Hip fractures are risky business: An analysis of the NSQIP data

Abstract

Introduction

Hip fractures are one of the most common types of orthopaedic injury with high rates of morbidity. Currently, no study has compared risk factors and adverse events following the different types of hip fracture surgeries. The purpose of this paper is to investigate the major and minor adverse events and risk factors for complication development associated with five common surgeries for the treatment of hip fractures using the NSQIP database.

Methods

Using the ACS-NSQIP database, complications for five forms of hip surgeries were selected and categorized into major and minor adverse events. Demographics and clinical variables were collected and an unadjusted bivariate logistic regression analyses was performed to determine significant risk factors for adverse events. Five multivariate regressions were run for each surgery as well as a combined regression analysis.

Results

A total of 9640 patients undergoing surgery for hip fracture were identified with an adverse events rate of 25.2% (n = 2433). Open reduction and internal fixation of a femoral neck fracture had the greatest percentage of all major events (16.6%) and total adverse events (27.4%), whereas partial hip hemiarthroplasty had the greatest percentage of all minor events (11.6%). Mortality was the most common major adverse event (44.9–50.6%). For minor complications, urinary tract infections were the most common minor adverse event (52.7–62.6%). Significant risk factors for development of any adverse event included age, BMI, gender, race, active smoking status, history of COPD, history of CHF, ASA score, dyspnoea, and functional status, with various combinations of these factors significantly affecting complication development for the individual surgeries.

Conclusions

Hip fractures are associated with significantly high numbers of adverse events. The type of surgery affects the type of complications developed and also has an effect on what risk factors significantly predict the development of a complication. Concerted efforts from orthopaedists should be made to identify higher risk patients and prevent the most common adverse events that occur postoperatively.

Introduction

Hip fractures total nearly 1.6 million cases across the world each year, with an estimated 21.3 million cases by 2050 costing a projected $446.3 billion in treatment [1], [2], [3]. Age and sex standardized hip fracture rates range from 1.86 to 47.74 cases per 10,000 depending on country, with rates in the United States from 1986 to 2005 averaging 957.3 cases per 100,000 women and 414.4 cases per 100,000 men over the age of 65 [4], [5]. By 2030, the total number of hip fractures in the United States alone is estimated to affect 289,000 patients [6].

Despite this seemingly common orthopaedic problem, morbidity and mortality rates continue to remain high. Reported 1-year mortality rates in the literature have ranged from 11.9 to 26% of study populations [5], [7], [8], [9], [10]. Morbidities are also high, with studies reporting average reduced life expectancies of 1.8 years or 25% of remaining life expectancy per patient with an aggregate of 2.9 million disability life years lost as a result of hip fracture [11], [12]. Complications secondary to hip fractures occur in up to 12–28% of patients and include pneumonia, urinary retention, and anaemia [13], [14], [15].

Many studies have investigated the morbidity and mortality rates of hip fractures using individual hospital data or larger databases such as Medicare cohorts. However, no single study has yet investigated these rates based on pre-operative risk factors on an international scale by using the expanded orthopaedic American College of Surgeons’ National Surgical Quality Improvement (NSQIP) database. This risk-adjusted database contains patient data from 462 hospitals in the US and 34 hospitals around the world and includes 135 patient variables ranging from preoperative risk factors to 30-day postoperative morbidities and mortalities. Recent NSQIP studies have investigated aggregate adverse event trends in all patients with hip fractures and have created risk calculators for morbidity and mortality for patients undergoing hip fracture surgery. However, these studies have not investigated adverse events and risk factors for morbidities and mortalities based on individual surgeries for the treatment of hip fractures [16], [17].

The purpose of this paper is to investigate the major and minor adverse events associated with five common surgeries for the treatment of hip fractures using NSQIP data. Based on significantly associated pre-operative risk factors resulting in adverse outcomes, we utilized multivariate analysis to determine which significant patient factors significantly contribute towards a morbidity or mortality outcome. By noting adverse outcome rates and significant risk factors, the practicing orthopaedist may be better equipped to avoid complications through patient education and modifying controllable risk factors.