Background: Septic arthritis is an orthopaedic emergency that can lead to significant morbidity and mortality if treatment is delayed. Myositis can present in a similar way to septic arthritis, particularly in a young child, but is treated differently. Clinicians must take both into account when assessing patients.
Case Description: A five-year-old girl presented with a swollen, sore knee on a background of minor trauma. Examination findings revealed severe sepsis, tonsillitis and a florid rash suspicious of scarlet fever. An orthopaedic opinion was requested for the possibility of septic arthritis of the knee. Due to swelling of the thigh, a provisional diagnosis of myositis secondary to Group A Streptococcal throat infection was made and confirmed by MRI scan of the lower leg. The patient was transferred to an intensive care unit for monitoring and antibiotic therapy.
Literature Review: There are reports of myositis being mistakenly diagnosed as septic arthritis of the knee leading to iatrogenic septic arthritis as a result of needle aspiration.
Clinical Relevance: This highlights the diagnostic challenge posed in the case of a young, septic child who presens with a swollen, painful limb. Repeated clinical examination and the judicious use of magnetic resonance scanning assists in this situation.
Joe Littlechild, Faz Alipour
Journal of Bone Research and Reports received 235 citations as per google scholar report