“Sclerotic Band” type of classification system and measurement of necrotic area for osteonecrosis of the femoral head

Osteonecrosis of the femoral head is a common orthopedic disease. Based on years of clinical experience and significant imaging data, this study aimed to elucidate a new type of it, to help improve prognosis in young adults and provide a basis for hip preservation treatment. From January 2014 to December 2016, a total of 211 patients undergoing hip preservation surgery for femoral head necrosis at our hospital were enrolled in this study. Coronal plane classification and cross-sectional area analysis were performed by nuclear magnetic resonance imaging (computed tomography optional) in cases meeting the inclusion criteria. Meanwhile, a new method of classification and calculating the necrotic area was proposed. The application simulation was conducted using sample cases. Additionally, treatment methods were recommended. We used our method to compare the outcome of the selected patients with the JIC classification so as to judge the advantages and disadvantages. The “ pressure bone trabecular angle ” of the femoral head was measured, and the “sclerotic band” (Zhang Ying) type of classification system and the “quartile” (Zhang Ying) method of measurement were used in 2 sample cases. After analysis, it is more accurate than JIC. The “Sclerotic band” type of classification system and "quartile" methods are new methods to evaluate the stability of femoral head necrosis. They are convenient for clinical application and easily adopted.