A retrospective multicenter study on the use of locking compression plates for scapulohumeral arthrodesis in small equids.

Objective: To report on technical aspects and outcomes after scapulohumeral arthrodesis (SHA) with a locking compression plate (LCP) in small equids.

Study Design: Retrospective multicenter case series.

Animals: Client-owned Shetland Ponies, Miniature Shetlands, and American Miniature Horses (n = 15).

Methods: Inclusion criteria were completed SHA with an LCP to treat scapulohumeral osteoarthritis/subluxation and availability of postoperative radiographs. Contributing surgeons completed a questionnaire to collect data. All radiographs were reviewed for this study. Follow-up information was obtained via re-admission to the hospital or telephone interview of the referring veterinarian or owner. Outcome was subjectively scored as excellent, good, moderate, or poor based on lameness and function.

Results: Sixteen SHAs were performed in 15 equids (body weight 65-145 kg) by nine different surgeons. A narrow 4.5/5.0 mm LCP (7-16 holes) was used in 14 of the 16 SHAs. Follow-up was collected 2.5 years after surgery (median; range: 9 weeks to 10 years). Major complications related to the SHAs were noted in 4 of the 13 horses alive long term, consisting of implant failure (n = 1), surgical site infection (n = 2), and scapular fracture (n = 1). The outcome was graded as excellent in 4, good in 5, and moderate in 4 horses. Two ponies were euthanized because scapulohumeral osteoarthritis and subluxation developed in the contralateral limb.

Conclusion: Although major complications occurred in about one-third of ponies, SHA with LCP led to long-term survival with good function in most ponies.

Clinical Significance: SHA with an LCP offers a high chance for good long-term outcome in small equids although contralateral disease may affect outcome.