Take intraoperative steps to reduce joint infection risk

OR practices, antibiotics form a first line of defense against PJI.

With an increasing number of total knee arthroplasty and total hip arthroplasty procedures being performed in the United States, the rate of failure has also increased. In its annual report, the American Joint Replacement Registry listed infection as a leading cause of TKA and THA revisions from 2012 to 2016. Research has also shown failures due to periprosthetic joint infection are expected to increase at an annual rate of between 38,000 cases and 270,000 cases by the year 2030.

“The true number [of periprosthetic joint infections] is not known because most of our information depends on registry data and institutional data, etc., but if I were to quote what is out in the literature, after primary, [periprosthetic joint infection] can be 1% to 2%,” Javad Parvizi, MD, FRCS, James Edwards professor of orthopedic surgery at Sidney Kimmel Medical College and Rothman Institute at Thomas Jefferson University Hospital, told Orthopedics Today. “The incidence is higher after revision. It can be all the way up to 15% to 20% after revision arthroplasty.”

Jeremy M. Gililland, MD, said periprosthetic joint infection (PJI) rates of 1% to 2% may not seem high, but the impact of PJI on a patient can be profound and may be associated with increased mortality and costs.

“There have been some papers that suggest having a periprosthetic joint infection can be as medically challenging to the patient as having cancer, and so it is not something we should take lightly,” Gililland, assistant professor of orthopedic surgery at University of Utah, told Orthopedics Today. “Obviously, we can successfully get a lot of people through surgery and even a high-risk patient may have only a 3% or 4% chance of having an infection; but, if that patient gets an infection, it is 100% detrimental to them.”

Source: Charlie Ehlert, University of Utah Health

Trends have recently changed in terms of intraoperative techniques orthopedic surgeons can use to reduce or prevent PJI, some of which involve incorporating new techniques and materials into primary THA and TKA procedures. In this Cover Story, orthopedic surgeons discuss some of these approaches and how they may impact the rate of PJI in patients undergoing primary THA and TKA.

Appropriate antibiotics

Administration of the appropriate dose of antibiotics at the appropriate time during a surgical case has been shown to reduce PJI risk, Bryan D. Springer, MD, from OrthoCarolina Hip and Knee Center, noted. Although the standard of care has been to administer three doses of antibiotics — one at the start of surgery and two during the hospital stay — recent CDC guidelines have changed that standard, he said.

“CDC has recently come out with guidelines that say you only need one dose of antibiotics and it is creating a lot of controversy because many thought that recommendation is based on either flawed data or data that were not applicable to joint replacement patients,” Springer said.

Researchers have studied whether antibiotic-loaded cement affects PJI rates, but they came back with mixed data, according to John J. Callaghan, MD, the Lawrence and Marilyn Dorr chair in adult reconstruction surgery at University of Iowa.

Low rates of success bring into question whether antibiotic-loaded cement is worth the expense, he noted.

Implant surface may matter

The results with implants coated with an antibacterial surface have also been reviewed in the literature.

“There have been explorations of trying to produce implants that have an antibacterial surface — modification of the surface of implants that is hostile to bacteria, but allows osteoblasts and chondrocytes to grow,” Parvizi, who is an Orthopedics Today Editorial Board Member, said.

However, Springer stressed that surgeons should be careful about how often antibiotics are used and how much a patient receives.

“One of the problems we get into with infection and joint infection is that everyone just wants to [use] more antibiotics and we have to be good antibiotic stewards so that we are not the ones who are complicit in creating antimicrobial resistance,” he said. “The best way to do that is to follow the guidelines that are out there that are evidence-based.”

Other intraoperative techniques

Several sources noted that using diluted betadine during surgery or toward the end of the surgery to decrease intraoperative contamination is another option surgeons can consider.

“There are several other types of irrigants that are out there, but [the dilute betadine lavage] is probably the one that gets the most attention and has, as of right now, the most data around it,” Springer said.

Minimizing bleeding during and after surgery has been shown to reduce the risk of PJI and that can be achieved using tranexamic acid, sources said.

“We have focused heavily on minimizing blood loss through the use of tranexamic acid, which has minimized the bleeding during and after surgery, which minimizes the risk of infection,” Matthew P. Abdel, MD, associate professor of orthopedic surgery at Mayo Clinic, told Orthopedics Today.

Maintain body temperature

Hypothermia may also lead to the development of infection, Springer said, so he advises surgeons to administer appropriate warming of patients to maintain their body temperature.

