Successful total hip arthroplasty in a miniature horse.
Authors: Cullen Matthew D, Pettitt Rob A, Tomlinson Andrew W, Louro Luis F, Bennell Alison J, Michael Robert, Stack John D
Journal: Veterinary surgery : VS
Summary
# Editorial Summary: Total Hip Arthroplasty in Miniature Horses Hip luxation in equines typically results in permanent disability or euthanasia, yet this case report demonstrates that total hip arthroplasty (THA) can be a viable salvage procedure even in diminutive patients. An 85 kg miniature horse stallion with a six-week-old craniodorsal hip luxation and substantial degenerative changes to the femoral head underwent cementless press-fit THA with an interlocking lateral bolt to stabilise the femoral stem, a technical modification likely necessary for the biomechanical demands of a quadruped. Despite a concerning perioperative complication—a coma-like episode attributed to hypovolemia from which the horse recovered—functional outcomes were notably successful: lameness improved from 2/10 at 12 weeks to 1/10 at five months, with restoration of cantering ability on both reins and sustained soundness persisting 32 months postoperatively without further intervention. For equine practitioners managing cases of hip luxation in miniature or Shetland breeds, this report provides evidence that THA should be considered as a realistic option rather than automatically defaulting to conservative or euthanasia protocols, particularly in valuable breeding stock. The technical adaptations required for smaller patients and the importance of vigilant postoperative fluid management are key takeaways for any centre considering this advanced procedure.
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Practical Takeaways
- •Total hip arthroplasty is a viable salvage option for miniature horses with severe, irreparable hip pathology; this case demonstrates feasibility in animals as small as 85 kg
- •Postoperative complications (such as hypovolemia) require vigilant monitoring even in successful cases, and horses can recover to functional soundness despite initial setbacks
- •Long-term outcomes appear favorable in appropriately selected cases, with durable results extending beyond 2.5 years postoperatively
Key Findings
- •Total hip arthroplasty using cementless press-fit implants was successfully performed in an 85 kg miniature horse with craniodorsal hip luxation and femoral head degeneration
- •The horse achieved recovery to mild (1/10) lameness at trot by 5 months postoperatively and maintained normal function for 32 months without further veterinary intervention
- •An interlocking lateral bolt for the femoral stem provided adequate stability in this undersized equine patient