Risk Factors Associated with Collapse of Distal Radius Fractures after Volar Locking Plate Fixation in Older Adults

<b>Background:</b> This study aimed to identify the risk factors associated with re-displacement or collapse of distal radius fractures treated using volar locking plates in older adults. <b>Methods:</b> We conducted a retrospective analysis of 131 patients aged ≥65 years with distal radius fractures who underwent volar locking plate fixation. The collapse was classified into three categories: 'radial collapse' was determined as the top decile of patients with the greatest decrease in radial inclination; 'dorsal collapse' was defined by volar tilt angle on lateral or 25° tilted lateral views and 'height collapse' by radial height. To identify the factors related to these three types of collapses, we compared the clinical and radiological parameters between the wrists with each type of collapsed and non-collapsed wrists. <b>Results:</b> Dorsal collapse had no significant associated factors and radial collapse had osteoporosis as a significant different factor. The height collapse group was associated with older age, had a higher prevalence of high-energy injury mechanisms and a limited range of flexion-extension at final follow-up and larger distance between the articular surface and distal screws. <b>Conclusions:</b> The volar locking plate may effectively prevent three types of collapses. Height collapse group included patients with increased age, high-energy injury mechanisms and limited range of flexion-extension at the time of final follow-up. To prevent collapse, the longest possible distal screws must be inserted just beneath the subchondral bone. <b>Level of Evidence:</b> Level IV (Therapeutic).