TABLE II.
Presentation Characteristics by Diagnosis Group (N = 96)
| Characteristic* | SA Group (N = 9) | LA Group (N = 87) | P Value† |
|---|---|---|---|
| Demographic | |||
| Age at presentation‡ (yr) | 8.6 ± 4.4 | 10.6 ± 3.9 | 0.17 |
| Male sex§ | 7 (78%) | 60 (69%) | 0.69 |
| Height‡ (cm) (n = 79) | 131.1 ± 26.3 | 146.6 ± 22.0 | 0.06 |
| Weight‡ (kg) | 31.9 ± 15.7 | 38.9 ± 17.8 | 0.26 |
| Presented to the emergency room§ | 7 (78%) | 56 (64%) | 0.43 |
| Clinical symptoms | |||
| Maximum temperature‡ (°C) (n = 90) | 38.6 ± 0.9 | 37.6 ± 1.4 | 0.02 |
| Had fever§ (n = 94) | 6 (75%) | 38 (44%) | 0.12 |
| Refused to bear weight§ | 4 (44%) | 18 (21%) | 0.12 |
| Laboratory values | |||
| First serum WBC count‡ (n = 90) (×103/mL) | 11.9 ± 4.8 | 9.5 ± 2.6 | 0.03 |
| Maximum serum WBC count‡ (n = 90) (×103/mL) | 13.6 ± 4.4 | 9.8 ± 2.7 | 0.003 |
| First serum CRP‡ (n = 74) (mg/L) | 8.1 ± 7.9 | 3.7 ± 4.1 | 0.04 |
| Maximum serum CRP‡ (n = 85) (mg/L) | 10.9 ± 8.3 | 4.3 ± 4.6 | 0.005 |
| First serum ESR‡ (n = 84) (mm/hr) | 69.1 ± 35.8 | 36 ± 23.1 | 0.005 |
| Maximum serum ESR‡ (n = 90) (mm/hr) | 84.5 ± 34.7 | 44.4 ± 29.2 | 0.003 |
| Underwent joint aspiration§ (n = 91) | 8 (89%) | 50 (61%) | 0.13 |
| Joint fluid WBC count‡ (×103/mL) | 76.2 ± 3.1 | 60.0 ± 3.9 | 0.30 |
| MRI measures | |||
| Subcutaneous edema§ | 0.003 | ||
| Absent | 1 (11%) | 50 (58%) | |
| <25% of circumference | 2 (22%) | 22 (25%) | |
| 25% to 50% of circumference | 4 (44%) | 12 (14%) | |
| 51% to 75% of circumference | 2 (22%) | 2 (2%) | |
| >75% of circumference | 0 (0%) | 1 (1%) | |
| Myositis§ | 7 (78%) | 74 (85%) | 0.47 |
| No. of muscles involved‡ | 1.4 ± 1.3 | 2.3 ± 1.5 | 0.12 |
| Type of muscle§ | |||
| Popliteus | 4 (44%) | 42 (48%) | 0.83 |
| Vastus medialis (n = 95) | 3 (33%) | 40 (47%) | 0.45 |
| Vastus lateralis (n = 95) | 3 (33%) | 63 (73%) | 0.02 |
| Biceps femoris (n = 95) | 2 (22%) | 23 (27%) | 0.77 |
| Medial gastrocnemius (n = 95) | 0 (0%) | 13 (15%) | 0.99 |
| Lateral gastrocnemius (n = 95) | 1 (11%) | 9 (11%) | 0.95 |
| Tibialis anterior (n = 95) | 0 (0%) | 8 (9%) | 0.99 |
| No. of popliteal lymph nodes‡ (n = 94) | 2 ± 1.3 | 4.1 ± 1.6 | 0.001 |
| Longest popliteal lymph node§ (n = 94) (mm) | 9.3 ± 3.6 | 12.5 ± 5.2 | 0.08 |
| Popliteal fluid present§ | 4 (44%) | 49 (56%) | 0.50 |
| Hemosiderin present§ | 0 (0%) | 6 (7%) | 0.99 |
| Synovial thickening present§ (n = 95) | 9 (100%) | 85 (99%) | 1.00 |
| Tissue inflammation | 0.92 | ||
| Confined to area around knee§ (n = 95) | 4 (44%) | 42 (49%) | |
| Extends superiorly or inferiorly >10 but ≤15 cm§ (n = 95) | 3 (33%) | 23 (27%) | |
| Extends >15 cm§ (n = 95) | 2 (22%) | 21 (24%) |
*
The n values in parentheses represent the total number of subjects with available data for the given category.
†
Bold values in this column are significant.
‡
The values are given as the mean and the standard deviation.
§
The values are given as the number of patients, with the percentage in parentheses.