AO-wrist arthrodesis: with and without arthrodesis of the third carpometacarpal joint.

The incorporation of the third carpometacarpal joint (CMCJ-3) during wrist arthrodesis is controversial. This retrospective study of 146 consecutive wrist arthrodeses with AO plate fixation specifically addresses this question. In 79 wrist arthrodeses the CMCJ-3 was also arthrodesed, and in 67 the CMCJ-3 was simply bridged. Problems relating specifically to the CMCJ-3 could not be analyzed clearly with the plate in situ. Therefore after plate removal only 81 wrists were evaluated with respect to the CMCJ-3. Of 47 wrists that had CMCJ-3 arthrodesis and plate removal, 20 developed a nonunion. Eleven of these were painful and further surgical treatment was required. In contrast, of 34 wrists with the CMCJ-3 bridged all but one remained free of symptoms after the plate had been removed. We conclude that the CMCJ-3 must not be included in the arthrodesis when performing an AO-wrist arthrodesis.