Osteonecrosis of the Femoral Head.

Objective:This review aimed to provide a current recommendation to multidisciplinary physicians for early detection, diagnosis, and treatment of corticosteroid-induced osteonecrosis of the femoral head (ONFH) based on a comprehensive analysis of the clinical literature.Data Sources:For the purpose o

Corticosteroid-induced Osteonecrosis of the Femoral Head: Detection, Diagnosis, and Treatment in Earlier Stages.

This chapter reviews a wide array of diseases linked loosely by the structure, function, and constituents of the circulatory and immune systems. As with many diseases, but especially with those classified as vascular, the causes of disruption vary appreciably, extending from genetic to infectious etiologies. Hence, while a wide range of conditions are included within this chapter, some, such as osteochondrosis dissicens or hypertrophic osteoarthopathy, could comfortably fit within other disease categories. Furthermore, because of the circulatory link between most of the disorders in this chapter, determining the exact etiology of a particular lesion is often difficult, if not impossible. In paleopathological contexts, rigorous differential diagnosis must be employed, as careful attention to the location and anatomical details of the pathological bone and nearby tissue will be crucial in formulating a diagnosis.

Circulatory, Reticuloendothelial, and Hematopoietic Disorders

Sickle cell disease (SCD) is one of the most common single disease disorders world-wide. It is remarkable for its clinical heterogeneity, even among individuals with identical genotypes. Some individuals experience morbidity and mortality in early childhood, while others have a relatively mild course, and normal or near normal life expectancy. Many clinical complications are associated with SCD; most notably frequent pain episodes, stroke, acute chest syndrome, avascular necrosis, nephropathy, retinopathy and pulmonary hypertension. While the effects of higher fetal hemoglobin (HbF) levels, UGTA1A polymorphisms, alpha-thalassemia and G6PD deficiency on SCD has been extensively studied, these variables do not explain all of the clinical heterogeneity of SCD. It is not known why some patients develop certain complications, and it is difficult to predict which complications a particular patient will experience. Much work has been done to identify genetic variants associated with these disease complications; many associations remain unvalidated. As the field continues to move beyond small sample collections and candidate gene approaches into whole genome sequencing and merging of samples from all over the world, we will identify more genetic variants associated with development of specific SCD related complications, and hopefully leverage this knowledge into targeted therapies.

Genetic modifiers of severity in sickle cell disease

Sickle cell disease (SCD) is among the most common genetic diseases in the United States, affecting approximately 100,000 people. In the United States, SCD is characterized by a shortened life expectancy of only about 50 years in severe subtypes, significant quality-of-life impairments, and increased healthcare utilization and spending. SCD is characterized by chronic hemolytic anemia, vaso-occlusion, and progressive vascular injury affecting multiple organ systems. The pathophysiology is directly related to polymerization of deoxygenated hemoglobin, leading to a cascade of pathologic events including erythrocyte sickling, vaso-occlusion, tissue ischemia, and reperfusion injury as well as hemolysis, abnormal activation of inflammatory and oxidative pathways, endothelial dysfunction, increased oxidative stress, and activation of coagulation pathways. These multifactorial abnormalities have both acute and chronic clinical consequences across multiple organ systems, including acute pain episodes, chronic pain syndromes, acute chest syndrome, anemia, stroke and silent cerebral infarcts, cognitive dysfunction, pulmonary hypertension, and a wide range of other clinical consequences. Hydroxyurea was the only approved treatment for SCD for nearly 2 decades; in 2017, L-glutamine oral powder was approved for the prevention of the acute complications of SCD. During the last several years there has been a dramatic increase in research into treatments that address distinct elements of SCD pathophysiology and even new curative approaches that provide new hope to patients and physicians for a clinically consequential disease that has long been neglected.

Sickle cell disease: current treatment and emerging therapies.

Osteonecrosis is one of the most devastating musculoskeletal manifestations of sickle cell disease and most commonly affects the femoral head. Although the exact pathophysiology of this condition in patients with sickle cell disease is unknown, it is suggested that red cell sickling and repetitive vaso-occlusion may be associated with tissue hypoxia, inflammation, and subsequent bone necrosis and collapse. If left untreated, osteonecrosis can be extremely debilitating and may lead to severe pain, loss of function, and degenerative joint changes. Although several conservative management approaches exist, total joint arthroplasty remains the most effective treatment intervention. A multidisciplinary approach among the primary care physician, hematologist, and orthopedic surgeon is essential in optimizing patient management.

Malick Bachabi

Papers

Osteonecrosis in Sickle Cell Disease.