Use of autogenous cartilage particles to create a model of naturally occurring degenerative joint disease in the horse.

The researchers designed an experiment to create a model of degenerative joint disease in horses by injecting cartilage particles into selected joints, take partial thickness cartilage biopsies, and applying exercise. Six adult mixed-breed horses were involved in the study and extensive effort was put in place to rule out pre-existing joint diseases before the experiment was conducted. Procedures, results, and possible implications of this study for the understanding of joint diseases are further discussed.

Methodology

• Initially, the study involved a thorough medical examination of the six horses to rule out any pre-existing joint diseases. The examination process included radiography and synovial fluid analysis.
• Samples of articular cartilage were harvested from each horse, using a motorised arthrotome under general anaesthesia. This cartilage was then ground and filtered to produce a concentrated suspension of cartilage particles.
• Two weeks after the initial harvesting, partial carpal and metacarpophalangeal joint synovial membrane and articular cartilage biopsies were carried out on the horses. The small cartilage particles suspension was then injected into the left metacarpophalangeal and middle carpal joints of each horse, which were designated as the treatment group.
• As a control in the experiment, the same volume of lactated Ringer’s solution, without the cartilage particles, was injected into the right forelimb joints of the horses. Bandages were applied to all operated joints after the horses recovered from anesthesia.

Understanding the Findings

• The researchers drew on previous clinical observations that suggested cartilage particles are abundant when exercise or ligament instability is added to a cartilage injury. These particles can contribute to joint inflammation and further erosion, possibly via two mechanisms – by adding abrasive ‘wear particles’ to the synovial membrane and by stimulating cells to produce proteinases that deplete the cartilage matrix.
• The experimental model was created to better understand these processes in a controlled setting, aiming to shed light on the natural progression of degenerative joint diseases. The implications of this research could be wide ranging, from more effective diagnosis and treatment approaches to improved understanding of how joint diseases develop over time.
• This study aimed to replicate mechanisms and processes of the degenerative joint disease in horses as closely as possible, to allow researchers to observe and understand it in a controlled laboratory environment.