A University of Pittsburgh study inspired by the late Freddie H. Fu, MD, one of the world’s leading orthopedic surgeons, is tackling a significant contributor to climate change: the health care sector. Engineers and physicians examined how one procedure in particular—anterior cruciate ligament (ACL) reconstruction—contributes to greenhouse gas emissions and how its impacts can be reduced.

The paper, “How Can the Environmental Impact of Orthopedic Surgery Be Measured and Reduced? Using Anterior Cruciate Ligament Reconstruction as a Test Case,” was published this month by Clinical Orthopedics and Related Research,

The investigators utilized a method known as life-cycle assessment (LCA), which analyzes the entire life cycle of a product, service, or industry, from raw material extraction, manufacturing, distribution, use, and end-of-life. Bilec was the first to apply this process to examining hospital room infant births in 2012 in a study with UPMC Magee-Womens Hospital.

“While life cycle assessment and material flow analysis (MFA) are tools in engineering and sustainability research, their potential has only recently been adapted to understanding the incredible impact that health care has on climate,” noted Bilec, who is also the Special Assistant to the Provost for Sustainability at Pitt. “This “cradle-to-grave” assessment takes a hard look at every product and process involved—in this case, with ACL surgery, everything from the materials used to make the devices used in surgery to the energy consumed, and the cost of disposing of the material. Partnerships with Pitt and UPMC are critical to advancing our collective strategic climate and environmental goals.

An unmatched carbon footprint

Greenhouse gas emissions seem easy to understand—a fuel is produced and consumed, and emissions are released into the atmosphere, as when driving a car or flying in a plane. However, according to first author Nathalia Cano, conducting an LCA on a complex process such as construction of a building or performing surgery results in astonishing carbon footprints.

“As health care professionals and researchers, we must explore ways to make our practices more sustainable without compromising patient outcomes,” Cano said. “With LCA and MFA as our toolbox, we examined scenarios throughout the operation to reduce environmental impact, including reducing resources, optimizing surgical practices, and exploring innovative materials and circular economy approaches.”

Some of their findings include:

• The carbon footprint of one ACLR is 47 kg of carbon dioxide equivalent (CO₂eq) or driving a typical gasoline-fueled passenger vehicle about 120 miles.
• The 130,000 ACLRs each year in the US produce approximately 6,110 metric tons of CO₂eq per year, or about 15 million miles driven.
• Products contributing most to global warming potential were disposable cotton for OR towels (9%) and laparotomy sponges (1%) and disposable plastics made of polypropylene (6%), including disposable fabrics such as drapes.
• Production of all products accounted for 58% of global warming potential, and energy for OR equipment and HVAC were responsible for 10% and 14%, respectively.
• Autoclaving steel surgical instruments was responsible for 9%, linens laundering for 4%, and waste disposal for 1% of global warming potential.

“Though the most important priority in surgery is excellent patient care, surgeons can and should also be mindful of the carbon footprint of our surgeries,” noted Ian Engler, MD, Orthopedic Sports Medicine Surgeon at the Central Maine Medical Center. “We make many decisions in patient care that lead to a big environmental footprint, and this research helps us guide efforts to integrate sustainability into orthopedic surgery.

“We presented this idea to Dr. Freddie Fu (left) several months before he passed. He said, ‘I thought I knew everything about the ACL, and here is something I didn’t know.’ His contagious enthusiasm jump-started the research and is the reason it came to be.”

Fu launched UPMC’s sports medicine program and was head team physician for Pitt’s Department of Athletics.

The study’s principal investigator is Melissa M. Bilec, Ph.D., the George M. and Eva M. Bevier Professor of Civil and Environmental Engineering at Pitt’s Swanson School of Engineering and co-director of the Mascaro Center for Sustainable Innovation; and first author is Nathalia Silva de Souza Lima Cano, MSc, Fulbright/CAPES Ph.D. Fellow at Pitt. Bilec partnered with Fu and his team at the University of Pittsburgh School of Medicine’s Department of Orthopedic Surgery, where he served as chair.