INTRODUCTION A variety of bone grafts and substitutes are available for filling bone defects in the distal radius after corrective osteotomy, but the harvesting of bone from the iliac crest is the gold standard as it allows easy access to corticocancellous bone of a desirable quality and quantity. The idea behind bone grafting is to provide optimal bone formation and structural stability, which is crucial for bone healing. However, the harvesting and use of bone from the iliac crest potentially comes with the risk of complications such as delayed union of the osteotomy defect; size mismatch between the graft and the osteotomy defect; longer operation time; donor site morbidity including nerve, arterial, and ureteral injury; herniation of abdominal contents; sacroiliac joint instability; pelvic fractures; hematoma and infection. As these disadvantages of bone grafting can have a major impact on patients' everyday lives, research is needed on whether bone grafting is genuinely necessary during corrective osteotomy and plate fixation of the distal radius

OBJECTIVE The objective of this study is to investigate whether harvested bone graft from the iliac crest necessary is during corrective osteotomy and plate fixation in patients with malunited distal radius fractures.

STUDY DESIGN This is a prospective, randomized, controlled multicenter study. Patients will undergo the following examinations once before the operation and five times afterwards: 1) the patients will fill out three questionnaires, 2) complications will be noted, 3) the wrist function will be measured, and 4) radiographs/CT scans will be made.

STUDY POPULATION All patients over the age of 18 years who have a symptomatic malunion after distal radius fracture and are eligible for surgical correction.

INTERVENTION Surgical correction in the form of open wedge corrective osteotomy and plate fixation without bone grafting.

USUAL CARE Open wedge corrective osteotomy and plate fixation with harvesting bone from the iliac crest.

OUTCOME MEASURES Primary outcomes: complications and quality of life. Secondary outcomes: time to complete bone healing, functional outcomes, and cost effectiveness.

Inclusion Criteria:

• Patients of either sex over the age of 18 years
• Symptomatic malunion of the distal radius
• Eligible for open wedge osteotomy and plate fixation with or without bone grafting from iliac crest.
• Patients are able to undergo postoperative follow-up of at least 12 months.

Exclusion Criteria:

• Patients who are pregnant
• Patients who have known systemic or metabolic disorders leading to progressive bone deterioration
• Patients who take chronic use of glucocorticoids.

A web based randomisation tool will used for randomization according to the GCP-guidelines. Prestratification per hospital will be performed. Patients and the treating surgeon cannot be blinded for the treatment because a part of these patients will undergo bone grafting derived from the iliac crest. The statistician will be blinded for the treatment.

6.3 Study