Cohen's MRI scoring system has limited value in predicting return to play.
OBJECTIVE
Numerous authors have hypothesised that MRI scoring systems provide a valid means of predicting return to play duration following an acute hamstring muscle strain. The purpose is to prospectively investigate the predictive value of the MRI scoring system of Cohen for return to sport (RTS), following an acute hamstring injury.


METHODS
Male football (soccer) players (n = 139) with acute onset posterior thigh pain underwent standardised clinical and MRI examinations within 5 days after injury. All players underwent a standardised physiotherapy regimen with RTS documented. The MRI scoring was statistically evaluated against RTS.


RESULTS
One hundred and ten MRI-positive hamstring injuries were evaluated with RTS duration ranging from 1 to 66 days. Total Cohen's MRI score accounted for approximately 4% of the variance in RTS duration. When comparing those with an MRI score of 10 or more took on average 9.8 days longer to RTS than those with an MRI score less than 10 (effect size: 0.85, p < 0.01).


CONCLUSIONS
Utilising the Cohen's MRI scoring system previously described, we were unable to provide a clinically useful prognosis for RTS in male soccer players. This may reflect the broader challenges of attempting to accurately determine RTS duration from imaging performed at a single point in time.


METHODS
Prospective case series, IV.
Aspetar, Orthopaedic and Sports Medicine Hospital, Doha, Qatar.|High Performance Sport NZ, Sport Research Institute of New Zealand, Millenium Institute of Sport and Health, Mairangi Bay, Auckland, New Zealand.
Bruce
B
Hamilton
Aspetar, Orthopaedic and Sports Medicine Hospital, Doha, Qatar.|Oslo Sports Trauma Research Center, Department of Sports Medicine, Norwegian School of Sports Science, Oslo, Norway.
Arnlaug
A
Wangensteen
Aspetar, Orthopaedic and Sports Medicine Hospital, Doha, Qatar.
Rod
R
Whiteley
Aspetar, Orthopaedic and Sports Medicine Hospital, Doha, Qatar.
Emad
E
Almusa
Aspetar, Orthopaedic and Sports Medicine Hospital, Doha, Qatar.
Liesel
L
Geertsema
Aspetar, Orthopaedic and Sports Medicine Hospital, Doha, Qatar.
Stephen
S
Targett
Aspetar, Orthopaedic and Sports Medicine Hospital, Doha, Qatar. johannes.tol@aspetar.com.|Acedemic Center for Evidence Based Medicine (ACES), Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands. johannes.tol@aspetar.com.
Johannes L
http://orcid.org/0000-0001-5322-8445
JL
Tol
D000293:Adolescent; D000328:Adult; D001265:Athletic Injuries / Q000000981:diagnostic imaging*; D000070633:Hamstring Muscles / Q000000981:diagnostic imaging* / Q000293:injuries; D006305:Health Status Indicators; D006801:Humans; D007869:Leg Injuries / Q000000981:diagnostic imaging*; D008279:Magnetic Resonance Imaging; D008297:Male; D010808:Physical Examination; D011379:Prognosis; D011446:Prospective Studies; D012008:Recurrence; D000068958:Return to Sport; D012916:Soccer / Q000293:injuries*; D013848:Thigh / Q000000981:diagnostic imaging / Q000293:injuries; D013997:Time Factors; D055815:Young Adult
MRI; Muscle injury; Return to play