[Spontaneous fixation of MP-joint of the index finger in flexion].

Spontaneous fixations of MP-joints of fingers and thumbs are rare and are often a challenging task for hand surgeons. We present a 25-year-old female office employee with a fixed painless MP-joint of the left index finger in 90° flexion with normal PIP- und DIP-joint range of motion. Using the palmar approach to the MP-joint the entrapped accessory collateral ligament which was constrained by a prominent radial condylus could be identified. Operative removal of the prominence has released the joint. An uncomplicated wound healing has followed with completely unrestricted range of motion. If a closed reduction should be considered, it ought to be done cautiously without anaesthetics. A failed -reduction entails an operative revision using the palmar approach.