metaCARpal Bone Osteosynthesis Trail

Official title

The CARBO Study (metaCARpal Bone Osteosynthesis)

Overview

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.

Interventions

• Procedure Non-operative treatment with early mobilization
  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.
• Procedure Operative treatment
  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.

Primary outcome measures

• Grip strength [Time frame: From enrollment to the end of follow-up at 12 months]

Secondary outcome measures (12)

• 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]

Eligibility 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).

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Sweden · 1 center

• Karolinska Institutet, Danderyd's hospital — Stockholm

Identifiers

NCT: NCT07357493 · 2025-04413-01 · FoUI-1022484

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