Average total weight of surgical waste and CO2 carbon footprint of orthopedic surgery in France, estimated on the basis of a representative panel.

Abstract

Background: Reduction of waste and carbon footprint can be optimized. Awareness of carbon sources and quantification of the waste are two key parameters. To our knowledge, there is no study in France on waste production by the surgical team during the operation in orthopedic surgery, in a global scope. Therefore, we performed an observational investigation aiming to: (1) quantify and characterize the weight of the wastes generated after a panel of orthopedic procedures, (2) calculate the CO₂ footprint generated by these wastes and extrapolate the figure at the national scale.

Hypothesis: Waste production is highly variable according to the types of procedures and infectious clinical waste is still a predominant source of waste and CO₂ emission.

Materials and methods: It is a comparative and prospective study in which a total of 14 procedures were selected as a representative panel: arthroplasties (hip, knee), spine fusions, arthroscopic procedures (shoulder, knee), nerve release, forefoot osteotomies, trauma procedures. The main outcome was the average total weight of waste for each of the fourteen categories (280 measurements: 140 times 2, at the end of each procedure), expressed in kilograms (kg), and the proportions of infectious clinical waste (ICW) and household wastes (HW), expressed in percentages. Ten measures were prospectively recorded for each type of procedure in a single teaching hospital from January to September 2022. The theoretical carbon footprint generated by the treatment of the wastes was estimated in kilograms of CO₂ equivalent (KgEqCO₂). The national extrapolation of the carbon footprint was performed by collecting the total number of procedures in France in 2021 using the VisuChir tool.

Results: A total of 937kg of waste were produced for the 140 procedures, amongst which 514kg of ICW (54.8%) and 423kg of HW (45.2%). The overall median waste weight was 5.9kg (Q1: 4.4, Q3: 8.1), ranging from 1.8kg to 18.3kg. The overall median waste weight for HW was 2.8kg (Q1: 2.5, Q3: 3.4), ranging from 1.8kg to 17.8kg. The overall median waste weight for ICW was 3.8kg (Q1: 2.7, Q3: 4.8), ranging from 0.8kg to 7.2kg. The knee surgeries were responsible for the heaviest waste weight; the least waste-productive procedures were the foot and the carpal tunnel release. The median proportions of ICW varied from 39% for the total knee replacements to 72% for the femoral nails. There was a significant inverse correlation between the total waste weight and the proportion of ICW: r=-0.47, p<10^-4. The total median estimated carbon footprint was 4.3KgCO₂Eq (Q1: 3.1, Q3: 5.8), ranging from 1.59KgCO₂Eq (Q1: 1.5, Q3: 1.8) and 7.07KgCO₂Eq (Q1: 6.7, Q3: 8.17). The total median estimated carbon footprint was 3.5KgCO₂Eq for ICW (Q1: 2.5, Q3: 4.5) and 0.76KgCO₂Eq (Q1: 0.54, Q3: 1.3) for HW. The national median estimated carbon footprint was 10.1 million KgEqCO₂ in 2021 for orthopedic surgery.

Conclusion: Our study revealed that in most cases more than half of the wastes were ICW. The total estimated national carbon footprint for orthopedic procedures was 10 million kilograms. The reduction of the ICW constitutes a cornerstone, as they are responsible for more carbon emissions.

Level of evidence: III; prospective comparative observational in vivo study.