Radiologic Sequelae of Pediatric Septic Arthritis of the Shoulder: A Retrospective Series and Proposed Classification

BACKGROUND: This study aimed to evaluate the long-term radiologic sequelae of pediatric septic arthritis of the shoulder and identify characteristic patterns of residual proximal humeral deformity. METHODS: A retrospective review was performed of children treated for septic arthritis of the shoulder at a tertiary pediatric orthopaedic center between 2010 and 2024. Inclusion criteria were confirmed septic shoulder, complete radiographic records, and a minimum 2-year follow-up. Radiographs at final follow-up were analyzed for epiphyseal, physeal, and articular abnormalities, and sequelae were classified according to severity and anatomic involvement. RESULTS: Twenty-three children were included, with a mean age at presentation of 31.7 months and a mean follow-up of 6.2 years. Twelve children presented during infancy, including 5 neonates. Multifocal musculoskeletal infection was present in 43.5%, and associated proximal humeral osteomyelitis in 52.2%. Methicillin-resistant Staphylococcus aureus was the most commonly isolated organism (39.1%). Radiologic sequelae were classified into 4 types: type I, complete recovery (17.4%); type II, epiphyseal irregularity/dysplasia (17.4%); type III, physeal arrest/bar formation (47.8%); and type IV, articular destruction/proximal humeral loss (17.3%). Neonates and children with multifocal infection more frequently developed severe type III/IV sequelae. CONCLUSION: Septic arthritis of the pediatric shoulder is associated with a high risk of permanent growth-related deformity, particularly in neonates and infants. Physeal injury is the most predominant long-term sequela. The proposed radiologic classification may aid prognostication, follow-up, and surgical planning in affected children. LEVEL OF EVIDENCE: Level IV.