The Posterior Approach is Associated with Lower Total Encounter and 90-Day Costs When Compared to the Direct Anterior Approach

Introduction The clinical impact of the surgical approach in total hip arthroplasty (THA) has been widely reviewed. This study evaluated the total encounter and 90-day costs of THA for two surgical approaches (posterior [P] and direct anterior [DA]) in one tertiary health system. Methods This is a retrospective review of 2,101 THA (1,092 P and 1,009 DA) by four surgeons (two with the highest volume of DA and P, respectively) from 2017 to 2022 at one academic center. Demographics, comorbidities, operative time, length of stay (LOS), 90-day hospital returns, and complications were compared. The total encounter cost and 90-day post-operative cost were itemized. Multivariable regression analyses evaluated associations with increased cost at each time point. Results The DA cohort had a higher median encounter cost ($8,348.66 versus 7,332.42, P < 0.01), resulting from higher intraoperative (P < 0.01) and radiology (P < 0.01) expenses. Regression analyses demonstrated the DA was independently associated with increased encounter costs (OR [odds ratio] 1.1; 95% CI [confidence interval] 1.1 to 1.1; P < 0.01). There was a higher incidence of 90-day Emergency Department (ED) visits in the DA cohort (16 versus 12%, P = 0.02), with a trend towards increased readmissions. There was no difference in 90-day reoperations. Median 90-day cost was higher in the DA cohort ($126.99 versus 0.00, P < 0.01), and regression analyses demonstrated the DA had an association with increased 90-day cost (OR 2.2; 95% CI 1.5 to 3.0; P < 0.01). Conclusion Despite a younger patient population, the DA was independently associated with increased encounters and 90-day costs in a single academic hospital system. This study may underestimate the cost difference, as capital costs such as specialized tables were not analyzed.