Orthopedic infections are common entities. Orthopedic infections can arise de novo, even in healthy hosts. Orthopedic infections are unfortunately a common surgical complication as well. Like all surgical complications, the only way to avoid encountering infection is to either ignore the problem or not to perform surgery in the first place. Otherwise, infections can and will occur. Infections, especially iatrogenic and nosocomial infections, are receiving increasing attention and visibility in the lay press. There is no shortage of popular media describing individual or institutional infectious complications and a rapidly evolving movement by the Centers for Medicare and Medicaid Services (CMS) to not reimburse institutions for the treatment of nosocomial infection. For this reason, infection prevention, recognition, and prompt attention are of paramount importance.
The most essential element of diagnosis is an appropriate index of suspicion. Orthopedic infections are frequently subtle, and without a high level of suspicion, treatment will be delayed. Diagnosis is especially difficult for postoperative wounds for a variety of reasons. The first and most important reason for this difficulty is denial: the quality of our work becomes questioned, and the path of least resistance is to deny that a problem exists. This is especially dangerous in the postoperative situation and in compromised hosts. Prompt treatment may salvage the index procedure, and patients with decreased physiologic reserve may possess the reserve to overcome a developing infection but not an established one. A second difficulty with postoperative wounds is the overlapping qualities of subcutaneous hematomas, delayed wound healing, and frank infection. Many postoperative wounds can be slow to heal without being infected. Likewise, different individuals will demonstrate differing levels of swelling, erythema, and tissue warmth in an uncomplicated postoperative course based simply on body habitus, coagulation status, or skin complexion. Our mandate to “do no harm” becomes most difficult in the complex patient who is most threatened, as unnecessary returns to the operating room for unsubstantiated infectious concerns may subject the patient to further risk. Accurate diagnosis remains difficult, as most signs of infection are subjective.
In the first century ad, Celsus described the quartet of calor (warmth), dolor (pain), rubor (redness), and tumor (swelling) as the essential quartet of infection. Two millennia later, these clinical clues are still the “vital signs” of infection. Beyond this, infection should be suspected in patients who are “going the wrong direction” after treatment. More intensive investigations, as detailed later by general category, are warranted in these individuals.
Any discussion of orthopedic infections varies tremendously based on etiology, because, for example, pediatric osteomyelitis is a very different entity than periprosthetic knee infections. Detailed discussions of specific infections are given in topical areas within this book. For the purposes of this chapter, different types of orthopedic infections will be discussed in general categories.
As alluded to earlier, orthopedic infections can be broadly divided into two categories. The first is spontaneous infection, where no orthopedic surgical intervention has occurred, ...