Associations between radiological grades and clinical severity, lay-off time, muscles involved, etiology and recurrence
| Total | Grade 0 | Grade 1 | Grade 2 | Grade 3 | |
|---|---|---|---|---|---|
| Injuries | 207 | 27 (13%) | 118 (57%) | 56 (27%) | 6 (3%) |
| Clinical severity | |||||
| Minimal | 5 (2%) | 1 (4%) | 4 (3%) | 0 | 0 |
| Mild | 29 (14%) | 12 (44%) | 13 (11%) | 4 (7%) | 0 |
| Moderate | 143 (69%) | 14 (52%) | 89 (75%) | 38 (68%) | 2 (33%) |
| Severe | 30 (15%) | 0 | 12 (10%) | 14 (25%) | 4 (67%) |
| Lay-off time (days)* | 19±17 | 8±3 | 17±10 | 22±11 | 73±60 |
| Muscles involved | |||||
| Biceps femoris | 150 (84%) | 101 (86%) | 45 (81%) | 5 (83%) | |
| Semimembranosus | 20 (11%) | 12 (10%) | 8 (14%) | 1 (17%) | |
| Semitendinosus | 9 (5%) | 5 (4%) | 3 (5%) | 0 | |
| Aetiology | |||||
| Trauma | 130 (64%) | 8 (31%) | 79 (69%) | 39 (70%) | 4 (67%) |
| Overuse | 72 (36%) | 18 (69%) | 35 (31%) | 17 (30%) | 2 (33%) |
| Recurrence | 34 (16%) | 2 (7%) | 20 (17%) | 12 (21%) | 0 |
Radiological grades were classified according to Peetrons27: grade 0 negative MRI without any visible pathology, grade 1 oedema but no architectural distortion, grade 2 architectural disruption indicating partial tear and grade 3 total muscle or tendon rupture. Clinical severity was classified according to the football consensus26: minimal (causing absence of 1–3 days), mild (absence 4–7 days), moderate (absence 8–28 days) and severe (absence>28 days).
↵* Values are mean±SD.