Trauma:
Maisonneuve fracture results from an external rotation force applied to the foot
Force at the medial ankle --> force is directed laterally, tearing the interosseous membrane that tethers the distal tibia to the fibula --> force directed upwards fracturing fibula
Definition:
Proximal fibula fracture + unstable ankle joint injury
Involves a ligamentous injury (distal tibiofibular syndesmosis +/- deep deltoid ligament) and/or fracture of the medial/posterior malleolus.
The fibula fracture usually occurs in proximal third but can be as distal as 6 cm above the ankle joint.
Tibiofibular syndesmosis: fibrous interosseous membrane connecting the tibia/fibula.
Disruption leads to joint instability
When to Suspect
Medial malleolar fracture or deltoid ligament tear without a distal fibular fracture
Widening of the distal tibiofibular joint without a distal fibular fracture
Tenderness over the proximal fibula in a patient with an “ankle sprain” or with displaced ankle fractures, including distal fibular fractures
X-Ray Findings
Abnormal when tibiofibular space >5mm, medial clear space >4mm
In addition to imaging of the ankle, tib-fib x-rays should also be obtained to evaluate the entire length of tibia/fibula.
Ankle radiographs can appear “normal” (may only have an occult deep deltoid ligament injury with minimal medial clear space widening
A stress view of the ankle should be obtained to help identify deep deltoid ligament with associated ankle joint instability.
Management
Examine all patients with ankle injuries for tenderness along the entire length of the fibula
Perform Squeeze Test: compression of the tibia/fibula just above the ankle joint. Ankle and/or distal lower leg pain is considered a positive test, suggests syndesmotic injury.
The common peroneal nerve courses over fibular head. Must perform a thorough neurologic exam.
Weakness of ankle dorsiflexion/subtalar joint (foot) eversion and/or numbness along the lateral lower leg/dorsum of the foot should raise clinical suspicion
Maisonneuve fractures are associated with ankle instability, require surgery.
If untreated the instability can lead to chronic pain and long-term disability.
Should reduce and place in a short leg splint, non-weight bearing, immediate orthopedic consult to be seen while in ED.
Admit patients with open fractures or neurovascular compromise
References
https://coreem.net/core/maisonneuve-fractures/
Tintinalli, 8th edition. Tintinalli’s emergency medicine A comprehensive study guide. McGraw-Hill Education.