Periprosthetic Knee Joint Infection Has a Higher Incidence Rate in Developing Countries; A Report From Two Regional Orthopaedic Hospitals in Southern Nigeria.

INTRODUCTION/OBJECTIVES: Periprosthetic joint infection (PJI) remains one of the most serious complications following total knee arthroplasty (TKA). This study evaluated the hospital-based incidence rate, risk factors and early functional outcomes of PJI after primary TKA in two regional orthopaedic hospitals in Southern Nigeria. METHODS: This was a retrospective-prospective two-centre cohort study on primary TKA procedures conducted between January 2022 and August 2025. Data from the arthroplasty registry of two regional hospitals were analysed for demographic characteristics, perioperative details, postoperative complications, and functional outcomes measured using the Visual Analogue Scale (VAS) and Knee Society Score (KSS). PJI was diagnosed using the Musculoskeletal Infection Society criteria. RESULTS: There were 392 primary TKAs from which 10 cases of PJI were identified over the period, giving an incidence rate of 2.6% (CI 1.0, 4.2. p = 0.307). Most infections were early PJIs. Staphylococcus aureus was the commonest organism isolated. Diabetes mellitus, obesity, surgical duration greater than 120 minutes, and drain use beyond 48 hours were not statistically significantly associated with the development of PJI. Patients without PJI recorded statistically significant improvement in VAS (p= 0.000), and KSS (p= 0.000), at three months, while those treated for PJI also demonstrated postoperative functional gains(p=0.023) CONCLUSION: The incidence of PJI in this setting is not statistically significantly higher than rates reported in high-income countries. Modifiable perioperative factors such as blood glucose control, reduced operative duration, and judicious use of drains will help reduce the risk. LEVEL OF EVIDENCE: III.