Unilateral Dislocation of the Posterior Tibialis Tendon (PTT) and Flexor Digitorum Longus Tendon With Contralateral PTT Subluxation in a Patient With Congenitally Shallow Flexor Groove

Introduction. Flexor tendon dislocation from the flexor tendon groove posterior of the medial malleolus has been previously described, and may be difficult to diagnose initially, but is amendable to surgical treatment with good outcomes. We present a unique case of unilateral dislocation of the posterior tibialis and flexor digitorum longus tendons with contralateral flexor digitorum longus subluxation that was treated surgically with a good outcome. Case Presentation. A 37-year-old active duty male sustained a dislocation and subluxation of the flexor tendons bilaterally after a forced dorsiflexion injury. Bilateral ankle magnetic resonance imaging revealed the injuries that this patient sustained and aided in surgical planning. Surgical Treatment. Bilateral flexor tendon groove deepening with periosteal flap elevation and retinacular repair. Discussion/Conclusion. This injury has not been previously described in the literature after a forced dorsiflexion mechanism. Advanced imaging is helpful as this injury may be initially misdiagnosed. This case shows that delayed bilateral reconstruction of the flexor tendon grooves and retinacula are reliable methods for pain relief to allow a patient to return to a physically demanding level of function. Levels of Evidence: Level V