Infections After Hip and Knee Replacements

Infections after knee or hip replacement surgery are, thankfully, rare. However, they do occur – according to the American Academy of Orthopaedic Surgeons around one in every 100 people will develop an infection following hip or knee replacement surgery – and you need to be aware of the risks.

They can range from easily treated superficial skin infections to the much more serious, and difficult to treat, deep prosthesis/implant infections.

Infections are a serious complication that can result in the replacement joint having to be removed.

Most infections occur within the first two years of surgery, but they can occur at any time after joint replacement. It is important to know what to do to prevent infection and the signs to look out for which might indicate a problem.

Read on to find out more >

How infections can occur

We all live with bacteria in our skin. Our immune system normally protects us against attack from bacteria. However, with an artificial joint implant, which is not part of our living tissues, our bodies are unable to attack the bacteria that can live on these implants. This can allow the bacteria to multiply and an infection to develop.

If such an infection is not treated it can become systemic, making it very difficult to treat. The person may become acutely unwell and the infected implant may loosen and become painful.

Even cleaning the implant during infection revision surgery may be ineffective in curing this type of infection and ultimately, it may be necessary to remove the infected implant.

Prevention of infections

Before, during and after surgery your medical team will take every precaution to prevent infection. You will normally be given antibiotics in the operating room which will be continued for a short while after surgery. Prosthetic implants are cleaned and packaged to ensure sterility.

The speed of the surgical procedure and the number of people entering and leaving the room during surgery is also believed to influence the risk of infection and an efficient procedure will help to minimise the amount of time that the joint is exposed and so lessen the infection risk.

How can I protect myself?

Before surgery, shower with an antibacterial and antiseptic cleanser but cease using it after surgery. Gargle with an antiseptic mouthwash before teeth brushing and avoid shaving your legs before surgery as this can dramatically reduce your risk of infection.

After a joint replacement, you will need to consider taking antibiotics before any kind of invasive procedure such as dental surgery or colonoscopy as this will help to minimise the risk of bacteria entering the bloodstream and settling on the artificial joint implant.

Bacteria can enter your bloodstream through a wound, or break, in your skin and the risk of infection is particularly high after a tooth extraction or root canal surgery. It is important to have a good preventative dental health regime. If you cut or burn yourself, clean the area with antiseptic and then bandage it. See your doctor if you develop any kind of infection however minor.

Risk factors

Certain health problems and lifestyle factors can also put you at increased risk of infection. These include:

Obesity with a BMI over 50
Diabetes
Smoking
Rheumatoid arthritis
Immune deficiencies such as HIV or lymphomas
Immune suppressive treatments such as chemotherapy or immunosuppressant medication such as oral corticosteroids
Previous joint replacement surgery or joint infection
Frequent urinary tract infections
Peripheral vascular disease
Enlarged prostate that causes urinary problems
Dermatitis or psoriasis

Types of infection

There are two types of infection that can occur after knee replacement or hip replacement surgery.

Superficial infection can occur at the incision site, normally within days or weeks of surgery. You should not ignore such an infection, even if it appears minor, as it can become a more major infection if left untreated.

Deep joint infections are more serious. They occur when the implant itself becomes infected and can develop weeks, months or even years after surgery.

You may need to undergo several surgical procedures to treat the problem and may, ultimately, have to have the implant removed.

Possible signs of an infection

Among the signs that might indicate you have an infection are:

Feeling generally unwell
High temperature of 38 degrees or above
Feverishness, shivering and chills
Unpleasant smelling discharge from the surgical site
Pain in the joint even when resting
Increased redness, swelling, heat or pain in and around the joint

It is essential to seek urgent medical attention if you suspect you may have an infection.

Diagnosis

Your doctor will examine your joint and will likely further investigate the problem with the use of blood tests, CT or MRI scan or an X-ray to diagnose the infection or may draw fluid from around the infected joint and send it to the lab for testing.

Treatment of infections

Superficial infections can normally be treated with antibiotics, either swallowed or administered intravenously. If you develop a deep infection within weeks of surgery you may be offered a procedure called debridement which involves removing infected tissue and cleaning out the implant. You will need to have intravenous antibiotics for six weeks after the procedure.

If you develop a deep infection over a longer period of time, the course of treatment normally entails:

removing the implant
cleaning the infected area and inserting a bone cement spacer block that has been treated with antibiotics into the area to kill the bacteria. You will also be given intravenous antibiotics and will need to use crutches while the spacer block is in place
When the infection has been cleared plans will be made for Revision joint replacement surgery to insert a new implant.

In safe hands with Mr Carrothers

Mr Andrew Carrothers is a specialist orthopaedic consultant with extensive experience in hip and knee replacements, as well as pelvis, foot and ankle surgery.

As a patient of Carrothers Orthopaedics the maximum care is taken to prevent infections following surgery and your comfort and aftercare is of the highest importance to us.