Subcutaneous rupture of the flexor hallucis longus tendon: a case report

It is well known that rupture of the flexor hallucis longus tendon can be associated with open injuries and that closed rupture of the flexor hallucis longus tendon is rare. Tendon injuries of the foot can occur secondary to direct, indirect, or repetitive injury. Repetitive tendon injuries can cause tendinitis or stenosing tenosynovitis. Tendinitis is associated with internal tendon injury that can present with tendon thickening, mucinoid degeneration, nodule development, or in situ partial tears. Stenosing tenosynovitis is the development of tendon adhesions within the tendon sheath that interfere with tendon gliding, known as trigger toe. The flexor hallucis longus tendon is susceptible to injury along its entire course. A total of 35 cases of complete or partial closed ruptures of the flexor hallucis longus tendon have been reported. We present the case of complete subcutaneous rupture of the flexor hallucis longus tendon associated with trauma at the proximal phalangeal head.