Carbon footprint comparison of surgery versus non-surgical care for metacarpal shaft fractures

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

Not applicable Interventional Karolinska Institutet · NCT07521943

This study will test whether surgery or non-surgical care for adults with metacarpal shaft fractures produces more carbon emissions over the year after injury.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment30 (estimated)
Ages18 Years and up
SexAll
SponsorKarolinska Institutet Academic / other
Locations1 site (Stockholm, Stockholm County)
Trial IDNCT07521943 on ClinicalTrials.gov

What this trial studies

This is a prospective multicentre observational comparative cohort conducted alongside the randomized CARBO trial at Karolinska Institutet and Danderyd's Hospital. Researchers will measure greenhouse gas emissions across the entire treatment pathway from injury to 12 months using a bottom-up carbon footprint approach and an environmentally extended input-output model where needed. Emissions within defined Scopes 2 and 3 will be expressed as kilograms of CO2 equivalent per treatment pathway, with primary outcome the difference in mean CO2e between surgical and non-operative groups and secondary outcomes including waste, emission hotspots, and direct cost differences. Appropriate statistical tests plus one-way sensitivity and scenario analyses will be used to estimate differences and test robustness.

Who should consider this trial

Good fit: Adults (age ≥18) with a single displaced spiral or oblique diaphyseal fracture of the second to fifth metacarpals within 10 days of injury, with prior normal bilateral hand function and ability to consent and follow up, are ideal candidates.

Not a fit: Patients with open (Gustilo-Anderson grade > I) or pathological fractures, significant ipsilateral injuries, inability to consent or adhere to the protocol, or children are not expected to be eligible or to benefit from this comparison.

Why it matters

Potential benefit: If successful, the findings could help clinicians choose lower-carbon treatment pathways that maintain clinical outcomes and reduce the environmental footprint of hand fracture care.

How similar studies have performed: Carbon footprint and life-cycle analyses have been performed for some orthopaedic procedures, but direct comparative carbon analyses specifically for metacarpal shaft fracture treatments are novel.

Eligibility criteria

Show full inclusion / exclusion criteria
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).

Where this trial is running

Stockholm, Stockholm County

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Metacarpal Shaft FracturesGreenhouse Gas Emissionsmetacarpal fracturescarbon dioxide emissionsLCA analysisgreenhouse gas emissionscarbon dioxide equivalent
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.