The distribution of osteomyelitis is influenced dramatically by the age of the patient, the specific causative organism, and the presence or absence of any underlying disorder or situation. in infants and children, acute osteomyelitis most commonly is caused by hematogenous spread. Staphylococcus aureus is the most common causative agent, followed by b-hemolytic streptococcus, Streptococcus pneumoniae, Escherichia coli, and Pseudomonas aeruginosa [7,8]. The incidence of infection by Haemophilus influenzae has declined dramatically because of widespread HIB vaccination [8-10]. Although any bone can be affected, the most commonly involved are the metaphyses of long bones, especially the distal femur and proximal tibia, followed by the distal humerus, distal radius, proximal femur, and proximal humerus . S aureus is also the most prevalent infecting organism later in life in osteomyelitis of the mature skeleton, and Gram-negative rods are found in the elderly. Fungal osteomyelitis is a complication of catheter-related fungemia, the use of illicit drugs contaminated by Candida sp, and prolonged neutropenia. P aeruginosa can be isolated from injectable drug users and from patients who have urinary catheters in place for long periods of time.
The most common form of musculoskeletal tuberculosis is tuberculous spondylitis. isolated extraspinal bone infection by Mycobacterium tuberculosis is less common. The most frequent form of musculoskeletal involvement, excluding the spine, is within muscles and soft tissues .
Osteomyelitis is a relatively uncommon complication of HIV-positive patients. Hematogenous dissemination of S aureus, however, is the most common source of infection in these individuals, especially in intravenous drug abusers, but Salmonella in these patients also has been reported. In a series of 560 HIV-positive patients, 12 cases of osteomyelitis were caused by either S aureus or Salmonella infection . Other bacteria, such as Neisseria gonorrhoeae , Cryptococcus neoformans, and Nocardia asteroids  also have been reported. All bones can be affected, in addition to the spine and vertebral bodies [15-17]. In these patients, some uncommon forms of bone infections, such as bacillary angiomatosis from an unusual bacillus (Bartonella henselae)  and M tuberculosis have been documented [19-21].
Was this article helpful?