Frailty Index and American Society of Anesthesiologists Grade as Determinants of Procedure Selection in Displaced Neck of Femur Fractures: A Retrospective Cohort Study with PRISMA-Guided Evidence Synthesis

Displaced intracapsular neck of femur (NOF) fractures is commonly managed with either hemiarthroplasty or total hip replacement (THR). While existing guidelines emphasize functional status, cognition, and medical fitness, these criteria may not fully capture physiological reserve. This study evaluates whether the frailty index and American Society of Anesthesiologists (ASA) grade are associated with real-world procedure selection. A retrospective cohort study was conducted, including patients with displaced intracapsular NOF fractures (Garden III–IV) treated between January 2024 and September 2025. Patients underwent either cemented THR or cemented bipolar hemiarthroplasty. Variables analyzed included age, frailty index (1–9), ASA grade, hemoglobin drop, length of stay (LOS), complications, and 30 day mortality. A PRISMA guided literature synthesis was performed to contextualize findings. Thirty-nine patients were included (THR: 28; hemiarthroplasty: 11). Patients undergoing THR were younger (68.36 ± 8.67 vs. 77.27 ± 8.76 years), less frail (3.79 ± 0.88 vs. 6.36 ± 0.67), and had lower ASA grades (2.04 ± 0.19 vs. 3.27 ± 0.47). Hemoglobin drop was greater following THR (2.23 ± 1.23 g/dL vs. 1.52 ± 1.14 g/dL). LOS was comparable between groups. One 30 day mortality occurred in the hemiarthroplasty group. Two deep infections occurred in diabetic patients in the hemiarthroplasty group.: Frailty index and ASA grade appear to be associated with arthroplasty selection in displaced NOF fractures in real world practice and may help support structured clinical decision making. Findings are hypothesis generating and require validation in larger prospective studies.