Introduction

Septic arthritis (SA) remains a life-threatening condition with substantial mortality. • Inflammatory markers are widely used clinically, but their prognostic value remains uncertain.

Aim: Evaluate mortality and identify predictors of adverse outcomes — focusing on clinical vs laboratory parameters.

Methods

Retrospective, single-centre study. • All patients undergoing surgery for SA, 2019–2025. • Outcomes: in-hospital and 1-year mortality. • Statistical analysis of associations with mortality. • Data collected: Demographics; o ASA classification; o Comorbidities; o Affected joint; o Hospital stay; Laboratory parameters — white blood cell count, Creactive protein; o Synovial fluid analysis; o Microbiology.

Results

N=49 Patients with orthopaedic infection, 60.7 years Mean age, 55.1% Male, 75.5% Knee involvement, 14.3% In-hospital mortality (n=7), 9.5% 1-year mortality (n=4)

ASA Classification In-hospital mortality by ASA classification - 85.7% of in-hospital deaths occurred in patients classified as ASA IV (p=0.001). ASA IV: strongest predictor of mortality

Hospital stay Length of hospital stay by survival status - 85.7% of Patients who died had a significantly longer hospital stay (74 vs 38 days; p=0.026). 1.9× longer hospital stay

Microbiology Mortality according to microbiological isolate. Mortality was numerically higher in ESBL-producing Klebsiella spp. and MRSA infections and lower in MSSA infection. Not statistically significant.

Predicted mortality - Strong association ASA IV Immunosuppression Hospital stay ( p = 0.001 p = 0.006 p = 0.026) 

No association found - Laboratory & demographic markers - Age Leukocyte count C-Reactive Protein Synovial WBC count Synovial differential Culture sterility

Conclusions - Septic arthritis carries significant mortality, particularly in patients with high ASA classification. ASA IV status outperforms traditional inflammatory biomarkers in predicting in-hospital mortality, underscoring the limited prognostic value of CRP and leukocyte counts. Early risk stratification based on global patient status rather than laboratory parameters may improve clinical decision-making. Multidrug-resistant pathogens may further increase risk and warrant close monitoring.