metaCARpal Bone Osteosynthesis Trail (CARBO)

Karolinska Institute

Status: Begins enrollment in 1 month

Conditions: Metacarpal Shaft Fractures

Treatments: Procedure: Non-operative treatment with early mobilization; Procedure: Operative treatment

Study type: Interventional

Funder types: Other

Identifiers

NCT07357493

FoUI-1022484 (Other Grant/Funding Number)

2025-04413-01

Details and patient eligibility

About

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.

Enrollment: 552 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Age ≥18 years.
• 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 (figure 1).
• Fractures with at least 2 mm of radiological displacement and/or malrotation of injured finger compared to uninjured side regardless of fracture displacement.
• Injury within 10 days prior to inclusion.
• Normal bilateral hand function prior to injury.

Exclusion criteria

• Presence of contaminated wounds with need for surgical debridement.
• Generalized degenerative joint condition.
• Prior injury to the hand with remaining disability.
• Dementia or other severe cognitive dysfunction.
• Language barrier impeding understanding of study purpose or questionnaires.
• Substance abuse.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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552 participants in 2 patient groups

Non-operative with early mobilization

Experimental group

Description:

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.

Treatment:

Procedure: Non-operative treatment with early mobilization

Operative

Active Comparator group

Description:

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.

Treatment:

Procedure: Operative treatment