The injury of the calcaneocuboid ligaments.

The selective rupture of the calcaneocuboid ligament is extremely rare and frequently misdiagnosed. This study tries to clarify the mechanism, classification and treatment of this entity. The necessity of radiographs with varus stress and in certain cases of computer tomography (CT) and magnetic resonance imaging (MRI), beside the routine antero-posterior and lateral views, is emphasized. Thirteen cases out of five-hundred-twenty-one sprain injuries of the ankle are described, classified and the therapy discussed: If on varus stress radiographs, there is a calcaneocuboid angle <10 degrees without a bony flake (type 1) strapping for six weeks is indicated. A calcaneocuboid angle >10 degrees with or without a small bony flake of the ligament insertion (type 2) should primarily be treated with a shoe cast for 6 weeks; if there are persistent symptoms a secondary peroneus brevis tendon graft is recommended. A calcaneocuboid angle >10 degrees with a big flake (type 3) should be treated by open reduction and refixation of the ligament. Complex injuries (type 4) are characterised by cuboid compression fracture and ligament rupture.