There are three grades of ankle sprains. Simple sprains, usually resulting from a twisting injury and involving only one ligament, are classified as Grade I. Eighty-five percent of simple ankle sprains affect the outside or lateral part of the ankle. I sprains may have symptoms only for two weeks. Grade II sprains have a higher level of disability. Grade III ankle sprains represent a complete disruption of all lateral ankle ligaments, with symptoms lasting up to 2-4 months.
High ankle sprains, on the other hand, can remain symptomatic for as long as nine months.
The examination for OCDs, which typically occur in the anterolateral or posteromedial dome of the talus, is different from that for a high ankle sprain, Okereke explained. If they are negative in the face of persistent symptoms and a suggestive physical exam 3-6 months after the injury, then an MRI is warranted. They are graded as stages I through IV, based on increasing order of detachment of the osteochondral fragment. The stage IV OCD lesion is a free fragment of bone and cartilage within the ankle joint. Earlier stages may respond to initial immobilization followed by rehabilitation of the ankle.