Abstract
Introduction
Total hip arthroplasty (THA) is gaining popularity as a treatment for displaced femoral neck fractures (FNF), especially in physiologically younger patients. While elective THA for primary osteoarthritis (OA) has demonstrated low rates of complications and readmissions, the outcomes of THA for FNF are less predictable. Additionally, these THA procedures are equally included in various alternative payment bundles. Therefore, the aim of this study is to assess postoperative complication rates after THA for primary OA compared with FNF.
Methods
The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database from 2008 to 2016 was queried. Patients were identified using the Current Procedural Terminology (CPT) code for THA (27130) and divided into groups by diagnosis; OA in one group and FNF in another. Univariate statistics were performed. T-test compared continuous variables between groups, and Chi-square test compared categorical variables. Multivariate and propensity matched logistic regression analyses were performed to control for risk factors of interest. The primary outcomes for this study were death or serious morbidity (surgical site infection (SSI), infection, respiratory complication, cardiac complication, sepsis, or blood loss anemia requiring postoperative transfusion). Additional secondary outcomes included the incidence of specific complications, total operative time (time from incision to closure), length of hospital stay and proportion of patients that were discharged home.
Results
Analyses included 139,635 patients undergoing THA. OA was the indication in 135,013 cases and FNF in 4,622 cases. Unadjusted analysis showed a significantly higher rate of mortality when THA was done for hip fracture (2.1% vs. 0.1%; p<0.001). There was also a significantly increased rate of serious morbidity for hip fracture patients; including cardiac complications (3.5% vs 0.96%; p<0.001), respiratory complications (1.3% vs 0.2%; p<0.001), postop transfusion (23.1% vs 9.36%; p<0.001), sepsis (0.95% vs 0.3%; p<0.001). There was a significantly higher percentage of patients requiring reoperation (4.5% vs 2.0%; p<0.001) and readmission (8.0% vs 3.5%; p<0.001) in the hip fracture group. There was a significantly higher percentage of patients in the hip fracture groups having operative time >90min (16.4% vs 10.1%; p<0.001), length of stay longer than 5 days (53.8% vs 7.5%; p<0.001), and a significantly lower percentage of patients who were discharged home (39.0% vs 78.0%; p<0.001). Propensity score matching resulted in a cohort of 6,968 patients; 3,484 in both the hip fracture and osteoarthritis groups. Mortality within 30 days was 530% higher, and major morbidity was 36% higher among FNF patients. Reoperation was 40% higher, readmission was 36% higher, operative length at the 90th percentile was 74% higher, prolonged length of stay was 838% higher, and discharge to home was 62% lower for the FNF group compared with OA patients. Logistic, reverse stepwise regression model () results were consistent with the propensity-matched analysis.
Discussion and Conclusion
This large database study showed a higher risk of postoperative complications including mortality, major morbidity, reoperation, readmission, prolonged operative time, increased length of stay, and decreased likelihood of discharge home in patients undergoing THA for FNF compared with OA. Without risk adjustment, the bundled payment methods that are applied to THA procedures including those performed for FNF are at a disadvantage and likely inadequate to cover the more costly episode of care related to treating hip fracture patients.