However, Gililland said surgeons should carefully choose the methods they use to keep patients warm as some of them may increase infection risk instead of decreasing it.

For example, some forced-air warming blankets “force warm air into a blanket that blows up and keeps the patient warm and there is a suggestion that forced-air warming may disrupt the airflow around the surgical site and potentially increase the risk for infection,” Gililland said. “I have not seen good data yet to prove that is absolutely the case, but there is some suggestion we should be avoiding the use of forced-air warming.”

Minimize environmental factors

PJI may also be acquired through the hospital environment or by the joint becoming seeded with bacteria, Springer said. Therefore, minimizing traffic in and out of the OR during surgery is a practice that has been implemented to reduce PJI risk. Most hospitals do not allow traffic in a total joint arthroplasty OR while the incision is open, except for emergencies, according to Abdel.

“It is the OR traffic that is the biggest risk because we know people shed bacteria, so limiting the number of people that come in and out of the operating room is important,” Springer said. “That is probably the biggest environmental thing, making sure that personnel in the room are clean, that they do not have hair falling off themselves, that all of the appropriate body areas are covered.”

Air filtration

Reducing airborne bacteria in the OR may have a positive impact on reducing PJI. ORs equipped with a laminar airflow system used to be common, but research has shown no significant reduction in PJI with its use, Parvizi said.

“In the past, we have looked at laminar flow ... trying to look at the way air flow is in the room and we have not found laminar flow to ... decrease the rates of PJI, but people are looking at other types of air filtration systems now,” Gililland said.

Researchers are also studying the use of ultraviolet light in the OR and its effect on PJI.

“I saw some technology on trying to clean the air with ultraviolet light that looked possibly helpful, but once again, that is just looking at particles in the air, not about whether or not getting rid of those particles in the air are going to prevent infection,” Callaghan said.

Performing a quick, efficient procedure will reduce the risk of bacteria entering the incision, he noted.

“Ourselves and others have shown that cases over 2 hours are definitely at an increased risk for infection, but some data supports every 20 or 30 minutes before that are even better,” Callaghan said.

Surgical wear, materials

“Many orthopedic surgeons follow the practice of double gloving, but we do not change our gloves as often as we should,” Gililland said.

“Outer gloves get contaminated and oftentimes we will be in the middle of a long case and change our gloves not nearly as frequently as we ought to. It is recommended that we need to be doing that more frequently,” he said.

Gililland and his colleagues have also studied the addition of chlorhexidine to the splash basin, which can become contaminated with tissue and blood throughout the surgery.

“We studied just adding a dilute chlorhexidine solution to that water bath and we did a randomized trial looking at whether or not that would have an impact on the actual bacteria growth within that solution at the end of the case. We found it had a drastic decrease in the amount of bacterial growth in the basin,” he said.

There have been some recommendations to stop the use of intraoperative splash basins, but these are still frequently used, according to Gililland.

“If an institution is still using splash basins, they may want to consider the addition of dilute chlorhexidine to decrease contamination,” he said.

Closure techniques, materials

Materials used during wound closure may also have an impact on reducing PJI risk, according to sources, with Gililland noting it has been shown there is decreased bacterial growth on monofilament sutures compared with braided sutures.

“Any time we are dealing with an infected bed, we try to use monofilament rather than braided sutures,” Gililland said. “There have been studies showing decreased bacterial growth on monofilament sutures because there is less of a 3-D structure to the suture at the microscopic level to which the bacteria can take hold and form biofilms.”

Some sources noted they have seen positive results using an occlusive dressing and surgical glue instead of staples during wound closure.

“[Closure methods] would include using [instant glue] for wound closure, as well as using an occlusive dressing over the top of the wound either with or without silver, which is thought to be antiseptic in its own right,” Callaghan said.

The closure technique may be more important in reducing PJI risk than the materials used, Springer noted.

“I think the most important thing is that you have consistency in how you close a wound,” he said.

Preoperative optimization

Prior to approving a patient for surgery, surgeons should consider modifiable and non-modifiable risk factors that may increase the patient’s risk of infection, sources said.

“Modifiable risk factors include diabetes, obesity and smoking, and non-modifiable risk factors could include things like having a transplant and being on immunosuppressant medication,” Abdel said.

Surgeons can optimize a patient’s modifiable risk factors to prepare them for surgery. According to Parvizi, this includes controlling a patient’s diabetes, correcting nutritional parameters, minimizing the administration of disease-modifying agents or immunosuppressant drugs, addressing any skin issues and stopping patients from smoking or excessively consuming alcohol.

