DISPLACEMENT OF THE RUPTURED ULNAR COLLATERAL LIGAMENT OF THE METACARPO-PHALANGEAL JOINT OF THE THUMB A Clinical and Anatomical Study

Abstract

Having observed several cases in which, after distal rupture, the ulnar collateral ligament of the metacarpo-phalangeal joint of the thumb had become folded over to point proximally, I set about making a systematic investigation of the pathological anatomy of rupture of this ligament. The investigation was carried out (in connection with operation) upon thirtynine patients with total rupture of the ligament. In the great majority of cases the ligament was found to have been displaced to a greater or lesser extent; the rupture was most often distal, and in most ofthese cases the ulnar expansion ofthe dorsal aponeurosis was interposed between the ruptured end of the ligament and the site of its attachment to the phalanx. These observations provide a strong argument in favour of operative treatment when this ligament is ruptured. The clinical investigation was supplemented by an anatomical study of fresh post-mortem specimens. The clinical material comprised thirty-nine consecutive cases of total rupture of the ulnar collateral ligament of the metacarpo-phalangeal joint of the thumb (all of them operated upon by the author) and one case in which radiographs provided indirect evidence that the ligament had been displaced (Case 3). Of the total of forty patients, thirty-four were operated upon within sixteen days of the accident (recent cases). The other six patients (older cases) were operated upon after seven weeks, four months, five months, nine months, eight years and ten years. The anatomical investigation was made on forty-two fresh post-mortem specimens.