IRREDUCIBLE PILON FRACTURE BY POSTERIOR TIBIALIS TENDON INTERPOSITION IN THE SYNDESMOSIS AND ANKLE JOINT

Abstract

　　A 15-year-old male was injured by jumping from a 2-m-high roof. X-ray and CT demonstrated right ankle pilon fracture. We performed emergency external fixation, but were unable to achieve a reducted position. After 3 days, we performed osteosynthesis of the fibula and posterior malleolar via the postero-lateral approach, and reducted the entrapped flexor digitorum longus tendon. After 16 days, we performed osteosynthesis of the anterior wall and medial malleolar and articular surfaces via the anterior approach. We then noted posterior tibialis tendon interposition in the syndesmosis and ankle joint. We reducted the tendon by partial removal of the posterior malleolar fixation. There have been 6 case reports of irreducible ankle dislocation fracture by posterior tibialis tendon interposition to the syndesmosis. In this case, the mechanism of interposition to the syndesmosis may have been similar to that in the previous 6 reports, but there has been no report of pilon fracture with posterior tibialis tendon interposition to the syndesmosis. In irreducible cases, diagnosis by CT is important.