 % | ||
Smoking | 16 | 39.0 % | 50 | 20.3 % | 66 | 23.0 % |
0.03
| |
Drug abuse | 7 | 17.1 % | 12 | 4.9 % | 19 | 6.6 % |
0.01
|
SSI group (n = 41) | Non-SSI group (n = 246) | Total (n = 287) |
p
| |||||
---|---|---|---|---|---|---|---|---|
n
|
%
|
n
|
%
|
n
|
%
| |||
AO category | B | 8 | 19.5 | 142 | 57.7 | 150 | 52.3 |
< 0.001
|
C | 33 | 80.5 | 104 | 42.3 | 137 | 47.7 | ||
AO subcategory | ||||||||
B1 | 2 | 4.8 | 24 | 9.8 | 26 | 9.1 | ||
B2 | 1 | 2.4 | 44 | 18.0 | 45 | 15.7 | ||
B3 | 5 | 12.2 | 74 | 30.3 | 79 | 27.5 | ||
C1 | 3 | 7.3 | 18 | 7.4 | 21 | 7.3 | ||
C2 | 6 | 14.6 | 12 | 4.9 | 18 | 6.3 | ||
C3 | 24 | 58.5 | 74 | 30.3 | 98 | 34.1 | ||
Concomitant injury of the affected knee | 22 | 53.6 | 96 | 36.4 | 118 | 41.1 |
0.01
| |
Compartment syndrome | 16 | 39.0 | 14 | 5.7 | 30 | 10.5 |
< 0.001
| |
Open fracture | 9 | 22.0 | 7 | 2.9 | 16 | 5.6 |
< 0.001
| |
Concomitant injury of other body region | 20 | 48.8 | 47 | 19.3 | 67 | 23.3 |
< 0.001
| |
Polytrauma | 8 | 19.5 | 17 | 7.0 | 25 | 8.7 |
0.01
|
Surgical procedure | SSI group (n = 41) | Non-SSI group (n = 246) | Total (n = 287) | |||
---|---|---|---|---|---|---|
n
|
%
|
n
|
%
|
n
|
%
| |
External fixation | 26 | 63.4 | 55 | 22.6 | 81 | 28.2 |
Plate | 8 | 19.5 | 69 | 28.3 | 77 | 26.8 |
Screw | 1 | 2.4 | 28 | 11.5 | 29 | 10.1 |
Plate and screw | 3 | 7.2 | 75 | 30.8 | 78 | 27.2 |
Double plate | 3 | 7.2 | 14 | 5.7 | 17 | 5.9 |
TKA | 0 | 0.0 | 2 | 08 | 2 | 0.7 |
Other | 0 | 0.0 | 3 | 1.2 | 3 | 1.0 |
Outcome data
SSI group (n = 41) | Non-SSI group (n = 246) | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Mean | SD | Min | Max | Mean | SD | Min | Max | Diff | 95 % confidence interval | p | ||
KOOS symptoms | 57.9 | 22.9 | 14.3 | 100 | 75.0 | 22.3 | 10.7 | 100 | -17.1 | -25.0 | -9.3 | < 0.001 |
KOOS pain | 54.5 | 28.8 | 0.0 | 100 | 75.4 | 23.4 | 2.8 | 100 | -20.9 | -30.5 | -11.2 | < 0.001 |
KOOS ADL | 48.8 | 27.5 | 0.0 | 100 | 80.5 | 22.6 | 0.0 | 100 | -31.7 | -40.9 | -22.5 | < 0.001 |
KOOS Sport/Rec | 36.9 | 37.1 | 0.0 | 100 | 41.0 | 35.7 | 0.0 | 100 | -4.2 | -16.9 | 8.5 | 0.51 |
KOOS QoL | 37.8 | 31.5 | 0.0 | 100 | 56.4 | 30.2 | 0.00 | 100 | -18.7 | -29.4 | -7.9 | 0.001 |
KOOS5 | 48.7 | 23.2 | 5.4 | 97.6 | 71.5 | 21.8 | 7.00 | 100 | -22.8 | -30.7 | -14.9 | < 0.001 |
