Published online by Cambridge University Press: 01 November 2006
A prospective, blinded, randomized and controlled study was conducted in horses with traumatic arthritis of the metacarpophalangeal joint in order to evaluate the efficacy of defocused carbon dioxide (CO2) laser therapy. Sixteen horses were randomly assigned to two groups: active laser (an output power of 16 W, scanned over 42 cm2, an average dose of 91 J cm− 2) and sham laser (the laser beam directed at the non-reflecting floor). All the horses received a total of five treatments during 1 week. The horses were evaluated with respect to the degree of initial lameness by conventional lameness examination and an objective accelerometer technique before the onset of treatment, and at 1 and 3 weeks. The concentrations of substance P (SP), prostaglandin E2 (PGE2) and Met-enkephalin-Arg-Phe (MEAP) in synovial fluid were also assessed. Our study demonstrates that there was no significant difference in lameness score between the laser- and the sham-treated group before the treatment and at 1 and 3 weeks after the initial examination. Moreover, no significant difference in the concentrations of SP, PGE2 and MEAP in synovial fluid in the active laser group compared with the sham-treated group was observed. In conclusion, this study suggests that treatment with defocused CO2 laser in the management of traumatic arthritis of the metacarpophalangeal joint is not statistically better than sham treatment at reducing the grade of lameness as evaluated by conventional lameness examination and accelerometer technique.