Objective <p>Proximal femoral bionic nail (PFBN) represents a novel biomechanical design for the internal fixation of intertrochanteric fractures in older adults. However, comparative real-world evidence between PFBN and the conventional proximal femoral nail antirotation (PFNA) remains limited, particularly in the presence of baseline differences in patient frailty and bone quality.</p> Methods <p>This retrospective study included 301 older patients with intertrochanteric fractures treated between January 2023 and December 2024. According to the fixation method, 201 patients were assigned to the PFNA group and 100 to the PFBN group. Perioperative outcomes, radiographic parameters, composite medical complications, implant-related mechanical complications, and functional recovery were compared between the two groups. The main outcome measures were radiographic stability, composite medical complications, implant-related mechanical complications, and Harris Hip Score (HHS). Although baseline bone mineral density was significantly lower in the PFNA group than in the PFBN group (<i>P</i> &lt; 0.001), no statistically significant difference was observed in tip-apex distance (TAD), suggesting broadly similar implant positioning. Multivariable logistic regression was used to adjust for potential confounding factors and to assess the association between implant type and composite medical complications.</p> Results <p>The PFBN group had a statistically longer but clinically small difference in operative time compared with the PFNA group (46.97 ± 11.90&#xa0;min vs. 44.17 ± 9.42&#xa0;min, <i>P</i> = 0.041), whereas intraoperative blood loss and length of hospital stay were similar between the two groups. Radiographic follow-up showed that the mean loss of neck-shaft angle was significantly smaller in the PFBN group than in the PFNA group (0.41 ± 0.57° vs. 2.80 ± 2.31°, <i>P</i> &lt; 0.001). During follow-up, implant-related mechanical complications occurred in 3 patients (1.5%) in the PFNA group, all of which were fixation failure events, whereas no implant-related mechanical complication was observed in the PFBN group. Although the crude difference in composite medical complications was not statistically significant, PFBN use was associated with a lower adjusted risk after covariate adjustment (adjusted odds ratio, 0.660; 95% confidence interval, 0.490–0.890; <i>P</i> = 0.006). In addition, HHS at 3 and 6 months was modestly higher in the PFBN group, whereas no significant between-group difference was found at 12 months.</p> Conclusion <p>Compared with PFNA, PFBN was associated with less loss of neck-shaft angle and a lower adjusted risk of composite medical complications, although the crude comparison of composite medical complications was not statistically significant. Early HHS scores were modestly higher in the PFBN group, but functional outcomes were comparable at 12 months. Given the single-center retrospective design and baseline imbalance, these findings should be interpreted cautiously and require confirmation in prospective multicenter studies.</p> Trial registration <p>Not applicable. This was a retrospective cohort study and did not prospectively assign participants to interventions.</p>