Mallet deformity of the finger. Five-year follow-up of conservative treatment.

We reviewed 31 patients at a mean of five years after mallet deformity of the finger had been treated with a thermoplastic splint. Intra-articular fractures were present in 35% of patients. Osteoarthritic changes had developed in 48%, most in association with fracture, and 29% had a swan-neck deformity. There was a loss of extension greater than 10 degrees in 35%; the average deficit at the interphalangeal joint was 8.3 degrees and the average flexion arc was 48.5 degrees. Despite these findings, patient satisfaction was generally high, with little evidence of functional impairment.