Ulnar Epiphysiodesis for Distal Radius Physeal Arrest: Comparing Early Detection to Late Presentation Management

BACKGROUND: Premature physeal arrest of the distal radius (PPAR) is a rare but serious complication following pediatric fractures that may result in ulnar impaction syndrome. The purpose of this study was to compare outcomes following distal ulnar epiphysiodesis between those identified without deformity (early cohort) and those identified with deformity (late cohort). The hypothesis was that treating children before deformity development would improve patient-reported outcomes (PROs). METHODS: All patients younger than 18 years of age who underwent ulnar epiphysiodesis due to PPAR from 2011 to 2022 were identified through a query of the electronic medical record. Demographics were collected, final QuickDASH (Disabilities Arm, Shoulder, Hand) and SANE (Single Assessment Numerical Evaluation) scores, and final ulnar variance. Two cohorts were developed based on whether or not they required a concomitant corrective osteotomy: the early cohort, without meaningful deformity at surgery; and the late cohort, with meaningful deformity (angular deformities outside the normal range for articular position or abnormal ulnar variance). Patients with >1 year of radiographic follow-up were divided into ≥2.5 and <2.5 mm ulnar variance at final follow-up, and PROs were compared. RESULTS: A total of 63 wrists (60 patients), 39 males and 40% Hispanic, were followed for a mean of 6.4±3.4 years (range: 2.0 to 12.3 y). The mean QuickDASH scores for the early (n=41 wrists) and late (n=22 wrists) cohorts were 6.7±12.1 and 5.7±9.0, and the mean SANE scores were 90.4±14.5 and 87.9±14.5, respectively. The ≥2.5 mm final ulnar variance cohort (n=7), and the <2.5 mm final ulnar variance cohort (n=12) were determined at a mean of 22.5±8.8 months (range: 12.4 to 50.5 mo) follow-up, with no difference in QuickDASH or SANE scores between these radiographic outcome cohorts. CONCLUSIONS: Both early-presenting (requiring no osteotomy) and late-presenting (osteotomy required) wrists with premature physeal arrest of the distal radius experienced similar functional outcomes at short-term duration of follow-up, suggesting that correction of the deformity and restoration/maintenance of radiographic parameters to the wrist are more important than timing of the ulnar epiphysiodesis. LEVEL OF EVIDENCE: Therapeutic, level IV.