Dr. Harwin and his staff take every possible precaution to help prevent infections in patients after hip and knee replacements. Dr. Harwin’s adult reconstruction service at Mount Sinai Beth Israel had one of the lowest infection rates in the country, and was consistently 40 to 90% lower than the New York state and national averages for total hip and total knee replacements.
Hip and knee replacements are very common, and rarely result in serious complications. However, there are still risks associated with hip and knee replacements, as there are with any surgical procedure. A small percentage of patients can develop an infection after a hip or knee replacement, either during the hospital stay, after going home, or even years after the procedure.
Knowing how infections happen, how to prevent infections, and how to spot early signs of an infection can help to reduce your risks.
How Infections Happen
Infection can occur when bacteria enters the body, whether through a cut or break in the skin, a major dental procedure (including extractions and root canals), or wounds from other surgical procedures. While there is bacteria present in our gastrointestinal tract and our skin, our immune system can typically take care of it. If any bacteria enters the bloodstream, your immune system can usually attack and kill it.
However, if bacteria reaches joint replacement implants, which are made of plastic and metal, our immune system may be unable to attack and kill the bacteria. Bacteria may then multiply, causing an infection.
Certain factors make you more susceptible to infection after a joint replacement procedure. Patients with diabetes mellitus, poor circulation in the hands or feet, or immune deficiencies like HIV or lymphoma have a higher risk of developing an infection. Obesity and immunosuppressive treatments like chemotherapy or corticosteroids can also increase the risk of an infection.
Signs and Symptoms of an Infection
If an infection is caught early on, your doctor may be able to treat it before it spreads deep into the joint replacement implants. Regularly check your surgical incision. Some redness or swelling is normal at the incision site, but if there is a sudden flare-up of redness and/or swelling, or it does not improve over time, you should tell your doctor. An increase in pain at the incision site, or any pus, drainage, or burning sensations at the incision site often indicate an infection.
If an infection is present, the area surrounding the wound may become warm to the touch, and you may develop a fever. It is normal to have less energy even several weeks after surgery, but you should gradually see some improvement in your energy levels as you heal. However, if you are constantly fatigued and see no improvement or a worsening in fatigue, this may be a sign that you have an infection. If the artificial joint previously functioned well and you experience an increase in pain or stiffness, this is also something you should tell your doctor.
Treatment for an infection will depend on how much the infection has spread. If the infection is superficial at the incision line, nonsurgical local treatment, along with antibiotics, may be effective in eliminating the infection. However, if the infection is deeper in the layers beneath the skin or around the implant, then surgery is necessary.
Nonsurgical Treatment for Infections
If an infection is superficial, it only affects the skin and soft tissues above the joint, but has not spread deep into the implants. In this case, the infection may still be in the early stages. Local wound care, along with antibiotics may be effective in treating the early stages of a superficial infection. If the infection involves a larger or deeper area, however, surgery may be needed to eliminate the infection.
If a deep infection is detected within several days of onset, your surgeon may be able to clear the infection with a débridement. During a débridement, the surgeon removes the infected soft tissues and thoroughly cleans the implant, replacing any plastic liners or spacers during the process. Following the procedure, patients receive IV antibiotics for about 6 weeks.
If the artificial joint becomes infected months or years after joint replacement surgery, or the infection has been present for longer than several days, the implant often needs to be removed and replaced. The procedure is usually done in stages.
During the first stage, the infected implant is removed and the joint and soft tissues are washed out. An antibiotic spacer is inserted into the joint to maintain normal joint alignment and allow for comfort and mobility until a new implant can be put in place. Spacers are comprised of bone cement mixed with antibiotics, which will flow into the joint and surrounding tissues over time, helping to heal the infection.
After the first stage of surgery is complete, the patient receives antibiotics for at least 6 weeks. Surgeons work with infectious disease specialists to treat the infection and determine when it has been cleared. Once the infection is cured, your surgeon can move on to the second phase: joint revision surgery. During this procedure, the surgeon removes the antibiotic spacer, washes out the joint once more, and places new implant components.
Your surgeon may take several steps to reduce the likelihood of an infection after joint replacement surgery. This includes:
- Antibiotics administered within an hour of the start of surgery and in continued intervals for 24 hours after surgery.
- Efficiency in the operating room to limit the time the joint is exposed.
- Limiting personnel coming in and out of the room during the procedure.
- Use of sterilized operating instruments and surgical implants.
- Preventative antibiotic use for patients with artificial joints. Antibiotics are recommended 1 hour prior to any invasive procedure to prevent bacteria from entering the bloodstream and infecting the artificial joint.
- In some cases, nasal screening before surgery is carried out to detect presence of bacteria. This can help your doctor determine which type of antibiotic you may need prior to surgery.
- Washing at home with a chlorhexidine solution in the days prior to surgery. This is recommended for all patients undergoing hip and knee replacements.
Although the risk for infection is generally low, it is important to understand the possibilities so that you can spot an infection early on and take necessary steps to protect yourself.