Metacarpal Shaft FracturesCARBONCT07357493
metaCARpal Bone Osteosynthesis Trail
A study testing Non-operative treatment with early mobilization and Operative treatment in people with Metacarpal Shaft Fractures, run by Karolinska Institutet at 1 site in Sweden.
Trial summary
Background Metacarpal shaft fractures account for 30-50% of hand fractures (Karl et al., 2015; Kollitz et al., 2014; van Onselen et al., 2003), with diaphyseal spiral and oblique fractures of the second to fifth ray posing unique challenges due to the risks of shortening and rotational deformities. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Metacarpal Shaft Fractures
- What is being tested?
- Non-operative treatment with early mobilization and Operative treatment
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 552 participants
- Where
- 1 siteSweden
- Study dates
- 23 Mar 2026to 15 Mar 2031
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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.
Who cannot join
- 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).
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Sweden1 site, 1 recruiting
- Recruiting
Karolinska Institutet, Danderyd's hospital
Stockholm, Stockholm County, 18288
Cecilia Mellstrand Navarro, MD, Ass Professor, +46 709 280114, cecilia.mellstrand.navarro@ki.se
Elsa Pihl, MD, PhD, +46739705669, elsa.pihl@ki.se
About this study
Official title: The CARBO Study (metaCARpal Bone Osteosynthesis)
Background Metacarpal shaft fractures account for 30-50% of hand fractures (Karl et al., 2015; Kollitz et al., 2014; van Onselen et al., 2003), with diaphyseal spiral and oblique fractures of the second to fifth ray posing unique challenges due to the risks of shortening and rotational deformities. Current standard care of displaced fractures involves operative fixation.
However, retrospective studies have indicated that nonoperative treatment, involving early mobilization or buddy taping, can achieve outcomes comparable to operative treatment (Daher et al., 2023). There is only one published, with a small sample size, randomized controlled trial (RCT) investigating this issue (Peyronson et al., 2023). This highlights the need for a robust multicenter RCT to address these gaps in evidence.
Read more
Aim The aim of this study is to compare the one-year outcomes of non-operative treatment involving immediate unrestricted mobilization versus operative treatment of displaced oblique or spiral diaphyseal metacarpal fractures in adults.
Materials and Methods This is a multicenter, pragmatic, prospective, noninferiority RCT involving 552 adult patients with displaced oblique and/or spiral diaphyseal metacarpal fractures of the second to fifth ray. Participants will be randomized 1:1 to receive either nonoperative treatment with unrestricted mobilization and rehabilitation) or operative treatment (with screw or plate fixation) followed by rehabilitation.
The primary outcome is grip-strength in the injured hand presented in kilograms at one year.
Secondary outcomes include questionnaires, complications, range of motion, patient reported outcome measures, health related quality of life, patient satisfaction, and radiographic healing.
A power calculation proposes a study size of 552 participants to detect a noninferiority margin of 10% in grip strength.
- Conditions
- Metacarpal Shaft Fractures
- Being tested
- Non-operative treatment with early mobilization, Operative treatment
- Keywords
- Non-operative, operative, metacarpal, shaft, displaced, mobilization
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Non-operative treatment with early mobilizationProcedure or surgery
Participants randomized to the nonoperative group will receive immediate unrestricted mobilization, with optional buddy taping or removable splinting for comfort. Closed reduction will not be attempted. Rehabilitation protocol with early mobilization will be standardized across study centers with printed standardized information to patients and rehabilitation staff.
Operative treatmentProcedure or surgery
Participants randomized to the operative group will undergo open reduction and internal fixation (ORIF) of the MSF. Peri-operative antibiotic prophylaxis will be administered according to local guidelines. The surgical approach and fixation method (e.g. compression screws and/or plate, not K-wires) will be at the discretion of the treating surgeon, following standard surgical principles. Postoperative immobilisation will adhere to surgeons' preference but not exceed two weeks fixation.
| Study group | Role | What they receive |
|---|---|---|
| Non-operative with early mobilization | Experimental | Participants randomized to the nonoperative group will receive immediate unrestricted mobilization, with optional buddy taping or removable splinting for comfort. Closed reduction will not be attempted. Rehabilitation protocol with early mobilization will be standardized across study centers with printed standardized information to patients and rehabilitation staff. Receives: Procedure: Non-operative treatment with early mobilization |
| Operative | Active comparator | Participants randomized to the operative group will undergo open reduction and internal fixation (ORIF) of the MSF. Peri-operative antibiotic prophylaxis will be administered according to local guidelines. The surgical approach and fixation method (e.g. compression screws and/or plate, not K-wires) will be at the discretion of the treating surgeon, following standard surgical principles. Postoperative immobilisation will adhere to surgeons' preference but not exceed two weeks fixation. Receives: Procedure: Operative treatment |
What is being measured
The primary outcome is the main question the study is designed to answer.
