Bear's implant infection

Any of you who have had major surgery for some injury that involved having metal implants placed in your body will have heard about the risk of infection.

Every time you open a body surgically, there is an infection risk. There are bacteria in the air that start landing on the tissue as soon as it is open, so the longer the procedure, the higher the risk. If there is damage to the surrounding tissues, especially to the blood supply, the risk skyrockets. Ill health such as diabetes, self-trauma such as licking at the surgical wound (no, this isn’t a good thing as many seem to think), poor nutrition, and getting cold during surgery, these factors all contribute to the risk of infection developing.

Using antibiotics around surgery time in some instances can help reduce that risk, but not always, and not completely. There are even studies that have shown that not only do antibiotics not prevent infection in some procedures, but they can result in a higher rate due to the development of drug-resistant bacteria.

As always in medicine, it’s not simple.

Metal implants are a particular problem, as the body produces a coating on the steel called a glycocalyx, which protects the bacteria from the body’s defense mechanisms. The bacteria can sit there for months or even years, then start multiplying and produce an infection. Infection associated with metal implants normally means the implants have to be removed as well.

Bear is a young Blue Heeler who got hit by a car late last year, resulting in multiple skin wounds and a particularly nasty front leg fracture.

The skin overlying this fracture was badly damaged, which made the infection risk very high for surgery. Bear had the fracture stabilised using a two-plate technique, combined with a bone graft taken from his shoulder.

As feared, the skin over the lower end of the leg had lost its blood supply and died off over the next few days, resulting in a relatively large open wound close to the implants. This was managed as an open wound with dressings and antibiotics until the fractures had healed.

There was a frequently discharging hole in the skin (which had regrown over the open wound) for the next several months, which would respond to antibiotics but then start discharging again. About six months after surgery, once we were satisfied the fractures were healed and that the infection was not going to resolve while the implants were still there, we went back into the leg and removed them all, taking swabs of the site for culture. Bear had six weeks of antibiotics after the implants were removed, to make sure the infection was removed.

This is a good example of how complications can, and do, occur, despite the best efforts to prevent them. Infection is not prevented by using antibiotics, though in some cases it might reduce the risk. There are many other factors involved, and some of these are completely outside of our control. You see many examples in the media of patients blaming someone for a mistake when infections occur in themselves, but unfortunately in the vast majority of cases, it is simply statistics: a certain number of patients having a procedure will get infected, whatever you do to try and prevent it.

The goal is to do what you can to minimise the risk and have a Plan B available in case one of those risks actually happens. We now give Risk and Complications documents to everyone whose pet is undergoing surgery and encourage all owners to ask questions about what surgery is planned, what could happen, and what the plan would be should it happen.

The good news in this case is Bear has now recovered from a pretty horrible set of injuries and can go back to being a dog again. Just keep off the road please Bear.

Paul Eason BVM&S MANZCVS (Surgery; Emergency and Critical Care Medicine)