The Effect of Bone Substitutes for Low-Energy Comminuted Distal Radius Fractures amongst Elderly Women Treated with Volar Locking Plate Fixation: A Propensity Score-Based Analysis

<b>Background:</b> This study aimed to investigate whether the use of artificial bone substitutes during volar locking plate (VLP) fixation for intra-articular comminuted distal radius fractures in elderly women improves radiographic and clinical outcomes. <b>Methods:</b> A retrospective study was conducted on female patients aged ≥65 years with intra-articular comminuted distal radius fractures (AO/OTA types B3, C2 and C3) treated with VLPs between 2018 and 2022. Patients were categorised into groups based on the use of β-tricalcium phosphate (β-TCP) as a bone substitute. A propensity score (PS) matched comparison utilising inverse probability of treatment weight was conducted comparing patients receiving standard versus β-TCP augmentation during fixation. Clinical and radiographic outcomes were evaluated. The screw-joint surface distance was assessed as a radiographic parameter indicative of optimal distal screw positioning adjacent to the subchondral bone. <b>Results:</b> The mean follow-up period was 9.9 months (range: 6-35 months). After PS matching, each group included 35 patients with comparable baseline characteristics. The screw-joint surface distance was significantly lower in the bone substitute group, indicating closer distal screw placement. However, at final follow-up, no significant differences were observed between the groups in radiographic or clinical outcomes. These results were consistent in inverse probability of treatment weighting (IPTW)-adjusted regression analysis. <b>Conclusions:</b> Closer placement of screws near the joint was observed in the bone substitute group, possibly reflecting improved intraoperative stability, but was not significantly associated with the prevention of postoperative correction loss or other clinical outcomes. Since clinical outcomes were similarly good regardless of its usage, artificial bone substitute may not be necessary for low-energy comminuted intra-articular fractures in elderly women. Further studies are warranted to determine its potential benefit in cases involving severe metaphyseal voids or joint instability. <b>Level of Evidence:</b> Level III (Therapeutic).