Effect of Nd:YAG laser energy on articular cartilage healing in the dog.

The effect of low dose neodymium:yttrium aluminum garnet (Nd:YAG) laser therapy on cartilage healing was studied. Partial- and full-thickness cartilage defects were surgically created in the femoral condyles of 20 adult dogs. The cartilage defects in one limb of each dog were exposed to 30 J of Nd:YAG laser energy. The dogs were euthanatized 1 week (n = 6), 1 month (n = 7), and 6 months (n = 7) after surgery. Plastic-embedded, undecalcified histologic sections of each cartilage defect were examined for evidence of cartilage healing. Special stains were used to determine the type of repair tissue present, and morphometric measurements of repair tissue were made. No effect of Nd:YAG laser therapy on cartilage healing was noted.