How does sleep apnea impact outcomes following primary total hip arthroplasty for femoral neck fractures: a matched-control analysis

Background Cross-sectional studies have demonstrated that the prevalence of sleep apnea (SA) to be increasing within the United States. While studies have shown the association of SA and its association on complications following elective orthopedic procedures, well-powered studies investigating its impact in a traumatic setting are limited. The purpose of this study was to determine whether SA patients undergoing primary total hip arthroplasty (THA) for femoral neck fractures have higher rates of: (1) hospital lengths of stay (LOS); (2) readmissions; (3) complications; and (4) healthcare expenditures. Methods The 100% Medicare Standard Analytical Files was queried from 2005 to 2014 for patients who sustained femoral neck fractures and were treated with primary THA. The study group consisted of patients with concomitant diagnoses of SA, whereas patients without SA served as controls. Study group patients were matched to controls in a 1:5 ratio by age, sex, and various comorbid conditions. Demographics of the cohorts were compared using Pearson's chi-squared analyses, and multivariate logistic regression analyses were used to calculate the odds (OR) of the effects of SA on postoperative outcomes. A p value less than 0.006 was considered to be statistically significant. Results The final query yielded 24,936 patients within the study (n = 4166) and control (n = 20,770) cohorts. SA patients had significantly longer in-hospital LOS (6 vs. 5 days, p < 0.0001) but similar readmission rates (24.12 vs. 20.50%; OR: 1.03, p = 0.476). SA patients had significantly higher frequency and odds of developing medical complications (72.66 vs. 43.85%; OR: 1.57, p < 0.0001), and higher healthcare costs ($22,743.79 vs. $21,572.89, p < 0.0001). Conclusion SA is associated with longer in-hospital LOS, higher rates of complications and healthcare expenditures. This study is vital as it can allow orthopaedists to educate patients with SA on the potential complications which may occur following their procedure.