Grip strength
The primary outcome is grip-strength measured in the injured hand using a JAMAR dynamometer at 12 months and presented in kilograms. Measurement method will follow the technical description presented in the HAKIR manual (HAKIR, 2023).
Measured: From enrollment to the end of follow-up at 12 months
Secondary outcomes (12)
Complications
infection, malunion, nerve injury, reoperation
Measured: From enrollment to the end of follow-up at 12 months
Pain in injured hand NRS
NRS (Numerical Rating Scale) at rest and when it is at its worst
Measured: From enrollment to the end of follow-up at 12 months
Rotational deformity
0 - no deformity, 1 - minimal deformity, 2 - clearly visible deformity but acceptable functional limitation, 3 - great deformity and functional limitation
Measured: 12 months
PROM - patient rated outcome measure
Quick-DASH-9 score (Gabel et al., 2009)
Measured: 6, 12 weeks, 12 months
Range of motion
total active motion and extension lag
Measured: 6, 12 weeks, 12 months
Pinch grip strength
Measured: 12 weeks, 12 months
Radiographic shortening
according to Sletten (Sletten et al., 2013)
Measured: 12 months
Radiographic healing
defined as bridging callus formation over the fracture line on a plain x-ray anterio-posterior and/or lateral projection. (Hayes et al., 2023)
Measured: 12 weeks, 12 months
Sick leave duration
in days
Measured: 12 months
Patient satisfaction
Patient Acceptable Symptom State, PASS (Daryoush et al., 2025)
Measured: From enrollment to the end of follow-up at 12 months
Quality of life measured by PROM
EQ-5D EuroQol Group, 1990; Taft et al., 2004)
Measured: From enrollment to the end of follow-up at 12 months
Quality of life measured by SF-12
SF-12 (EuroQol Group, 1990; Taft et al., 2004)
Measured: From enrollment to the end of follow-up at 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Jan 2026
- Study start23 Mar 2026
- Primary completion15 Mar 2030 (estimated)
- Study completion15 Mar 2031 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Metacarpal Shaft FracturesStudies of the same condition, open and under way.
- More trials run by Karolinska InstitutetThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Investigator
- Enrolment
- 552 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Karolinska Institutet
- Sponsor type
- University, hospital or other
- Collaborators
- Uppsala University, Umeå University, University of Oslo, Tampere University, Københavns Universitet, Göteborg University, Linkoeping University, Region Stockholm, Östersunds Hospital
- Responsible party
- Principal investigator, Cecilia Mellstrand Navarro, Karolinska Institutet
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07357493
- Sponsor's protocol ID
- 2025-04413-01
- Other IDs
- FoUI-1022484, 2025
- Acronym
- CARBO
- Status last verified
- Mar 2026
- First submitted
- 15 Dec 2025
- Last updated
- 24 Mar 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Data on group level will be made available upon reasonable request.
Study at a glance
From the registry record, last updated by the sponsor on 24 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The CARBO Study (metaCARpal Bone Osteosynthesis)
- ClinicalTrials.gov ID
- NCT07357493
- Acronym / sponsor ID
- CARBO / 2025-04413-01
- Conditions
- Metacarpal Shaft Fractures
- Keywords
- Non-operative, operative, metacarpal, shaft, displaced, mobilization
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 552 participants (estimated)
- Lead sponsor
- Karolinska InstitutetUniversity, hospital or other
- Collaborators
- Uppsala University, Umeå University, University of Oslo, Tampere University, Københavns Universitet, Göteborg University, Linkoeping University, Region Stockholm, Östersunds Hospital
- Study start
- 23 Mar 2026 (actual)
- Primary completion
- 15 Mar 2030 (estimated)
- Study completion
- 15 Mar 2031 (estimated)
- First posted
- 22 Jan 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Background Metacarpal shaft fractures account for 30-50% of hand fractures (Karl et al., 2015; Kollitz et al., 2014; van Onselen et al., 2003), with diaphyseal spiral and oblique fractures of the second to fifth ray posing unique challenges due to the risks of shortening and rotational deformities. Current standard care of displaced fractures involves operative fixation.
