This is Dupuytren's contracture principally affecting the ring finger. It is due to fibromatosis of the palmar fascia. It is more common in Northern European countries with a genetic/familial predisposition and has been associated with epilepsy, diabetes, alcoholism and repetitive injury. If hand function is good then surgery is not recommended. Palmar fasciectomy is undertaken in more advanced cases with intensive post-operative physiotherapy.