What a New Study Reveals About MRI and Predicting Muscle Injury Recurrence in Pro Athletes

In a study looking at acute muscle injuries in professional athletes, the use of magnetic resonance imaging (MRI) within a week prior to their return to play demonstrated significant re-injury risk with intermuscular edema, callus gap and transversal and/or mixed connective tissue gap.

Should magnetic resonance imaging (MRI) play a more prominent role in assessing an athlete’s ability to return to the field of play after rehabbing a lower extremity muscle injury?

In a recent retrospective study, published in Insights into Imaging, researchers reviewed MRI findings in 59 professional athletes who suffered their first acute lower-extremity muscle injury and were subsequently deemed to have had successful rehabilitation prior to returning to play. The study authors reviewed MRI scans obtained within six days of the acute muscle injury and within a week prior to the athletes’ return to play, according to the study.

The study authors noted a 15.2 percent rate (nine of 59 study participants) of injury recurrence. They found that MRI scans taken prior to the athletes’ return to play revealed that callus gap, intermuscular edema and transversal and/or mixed connective tissue gap were independently associated with elevated injury recurrence risk.

“The present results are clinically relevant, not only because of the identification of specific predictive radiological signs per se, but also for emphasizing the role of MRI performed prior to RTP (return to play), when from a clinical point of view, the player is asymptomatic and ready to return to competition,” wrote lead study author Jaime Isern Kebschull, M.D., Ph.D., a musculoskeletal radiologist affiliated with the Radiology Department at the Hospital Clinic of Barcelona in Spain, and colleagues.

The researchers also found that two of the aforementioned MRI findings in combination with interstitial feathery edema resulted in a nearly 30 percent risk of muscle injury recurrence.

Kebschull and colleagues noted that incomplete resolution of edema does not prohibit a successful return to play for the athlete. They also maintained that isolated intramuscular edema was not associated with increased occurrence of re-injury. However, Kebschull and colleagues said that intramuscular edema assessment can be complex.

“ … The different patterns of cotton-like (adaptive), interstitial feathery edema and intermuscular fluid on fluid sensitive patterns can be observed at baseline and control MRI studies, although cotton-like edema was only seen in 4% of participants at baseline, increasing to 40% and 55.6% in non-reinjury and re-injury groups, respectively, at MRI prior to (return to play) as a normal sign of adaptation during the healing process,” explained Kebschull and colleagues.

In regard to study limitations, the authors acknowledged that athlete age and sport-specific differences in physical therapy rehabilitation protocols were not assessed as potential factors with reinjury. They also noted that future studies with larger numbers of participants and re-injury events are necessary in order to extrapolate these findings to a broader athletic population.