Opioid Use Disorder Is Associated with an Increased Risk of Infection after Total Joint Arthroplasty: A Large Database Study
Authors: Sodhi Nipun , Anis Hiba K. , Acuña Alexander J. , Vakharia Rushabh M. , Gold Peter A. , Garbarino Luke J. , Mahmood Bilal M. , Ehiorobo Joseph O. , Grossman Eric L. , Higuera Carlos A. , Roche Martin W. , Mont Michael A. 
Published: July 2020

Abstract

Background
Recent studies have shown that patients with opioid use disorder have impaired immunity. However, few studies with large patient populations have evaluated the risks of surgical site infection (SSI) and prosthetic joint infection (PJI) with opioid use disorder after total joint arthroplasty (TJA), and there is a lack of evidence for revision TJA in particular.

Questions/purposes
Are patients with opioid use disorder who undergo (1) primary THA, (2) primary TKA, (3) revision THA, or (4) revision TKA at a higher risk of experiencing SSIs 90 days after surgery or PJIs 2 years after surgery than those who do not have opioid use disorder?

Methods
All primary and revision TJAs performed between 2005 and 2014 were identified from the Medicare Analytical Files of the PearlDiver Supercomputer using ICD-9 codes. This database is one of the largest nationwide databases; it comprehensively and longitudinally tracks patients based on all insurance claims rather than particular hospital visits, and has a low error rate (estimated at 1.3%). Boolean command operators were used to form a study group of patients with a history of opioid use disorder before surgery. ICD-9 diagnosis codes 304.00 to 304.02 and 305.50 to 305.52 were used to identify patients with opioid use disorder. Study group patients were matched 1:1 to control participants without opioid use disorder undergoing TJA, according to age, sex, and comorbidity burden (Elixhauser comorbidity index [ECI]). The ECI is comprised of 31 different comorbidities and can be used for large administrative databases. The query yielded a study population of 54,332 patients: 14,944 undergoing primary THA (opioid use disorder: n = 7472), 23,680 undergoing primary TKA (opioid use disorder: n = 11,840), 8116 undergoing revision THA (opioid use disorder: n = 4058), and 7592 undergoing revision TKA (opioid use disorder: n = 3796). The primary outcomes analyzed were SSI at 90 days and PJI at 2 years postoperatively, which were identified with ICD-9 codes. Logistic regression analyses were performed to calculate the risk that an infection would develop in a patient with opioid use disorder compared with the matched control patients without opioid use disorder.

Results
Patients with opioid use disorder undergoing primary THA had an increased risk of SSI at 90 days (OR 1.85 [95% CI 1.51 to 2.25]; p < 0.001) and PJI at 2 years (OR 1.66 [95% CI 1.42 to 1.93]; p < 0.001). Compared with matched controls, opioid use disorder patients undergoing primary TKA had an increased risk of SSI at 90 days (OR 1.72 [95% CI 1.46 to 2.02]; p < 0.001) and PJI at 2 years (OR 1.31 [95% CI 1.16 to 1.47]; p < 0.001). Similarly, for revision THAs, there was an increase in 90-day SSIs (OR 1.89 [95% CI 1.53 to 2.32]; p < 0.001) and 2-year PJIs (OR 4.24 [95% CI 3.67 to 4.89]; p < 0.001). The same held for revision TKAs for 90-day SSIs (OR 1.88 [95% CI 1.53 to 2.29]; p < 0.001) and 2-year PJIs (OR 4.94 [95% CI 4.24 to 5.76]; p < 0.001).

Conclusions
After accounting for age, sex, and comorbidity burden, these results revealed that patients with opioid use disorder undergoing TJA were at increased risk of having SSIs and PJIs. Based on these findings, healthcare systems and/or administrators should recognize the increased associated PJI and SSI risks in patients with opioid use disorder and enact clinical policies that reflect these associated risks. Additionally, these findings should encourage surgeons to pursue multidisciplinary approaches to help patients reduce their opioid consumption before their arthroplasty procedure.

Level of Evidence
Level III, therapeutic study.