Finger Sprains, Ultrasound Anatomy, and Pathology of Finger Ligaments.

The joints of the fingers play an important role in prehension. They must accomplish both great mobility in the sagittal plane to allow the fingers to roll up and great stability to ensure the grip is both precise and firm. The collateral ligaments and palmar plates are the main passive stabilizing structures between the interphalangeal (IP) and metacarpophalangeal (MCP) joints. Sprains with or without dislocation of the proximal IP joints of the fingers are common injuries in sports pathology and may involve not only the ligaments but also their bony insertion on the phalanges or extensor tendons. Certain entities are specific to the MCP joints: ligament ruptures with Stener-like effect under the sagittal bands and MCP flexion locking (locked finger). Radiographs and ultrasound usually enable a precise diagnosis, so appropriate treatment can be provided.