An Evaluation of Pathophysiology and Biomechanics of Selected Lamenesses in the Horse

INTRODUCTION-Laminitis and synovitis are two common causes of equine lameness. Laminitis is most often associated with hyperinsulinemia and osteoarthritis is most commonly the result of synovitis. The objective is to evaluate biomechanical and pathophysiologic events regarding laminitis and synovitis. MATERIALS AND METHODS-The first study evaluated biomechanical effects of insulin on lamellar strength. For this experiment, lamellar explants were harvested, incubated in media only (serving as a control) or media with a high concentration of insulin for 8 hours. After incubation, structural integrity was evaluated with a mechanical testing device. Data included load to failure (N), stress to failure (MPa), elongation to failure (mm), and Young’s modulus (MPa) to be evaluated with a mixed linear model (P2(PGE2), interleukin-1 receptor antagonist (IL-1ra), and collagenase-cleavage neoepitope (C2C) were performed. Statistical significance was assessed using a two-way repeated measures ANOVA with a Bonferroni correction (P RESULTS- Insulin significantly weakened the structural integrity of lamellar explants, but did not make them less stiff. A single injection of PRP improved subjective lameness scores, but did not improve the synovial environment. DISCUSSION- The use of a mechanical testing device to study hyperinsulinemia-induced lamellar failure through the exposure of lamellar explants to high concentrations of insulin provides a novel model to study that form of laminitis and evaluate potential therapies. Additional injections of PRP as recommended in human literature or a different composition of PRP may have improved results because the PRP used in the study did not improve the synovial environment using that model of synovitis