Radial Inclination and Volar Tilt Following Ulnar Epiphysiodesis for Distal Radius Physeal Arrest

Physeal arrest of the distal radius is a known complication after pediatric distal radius fractures. When this occurs, ulnar epiphysiodesis has been shown to prevent further ulnar positive variance. The purpose of this study is to determine any difference in the radial inclination (RI) and volar tilt (VT) of the distal radius pre-ulnar and post-ulnar epiphysiodesis and whether the final distal radius radiographic measurements are associated with clinical outcomes. A review of children who underwent ulnar epiphysiodesis for premature radial physeal closure at a single institution was performed over a 12-year period. Exclusion criteria included patient-reported outcome measures (PROMs) <1 year. Preoperative and final follow-up radiographic measurements were obtained for RI and VT, with interobserver reliability recorded. Cutoffs for acceptable RI and VT were set at >10 degrees and between -10 degrees and 25 degrees, respectively. PROMs were recorded using the quick-disabilities of the arm, shoulder, and hand questionnaire-9 (quickDASH-9) and Single Assessment Numeric Evaluation (SANE) scores. Forty-six wrists were included (age 13.9 ± 1.2 y) with a mean PROM duration of 5.2 ± 3.4 years (1.0 to 12.3 y). Neither RI (P = 0.123) nor VT (P = 0.305) changed significantly from preoperative to final follow-up. No significant correlation between distal radius measures and quickDASH-9 or SANE scores was observed: RI, P > 0.23, and VT, P > 0.28. Preoperatively, RI was unacceptable in 2 wrists, and VT was unacceptable in 5 wrists. While these 7 wrists became acceptable after ulnar epiphysiodesis, some acceptable wrists became unacceptable after the procedure. As predicted, distal radius radiographic parameters did not change after ulnar epiphysiodesis, and PROMs did not appear to correlate with acceptable RI or VT. The PROMs suggest that children do well with this procedure, but based on individual results, there appears to be room for improvement through future study and considerations for patient-specific treatment approaches. Level IV-cohort study.