Abstract:[Objective] To compare the efficacy of proximal femoral bionic nail (PFBN) and InterTAN intramedullary nail for unstable intertrochanteric fractures of the femur in the elderly. [Method] A retrospective analysis was conducted on 35 elderly patients with unstable intertrochanteric fractures of the femur who underwent surgical treatment in our hospital from June 2021 to December 2022. According to preoperative doctor-patient communication, 16 cases had the fractures fixed with the PFBN, while the remaining 19 cases were fixed with the InterTAN. The perioperative, follow-up, and imaging data were compared between two groups. [Result] All patients in both groups had corresponding surgical procedure completed successfully. Although the PFBN group had significantly greater surgical time [(111.6±15.9) min vs (98.9±15.9) min, P=0.025], incision length [(11.9±0.9) cm vs (10.9±1.1) cm, P=0.006], intraoperative fluoroscopy frequency [(19.2 ± 2.6) times vs (14.6±1.9) times, P<0.001], and the intraoperative blood loss [(145.6±2.6) ml vs (120.5±31.1) ml, P=0.043], compared to the InterTAN group, the former had significantly earlier postoperative walking time than the latter [(19.1±2.0) d vs (23.8±3.2) d, P<0.001] . The follow-up period lasted for (14.7±2.6) months in a mean , and the PFBN group had a significantly earlier recovery of full weight-bearing activity than the InterTAN group [(51.6±4.9) days vs (66.7±7.3) days, P<0.001]. The VAS scores significantly decreased (P<0.05), while Harris scores, hip flexion-extension ROM, and internal-external rotation ROM significantly increased in both groups over time (P<0.05). The PFBN group was significantly better than the InterTAN group regarding Harris score [(64.9 ± 5.4) vs (55.0±5.7), P<0.001] 1 month postoperatively, and [(73.1±4.8) vs (67.7±5.3), P=0.004] 3 months after operation. As for imaging, there was no statistically significant difference in the quality of fracture reduction and fracture healing time between the two groups (P>0.05). At the last follow-up, the PFBN group remained significantly greater the femoral neck shaft angle (FNSA) (P<0.05), while significantly less the tip apex distance (TAD) than the InterTAN group (P<0.05). [Conclusion] The PFBN used for unstable intertrochanteric fractures in the elderly does shorten bed rest time, allows walking under weight early, promotes the recovery of body function, and reduces hip varus.