Joint Replacement Infection
No surgical procedure is without risks, however. A small percentage of patients undergoing total joint replacement (roughly about 1 in 100) may develop an infection after the operation.
Joint replacement infections may occur in the wound or deep around the artificial implants. An infection may develop during your hospital stay or after you go home. Joint replacement infections can even occur years after your surgery.
Any infection in your body can spread to your joint replacement.
Infections are caused by bacteria. Although bacteria are abundant in our gastrointestinal tract and on our skin, they are usually kept in check by our immune system. For example, if bacteria make it into our bloodstream, our immune system rapidly responds and kills the invading bacteria.
Despite antibiotics and preventive treatments, patients with infected joint replacements often require surgery to cure the infection.
Cause
A total joint may become infected during the time of surgery or anywhere from weeks to years after the surgery.
The most common ways bacteria enter the body include:
• Through breaks or cuts in the skin
• During major dental procedures (such as a tooth extraction or root canal)
• Through wounds from other surgical procedures
Some people are at a higher risk for developing infections after a joint replacement procedure. Factors that increase the risk for infection include:
• Immune deficiencies (such as HIV or lymphoma)
• Diabetes mellitus
• Peripheral vascular disease (poor circulation to the hands and feet)
• Immunosuppressive treatments (such as chemotherapy or corticosteroids)
• Obesity
Diagnosis
Signs and symptoms of an infected joint replacement include:
• Increased pain or stiffness in a previously well-functioning joint
• Swelling
• Warmth and redness around the wound
• Wound drainage
• Fevers, chills and night sweats
• Fatigue
When total joint infection is suspected, early diagnosis and proper treatment increase the chances that the implants can be retained. Your doctor will discuss your medical history and conduct a detailed physical examination.
X-rays and bone scans can help your surgeon determine whether there is an infection in the implants. Specific blood tests can help identify an infection.
Treatment
Nonsurgical Treatment
In some cases, just the skin and soft tissues around the joint are infected, and the infection has not spread deep into the artificial joint itself. This is called a “superficial infection.” If the infection is caught early, the surgeon may prescribe intravenous (applied directly in your viewns) or oral antibiotics.
This treatment has a good success rate for early superficial infections.
Surgical Treatment
Infections that go beyond the superficial tissues and gain deep access to the artificial joint almost always require surgical treatment.
Debridement. Some infections can be cured with a surgical washout of the joint. After the procedure, intravenous (IV) antibiotics will be prescribed for approximately six weeks.
Staged surgery. In general, the longer the infection has been present, the harder it is to cure without removing the implant.
Late infections (those that occur months to years after the joint replacement surgery) and those infections that have been present for longer periods of time almost always require a staged surgery.
The first stage of this treatment includes:
• Removal of the implant
• Washout of the joint and soft tissues
• Placement of an antibiotic spacer
• Intravenous (IV) antibiotics
An antibiotic spacer is a device placed into the joint to maintain normal joint space and alignment. It also provides patient comfort and mobility while the infection is being treated.
Spacers are made with bone cement that is loaded with antibiotics. The antibiotics flow into the joint and surrounding tissues and, over time, help to eliminate the infection.
Second stage surgery will involve removal of the spacer and application of another artificial implant.
Single-stage surgery. In this procedure, the implants are removed, the joint is washed out (debrided), and new implants are placed all in one stage. Single-stage surgery is not as popular as two-stage surgery but is gaining wider acceptance as a method for treating total infected joints. Doctors continue to study the outcomes of single-stage surgery.
Prevention
At the time of original joint replacement surgery, there are several measures taken to minimize the risk of infection. Some of the steps have been proven to lower the risk of infection, and some are thought to help but have not been scientifically proven. The most important known measures to lower the risk of infection after total joint replacement include:
• Antibiotics before and after surgery. Antibiotics are given within one hour of the start of surgery (usually once in the operating room) and continued at intervals for 24 hours following the procedure.
• Short operating time and minimal operating room traffic. Efficiency in the operation by your surgeon helps to lower the risk of infection by limiting the time the joint is exposed. Limiting the number of operating room personnel entering and leaving the room is thought to the decreased risk of infection.
• Use of strict sterile techniques and sterilization instruments. Care is taken to ensure the operating site is sterile, the instruments have been autoclaved (sterilized) and not exposed to any contamination, and the implants are packaged to ensure their sterility.
• Preoperative nasal screening for bacterial colonization. There is some evidence that testing for the presence of bacteria (particularly the Staphylococcus species) in the nasal passages several weeks prior to surgery may help prevent joint infection. In institutions where this is performed, those patients that are found to have Staphylococcus in their nasal passages are given an intranasal antibacterial ointment prior to surgery. The type of bacteria that is found in the nasal passages may help your doctors determine which antibiotic you are given at the time of your surgery.
• Preoperative chlorhexidine wash. There is also evidence that home washing with a chlorhexidine solution (often in the form of soaked cloths) in the days leading up to surgery may help prevent infection. This may be particularly important if patients are known to have certain types of antibiotic-resistant bacteria on their skin or in their nasal passages (see above). Your surgeon will talk with you about this option.
• Long-term prophylaxis. Surgeons sometimes prescribe antibiotics for patients who have had joint replacements before they undergo dental work. This is done to protect the implants from bacteria that might enter the bloodstream during the dental procedure and cause infection. The American Academy of Orthopaedic Surgeons has developed recommendations for when antibiotics should be given before dental work and for which patients would benefit. In general, most people do not require antibiotics before dental procedures. There is little evidence that taking antibiotics before dental procedures is effective at preventing infection.