“Before we get to the operating room the most important thing is picking the right patients and making sure that any unhealthy patients are made healthy prior to surgery or optimizing patients prior to surgery,” Springertold Orthopedics Today. “That is always number one because those are hard issues to overcome once you get to the operating room no matter what techniques you have.”

Non-modifiable risk factors

Although a patient’s non-modifiable risk factors cannot be changed, surgeons should take these into consideration. Research has shown the possibility of genetic risks that predispose patients to a higher rate of PJI. Therefore, to understand this phenomenon, Gililland and colleagues searched a large Utah population database and found families that have significantly higher rates of PJI compared with the general population, which suggests there is a potential genetic predisposition to PJI.

“We know ... from several interesting studies that patients who have had prior PJI and then go on to have another total joint arthroplasty, say in another joint, are at a significantly elevated risk of having PJI in that joint they are having done,” Gililland said. “It may be they get cross-contamination from the joint that was infected in the past, but it also may be they have some sort of genetic predisposition to an increased chance of infection.”

According to Callaghan, molecular biology tests done prior to surgery may identify low grade organisms in the patient’s body which would allow surgeons to treat the patient with antibiotics intraoperatively.

“The idea would be that if we picked up those organisms, that we would then treat them intraoperatively and postoperatively, similar to what some people are doing now in high-risk patients where they are keeping patients who have a primary procedure on antibiotics for 6-weeks postoperatively,” Callaghan said.

Advice for reducing PJI

With so many intraoperative techniques available to reduce PJI, Abdel noted the best prevention is to employ all the behaviors instead of using one or two techniques.

“For PJI, it is a combination of everything from the beginning of the surgery to the end that makes a difference,” Abdel said. “It is never just one magic pill, medication or technique. It is doing all of the things that we know are good.”

However, despite various PJI prevention techniques that surgeons can use, they need to be careful intraoperatively when it comes to cases that are more complex, Parvizi said.

Callaghan advised surgeons to “not let up your guard” on infection prevention, even in patients who are not high risk.

“It is so easy because you see a lot less [infections] than we used to and most of the patients do not have that problem. But, for those couple or three or four in one thousand that come up, you have to do preventative measures for all of them and try to lower the rate of those three or four who would potentially get the infection. That is hard to do when things are going well,” Callaghan said.

Overall, it comes down to the understanding that the orthopedic surgeon and the surgical team play a key part in joint infection prevention.

“The biggest thing ... is understanding that the surgeon and the team do play a critical role at preventing infection, that we are ultimately the ones who are controlling the operating room and that doing all of those things that we mentioned is truly under our control,” Springer said. – by Casey Tingle

• References:
• American Joint Replacement Registry Annual Report 2017. Available at: www.ajrr.net/images/annual_reports/AJRR-2017-Annual-Report---Final.pdf. Accessed Nov. 20, 2017.
• Anderson MB, et al. J Bone Joint Surg Am. 2017;doi:10.2106/JBJS.16.00514.
• Berrios-Torres Si, et al. JAMA Surg. 2017;doi:10.1001/jamasurg.2017.0904.
• Lindgren KE, et al. J Arthroplasty. 2017;doi:10.1016/j.arth.2017.08.017.
• Parvizi J, et al. Bone Joint J. 2017;doi:10.1302/0301-620X.99B4.BJJ-2016-1212.R1.

• For more information:
• Matthew P. Abdel, MD, can be reached at 200 First St. SW, Rochester, MN 55905; email: abdel.matthew@mayo.edu.
• John J. Callaghan, MD, can be reached at 200 Hawkins Dr., Iowa City, IA 52242; email: john-callaghan@uiowa.edu.
• Jeremy M. Gililland, MD, can be reached at 590 Wakara Way, Salt Lake City, UT 84108; email: jeremy.gililland@hsc.utah.edu.
• Javad Parvizi, MD, FRCS, can be reached at Sheridan Building, Suite 1000, 125 S. 9th St., Philadelphia, PA 19107; email: javadparvizi@gmail.com.
• Bryan D. Springer, MD, can be reached at 2001 Vail Ave., Suite 200A, Charlotte, NC 28207; email: bryan.springer@orthocarolina.com.

Disclosures: Abdel reports he is a paid consultant for Stryker. Callaghan reports he has developed implants for DePuy Synthes. Springer reports he is a consultant for Stryker and Osteoremedies; receives royalties from Stryker; and is on the medical advisory board for Joint Purification Systems. Gililland and Parvizi report no relevant financial disclosures.

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