Enhanced bone screw fixation with biodegradable bone cement in osteoporotic bone model

Purpose: The purpose of this study was to study the potential of novel biodegradable PCL bone cement to improve bone screw fixation strength in osteoporotic bone. Methods: The biomechanical properties of bone cement (ε-polycaprolactone, PCL) and fixation strength were studied using biomechanical tests and bone screws fixed in an osteoporotic bone model. Removal torques and pullout strengths were assessed for cortical, self-tapping, and cancellous screws inserted in the osteoporotic bone model (polyurethane foam blocks with polycarbonate plate) with and without PCL bone cement. Open cell and cellular rigid foam blocks with a density of 0.12 g/cm3 were used in this model. Results: Removal torques were significantly (more than six-fold) improved with bone cement for cancellous screws. Furthermore, the bone cement improved pullout strengths three to 12 times over depending on the screw and model material.?Conclusions: Biodegradable bone cement turned out to be a very potential material to stabilize screw fixation in osteoporotic bone. The results warrant further research before safe clinical use, especially to clarify clinically relevant factors using real osteoporotic bone under human body conditions and dynamic fatigue testing for long-term performance.