Carpal arthrodesis using a minimally invasive approach and locking compression plates: Three cases

Summary Three horses with carpal instability due to comminuted second carpal bone fractures (Cases 1 and 3), fracture of the head of the second metacarpal bone (Case 1) or comminuted fractures of the fourth carpal bone, ulnar and intermediate carpal bones (Case 2) were treated by minimally invasive approach for partial (Cases 1 and 3) or pancarpal (Case 2) joint arthrodesis, using locking compression plates. The joint cartilage was removed by either an arthroscopic approach (middle carpal joint and antebrachiocarpal joint) or a percutaneous drilling technique (carpometacarpal joint). Two or 3 locking compression plates were contoured to the dorsolateral, dorsomedial and dorsoaxial aspects of the carpal joints using a custom-made tunnelling tool and a minimally invasive tunnelling technique, and the screws were positioned through stab incisions. All cases recovered well, were lame free at the walk, were able to trot and gallop and could be used for leisure and pasture activities (partial carpal arthrodesis) and breeding (pancarpal arthrodesis). Post-operative x-rays showed progressive joint fusion after 12 months (Case 1), 5 months (Case 2) and 10 months (Case 3). Case 2 with a pancarpal arthrodesis showed a mechanical lameness at the walk due to the inability to flex the carpus. Carpal flexion after carpometacarpal and middle carpal arthrodesis in Case 1 was calculated to be 42.6° and 44° in Case 3.