Mesenchymal stem cell therapy for equine tendinopathy.

This study explores the effect of using a type of stem cell therapy to treat tendon injuries in horses. The researchers believed that implanting these stem cells into the injured tendons would encourage the creation of proper tendon tissue instead of scar tissue, thus decreasing rates of re-injury.

Research and Methodology

• The researchers postulated that the use of marrow-derived stromal stem cells (BM-MSCs), implanted into the tendon in numbers greater than usually present in such tissue, would create a matrix more akin to a normal tendon matrix instead of scar tissue.
• This hypothesis revolved around the idea that replicating a normal tendon matrix would lower re-injury rates and improve the chances of returning to successful performance.

Techniques Used

• The research team used a clinical treatment method involving autologous (obtained from the same individual) implantation of BM-MSCs into serious acute superficial digital flexor tendon (SDFT) injuries.
• Bone marrow was extracted from the horse’s sternum while it was sedated. The BM-MSCs were then isolated, increased in number and, three weeks later, re-suspended in the bone marrow’s supernatant (the liquid lying above a solid residue after centrifugation).
• These cells were then implanted into the injured tendons while using ultrasound for guidance.
• The horse then underwent a 48-week rehabilitation period involving a progressively intensive exercise regimen.

Results

• By September 2006, this treatment had been used in 168 racehorses.
• The researchers found that 18% of the horses that had returned to full work had been re-injured, a significant reduction as compared to the 56% re-injury rate experienced by horses treated with conventional methods.
• No adverse effects were recorded, apart from the visibility of needle tracts using ultrasound.

Conclusion and Further Research

• The team concluded that autologous implantation of mesenchymal stem cells into tendon injuries could potentially improve clinical outcomes.
• However, they also noted that further research is required to provide definitive proof of efficacy, particularly through the use of randomized controlled trials.