Unstable Distal Diametaphyseal Radius Fracture in Children a Retrospective Comparative Study of K-Wire Versus Plate Fixation

Background/Objectives: Pediatric distal diametaphyseal radius fracture (DDRF) occurs in a challenging transitional zone between the metaphysis and diaphysis, presenting distinct biomechanical characteristics. This study compared outcomes of plate versus Kirschner wire (K-Wire) fixation—including different configurations—in a consecutive cohort of pediatric unstable DDRF. Methods: We conducted a single-center retrospective review of 63 patients (aged 6–15 years) treated between 2023 and 2025, divided into plate (n = 26) and K-Wire (n = 37) groups. The K-Wire cohort was subclassified as bicortical (n = 14), bicortical + intramedullary (n = 10), and intramedullary alone (n = 13). Outcomes included alignment quality, fracture healing by modified RUST (mRUST), and the Forearm Fracture Index (FFI). Multivariable regression was used to adjust for confounding. Results: Plate patients were older (11.92 ± 2.87 vs. 9.32 ± 2.96 years, p < 0.05) and heavier (43.23 ± 11.31 vs. 30.84 ± 11.19 kg, p < 0.001) and had higher FFI (median 1.13 vs. 1.09, p < 0.05). Multivariable regression showed plate fixation was independently associated with good alignment (adjusted OR = 14.48, p = 0.018). Bicortical K-Wires yielded the highest alignment rate among percutaneous techniques (85.7%), while bicortical + IM showed poor outcomes (0% good). The unadjusted 1-month healing advantage of K-Wires (mRUST 2.53 ± 0.60 vs. 2.19 ± 0.47, p = 0.022) was non-significant after adjusting for body weight (p = 0.248). The complication rate was low (3.2%, 2/63). At final follow-up (range 6–18 months), all patients demonstrated unrestricted wrist motion and forearm rotation, and functional outcomes were assessed clinically without validated patient-reported outcome measures. Conclusions: Plate fixation independently predicts superior alignment, whereas the K-Wire group’s higher 1-month mRUST scores were attributable to their younger, lighter profile rather than the implant itself. Among K-Wire options, bicortical configuration achieves reduction quality comparable to plates, while the bicortical + IM configuration should be avoided. In this cohort, plate fixation was more common among older, heavier patients with higher FFI, whereas younger, lighter patients more often received K-Wires; both methods demonstrated low complication rates.