Ulnar collateral ligament injuries of the thumb: a comprehensive review.

Injuries to the thumb ulnar collateral ligament (UCL) are common. Failure to address the ensuing laxity of the metacarpophalangeal joint can lead to compromised grip and pinch, pain, and ultimately osteoarthritis. Instability to valgus stress with the lack of a firm end point is a strong indicator of complete rupture of the UCL. Nonoperative treatment is reserved for incomplete ruptures of the thumb UCL. Operative intervention is typically performed for complete ruptures. Repair of acute ruptures and reconstruction for chronic injuries yield excellent results. Complications are rare and most patients show preservation of motion, key pinch, and grip strength.