Acute bone and joint infections are likely to require prompt treatment. The initial antibiotic is instituted empirically after taking a sufficiently representative sample from the affected bone or joint percutaneously or via a small cut. Attention should be paid to full identification of the etiology, as the treatment is straightforward if the causative organisms sensitivity to antibiotics is identified. This takes time and may not be possible in 30–70% of the cases.[11,15] Thus antibiotic is instituted empirically by taking into account the local setting and resistance pattern. In culture-negative OM or SA the course is completed with the empiric antibiotic if clinical recovery is observed.
Staphylococcus aureus, usually β-lactamase sensitive, is the overwhelmingly most common organism in all acute osteoarticular infections.[1,2] Therefore, 'staphylococcal penicillins' (cloxacillin and so on), first-generation cephalosporins and clindamycin are likely the most commonly used primary antibiotics, at least in a Western setting.[4,9–11] Methicillin-resistant S. aureus (MRSA) has no doubt become a problem in many parts of the world, but luckily, most strains have remained susceptible to clindamycin.[16,17] If this is not the case, vancomycin may be chosen.[2,18] Some newer antibiotics, such as linezolid, are useful but very costly and unfortunately are associated with some safety problems.
We usually start treatment with clindamycin or a first-generation cephalosporin, because MRSA remains rare and Kingella kingae is almost nonexistent in Scandinavia (and elsewhere in the Western world). However, the role of K. kingae might be rising.[21,22] Notably, K. kingae is invariably resistant to clindamycin, but sensitive to β-lactams (such as penicillin and cephalosporins).[22–24]K. kingae seems to especially affect children at age 4 years or less.
In terms of the first-line antibiotic, Streptococcus pyogenes and Streptococcus pneumoniae pose few problems,[9–11] because they too are sensitive to β-lactams.[26,27]Haemophilus influenzae type b (Hib) used to be a problem in SA among small children, but has now almost disappeared from countries with large-scale vaccination programs. If Hib is still present, ampi- or amoxicillin, or a second-generation cephalosporin (cefuroxime) are good choices to be used concomitantly with the other initial antibiotic until the agent is identified. In developing countries Salmonella spp. are common in osteoarticular infections; otherwise, it is very rare except in immunodeficient patients. In these circumstances one may also encounter other agents, such as Chlamydia, Mycobacterium tuberculosis and Pseudomonas spp. These infections warrant an approach different from the common cases of OM, SA and OM+SA.
Expert Rev Anti Infect Ther. 2011;9(12):1125-1131. © 2011 Expert Reviews Ltd.