Ulnar Distraction Osteogenesis in the Treatment of Forearm Deformities in Children With Multiple Hereditary Exostoses.

PURPOSE To report on the outcomes of using ulnar lengthening combined with acute angular correction for the treatment of forearm deformities in patients affected by multiple hereditary exostoses (MHE). Our hypothesis was that this procedure would improve both radiographic measurements and clinical outcomes with minimal complications. METHODS A retrospective chart review was performed on patients who had a diagnosis of MHE and had undergone ulnar lengthening via a uniplanar external fixator over a 12-year period. Clinical outcomes such as range of motion, pain, and surgical complications were assessed. Radiographic changes were measured using interval radiographs. RESULTS The series included 17 patients. Median age at surgery was 7 years (range, 3-14 years). Median follow up was 55 months (range, 5-125 months). Improvements occurred in radial and ulnar radii of curvature, carpal slip, ulnar variance, and carrying angle at the elbow. There was 1 major pin track infection. There were 2 failures of the external fixator requiring exchange. Premature consolidation occurred in 1 case. Elbow, forearm, and wrist motion was not affected. Radiocapitellar joint congruency did not change. No patient reported pain at final follow-up. CONCLUSIONS Our approach of using distraction osteogenesis of the ulna with angular correction in the radius and ulna as needed is able to correct carpal slip as well as to improve forearm bowing and elbow carrying angle. All of the patients maintained congruency of the radiocapitellar joint with no postoperative dislocations. Because of the low complication rate, the resolution of pain in patients who presented with pain, and the improvement of forearm bowing, this approach should be considered as a treatment option for children with MHE who are at risk for radiocapitellar dislocation. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic IV.