Timing and Causes of Systemic Readmissions After Hip Fracture Surgery: An 8-Year Retrospective Cohort Study

Systemic readmissions after hip fracture surgery impose a substantial clinical and economic burden. Hip fracture represents a sentinel orthopedic injury with prolonged postoperative vulnerability extending beyond the index admission. Evidence from the Middle East remains scarce, particularly regarding the incidence, causes, and timing of systemic readmissions in multiethnic populations. This study aimed to determine the one-year incidence, etiologies, and temporal distribution of systemic readmissions following proximal hip fracture surgery, and to explore whether commonly documented comorbidities showed any association with systemic readmission.

A retrospective cohort study was conducted at a tertiary-care hospital in the Middle East from January 2017 to January 2025. Kaplan-Meier analysis was the primary method used to describe one-year systemic readmission-free survival, while logistic regression was performed on an exploratory basis.

Among 284 patients, 35 experienced systemic readmissions within one year (12.3%). Infectious (31.4%), cardiovascular (20.0%), and pulmonary (20.0%) complications were the most frequent etiologies. Kaplan-Meier analysis demonstrated a one-year systemic readmission-free survival of 87.7%, with most readmissions clustering between 90 and 180 postoperative days. No comorbidity-including American Society of Anesthesiologists (ASA) class-was significantly associated with systemic readmission. Stratified survival curves showed no significant difference by ASA classification (log-rank p = 0.54).

Although no stable association between individual comorbidities and systemic readmission was identified in exploratory analyses, a distinct late postoperative vulnerability window (3-6 months) was identified. These findings provide important region-specific evidence and support the need for structured mid-term follow-up and multidisciplinary care pathways to reduce late systemic complications after hip fracture surgery. From an orthopedic perspective, these findings emphasize hip fracture surgery as the beginning of a prolonged recovery trajectory rather than an isolated surgical event.