Characteristics of intramuscular abnormal low-signal intensity on MRI (fibrous tissues) of initial injury and at return to play (RTP)
| Initial injury | RTP | |||
|---|---|---|---|---|
| Intramuscular fibrosis | ||||
| Present | 4/53 | 8% | 22/53 | 42% |
| Absent | 49/53 | 92% | 31/53 | 58% |
| Involved muscles | ||||
| Biceps femoris long head | 3/4 | 75% | 20/22 | 91% |
| Biceps femoris short head | 0/4 | 0% | 0/22 | 0% |
| Semitendinosus | 0/4 | 0% | 3/22 | 14% |
| Semimembranosus | 1/4 | 25% | 1/22 | 5% |
| Extent of fibrosis | ||||
| Median longitudinal length (minimum–maximum) | 78 mm | 72–88 | 48 mm | 8–190 |
| Median length on axial view (minimum–maximum) | 9.2 mm | 5.4–12.9 | 8.5 mm | 2.8–22.9 |
| Median width on axial view (minimum–maximum) | 4.4 mm | 1.3–9.0 | 4.5 mm | 1.5–20.6 |
MRI, magnetic resonance imaging; RTP, return to play.