Tendonitis around the ankle is a common condition in which the area surrounding the tendon becomes irritated. The most common tendons involved are the Achilles tendon (behind the ankle) and the peroneal tendons (outside or lateral part of the ankle). Many cases develop suddenly, after increased activity. The inflammatory reaction involves the tissue surrounding the tendon but not within the tendon tissue itself. This is in contrast to a condition known as tendonosis, in which the tendon tissue is damaged and becomes degenerative. Patients with tendonosis have more chronic symptoms and often the tendon itself is enlarged dramatically. In either case, most patients describe a sharp pain in the back or side of the ankle with activity. Motion is preserved, but painful. An MRI will ensure there is no tendonosis or tearing of the tendon.
Initial treatment includes activity modification, anti-inflammatory medication and physical therapy. Corticosteroid injection for peroneal tendonitis is quite helpful but Achilles tendon injection increases the risk of subsequent tendon rupture. There is some evidence that tendon degeneration is more common is patients who have taken fluoroquinolones (a type of antibiotic such a Cipro) so if you have taken these medications in the past, make sure you mention this at the time of the visit.
Physical therapy, custom orthotics and anti-inflammatory medication are helpful to relieve tendon irritation.