Читать книгу The SAGE Encyclopedia of Stem Cell Research - Группа авторов - Страница 176

Osteomyelitis indicates inflammation of the bone and marrow and may arise as a complication of any systemic infection. Most of the time, it manifests as a primary solitary focus of disease with all types of organisms (viruses, bacteria, parasites, fungi) producing the disease. Pyogenic osteomyelitis is always caused by bacteria and the organism can reach the bone by hematogeneous spread, extension from a contiguous site, and by direct implantation. Staphylococcus aureus is responsible for the majority of the cases in which an organism is recovered.

Other organisms commonly associated are Escherichia coli, pseudomonas, and Klebisella in patients with genitourinary tract infections and IV drug abusers and Haemophilus influenzae and group B streptococci in neonatal patients. The location of the infection within the bone is influenced by the osseous vascular circulation, which varies with age. The metaphyseal vessels penetrate the growth plate in neonates and localization of the organism in the metaphysis in children is common. In adults, the organisms are commonly isolated from epiphysis and subchondral regions.

Tuberculous osteomyelitis is prevalent in underdeveloped nations and the resurgence of this condition in the developed areas is occurring due to immigrants. The organism is usually blood borne and originates from a focus of acute visceral disease during the final stages of primary infection. Direct extension and spread via draining lymphatics may also occur. Immunosuppressed individuals frequently have multifocal bone involvement. The spine followed by the knees and hips are the most common sites of skeletal involvement. This type of osteomyelitis tends to be more destructive and resistant to control than the pyogenic type. A number of complications can arise from this condition, namely, permanent compression fractures, neurologic defects secondary to spinal cord or nerve compression, tuberculous arthritis, sinus tract formation, and amyloidosis.