Proximal interphalangeal arthrodesis in the horse. A retrospective study and a modified screw technique.

Arthrodesis of the proximal interphalangeal joint was used to treat lameness resulting from osteoarthrosis and for closed subluxation in 35 horses. Six horses had bilateral arthrodeses. Several conventional internal fixation techniques and a three converging screw method were used. Criteria for success included the horse performing its previous or intended athletic activity and the owner being satisfied with the outcome. Using these criteria, a successful outcome was obtained in 65% of the 26 animals in which adequate follow-up was available. A successful outcome was observed in four of six horses with bilateral arthrodeses. The internal fixation technique used did not influence the success rate, and the duration of postoperative casting was similar in successful and unsuccessful cases. The success rate of proximal interphalangeal arthrodeses was 46% in the fore limbs and 83% in the hind limbs. Complications included infection, cast ulcers, bone or implant failure, implant loosening, and laminitis.