Clinical Quiz Answer
Persistent Ankle Pain After a 'Simple Sprain'
Wayne Stokes, MD; G. Brett Western, MD
THE PHYSICIAN AND SPORTSMEDICINE - VOL 29 - NO. 4 - APRIL 2021
Anteroposterior, lateral, and mortise radiograph views of the right ankle revealed a displaced osteochondral fracture of the lateral dome of the talus. The mortise radiograph offers the best view (figure 2). Magnetic resonance imaging (MRI, figure 3) revealed a displaced 8-mm osteochondral fracture involving the midposterior portion of the lateral talar dome with associated subchondral edema. The fracture was displaced approximately 1 mm. Because of the history of persistent pain, swelling, and new radiologic findings, the patient was referred for orthopedic evaluation and treatment. The recommendation was for right ankle arthroscopy and debridement of her talar dome lesion.
Arthroscopy revealed a hinged 5 mm X 10 mm X 2 mm fragment. The fragment was excised and the defect debrided along with some hypertrophied synovial tissue. After initial use of crutches and "touch down" weight bearing for the first 10 days, the patient gradually increased weight bearing. Her ankle rehabilitation consisted of active range-of-motion exercises and progressive isometric exercises. At 2 months, she began a gradual return to full running and horseback riding without pain or swelling.
The ankle is the most commonly injured joint among athletes and also frequently injured in the general population (1,2). It is estimated that there are more than 23,000 ankle sprains requiring medical care in the United States per day (3). Of these, 85% are lateral sprains. Some evidence shows that over the short term many patients achieve a favorable outcome (4); however, there is a growing recognition of persistent disability associated with lateral ankle sprain (5,6). Of special concern to physicians and athletic trainers is that 20% to 40% of lateral ankle sprains can progress to chronic disorders (7). Our current case report illustrates the need for considering osteochondral talar lesions in patients who have ankles that do not heal after several weeks or months.
Etiology. Osteochondral lesions of the talus are often referred to as osteochondritis dissecans. Yet early on, Berndt and Harty (2) demonstrated that these lesions were actually transchondral fractures caused by trauma. Lateral talar lesions, as described in our patient, were often secondary to sprains caused by inversion with dorsiflexion. Medial talar lesions were typically found after an injury mechanism involving inversion with plantar flexion (8).
Signs and symptoms. Unlike injuries that are limited to cartilage, fractures that extend into subchondral bone cause pain, hemorrhage, and fibrin clot formation. A study by Loomer et al (9) showed that 86 of 92 patients (94%) with osteochondral lesions of the talus reported pain with activity as their primary symptom. Other common complaints included swelling and night pain. Only a few patients reported catching, locking, or giving way. The physical exam is not specific in detecting this type of lesion. Of the patients studied, the physical exam indicated that 15% had palpable swelling, 19% had an anterior drawer sign, and about half had decreased ankle motion with dorsiflexion.
Radiologic findings. Radiographic grading criteria incorporate fragmentation displacement and radiolucency of the defect to classify the lesions (8). If pain persists after 4 to 6 weeks, repeat radiographs should be done. The mortise view allows for a clearer view of the talar dome by eliminating the overlap of the fibula on the lateral talus. Technetium 99m bone scintigraphy is another very sensitive tool used for detecting osteochondral lesions. MRI can be used to document the precise location of the patient's injury, identify the presence of fragmentation, and visualize any associated bruising and edema.
Treatment. Berndt and Harty (2) found that lateral osteochondral lesions were associated with poorer prognosis, less likely to heal spontaneously, and more likely to require surgery. Medial lesions were associated with fewer symptoms and were more likely to heal spontaneously (8). Small, nondisplaced fractures can usually be treated initially with conservative measures such as rest, activity modification, nonsteroidal anti-inflammatory drugs, and taping. If conservative measures fail or a displaced fragment is found to be present upon radiologic exam, surgery may be required to alleviate the patient's symptoms. In treating talar osteochondral lesions, physicians should consider an orthopedic consultation to assess arthroscopic debridement for relieving pain and swelling.
In our case, the athlete presented following months of swelling and pain that was aggravated by activity after treatment for what appeared to be an uncomplicated ankle sprain. No specific physical findings in the acute setting can indicate osteochondral lesions, and initial radiographs are commonly negative with these injuries. In the patient in this case report, prolonged symptoms after proper treatment for a sprain led to repeat radiographs and the correct diagnosis and treatment.
Dr Stokes is assistant professor of orthopedics at Albert Einstein College of Medicine in New York City. Dr Western is a third-year family practice resident at Altoona Hospital in Altoona, Pennsylvania. Address correspondence to Wayne Stokes, MD, Beth Israel Medical Center, Singer Division, Orthopedic Rehabilitation, 13th floor, 170 E End Ave, New York, NY 10128.