Osteomyelitis is a serious bone infection, occurring rarely, that metastasizes to the bone through the bloodstream. Additionally, surgery or open fracture can also cause the bone infection. Normally, bones do have enough resistance power to evade the infection, but the introduction of microorganisms hematogenously from surrounding structures or direct immunization concerning a surgery can trigger the disease. The persistence of infection for a long time span is referred to as chronic osteomyelitis.
Studies over the years have put forward some important factors in the pathogenesis of the disease. These include immunity level of the host, type and location of the bone, co-morbidity of another disease, and the virulence of the infecting organism. Infecting organisms might possess various factors that can increase the possibility of osteomyelitis. As an example, S aureus may alter the defense mechanism of the host while promoting bacterial adherence at the same time. Scholars have affirmed that S aureus is the most common pathogenic organism preceded by Enterobacteriaceae and Pseudomonas. Some other(less known) organisms include anaerobe gram-negative bacilli.
Vertebrae are the most vulnerable sites for the infection in adults; nonetheless, the infection can also occur in the clavicle, pelvis, and long bones. Primary hematogenous osteomyelitis is more prevalent in children and infants. The possibility of the formation of the sinus tracts is also there when the infection extends to the soft tissues. Secondary hematogenous osteomyelitis, more often than not, occurs when any childhood infection is re-activated. Pseudomonal infections are more prevalent among intravenous drug users. Additionally, dental extractions and genitourinary infections may also lead to osteomyelitis.
Among widely known factors in posttraumatic osteomyelitis include the direct vaccination of a bacteria, internal fixation of fractures, infections in soft tissues, septic arthritis, and hospital-acquired infections. Hospital-acquired infections are triggered by fungal, viral, and bacterial pathogens. Most common among these infections include urinary tract infection, surgical site infection, and ventilator-associated pneumonia.
Posttraumatic osteomyelitis usually affects adults and occurs in the tibia. In this type too, S aureus is a prevalent organism. In contrast to the hematogenous osteomyelitis, posttraumatic osteomyelitis initiates out of the bony cortex. The patient might lose the stability of the bone, and experience soft-tissue damage. Mild fever and pain are also experienced in this condition.
Septic arthritis or the abnormalities in the joint margins arising out of the overdevelopment of the granular tissue ultimately metastasizes to the underlying bone leading to the infection. A research study suggested that septic arthritis in adults mostly affects the knee, and 38 percent of them are likely to get suffered from osteomyelitis eventually. However, septic is more likely in neonates than older children.
Osteomyelitis of vertebrae peps up with the advancing age, with most of the affected people age 50 or older. Though delay in the diagnosis might lead to various complications, this form of osteomyelitis is not fatal, courtesy to the development of antibiotics. The infection includes two adjacent vertebrae with the corresponding intervertebral desk. Lumbar spine is among the most affected organs followed by cervical regions and thoracic. Most of the patients experience localized tenderness and pain that may last from 3 weeks to 3 months. Approximately 50 percent patients also feel the mild fever. 50 percent of patients experience motor deficits.
Reference
Albert, E., & Berbari, F. (2012). Osteomyelitis: Review of Pathophysiology, Diagnostic Modalities, and Therapeutic Options . The Lebanese Medical Journal , 51-60.
