Managing Chronic Pain After An Ankle Sprain
A patient presents to the office with a history of an ankle sprain that occurred eight months ago. The patient was playing tennis and rolled his ankle during the match. He had to immediately stop and felt a snap in the lateral ankle. For the next week, he wore a lace-up ankle brace and iced the ankle.
He was able to walk on the ankle the day after the injury but had continued pain in the ankle that did not resolve for one month. At the one-month point, his doctor suggested the ankle was painful from the sprain and suggested a course of physical therapy.
The patient performed all of the physical therapy sessions for over two months. At this point, he did report a slight improvement but the patient continued to experience pain with any form of exercise and the ankle was painful with prolonged standing.
The patient dealt with the pain for two more months and then saw a second doctor. He suggested there was a probable tear of the lateral collateral ligaments and that the patient would need surgery for the repair of the ligaments. That physician did not obtain radiographs or a MRI and the patient now presents for a consultation about the ankle.
What Does The Exam Reveal?
Examination of the ankle shows light swelling of the anterolateral and lateral ankle. There is also mild swelling along the course of the peroneal tendons. The patient’s range of motion of the ankle is slightly tender with decreased dorsiflexion. The patient has tenderness with large circle motion of the ankle and mild pain along the course of the peroneal tendons with this activity.
Upon palpation of the ankle, we note a tenderness along the anterolateral ankle about the anterior talofibular ligament. The patient also has pain in the region of the lateral gutter of the ankle joint. An anterior drawer test on the affected extremity is positive. The patient has normal muscle strength and there are no gross vascular or neurologic changes.
We proceeded to obtain radiographs and stress radiographs of the ankle. The anterior drawer test and talar tilt stress tests for the affected extremity were slightly increased when we compared them to the contralateral ankle. However, we didn’t think this was the entire cause of the ankle pain.
An MRI of the ankle revealed synovitis and scar formation of the lateral ankle joint with tenosynovitis and a possible longitudinal tear of the peroneus brevis tendon. We also noted a lateral deviation of the peroneal tendons from the posterior fibular groove. The MRI also revealed a region of cartilage and bone inflammation along the lateral aspect of the talus, which was suggestive of a possible osteochondral lesion.
What Is The Differential Diagnosis?
1. Lateral ankle instability
2. Osteochondral lesion of the talus
3. Peroneal tendonitis or tendon tear
4. Synovitis and scar tissue in the ankle joint
The diagnosis is fairly complex to address, especially with the type of results one sees on the MRI. In general, the most important findings of the MRI are the osteochondral lesion that has not resolved in the past eight months, the scar tissue on the lateral ankle and the peroneal tenosynovitis. The lateral ligament tear is of less concern. It is important to remember that an old tear of the collateral ligament will still show as a thickening or tear on MRI months after it is healed. One should also pay close attention to the gross instability on anterior drawer/varus stress tests and stress films more than the MRI reading.
With regard to the peroneal tenosynovitis, there may be a tear of the tendon or an inflammation of the tendon that is secondary to the poor position of the tendon posterior to the fibula or from secondary guarding of the painful ankle. In this case, the position of the peroneal tendons not being posterior to the fibula and the involved peroneal inflammation are cause for concern.
The osteochondral lesion is also of concern as is the lateral ankle scar tissue. This scar tissue is mainly caused by chronic joint inflammation, which is primarily due to the old torn ligament and cartilage damage.
With so much information to digest, what is the proper treatment and how do you find out the true cause of the pain?
In early cases, bracing and physical therapy with antiinflammatory medication is suggested, but in more advanced cases like this, surgical care is often the only option.