2.1 Search strategy

Although this study followed a narrative review format, a structured and reproducible literature search was conducted to ensure methodological rigour and transparency. The search was performed in PubMed, Scopus, and Embase databases from inception to October 2025, without restriction on language or publication status.

The following combination of controlled vocabulary MeSH and free-text keywords was used: “carbon footprint” OR “sustainability” OR “environmental impact” OR “waste” OR “CO2e” OR “greenhouse gas” OR “climate impact” OR “ecological footprint” AND “orthopaedic” OR “orthopaedic” OR “surgery” OR “operation” OR “operating room” OR “surgical procedure”. Additional records were identified through manual searches of reference lists of included studies, relevant review articles, and institutional or policy reports.

2.2 Inclusion and exclusion criteria

Studies were included if they examined the environmental impact, waste generation, or carbon footprint in orthopaedic surgery, including original research, reviews, or institutional sustainability reports. Eligible works focused on orthopaedic procedures and reported outcomes like total or plastic waste, recyclable fraction, carbon dioxide equivalent (CO2e) emissions, energy use, or sustainability interventions. Exclusion criteria were non-orthopaedic domains, and analyses unrelated to hospital settings.

2.3 Screening and data handling

Two independent reviewers (AR, SB) screened all retrieved records by title and abstract, followed by full-text assessment for eligibility. Disagreements were resolved by discussion and consensus. For each included study, descriptive data and quantitative outcomes including waste weight, CO2e, and sustainability interventions were extracted. Studies were grouped narratively by theme; Waste quantification and composition, Energy and resource utilization, Anaesthetic and sterilisation emissions and Sustainability interventions and policy initiatives.

Given the heterogeneity in study design and outcome metrics, formal systematic review or meta-analysis was not attempted; instead, a thematic synthesis approach was adopted to summarize patterns and knowledge gaps.

2.4 Research objectives (RO)

The primary objective of this narrative review was to synthesize and contextualize available evidence on the carbon footprint, waste generation, and sustainability interventions in orthopaedic surgery. Specifically, the review aimed to:•RO1: To quantify and summarize reported measures of waste generation, energy use, and CO2e emissions in orthopaedic surgical procedures.•RO2: To identify and describe sustainability initiatives, recycling practices, and waste-reduction strategies implemented within orthopaedic surgery.•RO3: To evaluate methodological approaches used to assess environmental impact and highlight existing gaps to inform future sustainable orthopaedic practice.

3.1 Operating room energy

Operating theatres are among the most energy-intensive areas in hospitals, consuming 3–6 times more energy per square foot than non-OR areas.^10,11 While they occupy a relatively small portion of hospital space, they nonetheless contribute significantly to overall energy demands. The heating, ventilation, and air-conditioning (HVAC) systems in ORs may account for over 80 % of the theatre's total energy use, according to some bottom-up studies.¹¹

Laminar-flow ventilation may further increase energy demand, though estimates vary.¹² Some analyses suggest that ORs with these systems consume 3–6 times more energy than other hospital zones; however, exact incremental percentages (versus turbulent flow) depend heavily on the HVAC design and occupancy patterns.¹¹ The intensive use of surgical lighting, powered equipment such as suction and cautery, and continuous air exchanges compounds the environmental load, making the operating theatre a major contributor to healthcare-related CO2 emissions¹³

Mitigation strategies have increasingly focused on optimising energy efficiency without compromising infection control. Evidence supports the use of “setback” ventilation modes during non-operative hours, LED surgical lighting, and occupancy-based ventilation controls to substantially reduce consumption.¹⁴ Hospitals adopting renewable energy sources, such as solar or hybrid power, have reported measurable reductions in carbon emissions.¹⁵ Broader frameworks, including the NHS Net Zero Surgery initiative and Practice Green Health sustainability guidelines, advocate for benchmarking OR energy use, retrofitting HVAC systems, and integrating sustainability targets into surgical planning to achieve long-term carbon neutrality.¹⁶

3.2 Single-use instruments and implants

Orthopaedic procedures generate substantial waste due to extensive reliance on single-use sterile items, including drapes, gowns, syringes, suction canisters, and implant packaging. Life-cycle analyses indicate that these materials are among the largest direct contributors to surgical waste.¹⁷ In total knee arthroplasty, waste per case ranges from 4 to 10 kg, with 40–60 % composed of plastic, much of which is non-contaminated and potentially recyclable.¹⁸ The widespread adoption of single-use metallic instruments and pre-packaged implant trays, driven by infection-control concerns, has increased both waste volume and embedded carbon emissions.

