Abstract: Objective To investigate the related factors affecting postoperative hidden hemorrhage in elderly patients with femoral intertrochanteric fracture （FIF） treated with proximal femoral nail antirotation （PFNA）. Methods A total of 120 elderly FIF patients who received PFNA treatment in the Department of Orthopedics of The First People's Hospital of Xuzhou from May 2017 to May 2021 were selected as study subjects. Apparent, hidden, and total blood loss volumes after PFNA were calculated. The clinical data of all patients were statistically analyzed, and possible influencing factors were included. Univariate and multivariate analyses were used to find out the influencing factors of hidden hemorrhage after PFNA internal fixation in elderly FIF patients. Results The apparent, hidden, and total blood loss volumes after PFNA were （235.87±70.65） mL, （712.58±134.25） mL, and （947.77±208.91） mL, respectively. Univariate and multivariate logistic analysis results showed that age≥75 years old, unstable fractures, being complicated with hypertension or diabetes, operation time>60 min, and preoperative anticoagulation therapy were all risk factors for the occurrence of hidden hemorrhage after PFNA internal fixation in elderly FIF patients （P<0.05）. Conclusion Hidden hemorrhage is the main cause of perioperative blood loss in elderly FIF patients treated with PFNA internal fixation, and age≥75 years, unstable fractures, being complicated with hypertension or diabetes, operation time>60 min, and preoperative anticoagulation therapy are important risk factors for hidden hemorrhage. Therefore, relevant clinical measures are suggested for elderly patients with FIF undergoing PFNA internal fixation to improve prognosis and reduce the occurrence of hidden hemorrhage.

Key words: Femoral intertrochanteric fracture, Proximal femoral nail antirotation, Hidden hemorrhage, Risk factors