Maisonneuve injury with no fibula fracture: A case report

Background Ankle syndesmosis injury is difficult to diagnose accurately at the initial visit. Missed diagnosis or improper treatment can lead to chronic complications. Complete syndesmosis injury with a concomitant rupture of the interosseous membrane (IOM) is more unstable and severe. The relationship between this type of injury and Maisonneuve injury, in which the syndesmosis is also injured, has not been discussed in the literature previously. Case summary A 16-year-old patient sustained left medial malleolar fracture, and the associated inferior tibiofibular syndesmotic instability was overlooked. After open reduction and internal fixation of the medial malleolar fracture, inferior tibiofibular syndesmosis diastasis with IOM rupture was detected by auxiliary imaging. Secondary surgical intervention was performed to reduce anatomically and fix with two trans-syndesmosis screws. Twelve weeks later, the screws were removed. At the 6-mo follow-up, the patient gained full range of motion of the ankle. Conclusion Complete syndesmosis injury with IOM rupture should be considered Maisonneuve-type injury. Open reduction and internal fixation could obtain good outcomes.