Elevated risk of prosthetic infections in cannabis users after shoulder arthroplasty.

Introduction: An increasing number of states are beginning to legalize recreational cannabis use, and as such, more patients using cannabis are undergoing shoulder arthroplasty procedures. The present study sought to examine the impact of cannabis use on post-operative outcomes. The primary outcomes of interest were postoperative complications, which included infection, periprosthetic fractures, periprosthetic joint infections (PJI), dislocations, and aseptic loosening as well as medical complications. Secondary outcomes were risk factors for PJI and aseptic loosening at two-years.

Methods: A private, nationwide, all-payer database (Pearldiver Technologies) was queried to identify shoulder arthroplasty patients from 2010 to 2020. Those not using tobacco or cannabis ("control", n = 10,000), tobacco users (n = 10,000), cannabis users (n = 155), and concurrent tobacco and cannabis users (n = 9,842) were identified. Risk factors for PJI and aseptic loosening at two-years were further quantified utilizing multivariable logistic regression analysis.

Results: Compared to non-users, cannabis users experienced the highest odds for PJI and aseptic revisions, which were followed by concurrent cannabis and tobacco users and tobacco-only users. Concurrent users, as well as tobacco users were at higher risk for dislocation. Cannabis use was the most significant risk factor for PJI, followed by concurrent use and male sex.

Conclusions: Our study found cannabis use to cause greater risk for superficial and deep infection. More research involving randomized trials are needed to fully elucidate the impact of cannabis use on shoulder arthroplasty procedures. Clinically, these findings can appropriately guide surgeons and patients alike regarding expectations prior to undergoing TSA.