title: Evaluation of a diode laser for use in induction of tendinopathy in the superficial digital flexor tendon of horses.
abstract: OBJECTIVE
  To evaluate use of a diode laser to induce tendinopathy in the superficial digital flexor tendon (SDFT) of horses.
  
  
  METHODS
  4 equine cadavers and 5 adult horses.
  
  
  METHODS
  Cadaveric SDFT samples were exposed to a diode laser at various energy settings to determine an appropriate energy for use in in vivo experiments; lesion size was assessed histologically. In vivo experiments involved laser energy induction of lesions in the SDFT (2 preliminary horses [0, 25, 75, and 87.5 J] and 3 study horses [0 and 125 J]) and assessment of lesions. Study duration was 21 days, and lesions were assessed clinically and via ultrasonography, MRI, and histologic evaluation.
  
  
  RESULTS
  Lesion induction in cadaveric tissues resulted in a spherical cavitated core with surrounding tissue coagulation. Lesion size had a linear relationship (R2 = 0.9) with the energy administered. Size of in vivo lesions in preliminary horses indicated that larger lesions were required. In study horses, lesions induced with 125 J were ultrasonographically and histologically larger than were control lesions. At proximal and distal locations, pooled (preliminary and study horses) ultrasonographically assessed lesions were discrete and variable in size (mean ± SEM lesion percentage for control lesions, 8.5 ± 3%; for laser lesions, 12.2 ± 1.7%). Ultrasonography and MRI measurements were associated (R2 > 0.84) with cross-sectional area measurements.
  
  
  CONCLUSIONS
  In vivo diode laser-induced lesions did not reflect cadaveric lesions in repeatable size. Further research is required before diode lasers can reliably be used for inducing tendinopathy.
authors.affiliation: Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA.
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Vallance
authors.forename: Martin A
authors.initials: MA
authors.lastname: Vidal
authors.forename: Mary Beth
authors.initials: MB
authors.lastname: Whitcomb
authors.forename: Brian G
authors.initials: BG
authors.lastname: Murphy
authors.forename: Mathieu
authors.initials: M
authors.lastname: Spriet
authors.forename: Larry D
authors.initials: LD
authors.lastname: Galuppo
mesh_terms: D000818:Animals; D005260:Female; D006651:Histocytochemistry / Q000662:veterinary; D006734:Horse Diseases / Q000000981:diagnostic imaging / Q000473:pathology*; D006736:Horses; D054023:Lasers, Semiconductor / Q000592:standards*; D008279:Magnetic Resonance Imaging / Q000662:veterinary; D018709:Statistics, Nonparametric; D052256:Tendinopathy / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*; D014463:Ultrasonography