The effect of intra-articular methylprednisolone acetate and exercise on equine carpal subchondral and cancellous bone microhardness.

The research paper discusses a study on the impact of intra-articular Methylprednisolone Acetate (MPA) and exercise on the microhardness of equine carpal subchondral and cancellous bone, revealing that this administration of MPA has no significant effect on the adjustment of these bone types to short-term exercise.

Research Objective and Hypothesis

• The main objective of the paper was to explore the mechanical properties of intra-articular MPA and diluent-treated middle carpal subchondral and cancellous bone in horses engaged in a short-term treadmill exercise programme. The researchers hypothesized that these bone mechanical properties would be influenced by the intra-articular use of MPA.

Research Methodology

• Eight 2-year-old female horses underwent the study where MPA or a diluent was administered into the opposing middle carpal joints at intervals of two weeks, totaling four treatments for each horse.
• The horses were subjected to a standard treadmill exercise protocol until they were euthanized by day 70.
• The researchers collected osteochondral samples from standard sites on the dorsal aspect of the third, radial, and intermediate carpal bones. These samples were divided into the subchondral bone and cancellous bone portions, dried, embedded in resin, and then gold-coated.
• Microhardness measurements were taken at each test site to analyze the mechanical properties of the bone.

Research Findings

• Upon analysis, the researchers concluded that the intra-articular administration of MPA had no significant effect on the subchondral or cancellous bone’s adaptation to short-term exercise.
• At each test site, cancellous bone trabecular struts had an 18-19% higher microhardness value than the overlying subchondral bone indicating that the bone’s strength was not influenced by the administration of MPA.

Conclusions and Further Research

• The conclusions from this study indicate that the intra-articular administration of MPA at the given dose has no effect on the propensity of carpal bones to injury- a major concern among equine athletes undergoing high-intensity training.
• The authors suggest further investigation into the calcified cartilage layer, the effect of different corticosteroid preparations, and the diffusion of medication to fully determine the impact of such treatments on equine bone health.