Hamstring injuries are the most common pathology reported in professional soccer players and represent about 10-30% of all injuries. This study’s primary purpose was to identify specific injury patterns, location, and severity on MRI following acute hamstring injuries in a group of Major League Soccer (MLS) players. The secondary purpose was to present a new MRI classification protocol for identifying the location of hamstring injuries.
We retrospectively reviewed 19 MRIs ordered to evaluate suspected acute hamstring injuries during a period of 5 years. Intramuscular T2 hyperintensity was considered to represent muscle injury.
The long head of the biceps femoris was the injury site in 14 of 19 cases. It occurred in association with the semitendinous in four, semimembranous in one, and short head of the biceps in another of the injured athletes. Over half (11/19) of the reported cases sustained hamstring injuries that affected more than one muscle. A mean edema length of 10.6 cm was reported, with the severity of fiber disruption described as low in 7 (37%) and moderate in 12 (63%) of the 19 cases. We divided the total length of each muscle into 5 zones. The results demonstrate a prevalence of 14 cases affecting the distal Myotendinous junction.
The BFLH was the most commonly injured muscle in our cohort. Over half of the injuries were grade 2 fiber disruption severity, with no full-thickness injuries reported. This MRI classification allows a detailed muscle location and severity grading of acute hamstring injuries.
Hamstrings injuries; Soccer; MRI; Biceps femoris