However, retrospective studies have indicated that nonoperative treatment, involving early mobilization or buddy taping, can achieve outcomes comparable to operative treatment (Daher et al., 2023). There is only one published, with a small sample size, randomized controlled trial (RCT) investigating this issue (Peyronson et al., 2023). This highlights the need for a robust multicenter RCT to address these gaps in evidence.
Aim The aim of this study is to compare the one-year outcomes of non-operative treatment involving immediate unrestricted mobilization versus operative treatment of displaced oblique or spiral diaphyseal metacarpal fractures in adults.
Materials and Methods This is a multicenter, pragmatic, prospective, noninferiority RCT involving 552 adult patients with displaced oblique and/or spiral diaphyseal metacarpal fractures of the second to fifth ray. Participants will be randomized 1:1 to receive either nonoperative treatment with unrestricted mobilization and rehabilitation) or operative treatment (with screw or plate fixation) followed by rehabilitation.
The primary outcome is grip-strength in the injured hand presented in kilograms at one year.
Secondary outcomes include questionnaires, complications, range of motion, patient reported outcome measures, health related quality of life, patient satisfaction, and radiographic healing.
A power calculation proposes a study size of 552 participants to detect a noninferiority margin of 10% in grip strength.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Non-operative with early mobilization | Experimental | Procedure: Non-operative treatment with early mobilizationParticipants randomized to the nonoperative group will receive immediate unrestricted mobilization, with optional buddy taping or removable splinting for comfort. Closed reduction will not be attempted. Rehabilitation protocol with early mobilization will be standardized across study centers with printed standardized information to patients and rehabilitation staff. |
| Operative | Active comparator | Procedure: Operative treatmentParticipants randomized to the operative group will undergo open reduction and internal fixation (ORIF) of the MSF. Peri-operative antibiotic prophylaxis will be administered according to local guidelines. The surgical approach and fixation method (e.g. compression screws and/or plate, not K-wires) will be at the discretion of the treating surgeon, following standard surgical principles. Postoperative immobilisation will adhere to surgeons' preference but not exceed two weeks fixation. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- 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
Key exclusion criteria (3 listed)
- 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).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Non-operative treatment with early mobilizationParticipants randomized to the nonoperative group will receive immediate unrestricted mobilization, with optional buddy taping or removable splinting for comfort. Closed reduction will not be attempted. Rehabilitation protocol with early mobilization will be standardized across study centers with printed standardized information to patients and rehabilitation staff. | Procedure or surgery | Non-operative with early mobilization |
| Operative treatmentParticipants randomized to the operative group will undergo open reduction and internal fixation (ORIF) of the MSF. Peri-operative antibiotic prophylaxis will be administered according to local guidelines. The surgical approach and fixation method (e.g. compression screws and/or plate, not K-wires) will be at the discretion of the treating surgeon, following standard surgical principles. Postoperative immobilisation will adhere to surgeons' preference but not exceed two weeks fixation. | Procedure or surgery | Operative |
Primary outcome
Grip strength
Time frame: From enrollment to the end of follow-up at 12 months
The primary outcome is grip-strength measured in the injured hand using a JAMAR dynamometer at 12 months and presented in kilograms. Measurement method will follow the technical description presented in the HAKIR manual (HAKIR, 2023).
12 secondary outcomes
Complications
Time frame: From enrollment to the end of follow-up at 12 months
Pain in injured hand NRS
Time frame: From enrollment to the end of follow-up at 12 months
Rotational deformity
Time frame: 12 months
PROM - patient rated outcome measure
Time frame: 6, 12 weeks, 12 months
Range of motion
Time frame: 6, 12 weeks, 12 months
Pinch grip strength
Time frame: 12 weeks, 12 months
Radiographic shortening
Time frame: 12 months
Radiographic healing
Time frame: 12 weeks, 12 months
Sick leave duration
Time frame: 12 months
Patient satisfaction
Time frame: From enrollment to the end of follow-up at 12 months
Quality of life measured by PROM
Time frame: From enrollment to the end of follow-up at 12 months
Quality of life measured by SF-12
Time frame: From enrollment to the end of follow-up at 12 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Mar 2026.
- Individual participant dataSharing planned: No. Data on group level will be made available upon reasonable request.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Non-operative treatment with early mobilization and Operative treatment in people with Metacarpal Shaft Fractures, run by Karolinska Institutet at 1 site in Sweden.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 24 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Sweden. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Cecilia Mellstrand Navarro, Associate professor (+46709280114, cecilia.mellstrand.navarro@ki.se), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Grip strength (time frame: From enrollment to the end of follow-up at 12 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Mar 2026.