The use of ultrasound in the diagnosis of injuries of the ulnar collateral ligament of the thumb.

We describe the use of a specialist referral clinic and ultrasound assessment for all injuries to the ulnar collateral ligament of the metacarpophalangeal joint of the thumb presenting to an Accident and Emergency (A&E) department. Senior House Officers in the A&E department were able to correctly diagnose only 45% of the ruptures of the ulnar collateral ligament. The overall agreement between specialist clinic examination and ultrasound for injury to the ulnar collateral ligament was 85% (kappa 0.647). When compared with the operative finding ultrasound had a positive predictive value for rupture of 94%. An algorithm is presented for the assessment of injuries to the ulnar collateral ligament in A&E departments.