This study looks at children with forearm fractures that need surgery. The standard treatment uses titanium nails, which usually need to be removed in a second operation later. This study compares titanium nails with bioabsorbable nails, which gradually dissolve in the body and may help some children avoid another operation.

The study will compare how quickly the fractures heal on X-ray, and also look at complications, recovery, function, and the family's experience. Children who need surgery will be randomly assigned to one of the two treatments so the comparison is fair.

Hypothesis: The researchers expect that fractures treated with bioabsorbable nails will heal almost as quickly as fractures treated with titanium nails, while reducing the need for later implant removal surgery.

This clinical study will examine the treatment of displaced forearm fractures in children. Forearm fractures are very common in childhood. Most can be treated with a cast alone, but some fractures are too unstable or too badly displaced and need an operation to hold the bones in the correct position while they heal. In this study, we compare two types of intramedullary nails, which are thin rods placed inside the bone during surgery to stabilize the fracture. One type is made of titanium, which is the current standard treatment. The other type is bioabsorbable, which means it gradually dissolves in the body over time.

The main reason for studying the bioabsorbable nail is that it may allow children to avoid a second planned operation. In Denmark, titanium nails are usually removed in a later procedure, often 6 to 12 months after the first surgery. Even though that removal operation is generally safe, it still means another hospital visit, another anesthetic, another recovery period, and additional stress for the child and family. A dissolving nail could reduce this burden. However, because bioabsorbable nails are more flexible than titanium nails, there is a concern that the bone may heal a little more slowly.

The study will include children aged 3 to 13 years who have a displaced fracture in the shaft of one or both forearm bones and who need surgical treatment. Children who take part will be randomly assigned to one of two treatment groups. One group will receive a bioabsorbable nail and a cast for 4 weeks. The other group will receive a titanium nail and a cast for 2 weeks. The allocation is random so the two groups can be compared fairly. Families, the clinicians doing follow-up assessments, and the people evaluating the X-rays will, as far as possible, not know which type of nail the child received.

The main outcome in the study is how long it takes for the fracture to heal on X-ray. The study will also compare the two groups with respect to complications, pain, arm function, return to normal activities, and the child's and family's experience during recovery. The children will attend planned follow-up visits with clinical examinations and X-rays over time so the researchers can assess healing and safety in a standardized way.

Hypothesis:

The study hypothesis is that children treated with bioabsorbable intramedullary nails will have a healing time on X-ray that is not unacceptably longer than children treated with titanium nails. In other words, the researchers expect the bioabsorbable nail to provide nearly the same healing result as the titanium nail, while offering the important advantage that many children may avoid a second operation to remove the implant.

Inclusion Criteria:

• Diagnosis of a traumatic diaphyseal forearm fracture of the radius, ulna, or both
• Operative fixation required
• Fractures must be complete (not unicortical or greenstick) AND displaced >50% of bone width (after attempted closed reduction) AND/OR angulated >10° in any plane (after attempted closed reduction)
• Informed consent obtained

Exclusion Criteria:

• Conditions where internal fixation is contraindicated (e.g. active or potential infection)
• Grossly open fractures (Gustilo Anderson grade > 2)
• Fracture occurred more than 2 weeks prior
• Fractures that are well managed conservatively (undisplaced or minimally displaced)
• Previous ipsilateral forearm fracture (risk of closed medullary canal)
• Fractures unsuited for intramedullary nailing (e.g. multifragmentary, metaphyseal or epiphyseal)
• Concurrent ipsilateral wrist or elbow involvement (e.g. Monteggia or Galeazzi variants)
• Unable to participate in follow-up
• Existing bone pathology (e.g. tumor, osteogenesis imperfecta, degenerative disease)
• Participation in any other medical device or medicinal product study within the previous month that could influence in opinion of the PI the results of the present study

Intraoperative exclusion criteria:

• Fractures suitable for closed reduction and casting (see 6.3.9)
• Indication for treatment 1 (BIN) only
• Indication for treatment 2 (ESIN) only
• Intraoperative decision to use implants other than the devices under investigation

De-identified individual participant data collected during this study will not be made publicly available. Due to the small sample size, single-center design, and pediatric population, there is a relevant risk of participant re-identification even after de-identification. Aggregate study results will be reported in publications and presentations.

The following parties will be masked to treatment allocation: the participants, the parents, postoperative ward and outpatient clinic caregivers involved in routine care, clinicians performing follow-up assessments, radiograph reviewers, occupational/hand therapists performing functional assessments, and the statistician/data analyst. Participants and parents will remain masked until completion of the 6-month follow-up visit, unless earlier unblinding is required for patient safety. The operating surgeon and operating room staff cannot be masked because they must know which implant is used during surgery. A limited number of designated study personnel will remain unblinded for device logistics and, when relevant, planning of elective titanium nail removal.