Treatment of a mallet finger due to an intra-articular jracture of the diStal phalanx involving one-third or more of the articular sUlface is controversial. Twenty one malletjractures involving more than 33% ofthe articular sUrface and fractures associated with subluxation of the distal phalanx that could not be corrected by closed reduction are treated with an extension block pin and transarticular fIXation of the distal interphalangeal joint. The average patient age was 26.8 years and the average fracture size was 40.5% ofthe joint sUlface. The average delay after uyury was 5.6 days (range, 0-14 days) Average time to fracture union was 32 days. The average active flexion of the distal interphalangeal joint was 81.2° and the average extensor lag was 1.4°. There were no major complications. Using the established outcome criteria for mallet uyuries, 95.2% had excellent or good results. This surgical technique resulted in rapid fracture union with only minor complications and has excellent functional outcome.