Congratulations to Kevin Cronin (Lecturer in Diagnostic Imaging, UCD School of Medicine) and the team on their paper published in the British Journal of Sports Medicine.
Hamstring muscle injuries are the most prevalent injury sustained by elite-level football players. They account for as many as 24% and 12% of all injuries in European elite-level men’s and women’s football, respectively. The distal musculotendinous T junction (T-junction) of the biceps femoris muscle is formed by the confluence of the epimyseal surfaces of the anterolateral long head and posterolateral short head of the biceps femoris muscle. Entwisle et al reported that biceps femoris injuries involving the T-junction have a particularly high rate of reinjury, however, this observation has recently been challenged.
Optimal imaging modality
Ultrasound is a useful imaging modality for the assessment of suspected biceps femoris T-junction injuries. Ultrasound, unlike MRI, enables adequate visualisation of synchronous or dissociative movement of the long and short heads of the biceps femoris when the patient performs a resisted isometric knee flexor contraction. Dissociative movement of the long and shorts heads of the biceps femoris has been proposed as an indicator for consideration for surgical management.
Discussion
Ultrasound examination of the player included in this case identified a defect of the T-junction of the biceps femoris muscle involving the myotendinous connective tissue and myoaponeurotic connective tissue. Separation of both heads of the biceps femoris was noted when the player performed a resisted isometric knee flexor contraction. Periodic ultrasound examination was used throughout the injury management phases as an adjunct to monitor tissue healing and to ensure the absence of any structural defects before the player was sanctioned to return to sport. The player was sanctioned to return to sport 63 days after sustaining the injury and during a 1-year follow-up had not sustained a reinjury or subsequent hamstring muscle injury to the same limb. The decision to delay the player’s time to return to sport until the absence of any songraphically identified defects was an agreed empirical decision of the multidisciplinary care team, rather than an evidence-informed decision; as no research exists to support the idea that the absence of structural defects on ultrasound examination associates with more optimal outcomes.
Conclusion
Clinicians should consider the possibility of a T-junction injury when a patient describes sudden-onset distal posterior thigh pain. Ultrasound examination can be used effectively to diagnose acute T-junction injuries and can also assist in informing clinical decisions regarding a player’s suitability to return to sport.