Ortho Hors D'oeuvres (Answer):
To review, this is a 32 year-old male status post ankle pain after fall.
Questions and Answers:
1) What is the injury identified on radiographs?
In the above films there is a very visible oblique, minimally displaced fracture of the distal tibia (arrow). There is no obvious articular involvement visible on AP or lateral films. In classic 3-view ankle films, AP and lateral films are performed in addition to a 3rd view called the mortise view, which is specifically oriented to evaluate the tibiotalar joint space (also known as the mortise). The mortise has a superior and medial space; both spaces should be evaluated for widening in ankle or distal tibial/fibular fractures for ligamentous injury and joint space widening. A normal joint space is less than 4mm at both the superior and medial (circled) aspects. Although this patient did not receive formal mortise views, the mortise is well-visualized on this AP film and appears to be less than 4mm.
2) What are frequently associated injuries with this fracture pattern and what are the next steps in diagnostics?
The tibia and fibula are stabilized by a thick band of connective tissue called the tibiofibular syndesmosis. Patients are very unlikely to have isolated tibial or fibular fractures without another ligamentous or bony injury. One classic such injury is called the maisonneuve fracture: a fracture of the proximal third of the fibula associated with disruption of the distal tibiofibular syndesmosis. The mechanism of injury is from severe twisting of the ankle that disrupts the ligaments in the ankle. In some cases, patients will have ankle pain caused by severe ligament disruption without any fracture at all.
This patient had such an injury as seen below:
Palpation of the proximal fibula and gross examination of peroneal nerve function (dorsiflexion of the ankle and sensation to the lateral aspect of leg and top of foot) is recommended in all patients with ankle complaints. Joints above and below known bony injuries should always be radiographically evaluated regardless of symptoms or mechanism, especially in these cases as patients often have severe ankle pain with no pain over the fibula fracture site.
3) What is the appropriate emergency department management?
The ankle should be reduced as best as possible (though the ankle will be unstable) and put in a posterior slab with J-stirrups to provide lateral and medial stability. These patients should be made strictly nonweight-bearing and follow up within 72 hours with orthopedics for likely operative repair for ankle stability. A delay in repair can compromise functional outcome, so assuring follow-up is key in these patients.
References:
Millen, JC and Lindberg, D. Maisonneuve Fracture. The Journal of Emergency Medicine, 41 (2011): 77-8.
Stufkens S, van den Bekerom M, Doomberg J, van Dijk N, and Kloen, Peter. Evidence-Based Treatment of Maisonneuve Fractures. The Journal of Foot and Ankle Surgery, 50 (2011): 62-67.
Taweel N, Raikin S, Karanjia H, and Ahmad J. The Proximal Fibula Should Be Examined In All Patients with Ankle Injury: A Case Series of Missed Maisonneuve Fractures. The Journal of Emergency Medicine, 44 (2013): 251-55.
