The risk of adverse outcomes in extra-articular distal radius fractures is increased with malalignment in patients of all ages but mitigated in older patients

Purpose: The purpose of this study was to determine if malalignment after extra-articular distal radius fractures influenced patient-reported pain and disability at 1 year and to investigate how this relationship changes with age. Methods: Two hundred sixteen subjects with extra-articular distal radius fractures were followed. The influence of specific radiographic parameters and the overall acceptability of alignment on Patient-Rated Wrist Evaluation (PRWE) and Disabilities of Arm, Shoulder and Hand (DASH) scores were assessed. The relative risk (RR) of a poor outcome in the presence of malalignment of the distal radius at various ages was calculated; the RR was then used to calculate a number needed to harm. Results: Malalignment of the distal radius was associated with higher reports of pain and disability in patients <65 years of age. In patients aged >=65 years, no isolated radiography parameter was found to affect PRWE or DASH scores significanly; however, there was an increased risk of a poor outcome in fractures with malalignment when compared with fractures with acceptable alignment in all age groups. The RR of a poor outcome with malalignment showed a decreasing trend with increasing age, with a significant reduction after 65 years. In patients >=65 years of age, 8 malaligned fractures would require correction to prevent 1 poor outcome (based on DASH, or 9 based on PRWE); in younger patients, only 2 malaligned fractures would need correction to avoid 1 poor outcome (based on DASH, or 3 based on PRWE). Conclusions: Patients >=65 years of age showed no statistically significant relationship between malalignment of the distal radius and PRWE or DASH scores when the radiography parameters were examined in isolation and when clustered together. The relative risk data demonstrates, however, that patients at all ages have a higher risk of a poor outcome with malalignment of the distal radius when compared with those with acceptable alignment. Therefore, we conclude that the relationship between outcome and alignment of the radius should not be considered as an all-or-none phenomenon but rather considered as a decreasing gradient of risk, with the most significant change seen after patients reach 65 years of age.