Superficial infections are normally dealt with by antibiotics and are not discussed further here.
A deep infection is a serious complication and often results in the need for further surgery.
Two types of deep infection are recognised: -
Bacteria can reach the surgical site: - staphylococcus
The people most at risk of are those who: -
There is an estimated 0.5% to 1% risk of an infection following a hip replacement.
Symptoms may include a fever and pus or clear liquid oozing from the wound. There should be no clear discharge from the wound after 10 days and if there is you must inform your doctor.
Pain is another symptom, and in some cases the only symptom you will experience. However hip pain can come from a number of different conditions and is quite common up to three months post surgery. It is not necessarily indicative of an infection.
There is no single test to tell if you have an infection. You will certainly be sent for blood tests and possibly an aspiration. During an aspiration fluid is taken from the joint to determine if bacteria are present and what sort they are.
In order to identify bacteria they must be grown in the lab and this will take time.
With chronic infections there will be some destruction of the bone. This will show up on X-rays.
A final possibility is a nuclear scan where radioactive substance is injected into your arm and tracked. The efficacy of this technique is disputed.
It would seem that the easiest treatment would be to prescribe antibiotics but this is not the case. Following surgery scar tissue will form and scar tissue has fewer blood vessels. As antibiotics can only reach the site of the infection via blood vessels they have less opportunity of reaching the crucial place.
Furthermore the bacteria form a sticky coating which antibiotics are unable to penetrate.
There is also a question of which antibiotics to prescribe. Different bacteria demand different antibiotics and the best mix can only be determined once the bacteria have been identified.
Surgical treatment for deep infections is likely.
With an acute infection the bacteria won't have had time to do much damage to the surrounding bone and the site can be re-opened and cleaned out with a saline solution. In some cases the surgeon may replace some parts of the implant. A course of antibiotics will be prescribed lasting for anything up to three months.
With a chronic infection the situation is more serious and it is likely that the new hip will have to be removed. This is a more difficult procedure and the surgeon may try to avoid this by trying to clean out the infection first. In some cases, especially where the risk of further surgery is great, the surgeon may opt for long-term, even life-long antibiotics. These will not kill the bacteria, merely surpress it.
If the implant is removed the surgeon will either wash out the site and put in a new implant (referred to as a primary exchange) or take out the old implant, clean out the site, prescribe antibiotics for a few weeks and, only after that, put in the new joint. This is the more effective method.
Prophylactic (preventative) antibiotics given before surgery have lowered the rate of infection.
If bone cement is used this may contain prophylactic antibiotics.
A healthy, well-balanced diet will help your body deal with infections
Importantly but often overlooked is where you are treated. Choosing the right hospital is so important. Make sure you ask about post-op infection rates before agreeing to the procedure. Even if you want the operation to be carried out by a particular surgeon check which hospitals he works in as the infection rates may be very different. Infection control is only under the surgeons control whilst you are in theatre - after that it is the responsiblity of the nursing team and hospital management.
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