Indirect Hexapod Frame-assisted Reduction of Chronic Radial Head Dislocations in Children: 20-year Experience and Technical Tips.

Introduction: Acquired chronic radial head (RH) dislocations present a significant surgical challenge. Coexisting deformity, length discrepancy, and RH dysplasia, in multiply-operated patients often preclude acute correction. This study reports the clinical and radiological outcomes in children, treated with hexapod frames for gradual RH reduction.

Materials and methods: Patient cohort from a prospective database was reviewed to identity all hexapod frames for RH dislocations between 2000 and 2021. Patient demographics, clinical range, and radiographic parameters were recorded.

Results: From a cohort of 127 upper limb frames, 34 chronic RH dislocations (15 anterior and 17 posterior) were identified. Mean age at surgery was 10 years (5-17 years). Six pathologies were reported (17 post-traumatic, 11 multiple hereditary exostosis (MHE), two nail-patella syndrome, two Ollier's disease, one osteogenesis imperfecta, and one rickets). About 76% had a congruent RH reduction at final follow-up. Two MHE cases gradually re-dislocated. Five children had some mild persistent incongruency. Mean follow-up duration was 4.2 years (9 months to 11.5 years). Mean radiographic correction achieved in coronal plane 9°, sagittal plane 7°, and carrying angle 12°. Mean ulnar length gained was 7 mm, and final ulnar variance was 7 mm negative (congenital). All cases achieved bony union, with two requiring secondary bone grafting. Mean frame duration was 166 days. Mean final range of motion was 64° supination, 54° pronation, and 2°-138° flexion.

Conclusion: The majority of children having frame correction achieve complete correction or minor subluxation, which is well tolerated clinically. Frame-assisted reduction is an effective tool for selective complex cases, irrespective of the pathology driving the RH dislocation.

How to cite this article: Dorman S, Green N, Fernandes JA. Indirect Hexapod Frame-assisted Reduction of Chronic Radial Head Dislocations in Children: 20-year Experience and Technical Tips. Strategies Trauma Limb Reconstr 2024;19(3):164-168.