General characteristics of study populations
| . | Aim 1 . | Aim 2 . | ||
|---|---|---|---|---|
| Patients with lower-leg injury (N = 1288)* . | Controls (N = 1018)† . | Knee arthroscopy patients (N = 729)‡ . | ||
| Sex | Male, n (%) | 646 (50.2) | 581 (57.1) | 416 (57.1) |
| Age | Median in y (5th-95th percentile) | 46.2 (20.6-73.0) | 50.0 (24.0-67.0) | 49.4 (24.0-67.0) |
| BMI | <18.5 kg/m2, n (%) | 12 (1.0) | 1 (0.1) | 1 (0.1) |
| 18.5-25.0 kg/m2, n (%) | 569 (47.3) | 351 (35.0) | 257 (35.8) | |
| 25.0-30.0 kg/m2, n (%) | 439 (36.5) | 432 (43.2) | 308 (43.0) | |
| >30.0 kg/m2, n (%) | 182 (15.2) | 217 (21.7) | 151 (21.1) | |
| Comorbidity | Yes, n (%) | 138 (11.3) | 83 (8.3) | 58 (8.1) |
| Infections in last 2 mo | Yes, n (%) | 175 (14.6) | 139 (13.9) | 106 (14.8) |
| Smoking | Yes: currently, n (%) | 320 (26.8) | 190 (19.1) | 139 (19.4) |
| Yes: formerly, n (%) | 329 (27.5) | 333 (33.4) | 232 (32.4) | |
| Current use of oral contraceptives§ | Yes, n (%) of women | 110 (18.2) | 85 (19.9) | 54 (17.6) |
| Malignancy in last 5 y | Yes, n (%) | 34 (2.8) | 17 (1.7) | 12 (1.7) |
| ABO-blood type | Homozygote O, n (%) | 521 (43.3) | 403 (44.4) | 300 (46.5) |
| Heterozygote O, n (%) | 549 (45.6) | 411 (45.2) | 279 (43.3) | |
| Homozygote non-O, n (%) | 133 (11.1) | 94 (10.4) | 66 (10.2) | |
| Factor II 20210A mutation | Heterozygote, n (%) | 26 (2.1) | 22 (2.2) | 15 (2.1) |
| Factor V Leiden | Heterozygote, n (%) | 49 (4.0) | 34 (3.7) | 25 (3.8) |
| Homozygote, n (%) | 1 (0.1) | 0 (0.0) | 0 (0.0) | |
| Prophylactic LMWH (after blood sampling) | Yes, n (%) | 639 (49.6) | 513 (50.4) | 371 (50.9) |
| . | Aim 1 . | Aim 2 . | ||
|---|---|---|---|---|
| Patients with lower-leg injury (N = 1288)* . | Controls (N = 1018)† . | Knee arthroscopy patients (N = 729)‡ . | ||
| Sex | Male, n (%) | 646 (50.2) | 581 (57.1) | 416 (57.1) |
| Age | Median in y (5th-95th percentile) | 46.2 (20.6-73.0) | 50.0 (24.0-67.0) | 49.4 (24.0-67.0) |
| BMI | <18.5 kg/m2, n (%) | 12 (1.0) | 1 (0.1) | 1 (0.1) |
| 18.5-25.0 kg/m2, n (%) | 569 (47.3) | 351 (35.0) | 257 (35.8) | |
| 25.0-30.0 kg/m2, n (%) | 439 (36.5) | 432 (43.2) | 308 (43.0) | |
| >30.0 kg/m2, n (%) | 182 (15.2) | 217 (21.7) | 151 (21.1) | |
| Comorbidity | Yes, n (%) | 138 (11.3) | 83 (8.3) | 58 (8.1) |
| Infections in last 2 mo | Yes, n (%) | 175 (14.6) | 139 (13.9) | 106 (14.8) |
| Smoking | Yes: currently, n (%) | 320 (26.8) | 190 (19.1) | 139 (19.4) |
| Yes: formerly, n (%) | 329 (27.5) | 333 (33.4) | 232 (32.4) | |
| Current use of oral contraceptives§ | Yes, n (%) of women | 110 (18.2) | 85 (19.9) | 54 (17.6) |
| Malignancy in last 5 y | Yes, n (%) | 34 (2.8) | 17 (1.7) | 12 (1.7) |
| ABO-blood type | Homozygote O, n (%) | 521 (43.3) | 403 (44.4) | 300 (46.5) |
| Heterozygote O, n (%) | 549 (45.6) | 411 (45.2) | 279 (43.3) | |
| Homozygote non-O, n (%) | 133 (11.1) | 94 (10.4) | 66 (10.2) | |
| Factor II 20210A mutation | Heterozygote, n (%) | 26 (2.1) | 22 (2.2) | 15 (2.1) |
| Factor V Leiden | Heterozygote, n (%) | 49 (4.0) | 34 (3.7) | 25 (3.8) |
| Homozygote, n (%) | 1 (0.1) | 0 (0.0) | 0 (0.0) | |
| Prophylactic LMWH (after blood sampling) | Yes, n (%) | 639 (49.6) | 513 (50.4) | 371 (50.9) |
Percentages indicate proportions in nonmissing data only.
Numbers of missing data for patients with lower-leg injury: BMI (N = 86), comorbidity (N = 70), infection (N = 86), smoking (N = 93), oral contraceptives (N = 37), malignancy (N = 74), ABO blood type (N = 85), factor II mutation (N = 73), and factor V Leiden mutation (N = 77).
Control samples involved preoperative samples of patients who underwent knee arthroscopy. Numbers of missing data for controls: BMI (N = 17), comorbidity (N = 18), infection (N = 18), smoking (N = 21), oral contraceptives (N = 9), malignancy (N = 22), ABO blood type (N = 110), factor II mutation (N = 37), and factor V Leiden mutation (N = 88).
Numbers of missing data for patients who underwent knee arthroscopy: BMI (N = 12), comorbidity (N = 12), infection (N = 12), smoking (N = 12), oral contraceptives (N = 7), malignancy (N = 16), ABO blood type (N = 84), factor II mutation (N = 28), and factor V Leiden mutation (N = 70).
Oral contraceptives included any type of hormonal therapy, including oral contraceptives and intrauterine devices.