Legg-Calvé-Perthes disease: multipositional power Doppler sonography of the proximal femoral vascularity

Construction of ceRNA network based on RNA-seq for identifying prognostic lncRNA biomarkers in Perthes disease

Introduction: Legg-Calvé-Perthes disease or Perthes disease is a condition that occurs in children aged 2 to 15 years, and is characterized by osteonecrosis of the femoral head, which results in physical limitations. Despite ongoing research, the pathogenesis and molecular mechanisms underlying the development of Perthes disease remain unclear. In order to obtain further insights, the expression patterns of long non-coding RNAs (lncRNAs), miRNAs, and mRNAs in a rabbit model of Perthes disease were analyzed in this study by transcriptome sequencing. Methods and results: The results of RNA-seq analyses revealed that 77 lncRNAs, 239 miRNAs, and 1027 mRNAs were differentially expressed in the rabbit model. This finding suggested that multiple genetic pathways are involved in the development of Perthes disease. A weighted gene co-expression network analysis (WGCNA) network was subsequently constructed using the differentially expressed mRNAs (DEmRNAs), and network analysis revealed that the genes associated with angiogenesis and platelet activation were downregulated, which was consistent with the findings of Perthes disease. A competing endogenous RNA (ceRNA) network was additionally constructed using 29 differentially expressed lncRNAs (including HIF3A and LOC103350994), 28 differentially expressed miRNAs (including ocu-miR-574-5p and ocu-miR-324-3p), and 76 DEmRNAs (including ALOX12 and PTGER2). Disscusion: The results obtained herein provide novel perspectives regarding the pathogenesis and molecular mechanisms underlying the development of Perthes disease. The findings of this study can pave the way for the development of effective therapeutic strategies for Perthes disease in future.

From the radiologic pathology archives imaging of osteonecrosis: radiologic-pathologic correlation

Osteonecrosis is common and represents loss of blood supply to a region of bone. Common sites affected include the femoral head, humeral head, knee, femoral/tibial metadiaphysis, scaphoid, lunate, and talus. Symptomatic femoral head osteonecrosis accounts for 10,000-20,000 new cases annually in the United States. In contradistinction, metadiaphyseal osteonecrosis is often occult and asymptomatic. There are numerous causes of osteonecrosis most commonly related to trauma, corticosteroids, and idiopathic. Imaging of osteonecrosis is frequently diagnostic with a serpentine rim of sclerosis on radiographs, photopenia in early disease at bone scintigraphy, and maintained yellow marrow at MR imaging with a serpentine rim of high signal intensity (double-line sign) on images obtained with long repetition time sequences. These radiologic features correspond to the underlying pathology of osseous response to wall off the osteonecrotic process and attempts at repair with vascularized granulation tissue at the reactive interface. The long-term clinical importance of epiphyseal osteonecrosis is almost exclusively based on the likelihood of overlying articular collapse. MR imaging is generally considered the most sensitive and specific imaging modality both for early diagnosis and identifying features that increase the possibility of this complication. Treatment subsequent to articular collapse and development of secondary osteoarthritis typically requires reconstructive surgery. Malignant transformation of osteonecrosis is rare and almost exclusively associated with metadiaphyseal lesions. Imaging features of this dire sequela include aggressive bone destruction about the lesion margin, cortical involvement, and an associated soft-tissue mass. Recognizing the appearance of osteonecrosis, which reflects the underlying pathology, improves radiologic assessment and is important to guide optimal patient management.

Outcome measures for evaluation of treatments for osteonecrosis

With the advent of cell-based therapies, biologics, and pharmaceuticals for the potential treatment of osteonecrosis, it is important to conduct evaluations using scientifically accepted outcomes measures. For the treatment of osteonecrosis, most studies have focused on pain relief, surgery, or the need for surgery, disease progression (advancing stage), and change in lesion size. Quantification of imaging techniques continue to gain in sophistication but have not yet been validated for use in clinical trials. Despite recent interest in using biomarkers or genetic markers in the diagnosis and analysis of disease progression, more research is needed to determine the sensitivity and specificity of these techniques with respect to osteonecrosis.