Effect of focused and radial extracorporeal shock wave therapy on equine bone microdamage.
Authors: Da Costa Gómez Támara M, Radtke Catherine L, Kalscheur Vicki L, Swain Carol A, Scollay Mary C, Edwards Ryland B, Santschi Elizabeth M, Markel Mark D, Muir Peter
Journal: Veterinary surgery : VS
Summary
# Editorial Summary: Extracorporeal Shock Wave Therapy and Equine Bone Microdamage This ex vivo investigation examined whether focused and radial extracorporeal shock wave therapy (ESWT) alters microdamage patterns in equine metacarpal and metatarsal bone, using distal limb specimens from 11 racing Thoroughbreds with unilateral catastrophic injuries and five non-racing horses. Researchers applied 9,000 shockwaves of each modality (focused at 0.15 mJ/mm² and radial at 0.175 mJ/mm²) to paired bone segments, then quantified microcracks using basic fuchsin staining and histomorphometric analysis. Both ESWT modalities produced small but statistically significant increases in microcrack parameters: focused therapy increased microcrack density and surface density, whilst radial therapy increased microcrack length; notably, microcrack length correlated with racing intensity in Thoroughbreds, suggesting cumulative damage from athletic work. These findings carry important implications for practitioners considering ESWT as a therapeutic intervention—whilst the absolute increase in microdamage was modest in this controlled ex vivo model, the potential for in vivo microcracking may be amplified in actively raced horses where baseline microdamage is already elevated. The clinical relevance remains uncertain pending in vivo validation, but the data warrant cautious application of ESWT in high-performance animals and suggest the need for post-treatment monitoring protocols.
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Practical Takeaways
- •ESWT may increase bone microcracking rather than facilitate healing in equine distal limb bone; clinical efficacy claims should be reconsidered given this ex vivo evidence
- •If ESWT is used therapeutically, raced Thoroughbreds may be at higher risk for cumulative microdamage, suggesting caution with this modality in high-performance horses
- •The difference between focused and radial ESWT effects on microcrack patterns suggests these are not interchangeable modalities; if used, treatment type selection should be evidence-informed
Key Findings
- •Focused ESWT significantly increased microcrack density (Cr.Dn) and microcrack surface density (Cr.S.Dn) in equine metacarpal/metatarsal bone ex vivo
- •Radial ESWT significantly increased microcrack length (Cr.Le) but had different effects on microcrack density compared to focused therapy
- •In racing Thoroughbreds, microcrack length increased with increased number of races undertaken, suggesting cumulative in vivo microcracking
- •ESWT effects on microcracking were small but statistically significant, with potential to increase bone microdamage in vivo particularly in actively raced horses