Mitigation strategies focus on reintroducing reusable alternatives and optimising instrument usage. In current orthopaedic practice, biological reconstruction approaches and biologic augmentation are being used with increasing frequency.^19–22 Pilot audits demonstrate that using reusable metal suction tips, drapes, and standardised trays can reduce waste by 50–70 % while maintaining sterility.²³

Life-cycle assessments for surgical instrument trays show that reusable trays can reduce CO2e emissions by roughly 20–50 %, depending on sterilisation practices, reuse rates, and the items included.²⁴ Hospitals implementing procedure-specific tray optimisation and minimising redundant instruments report annual savings exceeding 200 kg CO2e per surgeon.²⁵ Additionally, integrating reprocessing with optimised sterilisation cycles reduces energy and water use, combining environmental benefits with adherence to infection-control standards.

3.3 Anaesthetic gases

While inhaled anaesthetic gases are potent greenhouse gases, their share of per-procedure CO2e varies. In certain hospital case series, anaesthetics contributed over half of OR emissions; however, other hospitals report much lower fractions, depending on practice patterns, agent choice, and flow rates.²⁶ Life-cycle assessments also show that the carbon impact of desflurane per MAC-hour is significantly higher than for sevoflurane or isoflurane; however, total anaesthetic emissions depend heavily on clinical use.²⁷ Desflurane has a 100-year global warming potential (GWP100) of approximately 2,540, meaning that on a per-kilogram basis, it can trap 2540 times more heat than CO2 over 100 years.²⁸

Mitigation strategies focus on low-carbon anaesthetic techniques. Transitioning to low-flow anaesthesia, such as sevoflurane or total intravenous anaesthesia (TIVA), or regional blocks can reduce greenhouse gas emissions by over 80 %.²⁹ The implementation of anaesthetic gas scavenging or capture systems allows for the recycling of agents, further minimising atmospheric release. The American Society of Anesthesiologists (ASA) Sustainability Task Force recommends combining low-flow protocols, agent substitution, and scavenging technology to achieve significant reductions in anaesthetic-related carbon emissions.³⁰

3.4 Sterilisation and reprocessing

The sterilisation of reusable surgical instruments is a significant, yet often overlooked, contributor to the carbon footprint of orthopaedic procedures. Autoclaving and washer–disinfectors consume substantial amounts of energy and water, with the environmental impact increasing proportionally to the frequency of reprocessing cycles.²⁴ Despite this, reusable instrument sets generally exhibit lower per-use emissions compared with single-use alternatives. For instance, a life-cycle assessment of reusable versus disposable trays demonstrated a 60–70 % reduction in CO2e emissions when reusable systems were employed.³¹ Optimising instrument trays by removing rarely used items not only reduces sterilisation load but also shortens OR setup time.

Mitigation strategies include load-based sterilisation, minimising idle autoclave cycles, and deploying energy-efficient steam sterilisers. Such optimisation can lower operating room carbon output by 10–15 % without compromising sterility.³² Additionally, using low-temperature hydrogen peroxide sterilisation for appropriate instruments further reduces energy and water consumption, supporting a more sustainable approach to surgical instrument reprocessing.³³

3.5 Procurement and supply chain

A substantial portion of the carbon footprint associated with orthopaedic surgery originates upstream in the supply chain, beyond direct hospital activities. Life-cycle analyses indicate that over 50 % of emissions in a typical procedure result from implant and consumable production, sterilisation, and transportation.³⁴ Implant manufacturing involves high-temperature metal processing, long-distance logistics, and carbon-intensive packaging. Overall, it contributes more to the overall environmental impact than intra-hospital energy use or waste management.

Mitigation strategies focus on sustainable procurement and supply chain management. Implementing Environmentally Preferable Purchasing (EPP) policies, prioritising suppliers with low-carbon manufacturing, local production, and recyclable packaging, can significantly reduce embedded emissions.³⁵ The Royal College of Surgeons’ Sustainability in Surgery report advocates for integrating environmental criteria into procurement decisions, promoting local sourcing, and requiring manufacturer-reported carbon footprints to guide purchasing choices. Widespread adoption of these frameworks, as seen in the UK and EU, provides a scalable model for global orthopaedic practice.

