Description of Proximal Tibiofibular Joint Pain
An injury to the proximal tibiofibular joint is rather rare, but can be debilitating in patients who have symptoms.
The proximal tibiofibular joint is located between the lateral tibial plateau of the tibia, and the head of the fibula. Typically, the proximal tibiofibular joint is injured in a fall when the ankle is plantar-flexed, with the stress being brought through the fibula, will cause the proximal fibula to sublux (partial dislocation) out of place over the lateral aspect of the knee joint. In other circumstances, significant trauma or a motor vehicle accident can cause a disruption of the proximal tibiofibular joint. In most circumstances, it is the posterior proximal tibiofibular joint ligament that is injured. This results in the fibula rotating away from the tibia during deep squatting.
Symptoms of an Injured Proximal Tibiofibular Joint:
- Instability of the joint, especially during deep squatting
- Visible bony deformity
- Concurrent irritation of the common peroneal nerve, because the common peroneal nerve crosses the lateral aspect of the fibular neck within 2-3 cm of the lateral aspect of the fibular head
The diagnosis of proximal tibiofibular joint instability is almost always based on a thorough clinical exam. In acute cases, it may be difficult to make the patient relax sufficiently to be able to examine for proximal tibiofibular joint instability, but usually having the knee flexed to 90 degrees and trying to perform an anterolateral subluxation maneuver of the proximal tibiofibular joint is sufficient to confirm this diagnosis. In chronic injuries, the instability may appear obvious when the patient performs a maximal squat.
It is important to compare the injured side to the normal contralateral side because some patients may have physiologic laxity of this joint. In more chronic cases, we have the patient squat down, which can often demonstrate that the proximal tibiofibular joint is being subluxed. Concurrent with this, we will perform a Tinel’s test by percussing over the common peroneal nerve to confirm the presence of dysesthesias or “zingers,” which translate down the leg.