Stenosing tenosynovitis and impingement of the peroneal tendons associated with hypertrophy of the peroneal tubercle.

We report three patients with lateral ankle and foot pain, with the diagnosis of stenosing tenosynovitis of the peroneus longus tendon associated with a markedly enlarged peroneal tubercle. Stenosing tenosynovitis of the peroneus longus tendon associated with an atraumatically enlarged peroneal tubercle has rarely been reported, and these reported cases were associated with an os peroneum. One of our patients had no demonstrable associated os peroneum but did have a bony tunnel enveloping the peroneus longus tendon. Our other two patients had an os peroneum, but were asymptomatic at the lateral outer border of the cuboid tunnel; one patient had involvement of the peroneus longus and brevis tendons.