Acute hamstring injury in football players: Association between anatomical location and extent of injury-A large single-center MRI report.
OBJECTIVE
To describe in detail the anatomic distribution of acute hamstring injuries in football players, and to assess the relationship between location and extent of edema and tears, all based on findings from MRI.


METHODS
Retrospective observational study.


METHODS
We included 275 consecutive male football players who had sustained acute hamstring injuries and had positive findings on MRI. For each subject, lesions were recorded at specific locations of the hamstring muscles, which were divided into proximal or distal: free tendon, myotendinous junction, muscle belly, and myofascial junction locations. For each lesion, we assessed the largest cross-sectional area of edema and/or tears. We calculated the prevalence of injuries by location. The relationships between locations and extent of edema and tears were assessed using a one-sample t-test, with significance set at p<0.05.


RESULTS
The long head of biceps femoris (LHBF) was most commonly affected (56.5%). Overall, injuries were most common in the myotendinous junction and in proximal locations. The proximal myotendinous junction was associated with a greater extent of edema in the LHBF and semitendinosus (ST) muscles (p<0.05). Proximal locations in the LHBF had larger edema than distal locations (p<0.05). Distal locations in the ST muscle had larger tears than proximal locations (p<0.05).


CONCLUSIONS
The proximal myotendinous junction (LHBF and ST muscles) and proximal locations (LHBF muscle) are more commonly affected and are associated with a greater extent of edema in acute hamstring muscle injury. Distal locations (ST muscle), however, seem to be more commonly associated with larger tears.
Aspetar, Orthopaedic and Sports Medicine Hospital, Qatar; Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, USA; Department of Radiology, Hospital do Coração and Teleimagem, Brazil.
Michel D
MD
Crema
Aspetar, Orthopaedic and Sports Medicine Hospital, Qatar; Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, USA.
Ali
A
Guermazi
Aspetar, Orthopaedic and Sports Medicine Hospital, Qatar.
Johannes L
JL
Tol
Clinical Epidemiology and Training Unit, Department of Medicine, Boston University School of Medicine, USA.
Jingbo
J
Niu
Aspetar, Orthopaedic and Sports Medicine Hospital, Qatar; Department of Sports Medicine, High Performance Sport New Zealand, New Zealand.
Bruce
B
Hamilton
Aspetar, Orthopaedic and Sports Medicine Hospital, Qatar; Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, USA; Department of Radiology, University of Erlangen-Nuremberg, Germany. Electronic address: frank.roemer@aspetar.com.
Frank W
FW
Roemer
D000293:Adolescent; D000328:Adult; D056352:Athletes; D004487:Edema / Q000000981:diagnostic imaging / Q000503:physiopathology; D005538:Football / Q000293:injuries*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging / Q000293:injuries*; D012189:Retrospective Studies; D017695:Soft Tissue Injuries / Q000000981:diagnostic imaging; D013848:Thigh / Q000000981:diagnostic imaging / Q000293:injuries*; D055815:Young Adult
Football; Hamstring; Leg injuries; Magnetic resonance imaging; Muscle skeletal; Soccer