Dylan Lawson’s research while affiliated with University of Pittsburgh and other places

Background The healthcare sector in the United States has increased its greenhouse gas emissions by 6% since 2010 and today has the highest per capita greenhouse gas emissions globally. Assessing the environmental impact and material use through the methods of life cycle assessment (LCA) and material flow analysis of healthcare procedures, products, and processes can aid in developing impactful strategies for reductions, yet such assessments have not been performed in orthopaedic surgery. We conducted an LCA and a material flow analysis on an ACL reconstruction (ACLR). The ACLR served as a test case on the assumption that, lessons learned, would likely prove relevant to other orthopaedic procedures. Questions/purposes (1) What are the life cycle environmental impacts of ACLR? (2) What is the material flow and material circularity of ACLR? (3) What potential interventions would best address the life cycle environmental impacts and material circularity of ACLR? Methods First, we conducted an LCA according to International Organization for Standardization standards for quantifying a product’s environmental impact across its entire life cycle. One result of an LCA is global warming potential measured in carbon dioxide equivalent (CO2eq), or the carbon footprint. Second, we conducted a material flow analysis of ACLR. Material flow analyses are used to quantify the amount of material in a determined system by tracking the input, usage, and output of materials, allowing for the identification of where materials are consumed inefficiently or lost to the environment. To contextualize the material flow analysis, we calculated the material circularity indicator (MCI) index. This is used to measure how materials are circulating in a system and to evaluate the extent to which materials are recovered, reused, and kept within the economic loop rather than disposed of as waste. These three methods are widely used in other fields, especially engineering, but are more limited in healthcare research. Three observations and data collection occurred during ACLRs at the University of Pittsburgh Medical Center Bethel Park Surgical Center in Pittsburgh, PA, USA, between 2022 and 2023. Data encompassing electricity usage, surgical equipment type, the use of heating, ventilation, and air conditioning (HVAC) systems, the production and reuse of reusable instruments and gowns, and the production and disposal of single-use surgical products were collected. Following data collection, we conducted the LCA and the material flow analysis and then calculated the MCI for a representation of a single ACLR. To identify strategies to reduce the environmental impact of ACLR, we modeled 11 possible sustainability interventions developed from our prior work and the work of others and compared those strategies against the impact of the baseline ACLR. Results Our results show that the ACLR generated an estimated life cycle greenhouse gas emissions of 47 kg of CO2eq, which is analogous to driving a typical gasoline-fueled passenger vehicle for 120 miles. The total mass of all products for one ACLR was 12.73 kg, including 7.55 kg for disposable materials and 5.19 kg for reusable materials. Concerning material circularity, ACLR had a baseline MCI index of 0.3. Employing LCA for the carbon footprint and the MCI for 11 sustainability interventions has indicated the potential to reduce greenhouse gas emissions by up to 42%, along with an increase in circularity (circularity describes how materials are circulating in a system and evaluates the extent to which materials are recovered, reused, and kept within the economic loop rather than disposed of as waste) of up to 79% per ACLR. Among the most impactful interventions are the reduction in the utilization of surgical pack products, reutilization of cotton towels and surgical gowns, maximization of energy efficiency, and increasing aluminum and paper recycling. Conclusion ACLR has a substantial carbon footprint, which can meaningfully be reduced by creating a custom pack without material wastage, reusing cotton towels, and maximizing recycling. Combining LCA, material flow analysis, and MCI can provide a thorough assessment of sustainability in orthopaedic surgery. Clinical Relevance Orthopaedic surgeons and staff can immediately reduce the environmental impact of orthopaedic procedures such as ACLR by opening fewer materials—via making custom packs and only opening what is needed in the operating room—and by incorporating more reusable materials such as towels. Larger scale medical center changes, such as implementing recycling programs and installing energy-efficient systems, also can make a meaningful difference in reducing environmental impact.

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 (CO 2 ) 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.