Hamstring Strain Grade on MRI and Return to Play in Elite Australian Cricket Players.

Abstract

Objective The aims of this study were to (1) examine the relationship between magnetic resonance imaging (MRI)-confirmed hamstring strain grade and time to return to play; (2) examine this relationship specifically in pace bowlers; and (3) describe the incidence, prevalence, and grade of MRI-confirmed hamstring strains in elite Australian cricket players. Design This is a retrospective cohort study. Setting Elite Australian cricket teams over 13.5 seasons were analyzed. Participants Four hundred seventy-eight male and 365 female contracted Australian cricketers participated in this study. Independent variable British Athletics Muscle Injury Classification system grading of hamstring strains, which had received MRI scan, was the independent variable. Main outcome measure The main outcome was time to return to play (days). Results One hundred forty-one hamstring strain injuries with available MRI imaging scans were recorded during the study period (average 3.2 per 100 players per season: male 4.5, female 1.2). The most commonly injured muscle was biceps femoris (63%, 95% confidence interval: 56%-71%) and the most frequent category of injury was grade 2C (27%, 20%-35%). Across all injury grades, players were unavailable for full participation for a median of 22 (interquartile range: 15-38) days and missed 3 (1-6) matches. The number of days unavailable were higher for injuries that were graded 2 or 3, compared with grade 1 injuries (P = 0.004 and P = 0.007, respectively), and injuries that included the tendon compared with those which did not (P = 0.002). Pace bowlers has a higher number of days unavailable compared with players with other dominant skills for grade B and C injuries combined (P = 0.046). Conclusions This study provides evidence that higher grade injuries and those involving the intramuscular tendon are associated with a more prolonged return to play. This finding should be viewed in context of the study limitation that MRI findings may have informed management.