Risk of DVT, ICU Admission, and Mortality in Pediatric Lower Extremity Musculoskeletal Infections Impact of MRSA and Elevated CRP

Background: Musculoskeletal infections (MSKIs), including osteomyelitis and pyogenic arthritis, present significant health risks in pediatric populations. This study evaluates the risks of septic deep vein thrombosis (DVT), intensive care unit (ICU) admission, and mortality in children diagnosed with lower extremity MSKIs, with a focus on methicillin-resistant Staphylococcus aureus (MRSA) infections. Methods: This retrospective cohort study from a multi-institutional database included 38,023 pediatric patients diagnosed with lower extremity MSKIs. Incidence and risk factors for DVT, ICU admission, and mortality were collected. Comparisons were made between age groups and MRSA versus non-MRSA infections. The association between CRP levels and outcomes was also examined. Multivariable logistic regression models were utilized. Results: The mean age of the cohort was 8.49 years. Overall, 1.52% of patients developed septic DVT, 0.49% required ICU admission, and 0.48% died. Patients with MRSA had significantly higher risks of DVT (RR 4.89, P < 0.001) and mortality (RR 3.57, P < 0.001) compared with those without MRSA. CRP levels were also markedly higher in MRSA patients (P < 0.001). When comparing age groups, those < 12 years had a higher risk of ICU admission (RR 2.03, P < 0.001), whereas the 12 to 18 age group had a higher risk of DVT (RR 0.71, P < 0.001). Among patients with DVT, the mortality risk was significantly increased (RR 5.18, P < 0.001). MRSA patients with DVT had the highest mortality risk (RR 5.38, P < 0.001) and elevated CRP levels (P < 0.001). Conclusions: Reporting the largest series of children with lower extremity MSKI, our study found increased risk of DVT, ICU admission, and mortality in pediatric patients with MRSA. MRSA patients with septic DVT had significantly higher level of CRP than those without DVT (100.95 mg/L vs. 61.59 mg/L, P < 0.001). MRSA infections with septic DVT had the highest rate of mortality (7.24%). Clinicians should consider proactive screening and aggressive management strategies for septic DVT in the at-risk population, especially in patients with high CRP.