Achilles tendon rupture associated with injury of the calcaneofibular ligament.

A 49-year-old man collided against an infielder when he slid into second base during a recreational baseball game. He was unable to continue in the game due to diffuse pain and swelling of his hindfoot. A rupture of the Achilles tendon was diagnosed incidentally on palpation and observation of a positive Thompson's squeeze test. Subcutaneous hemorrhage at the lateral aspect of the heel and a small bone fragment under the lateral malleolus on an anteroposterior plain radiograph indicated a fracture of the calcaneal wall. At surgery, a complete rupture of the Achilles tendon and an avulsion of the calcaneofibular ligament from the calcaneal wall were seen. Both injuries were surgically repaired, and the patient subsequently did well. The mechanism of injury was thought to be impact hyperdorsiflexion of the ankle with rupture of the Achilles tendon accompanied by an inversion injury. Using a literature search, it was found that this combination of injuries has not been previously reported.