Response to intravenous (IV) antibiotics usually occurs within 48 hours. Lack of improvement after 48 hours indicates that surgical drainage may be necessary or that an unusual pathogen may be present. Surgical drainage is indicated for extensive or severe disease, if the disease is chronic or atypical, the hip joint is involved, or sequestrum or spinal cord compression is present. Antibiotics are administered for a minimum of 4 to 6 weeks. After initial inpatient treatment and adequate clinical response, including decreases in CRP or ESR, transition to home therapy with oral or IV antibiotics may be considered if adherence is ensured.
Complications of acute osteomyelitis are uncommon and usually arise because of inadequate or delayed therapy or concomitant bacteremia. Vascular insufficiency, which affects delivery of antibiotics, and trauma are associated with higher rates of complications.
Hematogenous osteomyelitis has an excellent prognosis if treated promptly and if surgical drainage is performed when appropriate. The poorest outcomes are in neonates and in infants with involvement of the hip or shoulder joints (see Chapter 118). Approximately 2% to 4% of acute infections recur despite adequate therapy, and approximately 25% of these fail to respond to extensive surgical debridement and prolonged antimicrobial therapy, ultimately resulting in bone loss, sinus tract formation, or amputation (although rare). Sequelae related to skeletal growth disturbance are most common with neonatal osteomyelitis.
There are no effective means to prevent hematogenous S. aureus osteomyelitis. Universal immunization of infants with conjugate Haemophilus influenzae type b vaccine has practically eliminated serious bacterial infections from this organism, including bone and joint infections.
Children with puncture wounds to the foot should receive prompt irrigation, cleansing, debridement, removal of any visible foreign body or debris, and tetanus prophylaxis. The value of oral prophylactic antibiotics for preventing osteomyelitis after penetrating injury is uncertain.
Infectious arthritis (suppurative or septic arthritis) is a serious bacterial infection of the joint space resulting from hematogenous dissemination of bacteria. Infectious arthritis less often results from contiguous spread of infection from surrounding soft tissues or direct inoculation into the joint (penetrating trauma). Spread of osteomyelitis into the joint space is more common in children under 18 months of age and occurs via organisms passing through transphyseal vessels to the epiphysis (see Fig. 117-1A). The bacteria causing infectious arthritis are similar to bacteria causing osteomyelitis (Table 118-1). Lyme disease also may cause arthritis (see Chapter 122).
The arthritis of disseminated gonococcal infectionsincludes both reactive and suppurative forms in early and late gonococcal disease, respectively. With untreated genital infection, gonococcemia may occur with fever and a polyarticular, symmetric arthritis and rash, known as the arthritis-dermatitis syndrome. Bacterial cultures of the synovium are sterile at this stage, despite a relatively high prevalence of bacteremia. Monarticular arthritis of large, weight-bearing joints develops
S. aureus Anaerobic bacteria Streptococcus pneumoniae Pseudomonas aeruginosa Group A streptococci Enterobacteriaceae Kingella kingae Haemophilus influenzae type b*
N. gonorrhoeae Mycobacterium tuberculosis *The incidence of invasive infections caused by H. influenzae type b has diminished greatly with universal childhood Hib vaccination.
days to weeks later. Cultures of affected synovial fluid at this stage often yield the pathogen.