Spiral metacarpal fractures (metacarpal II-V) can be treated conservatively or with operation. With minimal displacement this fracture is usually treated with immobilisation or early mobilisation. With appreciable displacement especially any malrotation the patient usually is treated with an operation. This usually includes an open reduction of the fracture and fixation with plates and screws or just screws. Even if this is an standard procedure both mild and severe complications have been reported. New studies have shown that even displaced fractures can be treated with early mobilization. In those cases the fractures may heal with some shortening but very good function. An advantage of early mobilization is that the patient avoids the risk of an operation and the costs for the treatment are decreased markedly. The study is designed to answer the question if early mobilization is not inferior to operative treatment but with lower costs and without any operation related risks.

The study is designed as an prospective, randomised controlled trial. The patients are divided into two groups (operative and conservative treatment with early mobilisation). The operative group is treated with internal fixation and 2 weeks in a cast. The conservative group is instructed to do a fist to correct any malrotation and to rehabilitate quickly. By this procedure shortening oft he metacarpalfractures is limited by the function of the deep transverse metacarpal ligament connecting the distal parts of the metacarpalbones II-V. Furthermore the participants in the conservative group are allowed to use their hands without any restrictions. A physiotherapist controls that early mobilisation is carried out.

The participant will be seen for a follow-up at 1, 6 and 12 weeks and 1 year. Radiographs will be performed at 1v and 6v. The finger ranges of motion and pain will be evaluated with every follow-up, DASH score, range of motion, pain and grip-strength will be measured after 12v and 1 year. The investigators will measure return to driving, work and sport.

Complications will be registered continuously for all patients. The overall satisfaction of the patients and the costs for both treatments will be documented as well.

The study population is planned to be 21 patients in each group.

Inclusion Criteria:

• single spiral fractures of metacarpal bone II-V
• fracture line at least twice the length of the diameter of the bone at the level of the fracture
• at least 1-2mm displacement of the fracture and/or malrotation
• normal hand function before the injury
• fracture less than 10 days old

Exclusion Criteria:

• multiple metacarpal fractures
• open fractures
• incompliance or dementia
• fracture line not twice the length of the diameter of the bone at the level of the fracture
• abnormal hand function before the injury
• fracture more than 10 days old