Review Question - QID 215501

Dedicated knee radiographs should be obtained to determine if there is an associated proximal tibiofibular joint dislocation, which can be associated with peroneal nerve palsy.

Proximal tibiofibular joint dislocations are rare injuries and are often missed due to the subtle radiographic findings. They are often the result of high-energy trauma to the affected extremity (tibial shaft and plateau fractures) and twisting injuries during sports. Careful scrutiny of high-quality knee radiographs is required for the diagnosis. There is a high association with peroneal nerve palsy, especially with posteromedial dislocations.

Curatolo et al. reviewed common clinical conditions of the proximal tibiofibular joint. The authors discuss traumatic dislocations, fractures, chronic instability, and arthritis. In their review, they focus on diagnosis and treatment strategies.

Herzog et al. performed a retrospective study of 30 patients with proximal tibiofibular dislocation. They report this injury occurred in conjunction with tibial shaft and tibial plateau fractures with a high incidence of compartment syndrome (29%) and peroneal nerve palsy (36%), of which 30% of patients had neurologic recovery. The authors concluded that proximal tibiofibular dislocation is associated with a severely traumatized limb.

Sekiya and Kuhn reviewed the instability of the proximal tibiofibular joint. They reported the injury to the proximal tibiofibular joint is the result of violent twisting motions and can present with pain and prominence of the lateral aspect of the knee. Treatment for acute injuries includes closed reduction, followed by open reduction if unsuccessful, or arthrodesis, fibular head resection, and joint capsule reconstruction in chronic injuries.

Figure A is the AP radiograph of the right tibia and fibula with a tibial shaft fracture. Illustration A is an AP and lateral radiograph of the right knee depicting a proximal tibiofibular joint dislocation.

Incorrect answers
Answer 1: An EMG performed in the acute setting would provide little treatment utility. It takes approximately 3 weeks post-neurologic injury for an EMG to be diagnostically useful.
Answers 2 and 4: Further radiographic evaluation of the knee should be performed to evaluate for a concomitant knee injury, such as proximal tibiofibular joint dislocation, prior to further treatment.
Answer 5: An emergent peroneal nerve exploration and four-compartment fasciotomy are not necessary at this time. Further radiographic evaluation to assess possible injury of the proximal tibiofibular joint is the most appropriate next step.