Evaluation of Point-of-Care Ultrasonography Decision-Support Algorithm for the Diagnosis of Transient Synovitis in the Pediatric Emergency Department

Background: Transient synovitis (TS) is a self-limiting disease characterized clinically by acute hip pain. The diagnosis is confirmed by excluding other severe diseases.

Objectives: To evaluate the performance of a point-of-care ultrasonography-decision support algorithm (POCUS-DSA) in the diagnosis of TS among children presenting to the pediatric ED.

Methods: We analyzed all children with nontraumatic hip tenderness who met the POCUS-DSA criteria between 01/01/2014 and 31/12/2019. Patients with hip effusion who received the diagnosis of TS were scheduled for a follow-up visit in 5 to 7 days. Patients without hip effusion were assessed per clinician judgment. A final diagnosis of TS was made at the follow-up visit.

Results: Overall, 1461 children with nontraumatic hip tenderness attended the ED during the study period. POCUS-DSA was applied to 621 patients with a mean (SD) age of 5.5 (1.9) years. The accuracy of POCUS-DSA for the diagnosis of TS was as follows: sensitivity, 90.9% (95% CI, 88.3%-93.1%); specificity, 78.6% (95% CI, 60.5%-89.8%); PPV, 98.9% (95% CI, 97.6%-99.5%); NPV, 28.9% (95% CI, 20.0%-40.0%); positive LR, 4.25 (95% CI, 2.1-8.6); and negative LR, 0.12 (95% CI, 0.08-0.16).

Discussion: Study findings suggest that the POCUS-DSA can be helpful in ruling in the diagnosis of TS. To our knowledge, this study is the first to suggest a rule-in diagnostic tool for TS, instead of one of exclusion.