The authors assessed ulnar translation of the carpus following surgical treatment of 25 perilunate dislocations. Follow-up radiographs were completed at an average of 4.8 months after surgery and revealed ulnocarpal translation in 80% of cases (i.e., greater than 50% of the lunate was uncovered as measured by the Gilula method). Early pinning of the radiocarpal interval improved alignment and measurements of ulnar translation after pin removal.
The study findings highlight the frequent occurrence of ulnar translation of the carpus following perilunate injuries. This pattern of instability is associated with extensive ligamentous injury: volar and dorsal radiocarpal and ulnocarpal ligaments (Viegas et al 1995). Although the authors detected no significant change in radiocarpal alignment after pin removal, their follow-up interval was relatively short. Previous reports have documented recurrence of ulnocarpal translation regardless of the repair technique or surgical timing.