Persistent ankle pain after an ankle sprain could be a sign of a condition called osteochondral lesion of the talus (OLT). The talus is a bone in the ankle between the calcaneus (heel bone) below and the tibia (shin bone) above.
The bottom of the tibia forms a dome over the top of the talus. With OLT, a piece of cartilage from the talus gets pinched by this dome. In more severe cases, a fragment of cartilage breaks off the talus but stays wedged in place. In the worst cases, the fragment is floating free in the joint space.
Other terms used to describe OLT include osteochondritis dissecans, transchondral fracture, talar dome fracture, and flake fracture. The condition is fairly uncommon. It is difficult to diagnose using X-rays, MRIs, or CT scans.
The authors of this study used arthroscopy to diagnose and treat OLT. They graded the condition based on severity as Grade I (mild) through Grade IV (severe). Treatment results were compared to see if outcomes were better for milder forms of the condition. Results showed that arthroscopic grading of OLT does predict final outcome after surgery. This is something that cannot be accomplished with X-rays or other more advanced forms of imaging.
Milder lesions without fragmentation had better results. Patients were more likely to have a good-to-excellent outcome without complications if the cartilage was not torn away. They were not able to compare results based on specific surgery done because there were too many different kinds of operations performed.
For example, some patients had holes drilled in the talus where the fragment had broken off. This procedure is called microfracture. It stimulates new growth of fibrocartilage. Other patients had the loose piece of cartilage removed (excision) with smoothing of the bone where the piece was broken off. And some patients had both excision and drilling.
Almost three-fourths of the group had good-to-excellent results. Most were able to return to all preoperative levels of activity. A few patients had complications such as plantar fasciitis, nerve pain or injury, or pain around the puncture wounds where the arthroscope entered through the skin. These problems all disappeared during the first six months of recovery.
Results of treatment did not appear to be linked with age, gender, or the side affected (right or left ankle). Delays between injury and surgery did not seem to make any difference in the final results. Worker’s compensation patients did have poorer results compared with those who were not on worker’s comp.
Follow-up was for at least five years. So it was possible to see if the long-term results changed over time. They found that more than one-third of the patients had a deterioration of their good results over time. Deep aching and pain with swelling recurred. Limited motion and instability occurred with degeneration of the joint. The reason(s) for this change was unknown.
The authors were unable to provide treatment guidelines for OLT based on the results of this study. When to choose conservative care versus surgery remains a difficult decision. And it’s not clear how long conservative (nonoperative) care should be carried out before considering surgery. But the authors offered suggestions based on their own treatment methods. They recommended:
Further studies are underway to review the results of the surgical methods mentioned. The authors will continue to watch for outcomes of other studies and compare them to these treatment guidelines. They will pay special attention to long-term results. This will help surgeons advise patients as to the best way to treat OLT.