From the Mayo Clinic
Dupuytren's contracture is a hand deformity that usually develops slowly, over years. Dupuytren's contracture affects a layer of tissue that lies under the skin of your palm. Knots of tissue form under the skin — eventually forming a thick cord that can pull one or more of your fingers into a bent position.
Once this occurs, the fingers affected by Dupuytren's contracture can't be straightened completely, which can complicate everyday activities such as placing your hands in your pockets, putting on gloves or shaking hands.
Dupuytren's contracture most commonly affects the ring finger and pinky, and occurs most often in older men of Northern European descent. A number of treatments are available to slow the progression of Dupuytren's contracture and relieve symptoms.