An injury to the proximal tibiofibular joint is rather rare, but can be debilitating in patients who have symptoms.
Description of Proximal Tibiofibular Joint Pain
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:
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.
Treatment of Proximal Tibiofibular Joint Instability
The treatment of proximal tibiofibular joint instability usually depends upon whether it is an acute or chronic injury. In acute cases, we have found that immobilization in a brace in full extension for 3 weeks is often very effective to allow the posterior proximal tibiofibular joint ligament tear to scar in sufficiently such that there is no instability. However, in chronic cases, immobilization would not be sufficient to achieve this goal. Thus, Dr. LaPrade and his team have developed an anatomic proximal posterior tibiofibular joint reconstruction procedure. We have found it to be very effective at restoring stability to this joint and not resulting in joint overconstraint. In the past, while others have often treated this instability of this joint by fusing it, we have reported through research that a proximal posterior tibiofibular joint ligament reconstruction is easily performed, does not overconstrain the joint and has decreased the chance of leading to ankle pathology further down the line.
In addition, we frequently perform a common peroneal nerve neurolysis concurrent with the ligament reconstruction to release the scar tissue around the common peroneal nerve so that any further nerve irritation will not occur after surgery due to postoperative swelling or scar tissue entrapment.
Patients who undergo this reconstruction are kept on crutches for 6 weeks with no to minimal weight-bearing movement, but are allowed full range of motion. After 6 weeks postoperatively, patients may start to use a stationary bike with low resistance. We anticipate that our patients will return back to full activities about 4-5 months after surgery, following the rehabilitation program.