Factors associated with periprosthetic joint infection following hip or knee arthroplasty: a single-centre, registry-linked cohort study of 30,102 cases conducted at a national orthopaedic treatment centre

Periprosthetic joint infection (PJI) is a devastating complication following lower limb arthroplasty that is associated with major physical, psychological, and social harm, yet its aetiology remains poorly evaluated. The aim of this study was to identify characteristics associated with an increased risk of PJI following primary total hip (THA) or total knee arthroplasty (TKA) performed for arthritis. A retrospective cohort study was conducted using prospectively collected clinical data from a bespoke institutional database, at a single high-volume study centre. THA and TKA cases performed for end-stage arthritis between 1 January 2010 and 31 December 2021 were included. Variables collected included: demographic details, clinical factors, surgical factors, and perioperative management factors. The primary outcome measure was PJI related to the same prosthetic joint from two weeks to 11 years, and was further sub-categorized as superficial or deep infection. A total of 30,102 procedures (15,191 THA and 14,911 TKA) performed in 25,829 patients were included. On adjusted analyses, factors independently associated with an increased risk of deep infection in THA were male sex (OR 1.96 (95% CI 1.18 to 3.26); p = 0.009); perioperative blood transfusion (OR 4.82 (95% CI 1.42 to 16.37); p = 0.012); obesity class II (OR 3.55 (95% CI 1.37 to 9.24); p = 0.009); and obesity class III (OR 3.68 (95% CI 1.16 to 12.88); p = 0.028). Factors independently associated with an increased risk of deep infection in TKA were perioperative blood transfusion (OR 9.74 (95% CI 3.81 to 24.9); p < 0.001) and operating time (OR 1.01 (95% CI 1.00 to 1.02); p = 0.049). The findings highlight the importance of holistic strategies to support personalized weight optimization while awaiting surgery, management of perioperative anaemia, and transfusion minimization strategies. [Abstract copyright: © 2026 The British Editorial Society of Bone & Joint Surgery.]