Arthrodesis for congenital flexural deformity of the metacarpophalangeal and metatarsophalangeal joints.

This research examines the use of arthrodesis, a surgical technique, in the treatment of severe congenital flexural deformities of certain joints in a llama, a miniature horse, and a miniature donkey.

Research Methodology

• The research was based on three case subjects – a llama, a miniature horse, and a miniature donkey.
• All subjects had severe bilateral congenital flexural deformities of the Metacarpophalangeal and Metatarsophalangeal joints.
• The treatment involved arthrodesis with dynamic compression plating or external skeletal fixation.

Treatment Approach

• In all cases, the flexor tendons were found to be more taut than the suspensory ligaments and were transected (cut).
• In the llama, the suspensory ligament was also transected, but this resulted in overcorrection leading to ischemic necrosis (tissue death due to a lack of blood supply) of one distal limb and subluxation (misalignment) of the other fetlock joint.
• In the horse and donkey, the suspensory ligament was preserved, and a wedge osteotomy (a bone cutting procedure to realign the joint) was performed to correct the deformity.

Research Findings

• The study found arthrodesis to be effective in treating severe congenital flexural deformities in these animals.
• However, the various treatment approaches had different outcomes. Transecting the suspensory ligament led to overcorrection in the llama, which caused further health issues. By contrast, preserving the suspensory ligament and performing a wedge osteotomy was successful in the miniature horse and donkey.
• The research indicates that the condition of the suspensory ligament and the specific surgical approach have significant impacts on the outcome of the treatment.