Surgeons do everything they can to prevent and avoid infections of any kind after surgery. With joint replacement, there can be skin, wound (or other soft tissue), bone, and periprosthetic (around the implant) infections.
How does a patient know if his or her knee (joint) implant is infected? The first symptoms are constant knee pain, stiffness, and loss of knee motion. The presence of any risk factors raises the suspicion of infection. Risk factors include smoking, alcohol abuse, and obesity> A history of diabetes, cancer, chemotherapy, rheumatoid arthritis, or blood clotting disorders add to the risk.
Blood tests help confirm the diagnosis. The authors provide a detailed discussion of lab values used to assess patients for infection. Using inflammatory markers in the blood isn’t a cut and dried process. Early on after surgery, there are always increased levels of inflammatory cells as the body works to heal the surgical area. There’s a fine line between normal and abnormal elevation of blood markers.
Once it looks like an infection might be present, the surgeon removes a bit of fluid from the joint and has that analyzed. The results of the fluid culture may support a diagnosis of infection. But the surgeon knows that there can be false-negatives (i.e., test comes back negative when there really is an infection).
Antibiotic treatment is the first-line approach to management of periprosthetic infections following total knee replacement. Surgery is often a part of the plan of care as well. The surgeon cleans the joint out of any infection (a procedure referred to as debridement.
If you think something unusual is going on, it’s best to get in to see your surgeon right away. Early diagnosis and treatment can help reduce the severity of problems and restore the natural healing process. If nothing else, at least call your surgeon’s office and let the staff know of your concerns and suspicions. They will direct you from there!