Malunion of distal radius fractures in children

BACKGROUND AND PURPOSE Distal forearm fractures in children have excellent remodeling potential. The current literature states that 15° is the maximum acceptable angulation limit, though studies focusing on remodeling capacity above this value are lacking. We present data on the remodeling process in children with distal radius malunions with an angulation of ≥ 15°. PATIENTS AND METHODS Retrospectively, we radiographically evaluated the remodeling in 33 children (aged 3-14 years) with 40 distal radius fractures healed in ≥ 15° angulation in the dorsovolar (DV) plane (n = 32) and/or the radioulnar (RU) plane (n = 8). Malunion angulation at the start and at last follow-up was measured on AP and lateral-view radiographs. Mean follow-up time was 9 (3-29) months. RESULTS All fractures showed remodeling. Mean DV malunion angulation was 23° (15-49) and mean RU malunion angulation was 21° (15-33). At follow-up, this had remodeled to mean 8° (-2 to 21) DV and 10° (3-17) RU. Mean remodeling speed (RS) was 2.5° (0.4-7.6) per month. There was a negative correlation between RS and remodeling time (RT) and a positive correlation between RS and malunion angulation. The relationship between RS and RT was exponential. RS was not found to be related to age or sex. INTERPRETATION Remodeling speed decreases exponentially over time. Its starting value depends on the amount of angulation of distal radius fractures. This compensates for the increased need for remodeling in severely angulated fractures.