3.6 Waste management and disposal

Post-operative waste management represents an important, albeit indirect, source of greenhouse gas emissions in orthopaedic surgery. Incineration of contaminated or biohazardous waste releases CO2, nitrogen oxides, and dioxins, while non-recyclable plastics often accumulate in landfills.³⁶ Although this stage accounts for a relatively small fraction of total life-cycle emissions, its cumulative impact is substantial given the large volume of surgical waste generated.³⁷ Audits in orthopaedic theatres reveal that 40–60 % of surgical waste is incorrectly disposed of in biohazard bins, increasing incineration load and disposal costs.³⁸

Mitigation strategies focus on improved segregation and recycling programs. Properly separating infectious from non-infectious waste can reduce incineration volumes by up to 60 %, as a significant portion of operating room waste is non-contaminated and recyclable. Institutions implementing colour-coded waste systems combined with staff training have achieved over 30 % reductions in landfill contributions and enhanced recycling efficiency.³⁹ Additional interventions include single-stream recycling, reprocessing clean packaging materials, and composting organic waste, collectively contributing to the development of a more sustainable “green OR.”

4.1 RO1: environmental burden of orthopaedic surgery: waste and carbon emissions

Orthopaedic ORs are among the most resource-intensive hospital environments, producing significant volumes of solid waste and GHG emissions. Waste audits across orthopaedic subspecialties report a mean solid waste per case ranging from 4 to 9 kg, depending on procedure type and institutional waste segregation practices. In shoulder and arthroplasty series, mean waste generation per case was reported at 6.2 kg and 8.2 kg, respectively, with arthroplasty producing the highest volumes due to large implant packaging and draping materials.⁴⁰ Plastic constitutes nearly 45–55 % of total OR waste, dominated by sterile packaging, disposable drapes, and single-use suction or irrigation components.³⁸

Life-cycle assessments (LCAs) and carbon accounting studies reveal wide variability in reported CO2 equivalent (CO2e) emissions, reflecting methodological differences and system boundaries. Systematic reviews encompassing more than 100 individual LCAs found per-procedure emissions ranging from 28 kg to over 500 kg CO2e, with orthopaedic arthroplasty and complex spine procedures among the highest contributors.⁴¹ Specific LCAs of total knee replacement report total footprints of 80–150 kg CO2e per case, mainly from implant manufacture, energy-intensive sterilisation, and single-use instrumentation.⁴² Spine fusion procedures, involving extensive instrumentation and prolonged operative time, can exceed 150 kg CO2e per case, ranking among the highest in surgical subspecialties.^43,44 Procedure-specific LCAs (arthroplasty and complex spine surgery) consistently identify upstream manufacturing, consumables, sterilisation and OR energy as major contributors to the total footprint.^41,45 These findings collectively highlight the substantial environmental burden embedded in orthopaedic practice, dominated by material and energy inputs that are often underreported in hospital carbon accounting.

4.2 RO2: sustainable practices and waste-reduction strategies in orthopaedic operating theatres

Multiple intervention studies have demonstrated the potential to mitigate the environmental footprint of orthopaedic surgery through targeted system redesign and behavioural change. Instrument-tray optimisation, by eliminating rarely used tools, reduces sterilisation load and per-procedure energy consumption, achieving 10–30 % reductions in both cycle time and resource use.⁴⁶ Reusable instrumentation and containers, when validated for sterility, provide measurable life-cycle advantages compared to single-use counterparts, reducing waste volume and embodied CO2e while maintaining infection control standards.⁴⁷

Improved waste segregation programs, particularly in distinguishing between non-infectious and biohazardous waste, have been shown to divert 30–40 % of surgical waste away from incineration in real-world audits, although local results vary significantly. The implementation of such “green theatre” initiatives has demonstrated reductions of 20–30 % in total waste without compromising workflow or sterility.⁴⁸ In the anaesthesia domain, substitution of high-global-warming-potential (GWP) volatile agents (desflurane, nitrous oxide) with low-GWP alternatives (sevoflurane or total intravenous anaesthesia) and adoption of low-flow techniques yield some of the largest direct CO2e reductions achievable in the OR setting.⁴⁹ At the institutional level, environmentally preferable procurement (EPP) and local sourcing have been identified as crucial strategies to address the upstream manufacturing emissions that dominate the carbon footprint of implants and consumables.⁵⁰ Collectively, these measures represent achievable, evidence-based strategies for greening orthopaedic operating rooms.

4.3 RO3: assessment methodologies and gaps in environmental impact research

Despite increasing interest in sustainable healthcare, methodological heterogeneity remains a key limitation in the environmental assessment of orthopaedic procedures. Current LCAs differ in system boundaries; some restrict analysis to in-theatre activities “gate-to-gate”, while others adopt broader “cradle-to-grave” frameworks encompassing manufacture, transport, and end-of-life disposal.^41,51,52 Such inconsistencies lead to wide variability in reported CO2e and complicate cross-study comparisons. Furthermore, many LCAs omit key emissions sources, such as anaesthetic gases or supply-chain transport, underestimating total impacts.

