Legg–Calvé–Perthes disease presenting with osteoarthritis: Mechanisms of the development and prospects of conservative therapy using bisphosphonates

BACKGROUND: Aseptic necrosis of the femoral head in children remains a subject of great interest among specialists, despite its long history of study. The LeggCalvPerthes disease is the most common form of aseptic necrosis of the femoral head in children. The necrotic lesion in the femoral head results from the blockage of the arterial blood supply to the epiphysis, leading to its infarction. Some children experience a more aggressive disease course, with signs of osteoarthritis, which can result in the early development of coxarthrosis. Numerous publications have demonstrated the successful use of bisphosphonates in adult patients with aseptic necrosis of the femoral head. AIM: To generalize data on the use of bisphosphonates in children with the LeggCalvPerthes disease presenting with signs of osteoarthritis through the analysis of contemporary global literature. MATERIALS AND METHODS: A literature search was conducted in the open databases of PubMed, Science Direct, and Google Scholar, and the analysis depth spanned 20 years. The search terms used included LeggCalvPerthes disease, aseptic (avascular) necrosis of the femoral head, and bisphosphonates. The review encompassed the literature on bisphosphonates, their biological action, effectiveness of their use in patients with aseptic necrosis of the femoral head, and results of our research. RESULTS: Studies on the efficacy of bisphosphonates in children with LeggCalvPerthes disease are limited. Currently, the effect of bisphosphonates on disease course and outcome is unknown. Despite this, mechanisms of chronic inflammation are increasingly mentioned in the literature, which may directly or indirectly influence the clinical course and outcome of the disease. The key is the hyperactivity of osteoclasts in osteonecrosis. The experience of using bisphosphonates in adult patients with aseptic necrosis of the femoral head had positive results in preventing the progression of the deformity of femoral head deformity. CONCLUSIONS: Bisphosphonates are specific inhibitors of osteoclast activity, which has been used in many diseases. The results and inferences of using bisphosphonates in children with LeggCalvPerthes disease will lead to the formulation of a new treatment algorithm.