Racial variations in complications and costs following total knee arthroplasty: a retrospective matched cohort study

In this study, we evaluate how race corresponds to specific complications and costs following total knee arthroplasty (TKA). Our hypothesis was that minority patients, comprising Black, Asian, and Hispanic patients, would have higher complication and revision rates and costs than White patients.

Data from 2014 to 2016 were collected from a large commercial insurance database. TKA patients were assigned under Current Procedural Terminology (CPT-27447) and International Statistical Classification of Diseases (ICD-9-P-8154) codes. Minority patients were compared to White patients before and after matching for age, gender, and tobacco use, diabetes, and obesity comorbidities. Standardized complications, revisions, and total costs at 30 days, 90 days, and 1 year were compared between the groups using unequal variance t tests.

Overall, 140,601 White (92%), 10,247 Black (6.7%), 1072 Asian (0.67%), and 1725 Hispanic (1.1%) TKA patients were included. At baseline, minority patients had 7-10% longer lengths of stay (p = 0.0001) and Black and Hispanic patients had higher Charlson and Elixhauser comorbidity indices (p = 0.0001), while Asian patients had a lower Elixhauser comorbidity index (p < 0.0001). Black patients had significantly higher complication rates and higher rates of revision (p = 0.03). Minority patients were charged 10-32% more (p < 0.0001). Following matching, all minority patients had lengths of stay 8-10% longer (p = 0.001) and Black patients had higher Charlson and Elixhauser comorbidity indices (p < 0.0001) while Asian patients had a lower Elixhauser comorbidity index (p = 0.0008). Black patients had more equal complication rates and there was no significant difference in revisions in any minority cohort. All minority cohorts had significantly higher total costs at all time points, ranging from 9 to 31% (p < 0.0001).

Compared to White patients, Black patients had significantly increased rates of complications, along with greater total costs, but not revisions. Asian and Hispanic patients, however, did not have significant differences in complications or revisions yet still had higher costs. As a result, this study corroborates our hypothesis that Black patients have higher rates of complications and costs than White patients following total knee arthroplasty and recommends efforts be taken to tackle health inequities to create more fairness in healthcare. This same hypothesis, however, was not supported when evaluating Asian and Hispanic patients, probably because of the few patients included in the database and deserves further investigation.