Skip to content

The CARBO CARBON Study: a Prospective Observational Comparative Cohort Study on CO2 Emissions From Metacarpal Shaft Fracture Treatment

The CARBO CARBON Study: a Prospective Observational Comparative Cohort Study on CO2 Emissions From Metacarpal Shaft Fracture Treatment

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07521943
Acronym
CARBO CARBON
Enrollment
30
Registered
2026-04-13
Start date
2026-03-23
Completion date
2028-03-01
Last updated
2026-04-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Metacarpal Shaft Fractures, Greenhouse Gas Emissions

Keywords

metacarpal fractures, carbon dioxide emissions, LCA analysis, greenhouse gas emissions, carbon dioxide equivalent

Brief summary

This study examines the environmental impact of two common treatments for hand fractures (metacarpal shaft fractures): surgery and non-surgical care. Healthcare contributes significantly to climate change, and orthopedic surgery in particular can generate substantial greenhouse gas emissions. Although surgery is frequently used for these fractures, it is not always clearly more effective than non-surgical treatment, and the difference in environmental impact between these options is not well understood. In this study, researchers will measure and compare the carbon footprint of each treatment pathway, from injury through one year of follow-up. This includes emissions related to medical equipment, energy use, medications, and waste. The goal is to calculate the difference in environmental impact between treatments and to highlight key sources of emissions. The findings may help guide more sustainable healthcare practices without compromising patient care.

Detailed description

Healthcare contributes substantially to global greenhouse gas emissions, with orthopaedic surgery representing a resource- and carbon-intensive part of the healthcare system. For metacarpal shaft fractures, surgical treatment is widely used despite limited evidence of superiority over non-operative management. The difference in environmental impact of the two treatment options remains unexplored. This prospective multicentre observational comparative cohort study is conducted alongside a randomized controlled trial (The CARBO trial). Carbon emissions will be estimated using mainly a carbon foot printing bottom-up approach based on detailed activity data for materials, energy use, pharmaceuticals and waste across the treatment pathway from injury to 12 months post-treatment. Where a bottom-up approach is unavailable, an environmentally extended input-output (EEIO) model will be applied. Emissions will be calculated within defined system boundaries within Scopes 2 and 3 and expressed as kilograms of carbon dioxide equivalent (CO₂e) per treatment pathway. The primary outcome is the difference in mean CO₂e between treatment groups. Secondary outcomes include waste generation, emission hotspots and direct cost differences. Appropriate parametric or non-parametric statistical tests will be applied to estimate the differences between treatments. The robustness of the primary outcome (CO₂e emissions) will be evaluated using one-way sensitivity analyses and scenario analyses in which key model parameters are varied. The study evaluates environmental impact only and does not involve analysis of personal data. Ethical approval has been obtained from the Swedish Ethical Review Authority (DNR 2025-04413-01; amendment DNR 2025-07659-02). Results will be disseminated through peer-reviewed publications.

Interventions

Non-operative treatment through immediate unrestricted mobilization with optional buddy taping or removable splinting for comfort.

Open reduction and internal fixation with plate and screws or screws only, followed by postoperative imobilisation and rehabilitation.

Sponsors

Karolinska Institutet
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

Inclusion criteria

Age ≥18 years. Access to a valid e-mail. Injury within 10 days prior to inclusion. Normal bilateral hand function prior to injury. Ability and willingness to provide written informed consent Single, displaced spiral or oblique diaphyseal fracture of the second to fifth metacarpals with definition of diaphysis as described by AO 2018 (AO/OTA as 77.2-5.2A) (Meinberg et al., 2018). Fracture line length at least twice the diameter of the bone at the level of the fracture. Fractures with at least 2 mm of radiological displacement and/or malrotation of injured finger compared to uninjured side regardless of fracture displacement.

Exclusion criteria

The patient is not expected to have difficulty adhering to the study protocol (e.g., due to insufficient language proficiency, dementia, substance abuse, or other reasons). The patient does not have an open fracture (Gustilo-Anderson grade \> I) or a pathological fracture. The patient does not have an ipsilateral fracture of the upper extremity, polytrauma, or generalized joint dysfunction (e.g., rheumatoid arthritis).

Design outcomes

Primary

MeasureTime frameDescription
Carbon dioxide equivalent12 monthsThe primary outccome is the difference in the mean carbon dioxide equivalent (CO₂e) emissions between the treatment pathways early rehabilitation without surgery and surgical treatment followed by rehabilitation of metacarpal shaft fractures. Our functional unit is defined as the full treatment pathway from injury to 12 months post-treatment

Secondary

MeasureTime frameDescription
Waste12 monthsInclude the total weight of combustible waste generated at each healthcare visit, measured in kilograms using a calibrated hanging scale
Emission hotspots12 monthsIdentification of major emission hotspots (e.g., operating room energy use, single-use materials, pharmaceuticals, transport).
Direct costs12 monthsDifference in direct costs within our study boundary between the treatment methods.

Countries

Sweden

Contacts

CONTACTCecilia Mellstrand Navarro, MD, PhD
cecilia.mellstrand.navarro@ki.se+46709280114
CONTACTElsa Pihl, MD, PhD
elsa.pihl@ki.se+46 8 123 550 00
PRINCIPAL_INVESTIGATORCecilia Mellstrand Navarro, MD, PhD, ass professor

Karolinska Institutet

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Apr 14, 2026