I went to the doctor for a problem with my wrist but they couldn't find anything wrong. Six weeks later, the thing blows up and I find out it was a staph infection of all things. Now I have to have surgery -- how could they have missed something so simple?
Recognizing and diagnosing joint infections referred to as septic arthritis isn't always easy. The patient may not have a known history, trauma, or other event they can link with the new symptoms of joint pain, redness, and swelling.
Many surgeons rely on their own clinical expertise for this one. Lab tests (blood work, joint fluid analysis) give some idea of what's going on but are not accurate enough to be used as the only means of diagnosis. For example, some bacteria don't show up in the joint fluid culture at all.
In fact, in the case of gonococcal bacteria, the culture is negative 50 per cent of the time when the patient really does have an infectious process going on. Elevated white blood cells and sed rate (erythrocyte sedimentation rate) suggest an inflammatory response but aren't specific enough to say what for sure.
With aspiration (removal) of joint fluid, lab analysis will eventually be positive -- but sometimes, not until significant damage has been done to the joint. The bacteria can spread beyond the joint and cause further systemic problems. It's far better to find out quickly that there is a bacterial infection and nip it in the bud, so-to-speak.
But no one test is "definitive" -- capable of diagnosing the problem accurately or immediately. The synovial fluid aspiration and analysis is really the best we have available right now. But this test misses almost as many cases of infection as it catches.
What physicians really need is an evidence-based Clinical Practice Guideline. Such a document would offer guidelines for evaluating, diagnosing, and treating a septic wrist joint. But much more research is going to have to be done before such a set of clinical guidelines can be written.