LongTerm Outcomes of Suspected Transient Synovitis of the Hip in NonAspirated Patients

BACKGROUND: Transient synovitis is a common cause of pediatric hip pain that must be distinguished from septic arthritis. Although the literature includes outcome data for aspirated hips, long-term outcomes in patients managed presumptively without aspiration remain limited. This study aimed to characterize the long-term clinical outcomes of children with presumed transient synovitis managed without hip aspiration. METHODS: A retrospective study of pediatric patients diagnosed with transient synovitis and managed presumptively without aspiration. Collected variables included demographics, clinical presentation, laboratory values, and longitudinal outcomes. Outcomes assessed included residual symptoms, recurrence of symptoms or transient synovitis, admission, and rheumatologic or sequelae diagnoses at 4 weeks, 6 months, 1 year, and 5 years, as well as across overall follow-up. Time to recurrence was determined using documented free-text data and by the first follow-up interval with recurrence. Analyses were descriptive. RESULTS: A total of 220 patients with transient synovitis were included. The mean age at diagnosis was 5.96±3.39 years, and 68.9% were male. Fever was present in 13.2% of patients, and the mean weightbearing score at presentation was 1.04±0.81. The mean WBC, ESR, and CRP were 9.56±3.54, 18.53±15.71, and 3.00±13.15, respectively. Mean follow-up was 9.41±4.26 years. Residual symptoms were observed in 4.3% of patients and recurrence in 2.6% across available follow-up. A rheumatologic or sequelae diagnosis was identified in 3.2% of patients, including juvenile idiopathic arthritis, Legg-Calvé-Perthes disease, and chronic arthralgia. No patients were later diagnosed with an infectious etiology or required a change in management. CONCLUSION: Pediatric transient synovitis managed without hip aspiration was associated with favorable long-term outcomes, including no missed diagnosis of septic arthritis, and low rates of persistent symptoms and recurrence. However, a small proportion of patients were later diagnosed with rheumatologic disease or other sequelae, supporting the need for continued clinical follow-up in cases with atypical, prolonged, or recurrent symptoms. LEVEL OF EVIDENCE: Level III-retrospective study.