A STUDY OF LASER-BASED REMOVAL OF POLYMETHYLMETHACRYLATE BONE-CEMENT

Complications are often produced with the removal of bone cement from the femoral cavity in the treatment of a failed hip prosthesis. Apart from being slow and difficult the conventional process runs the risk o f producing damage to the femur. Ultrasonic techniques have been sugge sted to achieve these ends but removal of the cement by this approach is not entirely easy. The alternative laser-based approach would seem to have significant advantages over conventional techniques. The laser is capable of delivering energy to a specific region or surface under close control. The choice of laser is determined by its ability to ab late the cement and the ease with which it can be delivered to the bas e of the femur cavity. This paper examines several laser wavelengths: CO2 (10.6 mu m), excimer (248 nm), Hol:YAG (2.12 mu m), and presents p olymethylmethacrylate (PMMA) vaporization thresholds for each laser.