Possible Risk Factors for Acute and Chronic Deep Periprosthetic Joint Infections in Primary Total Knee Arthroplasty. Do BMI, Smoking, Urinary Tract Infections, Gender, and ASA Classification Have an Impact?

Purpose: Aim of this retrospective study was to evaluate the impact of the patient related factors body mass index (BMI), urinary tract infection, current smoking, gender, and American Society of Anesthesiologists (ASA) classification on the incidence of acute and chronic deep periprosthetic joint infections (PJI) in total knee arthroplasty (TKA).

Methods: All patients undergoing revision surgery for a deep PJI of primary TKA between July 2012 and December 2016 were included in this study. All relevant data was collected from the medical records. Acute deep PJI was defined when PJI was diagnosed within the first 6 weeks after primary TKA, chronic PJI was defined when patients demonstrated PJI later than 6 weeks after primary TKA.

Results: A total of 57 patients was included in this study with 13 cases of acute PJI and 44 of chronic PJI. Overweight patients (BMI > 25 kg/m) represent a significantly larger proportion in both PJI groups (p < 0.05). Current smokers had an significantly increased risk for acute and chronic PJI (p < 0.05). In the acute PJI group 46.2% patients had an postoperative urinary tract infection.

Conclusion: An elevated BMI (>25 kg/m), current smoking and urinary tract infection are possible risk factors for acute and chronic deep PJI. After primary TKA screening for urinary tract infection is recommendable to prevent predominantly acute deep PJI.