Benefit of Expedited Time to Hip Fracture Surgery Differs Based on Patient Risk Profile

Abstract

Objectives: To identify which hip fracture patients benefit the most from operative repair within 24 hours of Emergency Department (ED) presentation based on patient risk stratification.

Methods: Design: Retrospective Cohort.

Setting: Academic Medical Center.

Patient selection criteria: Patients operatively treated for an AO/OTA 31A, 31B, or 32A hip fracture.

Outcome measures and comparisons: Each patient was placed into an "individualized risk quartile" (IRQ) using a validated risk stratification tool (The Score for Trauma Triage in the Geriatric and Middle-Aged [STTGMA], a tool proven to predict inpatient mortality in trauma patients). Patients were risk stratified into minimal-, low-, moderate-, and high-risk IRQ's. In each cohort, patients were separated into three groups based on their time from ED arrival to surgery (< 24 hours, > 24 hours and < 48 hours, and > 48 hours). Each of these 12 groups was analyzed for complications (minor inpatient complications included acute kidney injury, urinary tract infection, decubitus ulcer, and acute blood loss anemia, while major inpatient complications included sepsis or septic shock, pneumonia, acute respiratory failure, stroke, myocardial infarction, cardiac arrest, and deep vein thrombosis or pulmonary embolism), mortality rates, and hospital quality measures (length of stay and readmission rates). The results were compared across cohorts.

Results: A total of 2472 patients were identified: the mean age of the cohort was 80.6 ± 10.3 and was predominantly female (69%) and white (71%). The data demonstrated improved outcomes (complications, mortality rates, hospital quality measures) across all patients (non-risk stratified) for surgery within 24 hours compared to surgery between 24 hours and 48 hours and surgery greater than 48 hours (all outcomes p<0.050). However, these effects were not evenly distributed among the IRQ's. In the IRQ4 cohort, major complication rates progressed from 20% to 25% to 34% as a function of time to surgery (p=0.007). IRQ1 did not demonstrate similar results (p=0.756), with the rates essentially static across surgery time points (3% to 2% to 4%). A similar trend was seen when analyzing mortality at 1-year for highest risk patients, with similar 1-year mortality rates across operating room windows of IRQs 1-3 (IRQ1: p=0.061, IRQ2: p=0.259, IRQ3: p=0.524), but increased in IRQ4 with increasing time to surgery (21% vs 33% vs 33%, p=0.006).

Conclusions: This study demonstrates a differential impact of expedited time to surgery on patients when stratified by risk profile. The lowest risk hip fracture patients do not fare worse if operated on within 48 hours as compared to 24 hours.

Level of evidence: III.