Cylindrical press-fit osteochondral allografts for resurfacing the equine metatarsophalangeal joint.
Authors: Pearce Simon G, Hurtig Mark B, Boure Ludovic P, Radcliffe Rolfe M, Richardson Dean W
Journal: Veterinary surgery : VS
Summary
# Cylindrical press-fit osteochondral allografts for resurfacing the equine metatarsophalangeal joint Cartilage defects in the equine fetlock remain a significant clinical challenge given the joint's demanding biomechanical role in locomotion; this 2003 study examined whether cylindrical osteochondral allografts could successfully resurface damaged articular surfaces, using ten mature horses with six receiving grafts (6.5-mm diameter) placed into the medial and lateral metatarsal condyles whilst four underwent sham surgery. At the 25-week endpoint, most grafted sites demonstrated over 90% articular cartilage coverage with good incorporation and cartilage survival on histological and microradiographic analysis, though sulphated glycosaminoglycan concentration was reduced in grafted tissue, and only two horses were sound. The authors attribute these encouraging tissue responses to accurate graft congruency, stable press-fit fixation, and use of orthotopic (same-location) tissue, with the allograft bone itself not compromising cartilage viability despite host responses. Whilst these results suggest osteochondral allografting has biological potential for fetlock resurfacing, the authors note that refinements in instrumentation to reduce graft damage and surface incongruency, plus development of larger grafts to address greater defect areas, would be necessary before clinical translation—making this foundational work valuable context for understanding why such techniques remain largely experimental in equine practice today.
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Practical Takeaways
- •Osteochondral allografting shows promise for fetlock joint resurfacing but remains experimental; current technique limitations (graft congruency, instrumentation) must be resolved before clinical application
- •Stable orthotopic graft placement and adequate fixation are critical to cartilage survival; host bone response does not compromise the graft cartilage viability
- •Larger grafts and refined surgical instrumentation are needed to resurface clinically significant surface areas and reduce technique-related surface irregularities
Key Findings
- •Cylindrical osteochondral allografts achieved fair to excellent congruency with surrounding cartilage in the equine fetlock joint
- •Most grafts maintained >90% articular cartilage coverage with good incorporation at 25 weeks post-transplantation
- •Two of six grafted horses were sound at 25 weeks; no procedure-related complications occurred
- •Decreased sulphated glycosaminoglycan concentration in grafted tissue suggests altered cartilage biochemistry despite histological viability