Like a Lizard: Repair of Perthes Disease Occurs Through Recapitulation of Development of the Proximal Femoral Epiphysis

Introduction: Legg-Calve-Perthes Disease (LCPD) is a complex condition with limited understanding about its healing process. The mechanism of LCPD believed to differ significantly from adult hip avascular necrosis (AVN), thus necessitating an exploration into alternative mechanisms. Our research focused on these mechanisms using review histologic specimens, thorough literature review, and translational basic science studies. Methods: Histologic Review: IRB-approved biopsies five Stage 2 cases undergoing hinged abduction were analyzed confirm the presence cartilage in areas fragmentation. Literature Search: A comprehensive was performed, scrutinizing publications role during Perthes’ original observations subsequent Mouse Model: mouse model, chosen for resemblance LCPD, used study chondrocyte-derived VEGF’s angiogenesis ossification. VEGF blockade employed function. Results: All showed robust fragmentation (Figure 1). Histological analysis confirmed leading new bone formation areas, akin physis’ zone identified consistent documentation past studies dating back Perthes, but this process previously not clearly defined. Chondrocytes observed produce significant amount right before vascularization hip. Blockade production halted both These findings point towards promoting ossification femoral head. Conclusion: support theory that chondrification part unique reparative LCPD. by chondrocytes appears be integral We propose superior form creeping substitution, rather endochondral-mediated ossification, much like lizard regrowing tail. Significance: clarify can inform future treatment protocols. Treatment protocols should consider biological processes optimize outcomes Further are required fully elucidate implications management Specifically, it emphasizes importance supporting than focusing solely anti-resorptive osteogenics.