Poster 147: Identifying Opportunities to Improve the Environmental Sustainability of ACL Reconstruction: A Life Cycle Analysis

Abstract

Objectives: Environmental sustainability is a topic of increasing recognition within the field of orthopaedic surgery. To decrease the carbon footprint of orthopaedic procedures, the baseline carbon footprint of said procedures must be calculated. Life cycle assessment (LCA) is the most rigorous means of establishing the overall carbon footprint of a system and also identifies the carbon contribution of each step of the process. The latter allows for a targeted carbon reduction approach to address the steps with the greatest potential impact. Methods: An LCA was employed to analyze the environmental impacts of an anterior cruciate ligament reconstruction (ACL-R). The environmental impacts were estimated using TRACI 2.1 (Tool for Reduction and Assessment of Chemicals and Other Environmental Impacts), which was developed by the Environmental Protection Agency. The system boundary of this study included production of single-use items, production of reusable items, waste management, and energy consumed in an operating room (OR) (e.g., monitors, lighting fixtures). Required data regarding type and quantity of materials utilized in an ACL-R were collected via material audit. The material audit encompassed measuring and documenting the mass of surgical items and instruments, as well as identifying material composition of different items. During the audit, surgical materials or instruments were disassembled to measure mass of specific materials. To measure the impacts of different gases produced, such as carbon dioxide (CO2) and methane, values were converted to the Global Warming Potential (GWP), a metric that indicates how different gases warm the earth relative to carbon dioxide (CO2) equivalents. Results: The preliminary results, which represented the impacts from manufacturing single-use materials, showed that plastics followed by cotton were the major contributors of ACL-R to global warming by being responsible for 47% and 44% of the total GWP, respectively. Initial results also showed that plastics (64%) and cotton (32%) had the highest ozone depletion potential compared to other materials. Among the six types of plastics that were identified in the single-use items, polyvinyl chloride (PVC) most contributed to depleting the ozone layer. PVC was most commonly found in suction tubing. Of the single-use materials, OR towels were the predominant source of cotton. Finally, the cumulative energy demand of producing materials for one ACL-R was 598 MJ, which was dominated by production of plastics-based materials (374 MJ). Conclusions: These findings help identify areas of improvement for the environmental sustainability of ACL-R using LCA. The initial total GWP from production of single-use materials was estimated as 24 kgCO2eq, which is similar to the CO2 emissions from driving a car for 60 miles. Of the single-use surgical items utilized, suction tubing and OR towels demonstrated a significant environmental impact due to their composition of PVC and cotton, respectively. Thus, strategies to minimize the use of these items will improve the environmental sustainability of ACL-R. Limitations of this study include the limited generalizability of these findings to other ACL-R surgeries using dissimilar materials, potential for error while weighing and determining the composition of surgical materials, and the focused evaluation of just single-use items for these preliminary results. To better identify opportunities to improve the environmental sustainability of ACL-R, further analysis of this data will aim to determine the additional impact of electricity usage, reusable surgical items, and anesthetic gases. The environmental impact from the production of single-use surgical materials for ACL-R was similar to the CO2 emissions from driving a car for 60 miles. Judicious usage of suction tubing and OR towels are opportunities for surgeons to improve the environmental sustainability of ACL-R.