In vitro effects of Nd:YAG laser radiation on cartilage metabolism.

Laser therapy is being increasingly applied in the treatment of diverse forms of arthritis without a firm scientific basis for its safety or efficacy. Our study in part addresses this issue by assessing the in vitro effect of Nd:YAG laser radiation on mature normal bovine articular cartilage metabolism. Normal pulsed mode delivery of defined energy levels could be shown to consistently upregulate cartilage proteoglycan, collagen, noncollagen protein and DNA synthesis in the absence of histologic or biochemical evidence of enhanced matrix catabolism. Laser induced repair could be shown biochemically in in vitro model systems of enzymatically mediated cartilage matrix depletion. Results suggest that Nd:YAG radiation applied directly at surgery or via arthroscopy may provide a potential means of effecting cartilage healing. Further studies are necessary to substantiate such usage.