Geographic bias is also evident: the vast majority of data originates from high-income countries, with minimal representation from low- and middle-income settings, where waste segregation infrastructure and energy sources differ markedly. Reviews emphasise the need for standardised reporting frameworks, including consistent waste classification, defined system boundaries, and transparent emission factors, to facilitate meta-analysis and benchmarking.⁵³ Recent qualitative systematic reviews have also highlighted the paucity of implementation science approaches, noting that while environmental metrics are increasingly reported, behavioural and organisational determinants of sustainability adoption remain poorly studied.⁵⁴ Future research should therefore prioritise multicenter collaborations, inclusion of diverse healthcare settings, and integration of supplier-reported carbon footprints to establish globally applicable benchmarks for sustainable orthopaedic care.

5.1 Institutional-level interventions

5.2 Clinical-level interventions

5.3 Industry and policy-level interventions

6.1 Infection-control concerns

One of the strongest practical hurdles relates to the perception among surgical teams that sustainable changes, particularly the use of reusable instruments, drapes, gowns, or a reduction in single-use items, might compromise sterility or increase infection risks. For example, a large global survey found that while many surgeons were willing to use reusable instruments, more than half reported limited access to them, and concerns about safety, durability and sterility remained prominent.⁶¹

Institutional guidance notes that “misconceptions around infection risk of reusable equipment, waste sorting, perceived cost or perceived workload” are major barriers.

In settings with limited resources, the inability to meet standard sterilisation infrastructure further increases hesitancy: a report from low- and middle-income countries (LMICs) highlighted that surgical procedures may become unsustainable without robust infection prevention and control programmes.⁶² Thus, for orthopaedic surgery, where implants, instrumentation trays and long operating room times are common, concerns over SSIs, prosthetic joint infection risk or sterility deviations often trump ecological goals, acting as a significant barrier to change.

6.2 Lack of standardisation or policy enforcement

Procedural and organisational standards are often absent or inconsistently applied, which undermines the uptake of sustainable practices. A systematic review of staff attitudes in operating theatres across high-income countries identified a lack of evidence exploring enablers, but consistently found barriers such as “facilities and equipment, time, and incentive” for sustainability adoption.⁶³

The “Green Surgery Report” highlights that although many surgical teams are motivated to improve sustainability, they feel “disempowered” in the absence of clear policies, leadership and governance structures.⁶⁴ In orthopaedics, where large-scale implant supply chains, instrument sets and waste segregation systems are complex, the absence of standardised metrics (definitions for contaminated vs uncontaminated waste) and institutional mandates further impedes progress.

6.3 Cost perception vs long-term savings

A recurring barrier is the upfront cost of implementing sustainability initiatives compared to the delayed, less tangible long-term savings. For example, waste-reduction interventions, reusable instrument programmes, or energy system upgrades require initial investment in training, equipment or infrastructure. The Medical Journal of Australia, in an exploration of barriers, identified that “the immediate cost of implementing waste management compared with the long-term realisation of environmental and economic benefits” was a major barrier.⁶⁵

In the surgical environment, decision-makers may prioritise short-term budget constraints and regulatory/compliance demands, such as infection control accreditation, over environmental goals. This is particularly relevant in orthopaedics, where implant costs dominate and sustainability benefits, such as reduced CO2e or waste weight, are less immediately visible. Additionally, the perceived administrative burden, staff training, tracking reusable instrument cycles, and measuring outcomes can discourage adoption even when economic models suggest savings over time.

6.4 Data gaps in developing countries

Finally, there exists a considerable evidence gap in LMICs related to sustainable surgical practice. LMICs face unique challenges, including limited infrastructure, inconsistent power/water supplies, and minimal sterilisation capacity, which heighten the risk of unintended consequences when implementing sustainability strategies. A recent commentary on global surgery argued that “efforts to expand surgical access without sustainable infrastructure risk exacerbating environmental burdens” in vulnerable populations.⁶⁶

In addition, a study from referral hospitals in Rwanda found that although knowledge and practice of waste management were modest (54 %/55 %), major barriers included a lack of equipment (71 %), negligence (66 %), and inadequate training (57 %).⁶⁷ These data limitations mean that many sustainability recommendations are drawn from high-income country settings, which may not be directly transferable to LMIC orthopaedic contexts. Without locally relevant metrics such as per-case waste in a low-resource OR, regional sterilisation energy sources, and local recycling infrastructure, it is difficult to benchmark or prioritise interventions.