Effects of extracorporeal shock wave therapy and radial pressure wave therapy on elasticity and microstructure of equine cortical bone.

ABSTRACT

OBJECTIVE: To measure changes in the modulus of elasticity (E) and describe histologic findings after extracorporeal shock wave therapy and radial pressure wave therapy on equine cortical bone specimens. SAMPLE POPULATION 16 bone specimens from the proximodorsal cortex of an equine third metacarpal or metatarsal bone. PROCEDURE Baseline E was determined by the density (p) and unidirectional ultrasound transmission velocity (C) of each specimen according to the equation E = pC2. Eight specimens were treated with 500 pulses of 0.15 mJ/mm2 of extracorporeal shock wave therapy, and 8 specimens were treated with 500 pulses of 0.16 mJ/mm2of radial pressure wave therapy. After treatment, C was determined again. Four treatment sessions resulted in 2,000 pulses and 5 C measurements. The p of each sample was measured again. Mean post-treatment E was calculated for each group. Nondecalcified sections of all specimens were stained with toluidine blue or basic fuchsin for histologic evaluation. RESULTS: Overall treatment group effect was not significant for C or E. Final E was not different from baseline values for extracorporeal shock wave therapy and radial pressure wave therapy. No histologic changes could be attributed to either treatment modality. CONCLUSIONS AND CLINICAL RELEVANCE Extracorporeal shock wave therapy and radial pressure wave therapy did not affect the material properties of equine bone at the energy and pulse values used in this study.