Hip Implant Surgery Infections
How and Why Do Hip Implant Infections Happen?
Infection is a possible negative side-effect of getting a hip implant. Unfortunately, about 1/100 hip-implant patients experience a hip infection after their implant surgery. So it is important for hip implant patients to understand infections. But infections are complex. There are a variety of different ways a hip can get infected, and there are many different types of infection. There are at least two devices that aren’t hip implants themselves, but which greatly increase the chances of infection following a hip implant. This article explains all you need to know about infection following hip-implant surgery, so you can recognize how serious it can be, whether or not you have one, and what your next steps should be.
Causes of Hip Implant Infections
An infection is caused when bacteria enters a patient’s body, and the patient’s immune system can’t fight it off. Generally, if bacteria enters the body, a patient’s immune system will fight it off. But the immune system travels through blood. Because a hip implant is made of metal or plastic, it is hard for blood to travel around it. This makes it hard for the immune system to kill an infection near the implant. This means that if a patient develops an infection at the hip implant, their body probably won’t fight it off on its own, so they’ll need medical treatment. Some people are more susceptible to infection. These more susceptible people are those who have conditions like:
- Cut in the skin, or recently removed tooth;
- Immune deficiency (like HIV);
- Diabetes mellitus;
- Peripheral vascular disease (bad circulation to hands and feet);
- Immunosuppressive treatments (like chemotherapy or corticosteroids); and
How Does Hip Infection Happen?
- Intraoperative contamination;
- Delayed contamination;
- Contamination by direct spread; and
- Reactivation of an indolent infection.
Intraoperative ContaminationThis infection occurs during implant surgery. Its caused by an infected implant being put into the patient, an infected tool being used, or infected air going over the patient. Its main symptom—fever—typically starts immediately after the operation.
Delayed ContaminationThis infection occurs after surgery. Its symptoms usually start a few years after the operation. It’s caused when bacteria from somewhere else in the body (usually a skin, tooth, lung, or urinary tract infection) spreads to the hip implant, and infects it. The main symptoms of this type of infection are fever and hip pain.
Contamination by Direct SpreadThis infection occurs after surgery. It is caused when the scar from the incision (cut) where the implant was inserted doesn’t heal fast enough. The incision is like a door for bacteria in the outside world; they use it to invade the body. The longer it takes the incision to heal, the longer the door is open, and the greater the chance some bacteria will come in.
Reactivation of Indolent InfectionThis infection occurs after surgery. Even when a patient’s body defeats an infection, a tiny amount of bacteria can remain. Getting a hip implant lowers the patient’s immune system. So if the patient already has bacteria living near the implant, the lowered immune system gives that resident bacteria a chance to strike while the body is weak. This type of infection usually occurs in people who’ve already had a hip surgery of some kind—for example, because of dislocation or fracture.
What Types of Hip Infections Are There?
There are two types of hip infection, classified based on what type of tissue they affect:
- Acute infection; and
- Chronic infection.
This is infection of the soft tissue—muscles and tendons. It’s less serious than chronic infection because it requires less painful treatment. Acute infection can eventually lead to chronic infection. So it’s essential that this type of infection be discovered and treated as soon as possible. Treatment for this type of infection requires reopening the incision, cutting away all of the infected tissue (“debridement”), and cleaning the area around the implant with antibacterial soap. This treatment doesn’t require the removal of any bone. It also doesn’t require the removal of the original implant. However, it sometimes requires that the original implant be dislocated so that the antibacterial soap can be used to clean out the hip socket. Debridement and cleaning with antibacterial soap is very effective within three weeks of the original implant surgery. Conversely, it’s rarely effective more than 6 weeks after the original implant surgery. If debridement and cleaning doesn’t get rid of the acute infection, then it may need to be fought with the same treatment used against chronic infection. Contamination by direct spread usually causes this type of infection.
This is infection of the soft tissue plus infection bone. It’s very serious because it always requires painful surgery to treat. Treatment for this type of infection requires all of the following steps:
- Reopening the incision;
- Removing the infected soft tissue (“debridement”);
- Removing the infected bone;
- Removing the original implant;
- Cleaning the area around the implant with antibacterial soap; and
- Inserting a new hip implant.
Reactivation of indolent infection usually causes this type of infection.
Bair Hugger Infections
The Bair Hugger is a device that blows hot air over a patient during surgery to keep the patient warm. This process is called “forced air warming” (“FAW”). One study found a significant increase in deep joint infections when FAW is used during surgery. This increased risk of infection happens for two reasons.
- Disruption of clean airflow; and
- Direct Contamination.
Disruption of Clean Airflow
FAW can indirectly infect the air that flows over patients. In surgery, everything that will touch the patient is sterilized (the “surgical field”). Even the airflow in the room where surgery takes place is carefully planned out. The room is designed so that air which will blow over the patient only blows over sterile things first. But the Bair Hugger can mess with the surgical field. When the Bair Huger blows hot air over a patient, it disrupts the planned airflow of the room. This disrupted airflow causes other air in the room to move around in unintended ways. This other air is unclean—it has blown over things with bacteria in it, so it has bacteria in it. Sometimes the unclean air blows over the patient. And because the unclean air has bacteria in it, bacteria can enter the incision, and cause an infection.
The FAW can also directly contaminate the air that flows over patients. Since FAWs blow hot air directly over patients, they have special filters to clean the air they intake. But no machine is perfect. Sometimes these filters fail to block all of the bacteria in the incoming air, and bacteria can grow in the device. If bacteria grows in the FAW, it can then be blown out over the patient, and into the incision.
Hip Infections and Heater-Cooler Devices
A heater-cooler device is a closed system with a tank of water and some tubes. It heats or cools water to the desired temperature. Then it circulates the water over an external device to make the external device the same temperature as the water. The heater-cooler keeps itself from overheating by blowing air out of an exhaust fan. That’s where things get problematic. Bacteria grows inside the water tank, and then gets blown out through the exhaust fan into the air (“aerosolized”). From here, the heater-cooler device harms people in the same way as the Bair Hugger and other FAWs. Again, everything in the room where surgery occurs is meticulously planned out to keep unclean things from touching the patient. Even the airflow is planned so that air which flows over the patient only touches clean things first. And any air which flows over unclean things isn’t supposed to flow over the patient. The heater-cooler is not supposed to have any bacteria in it. So the setup of the room allows air from the heater-cooler to blow over the patient. The result is unclean air from the heater-cooler blowing out over the patient, and into the incision.
As you can see, getting a hip implant can cause a patient to get a hip infection. And infections are complex. They come in many shapes and sizes, each requiring treatment in its own way. If have symptoms of infection (fever or hip pain), contact your doctor right away, because the window to get the least painful treatment for that infection closes after 6 weeks. Once you’ve contacted your doctor, contact the attorneys at GoldenbergLaw.