The biological effects of carbon dioxide laser surgery on rabbit articular cartilage

A pulsed carbon dioxide laser made predetermined superficial and deep (subchondral) lesions through arthrotomies on the femoral condyles of adult New Zealand rabbits. Twenty rabbits, including controls, were divided into acute, 1-, 3-, 6-, and 12-month sacrifice groups. Early sacrifice groups showed some fibrous ingrowth from the deep lesions, but not the superficial lesions, and this was not seen in the 6- or 12-month groups. Cells below and adjacent to the laser lesions appeared viable when compared with controls. In each group studied, no histologic evidence of healing or fibrous covering in the superficial or deep laser lesions was found. No adverse clinical effects (synovitis, infection) were found in the laser groups, and the laser permitted excellent depth control during vaporization. However, the authors caution against irradiating articular cartilage.