Total replacement of the metatarsophalangeal joint in the horse. A single pilot study.

The research study reported a successful procedure of replacing an equine metatarsophalangeal joint with a human total condylar knee prosthesis, observing little signs of lameness in the horse subsequently, despite noticeably reduced joint flexibility. This encourages further investigation into using endoprosthesis for such equine joint replacements.

Objective of the Study

• The primary objective of this study was to investigate the feasibility of replacing an equine metatarsophalangeal joint with a human condylar knee prosthesis. The researchers wanted to observe whether a horse fitted with a prosthetic joint could still function optimally.

Methodology

• In this pilot study, the researchers implanted an endoprosthesis (internal prosthesis) to replace the metatarsophalangeal joint in a horse.
• The chosen replacement was a human total condylar knee prosthesis.
• After the implantation, the animal was observed over a period to monitor the effects of the procedure.

Findings of the Study

• The post-operative observations revealed that the horse showed nearly no signs of lameness when walking. This indicated that the animal was able to bear weight on the limb operated on.
• However, there was a significant reduction in the joint’s flexion and extension, which implies a reduced range of motion in the joint.
• Despite the reduced flexibility, the clinical and histological observations deemed the operation a success, suggesting that the overall viability of using an endoprosthesis for such equine joint replacements is worth further exploration.