Avascular Necrosis Of Femoral Epiphysis Research Articles

Inhibition of Toll-Like Receptor 4 Signaling Pathway Accelerates the Repair of Avascular Necrosis of Femoral Epiphysis through Regulating Macrophage Polarization in Perthes Disease.

Legg-Calvé-Perthes disease (LCPD) is still a refractory disease in children's orthopedics. With the introduction of the concept of "osteoimmunology", the immune-inflammatory mechanisms between bone and immune system have become a research focus of LCPD. However, few studies have reported on the pathological role of inflammation-related receptors such as toll-like receptors (TLRs) as well as immune cells such as macrophages in LCPD. This study was for investigating the mechanism of TLR4 signaling pathway on the direction of macrophage polarization and the repair of avascular necrosis of femoral epiphysis in LCPD. With GSE57614 and GSE74089, differentially expressed genes were screened. Through enrichment analysis and protein-protein interaction network, the functions of TLR4 were explored. Furthermore, immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), hematoxylin & eosin (H&E) staining, micro-CT, tartrate-resistant acid phosphatase (TRAP) dyeing and western blotting were performed for determining the influences of TAK-242 (a TLR4 inhibitor) on the repair of avascular necrosis of femoral epiphysis in rat models. Totally 40 co-expression genes were screened as well as enriched in TLR4 signaling pathway. Immunohistochemistry and ELISA analyses certified that TLR4 facilitated macrophage polarization toward the M1 phenotype and prevented macrophage polarization toward the M2 phenotype. Besides, the results of H&E and TRAP staining, micro-CT, and western blotting showed that TAK-242 can inhibit osteoclastogenesis and promote osteogenesis. Inhibition of TLR4 signaling pathway accelerated the repair of avascular necrosis of femoral epiphysis by regulating macrophage polarization in LCPD.

Legg-Calve-Perthes disease.

We report a case of a 9-year-old male who presented with limping gait. The primary concern of the parents was that, he started walking in an awkward fashion two months ago. The birth and developmental history were uneventful. Child complaint of mild inconsistent pain in left hip joint. On observation in standing posture, asymmetry was noted as he was bearing less weight on left lower limb due to pain. On examination, in supine lying, active as well as passive abduction of left hip were terminally limited by pain. When he was made to stand on right leg, pelvis was neutral. On the other hand, trunk shifted to left side while he attempted single leg standing on left leg and it was difficult to maintain balance. Thus, Trendelenburg sign was positive. Trendelenburg gait was evident as the trunk shifted to the stance side. X-ray reveals smaller and compressed femoral epiphyseal size with blurred epiphyseal plate on the left side. Stage I changes in imaging were noted according to Waldenstrom's classification along with Stulberg class III of Perthes disease. Legg-Calve-Perthes disease is insidious onset idiopathic avascular necrosis of femoral epiphysis in children, commonly between five to eight years of age. Physiotherapy intervention comprised active range of motion of left hip joint in non-weight bearing position, isometric exercise of gluteal muscles, prescription of weight relieving trilateral orthosis, parent and child education about de-loading of hip joint and avoiding high impact activities. Containment surgery for left hip was planned by orthopaedic surgeon.