Ex vivo evaluation of carpal flexion after partial carpal arthrodesis in horses.

ABSTRACT

OBJECTIVE: To determine degrees of flexion after arthrodesis of the antebrachiocarpal (ABC) joint, middle carpal (MC), and carpometacarpal (CMC) joints combined (MC/CMC), and carpometacarpal (CMC) joint alone. STUDY DESIGN: Ex vivo study. ANIMALS Forelimbs (n = 9) from 2- to 10-year-old Quarter Horses (5), Thoroughbred (2), and American Paint Horse (2). METHODS: Using 2 locking compression plates, 3 partial carpal arthrodesis techniques were performed. Cables and deadweights were connected to limbs and each angle of flexion determined 3 times using a protractor and then averaged. Control measurements were obtained before and after arthrodesis, the techniques randomized with Latin square design. Descriptive data were analyzed with Levene's test, Q-Q plots, ANOVA, and Bonferroni test. RESULTS: Mean ± SD carpal flexion results were controls 150° ± 8°, CMC arthrodesis 149° ± 9°, MC/CMC arthrodesis 43° ± 7.6°, and ABC arthrodesis 25° ± 6.3°. There was no significant reduction in flexion after a CMC arthrodesis compared with controls (P = .21), but there was after ABC (P < .001) and MC/CMC arthrodesis (P < .001), with the ABC arthrodesis significantly reduced compared with an MC/CMC arthrodesis (P < .001). CONCLUSIONS: Whereas CMC arthrodesis does not affect carpal flexion, CMC/MC and ABC arthrodesis markedly reduce the degree of carpal flexion.