Injuries of the Metacarpophalangeal Joint of the Thumb

A review of fifty patients with injury to the ulnar collateral ligament of the metacarpophalangeal joint of thumb has been carried out. In over two thirds the injury resulted from a simple fall. In one third of the cases there was a delay in treatment of over a month. In thirty cases operation confirmed the diagnosis of rupture of the ligament. In eighteen cases where operation was carried out within a week of injury a simple repair of the ligament was readily possible. In fifteen of the eighteen cases the ligament had been avulsed from the phalangeal attachment and the typical displacement described by Stener was confirmed. The findings of the ruptured ligament in all recent cases was completely at variance with the experimental and clinical findings reported by Kaplan (1960, 1961). In late cases the choice lies between attempted repair of the ligament, reconstruction of a new ligament or arthrodesis. In this series the numbers are small but the six patients who had arthrodesis has an excellent functional thumb with no subjective or objective abnormality. In eight cases the ulnar collateral ligament had avulsed the phalangeal fragment at its attachment. In the one case where the fragment required operative fixation an excellent result was obtained. While the thumb appeared objectively normal all but one still had pain. In seven patients with what were considered incomplete tears of the ulnar collateral ligament operation was not performed. One patient had been treated in plaster and had a normal thumb objectively but ahd slight pain on writing. The remainder had no treatment and were all complaining of pain at follow-up more than a year after injury. It would seem that all patients who have injuries to the metacarpophalangeal joint of thumb area and are complaining of apin on the ulnar side, even when instability cannot be demonstrated by a stress film, should be immobilised in plaster for a minimum of four weeks.