Evaluation of predictive factors of septic wrist to avoid overdiagnosis

The existing diagnostic criteria for septic wrist are nonspecific, exposing patients with noninfectious etiologies to surgical morbidity. This study aimed to identify predictors differentiating septic wrist from other etiologies.

An institutional review board-approved retrospective review was conducted on patients with a presumed diagnosis of septic wrist (2003-2022). Bivariate and multiple regression analyses were performed to identify correlation between confirmed septic wrist and comorbidities (autoimmune diseases, immunosuppression, crystalline arthropathy, intravenous [IV] drug use, smoking), penetrating trauma, fever, multi-joint involvement, inflammatory markers (erythrocyte sedimentation rate [ESR]/C-reactive protein [CRP]/white blood cells [WBC]), serum uric acid level, blood cultures, imaging findings, and synovial fluid analysis. Categorical data were reported as median [interquartile range].

Hundred and sixty-eight (58 females and 110 males) patients were included. The median length of hospitalization and follow-up were 6[7] days and 1[3] months. Eighty-nine (53%) patients had septic wrist confirmed with Gram stain/culture, 48 (29%) patients received alternative diagnoses, and 31 (18%) patients had undetermined diagnoses. Concomitant septic wrist and crystalline arthropathy were identified in 9 patients (6.6% of total patients). Out of the 48 patients who received alternative diagnoses, 12 (25%) underwent open drainage. Elevated synovial WBC count (95,409.4 ± 85,926.2) showed a trend of association with septic wrist (p = 0.08). Negative synovial crystals (p = 0.01), positive blood culture (p = 0.04), negative history of crystalline arthropathy (p = 0.08), and multi-joint involvement (p = 0.05) were identified as predictors of septic wrist with a combined sensitivity of 87.5%, specificity of 86.2%, and area under the curve 0.93.

Current diagnostic criteria for septic wrist have low specificity. Negative history of crystalline arthropathy, multi-joint involvement, absence of synovial crystals, and positive blood culture are helpful indicators for predicting septic wrist in patients presenting with a painful, erythematous, and swollen wrist.