The risk analysis index predicts 30-day periprosthetic fracture following primary total hip arthroplasty.

Abstract

As the number of patients requiring total hip arthroplasty (THA) continues to increase, it is critical to develop tools that predict postoperative periprosthetic fracture (PPF). One way to risk stratify patients undergoing THA is using a frailty score. Recently, the Risk Analysis Index (RAI) has emerged as a potentially more accurate marker of frailty and predictor of postoperative complications following spine surgery. Our study aims to assess the association between frailty, as rated by RAI, and PPF within 30 days following primary THA. The ACS NSQIP database was queried from the years 2015-2020 analyzing patients who underwent primary THA. The RAI scored patients on a scale from 0 to 81 and grouped them into four categories based on their frailty score: robust, normal, frail, and severely frail. Multivariate analysis was performed, controlling for age, female sex, American Society of Anesthesiologists (ASA) score, and tobacco smoking, with the primary outcome being PPF within 30 days of surgery. A total of 186,756 patients were included in this study- 372 (0.2 %) of which had PPFs within the 30-day postoperative period. Increasing frailty, as measured by RAI, was a significant predictor of PPF following primary THA in normal, frail, and severely frail patients. Female sex and ASA status also showed increased risk of PPF. Furthermore, each additional unit on the RAI scale increased the odds of PPF by 7.5 %. Frailty has been identified as a predictor of adverse postoperative outcomes in patients undergoing THA, however, this study is the first to find a significant association between frailty and PPF within 30 days of THA. Incorporating frailty assessment into preoperative discussions may aid surgeons in risk stratification, inform surgical decision-making, and enhance the effectiveness of postoperative monitoring following THA.