Multivariable models
Coefficient | 95 % Confidence interval |
p
| |||||
---|---|---|---|---|---|---|---|
KOOS | SSI | -15.3 | -23.3 | -7.2 | < 0.001 | ||
symptoms | AO C vs. B | -11.2 | -17.3 | -5.1 | < 0.001 | ||
Concomitant injury | -5.9 | -10.0 | -1.8 | 0.004 | |||
KOOS | SSI | -13.3 | -22.8 | -3.7 | 0.006 | ||
pain | Pre-existing conditions | ||||||
1–3 | -4.0 | -10.4 | 2.4 | 0.22 | |||
4–5 | -11.3 | -30.0 | 7.4 | 0.23 | |||
≥ 6 | -27.6 | -51.8 | -3.4 | 0.023 | |||
AO C vs. B | -12.1 | -19.6 | -4.5 | 0.002 | |||
Compartment syndrome | -10.9 | -22.8 | 1.1 | 0.070 | |||
External fixation | 5.1 | -3.7 | 13.9 | 0.25 | |||
KOOS | SSI | -22.8 | -31.6 | -14.0 | < 0.0.001 | ||
ADL | Pre-existing conditions | ||||||
1–3 | -9.1 | -15.1 | -3.0 | 0.003 | |||
4–5 | -12.3 | -29.9 | 5.3 | 0.165 | |||
≥ 6 | -30.3 | -53.1 | -7.6 | 0.008 | |||
AO C vs. B | -10.5 | -17.0 | -4.0 | 0.001 | |||
Compartment syndrome | -10.6 | -21.7 | 0.5 | 0.058 | |||
KOOS | Pre-existing conditions | ||||||
Sport/Rec | 1–3 | -20.7 | -29.9 | -11.4 | < 0.001 | ||
4–5 | -23.7 | -50.3 | 2.9 | 0.076 | |||
≥ 6 | -23.7 | -58.5 | 11.1 | 0.175 | |||
AO C vs. B | -9.8 | -19.0 | -0.5 | 0.036 | |||
Concomitant injury | -6.8 | -13.3 | -0.3 | 0.036 | |||
KOOS | Body weight (10 kg) | -2.5 | -4.8 | -0.2 | 0.033 | ||
QoL | Pre-existing conditions | ||||||
1–3 | -8.3 | -16.2 | -0.4 | 0.037 | |||
4–5 | -19.1 | -41.9 | 3.6 | 0.094 | |||
≥ 6 | -14.2 | -43.9 | 15.6 | 0.34 | |||
AO C vs. B | -14.2 | -22.6 | -5.8 | < 0.001 | |||
Compartment syndrome | -15.9 | -29.6 | -2.2 | 0.021 | |||
KOOS5 | SSI | -16.2 | -24.7 | -7.6 | < 0.001 | ||
Pre-existing conditions | |||||||
1–3 | -8.4 | -14.1 | -2.7 | 0.004 | |||
4–5 | -13.7 | -30.2 | 2.8 | 0.099 | |||
≥ 6 | -23.5 | -44.8 | -2.1 | 0.029 | |||
AO C vs. B | -10.7 | -16.8 | -4.5 | 0.001 | |||
Concomitant injury | -3.6 | -7.7 | 0.5 | 0.082 | |||
Compartment syndrome | -9.1 | -19.6 | 1.3 | 0.081 | |||
Lysholm knee scoring scale | SSI | -11.4 | -22.1 | -0.6 | 0.036 | ||
Pre-existing conditions | |||||||
1–3 | -7.9 | -15.8 | 0.0 | 0.047 | |||
4–5 | -14.1 | -37.0 | 8.7 | 0.22 | |||
≥ 6 | -17.5 | -47.3 | 12.3 | 0.24 | |||
AO C vs. B | -15.3 | -23.5 | -7.0 | < 0.001 |