A Novel Dynamic Ultrasound Assessment of T-Junction Hamstring Injury during Gym-Based Exercises: A Case Report in an Elite Football Player.

Background: "T-Junction" or distal musculotendinous junction (DMTJ) hamstring injuries have become a true enigma for clinicians as demonstrated by the high recurrence rate. Magnetic Resonance Imaging (MRI) can sometimes fail to provide an accurate assessment of these injuries, probably because of the dynamic function that this structure provides to offer stability at the synchronous movement of the two heads of biceps femoris. The aim of the present case report was to describe a novel method for dynamic ultrasound evaluation of the DMTJ performed during functional loading exercises and to explore its potential role in return-to-play (RTP) decision-making. Study design: Case Report. Case description: A 23-year-old male elite football player sustained a DMTJ injury. MRI revealed a complete rupture of the superficial portion (myotendinous) and the deep portion (myoaponeurotic) of the T-Junction. The injury occurred initially during high speed non-linear running action.The initial diagnosis was made using a 3T MRI scan. Subsequently, three dynamic ultrasound evaluations were performed at weeks 3, 6 and 9 during two different gym-based exercises: the single-leg barbell Romanian deadlift and the single-leg hamstrings slider with ipsilateral trunk rotation. Additional 3Tesla MRIs were conducted to assess healing and structural changes at weeks 5,8 and 14. Outcomes: The player returned to competitive activity 10 weeks after the injury and experienced no re-injury during the subsequent 4-month follow-up period. Improvements in the synchronous movement between BFlh and BFsh were seen on the progressive evaluations as well as the scar healing progression. Dynamic ultrasound assessment during the SL-RDL appeared to provide clearer visualization of interhead hamstring movement than during the slider exercise. Further investigation in larger cohorts is warranted to establish the reliability, validity, and prognostic utility of this novel assessment modality for athletes with this injury. Conclusions: In this single case, dynamic ultrasound of the DMTJ provided valuable information regarding interhead synchrony of the biceps femoris. This approach may complement MRI and support informed return to play decision-making following T-Junction hamstring injuries. Level of Evidence: 5.