Magnetic resonance imaging in acute hamstring injury: can we provide a return to play prognosis?

BACKGROUND: Sports physicians are increasingly requested to perform magnetic resonance imaging (MRI) of acute hamstring muscle injuries and to provide a prognosis of the time to return to play (RTP) on the basis of their findings.

OBJECTIVES: To systematically review the literature on the prognostic value of MRI findings for time to RTP in acute hamstring muscle injuries.

DATA SOURCES: The databases of PubMed, EMBASE, CINAHL, Web of Science and Cochrane Library were searched in June 2013.

STUDY ELIGIBILITY CRITERIA: Studies evaluating MRI as a prognostic tool for determining time to RTP in athletes with acute hamstring injuries were eligible for inclusion.

DATA ANALYSIS: Two authors independently screened the search results and assessed risk of bias using criteria for quality appraisal of prognosis studies. A best-evidence synthesis was used to identify the level of evidence.

RESULTS: Of the 12 studies included, one had a low risk of bias and 11 a high risk of bias. There is moderate evidence that injuries without hyperintensity on fluid-sensitive sequences are associated with a shorter time to RTP and that injuries involving the proximal free tendon are associated with a longer time to RTP. Limited evidence was found for an association of central tendon disruption, injury not affecting the musculotendinous junction and a total rupture with a longer time to RTP. The other MRI findings studied showed either no association or there was conflicting evidence.

CONCLUSION: There is currently no strong evidence for any MRI finding that gives a prognosis on the time to RTP after an acute hamstring injury, owing to considerable risks of bias in the studies on this topic.