The prevalence of Legg-Calvé-Perthes disease among paediatric patients with transient synovitis of the hip: a systematic review and meta-analysis.

BACKGROUND

Transient synovitis of the hip is the most common cause of limping in paediatric emergency departments. There is no consensus regarding routine follow-up after hip synovitis among children, and there are no standardized criteria for selecting cases that warrant follow-up due to persistent or recurring symptoms to rule out the possibility of Legg-Calvé-Perthes disease. Delayed treatment of Legg-Calvé-Perthes disease may increase the risk of developing early secondary coxarthrosis. Understanding the prevalence of Legg-Calvé-Perthes disease among paediatric patients with transient synovitis of the hip is of paramount importance and could empower both parents and paediatricians to make well-informed decisions when selecting follow-up care for children, thus ensuring that no cases of Legg-Calvé-Perthes disease are missed among diagnosis paediatric patients with transient synovitis of the hip. The aim of this review was to estimate the prevalence of Legg-Calvé-Perthes disease among paediatric patients with transient synovitis of the hip.

METHODS

This study was conducted in strict accordance with the PRISMA guidelines and was registered with PROSPERO. The PubMed, Embase, and Cochrane Library databases were comprehensively searched up to July 2024 to identify relevant studies. The inclusion criteria were as follows: patients diagnosed with transient synovitis of the hip; patients aged up to 18 years; and studies with a minimum of 10 cases of paediatric transient synovitis of the hip. To pool the prevalence rates from individual studies, we utilized a random-effects meta-analysis. To assess the quality of the included studies in detail, we employed the Joanna Briggs Institute's quality assessment checklist.

RESULTS

A total of 19 studies were ultimately included for the final analysis, with 2,617 paediatric cases of transient synovitis of the hip. The results of meta-analysis revealed that the pooled prevalence estimate of Legg-Calvé-Perthes disease among all paediatric patients with transient synovitis of the hip was 2.7% (95% CI 1.4-5.1). Significant heterogeneity was observed across the studies included in this analysis (I = 79.990%; P = 0.000). The pooled prevalence estimate of Legg-Calvé-Perthes disease among paediatric patients with recurrent or persistent transient synovitis of the hip was 36.3% (95% CI 21.6-54.2). Significant heterogeneity was also observed across the studies included in this analysis (I = 51.519%; P = 0.036). Furthermore, the follow-up period varied from 6 weeks to 24 months. The primary diagnostic imaging modality utilized for identifying Perthes disease was X-ray.

CONCLUSION

Our study revealed that among paediatric patients with transient synovitis of the hip, routine X-ray follow-up of the hips after 6 weeks to rule out Legg-Calvé-Perthes disease is warranted only in patients who exhibit persistent or recurrent symptoms.