Idiopathic extension contracture of the little metacarpophalangeal joint.

We describe 4 patients with an extension contracture of the little metacarpophalangeal joint without definite cause. We encountered this entity only in adolescent girls. When treated conservatively, we observed no improvements in motion. The main pathology of this entity was a hypertrophied dorsal capsule. The 2 patients treated by surgical release of the fifth dorsal capsule and collateral ligaments achieved considerable flexion 2 years later.