Grading osteoarthritis and decision making in cartilage repair

Introduction

For years we considered osteoarthritis (OA) a relentless degenerative condition leading to end stage disease. Though there are no cures in sight we now speak in terms of trajectory modification. This translates into the horse living with the condition, and providing medical interventions as well as management changes. To that end we have better tools to monitor and modify OA progression including innovations in imaging and biochemical biomarkers. In a field that seems crowded and confusing because of the rate of innovation, better diagnostic tools are emerging to help us make valid decisions about therapy.

In the past, equine medicine kept pace and even led the field of cartilage repair and OA, but as other speakers today will demonstrate, the success and commercialization of human cartilage repair therapy in Europe and Asia have driven approvals for second and third generation cell and biologic therapy products. Our speakers today will help us broadly consider the evidence for medical and surgical therapies arising from veterinary and human clinical trials, but consensus in veterinary medicine is harder to achieve for a number of reasons.

Since this is a burgeoning, and commercially viable focus of biotech development, there are many opinion makers and influencers working to shape our use of biologic and cellular therapies. The U.S. FDA has issued warnings and fines to companies operating in this space¹ , and established regulations that require registration of animal stem cell trials, record keeping and inspection. Unless a therapy is autogenous and “minimally manipulated” it is considered a drug for regulatory purposes. The International Society for Cell and Gene Therapy (ISCT) has commissioned a task force on the Use of Unproven and/or Unethical Cell and Gene Therapy² . So some caution is needed because of the new products and therapeutic regimes are evolving. In the past there has been a tendency in veterinary medicine to acknowledge prominent practitioners and academics and other opinion makers based on their experience with interventions and therapies. This seldom helped progress or create consensus about rationale therapy. As a rule, if a condition or problem has one or two widely acknowledged standard treatments, this is a good indication of efficacy. The current status of regenerative medicine treatments for equine injuries (joint, tendon) is more confusing. There are many proposed therapy regimes, including variables in duration of treatment, number of treatments, dose, and the use of adjunctive therapies. This is a worry because the equestrian population is hungry for solutions, putting pressure on us and driving business decisions for horse owners and trainers that may be illogical. At present we are doing our best to characterize the biologic therapy potency, duration of effect and dose response of regenerative therapies, but in the meantime most of us are making educated guesses about therapy regimes rather than practicing evidence-based medicine. [...]