gms | German Medical Science

Objectives/Interrogation: Conservative treatment of both-bone forearm fractures in children can result in a malunion with impairment in pronosupination. Three-dimensional (3D) planned corrective osteotomy has been described as a promising technique for accurate reconstruction of these malunions. The objective of this study is to evaluate the functional ouctome and accuracy of the achieved correction after 3D-planned corrective osteotomies for malunited diaphyseal both-bone forearm fractures in children.

Methods: Patients with paediatric malunited diaphyseal both-bone forearm fractures underwent 3D-planned corrective osteotomy. Inclusion criteria were a paediatric both-bone forearm malunion with a pro- or supination of <50°, unsatisfactory improvement after conservative treatment and a minimum age of 10 years. Exclusion criteria was an osseous deformity of the contralateral forearm. A 3D-planned corrective osteotomy was performed according to the following steps: (1) CT scans of both forearms are obtained; (2) the location and degree of deformity is determined by overlaying a virtual model of the malunited bones on a mirrored version of the healthy contralateral side; (3) virtual cutting planes are set to best match the contralateral side; (4) patient-specific guides are 3D-printed and used during surgery. Our primary outcome measure was the gain in pronosupination at 12 months follow-up. Our secondary outcome measure was the accuracy of the achieved correction on CT relative to the preoperative plan.

Results and Conclusions: Six participants underwent 3D-planned corrective osteotomies for paediatric malunited both-bone forearm fractures. There was a median age at trauma of 9 and a median age at osteotomy of 14 years. Pre-operatively there was a mean pronosupination of 66° compared to 150° of the contralateral side, a deficit of 66%. At 12 months follow-up there was a pronosupination of 118°, a remaining deficit of 21% compared to the contralateral side. An anatomical correction in coronal, sagittal and axial direction was achieved in 10 out of the 12 operated forearm bones, as confirmed by CT. There was one case of overcorrection of the radius (9° dorsally) and one case of overcorrection of the ulna (5° radially, 4° dorsally).

This prospective study demonstrates that 3D-planned corrective osteotomy for paediatric malunited diaphyseal both-bone forearm fractures provides an accurate correction and leads to a reliable improvement in pronosupination.