Boutonniere Deformity Treatment: Symptoms, Classification, Diagnosis & Recovery

Boutonniere deformity occurs when the central joint of a finger (or, less usually, a toe) becomes locked in a bent position and cannot straighten, while the joint toward the tip of the finger or toe bends upwards. It is often caused by an injury to the central slip tendon, which is responsible for straightening the finger at the middle joint. This injury can produce a rip in the tendon, resulting in deformity, as well as arthritis, which weakens or displaces the tendon.