Joint Replacement Infection

Joint replacement infections are a very dangerous surgical complications after knee and hip replacement. In these cases, bacteria can adhere to the implant itself, which makes the infection difficult to treat. Even if caught early, joint replacement infections sometimes require the implant to be removed or replaced—a serious and complex surgery that can take months to recover from.

These infections are rare, occurring in 1% to 2% of patients. But given that joint replacement surgery has become one of the world's most common elective procedures, this means that thousands of people are affected each year.

Joint replacement infection symptoms don't differ much from traditional infection symptoms, so patients should be vigilant for the following:

• Increased pain and stiffness in the joint
• Redness, warmth, and/or swelling around the incision
• Wound drainage
• Fever

Most patients have no identifiable cause for developing an infection. It can happen during the procedure or virtually anytime thereafter, even years later. Possible causes can be bacteria entering the body through a cut or even another surgical procedure later on.

Some known factors raise your risk:

• Diabetes
• Obesity
• Smoking

If you suspect an infection, see a doctor immediately. Most diagnoses include a physical exam, X-rays and/or bone scans, and blood tests to look for an immune response (white blood cells) as well as inflammation.

Your doctor may also use a needle to draw fluid from the (potentially) infected joint and test for bacteria.

These infections are difficult to treat because the bacteria strike the prosthetic itself, which is typically made from metal and plastic.

Since fighting infections depends on blood flow (which artificial implants obviously don't have) both for an effective immune system response and to deliver antibiotics to the area, joint replacements can become safe havens for bacteria.

Treatment includes the following:

Some infections may be cleaned surgically with the surgeon manually cleansing (debriding) the implant and removing infected tissue (debriding).

However, even with aggressive antibiotic treatment and surgical cleansing, the infection may persist.

Many times the only way to cure an infection is to remove the entire implant and redo the joint replacement; this procedure is also called revision.

This is a long, multi-stage process that takes place over months, with the surgeon removing the infected implant, cleansing the joint cavity, and implanting a temporary joint spacer to keep bones aligned. The patient then undergoes at least six weeks of IV antibiotic treatment, plus whatever recovery time is required.

The second stage of the surgery includes removing the joint spacer, once again cleansing the cavity, and installing a new implant.

This outcome is why joint replacement infections are so serious.

While joints can often become infected after surgery, surgical staff have routine procedures in place to prevent infections after joint replacement surgery.

The most common measures taken to prevent joint replacement infections are:

• Antibiotics before and after surgery: Antibiotics are given within one hour of the start of surgery and continued for a short period following the procedure. Different antibiotics may be used depending on the patient's individual history of infection, allergies to specific medications, and other concerns.
• Short operating time and minimal operating room traffic: Surgical efficiency can help lower infection risk by limiting the time the joint is exposed. Limiting the number of operating room personnel entering and leaving the room is also thought to decrease risk.
• Use of strict sterilization techniques: Care is taken to ensure the operating site is sterile. Reusable instruments are sterilized in an autoclave and not exposed to any contamination. The implants are packaged to ensure their sterility. Disposable items are sterile and discarded after use.

Infection after joint replacement surgery is among the most feared complications of this surgical procedure. If you experience any symptoms, contact your doctor immediately.