Disposable or reusable? Consumers face that choice many times each day. Should we buy a bottle of water for the gym or fill a thermos at home? Should we eat dinner on paper plates or use the dishes? Which to choose depends on many factors, including convenience, cost and the environment.

The choice is a little more complicated in the world of medical devices. Making surgical instruments from materials like stainless steel is expensive and energy-intensive. But, cleaning and sterilizing those instruments so they can be safely reused is also expensive and energy-intensive. What if instruments could be made from less expensive materials, such thermoplastic, so they could simply be used once and thrown away?

The results of a study from Solvay Specialty Polymers, a supplier of high-performance thermoplastics, are challenging perceptions that single-use medical instruments have a negative environmental impact vs. reusable instruments. Working with Medacta International, a manufacturer of orthopedic implants, neurosurgical systems and instrumentation, and Swiss Climate, an independent sustainability consultant, Solvay conducted a cradle-to-grave life-cycle analysis to measure the environmental impact of high-performance polymers in healthcare applications.

“Despite the tremendous promise of the single-use concept for reducing the frequency of hospital-acquired infections, concerns over increased waste have led to the perception that single-use instrumentation is less environmentally friendly than traditional systems,” says Bianca Shemper, sustainability manager for Solvay Specialty Polymers. “With Medacta’s help, we methodically explored those concerns to determine whether the alleged environmental impact of a single-use instrument kit outweighed its clear potential benefits.”

Applying the ISO 14044 standard for life cycle analysis, the group focused its study on the cumulative environmental impact of a surgical instrument kit for knee replacement manufactured by Medacta. The kit is available with either all-metal reusable instruments (GMK) or with single-use instruments (GMK Efficiency) injection-molded from several high-performance, medical-grade polymers from Solvay. The analysis encompassed the complete cradle-to-grave life cycle of both kit options, including their raw materials, production, use and disposal, as well as post-use management, reuse and recovery.

Overall, the life-cycle analysis of Medacta’s surgery kit demonstrated that the carbon footprint of GMK Efficiency single-use instrumentation is neutral when compared to the average CO₂ equivalent annual emission of a hospital using conventional metal reusable instrumentation. These findings counter existing industry perceptions about the negative environmental impact of single-use instrumentation, and reinforce the viability of metal-to-plastic conversion for these applications. Further, the findings allowed Medacta to apply Swiss Climate’s respected CO₂ Neutral stamp to its GMK Efficiency single-use surgical instrument kit for knee replacement.

Additional input from Swiss Climate found that GMK Efficiency single-use instrumentation eliminates the need for repeated washing and sterilization, which can save up to 115 gallons of water for each surgical knee procedure.

High-performance polymers, including polysulfone, polyphenylsulfone, polyaryletherketone, polyetheretherketone, and polyarylamide, offer better mechanical performance than engineering resins, as well as broader chemical resistance, higher thermal properties and, in some cases, inherent flame retardance without the need for additives. These materials are also compatible with a broad range of sterilization technologies, such as steam, ethylene oxide, vaporized hydrogen peroxide, and high-energy gamma radiation.