Culture-positive left shoulder septic arthritis with suspected contralateral involvement secondary to Staphylococcus aureus bacteraemia.

Septic arthritis is an orthopaedic emergency typically presenting with inflammatory clinical signs. Atypical presentations of septic arthritis are defined in this report specifically as those lacking the classic clinical signs (erythema, swelling, joint warmth and fever) despite an active intra-articular infection. Atypical presentations may delay diagnosis due to diagnostic uncertainty and cause avoidable damage to affected joints. This case report describes an elderly patient with diabetes mellitus who presented with bilateral shoulder pain and raised inflammatory markers without fever, overlying erythema, joint swelling or joint warmth. The clinical course, differential diagnosis, management with bilateral shoulder washout and antibiotics and efforts to identify a central source of infection are detailed in this report. This case highlights the need for a high index of suspicion for septic arthritis when patients present with joint pain lacking common clinical signs of septic arthritis. Early joint aspiration, antibiotic therapy and surgical management are critical to optimising outcomes, even in the absence of classic clinical signs.