A Comparison of the CO 2 Laser to Cryosurgery as an Adjuvant to Surgical Curettage in the Local Control of Bone Tumors

Abstract

The carbon dioxide laser was compared to cryosurgery as a potential adjuvant to surgical curettage in the local control of bone tumors. Bone defects simulating tumor cavities were created in the femoral condyles of 20 skeletally mature dogs. The cavity was then subjected either to 30 W CO₂ laser irradiation or a double freeze–thaw cycle with liquid nitrogen. The femora were examined at 1, 2, 4, and 8 weeks, with roentgenograms, tetracycline fluorescence studies, and whole mount histology. The laser-irradiated cavities sloughed a relatively narrow zone of devitalized bone before timely healing with lamellar bone, whereas those treated with cryosurgery demonstrated an extensive zone of necrosis and were slower to heal. Bone necrosis occurred from 0.6 to 1.5 mm surrounding the laser-irradiated cavities compared to 7 to 12 mm of necrosis surrounding the liquid nitrogen-treated group. In addition, bone graft incorporation in the laser-irradiated group occurred in one quarter the time it took to incorporate in the cryosurgery group. There were no complications in the laser-irradiated group. There was a pathologic fracture through the liquid nitrogen-treated cavity in one dog in the cryosurgery group. We concluded that CO₂ laser surgery could be extremely effective as an adjuvant to surgical curettage in the local control of bone tumors. The laser offers the advantage of precision without extensive peripheral damage, a factor necessary, for example, near articular cartilage if a joint is to be preserved.