Detecting The Cause Of Chronic Ankle Pain
It is often challenging to treat patients who have chronic ankle pain. There is an array of potential causes so it’s essential to be very thorough in arriving at your diagnosis. For example, consider the case of an active 34-year-old male who runs and plays tennis, basketball and beach volleyball. In the past six months, he says he has had acute ankle pain in certain situations and chronic pain in other situations.
More specifically, the patient says the pain is worst when he is engaged in activities involving toe raises or when he is on the ball of his foot for extended periods of time. He also says there has been an increase in chronic pain with normal ambulation in the previous three months. According to the patient, the pain is accentuated when he wears certain shoes or if he is barefoot for long periods of time. He has had a history of multiple ankle sprains in the past 20 years, with the last one occurring only a year ago. He has not had one recently only because he has had to decrease his level of activity due to the increased pain.
Yet the region of pain has changed in the previous two months. Prior to that period, he was able to perform sports activities, yet he would experience soreness in the anterior ankle region the next day. In the past two months, he has experienced that same soreness with increased activity, yet he also has a chronic nagging pain in the posterior and retro-fibular regions of the painful ankle. The patient feels a “bruising” of the posterior ankle with a dull ache after a short period of ambulation.
What The Examination Reveals
A physical examination reveals a fit young man in no acute distress. The patient stands with a fairly rectus stance. There is a slight cavus to the foot, yet it is stable in all planes. A mild genu recurvatum is noted during lateral observation. Upon performing a pedal exam, it is noted that the patient has bilateral symmetrical pulses. Neurologically, all examinations are normal without loss of any sensatory or deep tendon reflexes. Dermatologically, there is mild edema on the antero-lateral ankle with extension on the posterior region of the fibular malleolus. There is no ecchymosis or erythema.
The patient has a full range of motion without guarding or pain on the lateral ankle region. There is tenderness in the posterior fibula along the course of both peroneal tendons. It is noted that the peroneal tendons are painful below the fibular malleolus and the patient has decreased pain along the more distal regions of the two tendons. There is a positive anterior drawer of the ankle with a lateral ankle “pucker” sign. There is minimal lateral varus instability or subtalar instability. The Achilles is slightly tight when the patient’s knee is straight, yet it’s normal with the knee bent 90 degrees.
What Is The Differential Diagnosis?
1. An osteochondral lesion of the medial or lateral ankle
2. Sinus tarsi syndrome
3. Lateral ankle instability with a tear of one or more lateral ankle ligaments
4. A tear of one or both of the peroneal tendons
Pertinent Points On Testing
Depending on your level of suspicion, you would want to order tests that would cover the majority, if not all, of the above possibilities. Begin with standard radiographs. Although there is a great deal of information on the radiographs, you’ll need a MRI or diagnostic ultrasound to detect soft tissue disorders. In most cases, I believe the MRI is a better test unless you have a great deal of expertise in ultrasound.
In this case, standard radiographs show a well-positioned ankle without signs of degenerative changes. The images show no osteochondral lesion and a stable ankle mortise. On the anterior views, there is a large bone fragment in the anterior lateral gutter of the ankle, which is in close proximity to the distal fibula. The lateral radiograph reveals a well positioned rearfoot and ankle with mild anterior displacement of the talus in the ankle mortise.