Bone bruise vs. non-displaced fracture on MRI: a novel grading system for predicting return-to-play

Objective To devise an MRI grading scheme for osseous contusion patterns in elite hockey players for predicting return-to-play (RTP). Methods A retrospective review was performed to identify traumatic lower extremity osseous injuries in professional hockey players. A total of 28 injuries (17 players) were identified over a 10-year period. All had MRIs acquired at ≥ 1.5 T within a mean interval of 2 days from initial injury. MRIs were retrospectively reviewed by 3 musculoskeletal radiologists for osseous contusion pattern, classified as grade 1 (mild), 2 (moderate), or 3 (severe). Grade 3 contusions were further subdivided by the presence or absence of fracture, defined as discrete cortical disruption on MRI or follow-up CT. RTP was calculated from date of injury to next game played based on game log data. Statistical analysis was performed using ANOVA and post hoc unpaired t test. Results Mean RTP for grade 1, 2, and 3 injuries was 2.8, 4.5, and 20.3 days, respectively. Grade 3 injuries without and with cortical fractures had mean RTP of 18.3 and 21.4 days, respectively. ANOVA analysis between groups achieved statistical significance ( p