• BACKGROUND
    • Although several studies have reported outcomes of primary total knee arthroplasty (TKA) in patients with rheumatoid arthritis, very little has been reported on the outcomes of this procedure in patients with other inflammatory arthritides.
  • METHODS
    • This study used a national database to evaluate 90-day postoperative complication rates, readmission rates, and revision rates after TKA in patients with inflammatory arthritis. Patients with rheumatoid arthritis (n = 153,531), psoriatic arthritis (n = 7,918), and ankylosing spondylitis (n = 4,575) were compared with patients with osteoarthritis (n = 1,751,938) who underwent TKA from 2005 to 2012.
  • RESULTS
    • The rates of systemic complications, infection, revision, and 90-day readmission after TKA in patients with different types of inflammatory arthritis were significantly higher than those in control patients with osteoarthritis (P < 0.0001). No differences were found in the rates of systemic or local complications, revision, or readmission among the types of inflammatory arthritis.
  • CONCLUSION
    • Inflammatory arthritis is associated with increased rates of perioperative complications, revision, and 90-day readmission after primary TKA.
  • LEVEL OF EVIDENCE
    • Level III.