Legg-Calvé-Perthes disease: classifications and prognostic factors.

INTRODUCTION Legg-Calvé-Perthes Disease (LCPD) represents idiopathic avascular necrosis of femoral head in pediatric population. Indications for treatment depend mostly on prognosis about femoral head sphericity and hip congruence at the end of growth. The aim of this review is to highline prognostic factors of LCPD. METHODS Bibliographic search in PubMed allowed selection of 33 articles concerning prognostic factors and/or classification of LCPD. CONCLUSION Clinical factors of poor prognosis are overweight, female sex, age exceeding 6 years old, and lack of hip abduction. Radiologically, Herring's classification is consensual because of its high prognostic value and very good reproducibility. The other signs of femoral head "at-risk" and the assessment of the reduction in abduction of the femoral head in the acetabulum are also prognostic of late evolution. MRI seems to be a future tool in assessing the fate of hips in LCPD. It is likely that a better understanding of LCPD etiology would precise the prognosis of this disease.