Predictive features for Septic Arthritis in Immunocompetent
Prompt diagnosis of septic arthritis is imperative to prevent irreversible joint damage. Immunocompromised patients are at an increased risk of septic arthritis as well as secondary systemic infection. The aim of this study were to identify features predictive of septic arthritis and to determine whether these features differed between immunocompetent and immunocompromised patients.

A single institution retrospective cohort study was performed of 173 immunocompetent and 70 immunocompromised patients who underwent aspiration or arthrotomy for suspected septic arthritis.

--In the regression analysis, independent predictive factors for septic arthritis in immunocompetent patients were younger age, presence of radiographic abnormalities, and C-reactive protein (CRP).

--For immunocompromised patients, only CRP was an independent continuous predictive factor for septic arthritis.

--A risk stratification tool for predicting septic arthritis in immunocompetent patients using age less than 55 years, CRP more than 100 mg/dL, and presence of radiographic abnormalities was developed.

--A similar tool was created using CRP more than 180 mg/dL and radiographic abnormalities in immunocompromised patients.

Immunocompromised and immunocompetent patients have different prognostic variables for septic arthritis, implying different clinical manifestations. The risk stratification methods that have been created can be used to predict the likelihood of septic arthritis in both categories. In the absence of appropriate data from synovial aspiration, this could allow for a more precise selection of patients for surgical intervention.