Radial head distalisation with an external ring fixator as a therapy option in children with chronic posttraumatic radiocapitellar dislocations.

Purpose: Missed monteggia-type injuries in children can result in chronic radial head dislocation with anatomic changes and osteoarticular remodeling of the radial head. In later stages, joint reconstruction is impossible and a functional radial head distalization can be a therapy option in symptomatic patients.
Methods: From 2010 to 2018, 46 patients (18 female and 28 male, mean age 11.8 (4-20)) with chronic radius head dislocation treated in our institution were retrospectively analyzed. A radial head distalization was performed in symptomatic patients at the time of ulna lengthening and angulation by use of an external ring fixator. We analyzed the surgical and radiographic data as well as the clinical outcome of the patients measured by DASH and Mayo Elbow score.
Results: 16 patients (6 female, 10 male) fulfilled the criteria for functional radial head distalization. Main reason was Monteggia injury in 11 cases, and radial head fracture in 5 cases. Average follow-up was 5.1 years (range 1-9, SD 2.1). Mean time from injury was 4.14 years (range: 4 months to 12 years, SD 3.5 years). Mean duration of external fixation was 106 days (range 56-182, SD 31.2), lengthening was 21.3 mm (range 12-42, SD 8.8). Average degree of sagittal angulation 14.8° (0-32°, SD 10.7°), coronal angulation 4.4° (0-25°, SD 7.3°). DASH score showed a good result with 2.4, and the MAYO Elbow Score was excellent (95/100). No secondary luxation of the radius head was detected.
Conclusion: Radial head distalization with external ring fixator can be a therapy option for chronic radius head dislocations in symptomatic patients without losing stability of the elbow joint in contrast to radial head resection.
(© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)