Proximal interphalangeal locking compression plate for pastern arthrodesis in horses

Background Outcomes following proximal interphalangeal joint (PIPJ) arthrodesis by a variety of surgical methods are available. Reports detailing clinical outcomes following PIPJ arthrodesis utilising the proximal interphalangeal joint locking compression plate (PIP-LCP) and abaxial transarticular lag screws technique are limited. Objectives To report survival, radiographic and clinical outcomes following PIPJ arthrodesis with PIP-LCP and abaxial transarticular lag screw fixation. Study design Retrospective case series. Methods Medical records of all horses undergoing pastern arthrodesis from 2009 to 2018 were reviewed. Arthrodeses performed using a 3-hole, 4.5 mm narrow LCP, specifically designed for the proximal interphalangeal joint, were included. Patient details, presentation, radiographic findings, intraoperative and post-operative data, and complications were documented. Short- and long-term follow-up was available for 23 horses. Results Thirty PIPJ arthrodeses were performed in 29 horses meeting the criteria for inclusion. Twenty-eight horses (97%, 95% CI 83-100) survived to discharge. Twenty-three horses (79%, 95% CI 60%-92%) had successful outcomes including 12 of the 15 forelimb cases and 11 of the 13 hindlimb cases with available follow-up. Fifteen of 19 performance horses returned to athletic activity. Soundness in performance horses was recognised at less than 3 months in one case, 3 to 6 months in six cases, 6 to 12 months in five cases, and greater than 12 months in six cases. Complications included three implant infections, support limb laminitis (two horses), and fragmentation of the extensor process of the distal phalanx (one horse). Main limitations A retrospectively reviewed, small study population with a variety of breeds and disciplines. Conclusions The PIP-LCP construct provides a very good prognosis for performance and an excellent prognosis for pasture soundness.