Issue: February 2016
February 11, 2016
14 min read

More research needed for guidance on one-stage vs two-stage exchange to treat PJI after TKA

Issue: February 2016
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When it comes to the treatment of periprosthetic joint infection following total knee arthroplasty, patients will usually undergo a one-stage or two-stage exchange. Although other techniques are available, not all techniques have the best result if the implant is not removed.

“We are all frustrated that irrigation and debridement has a 60% to 70% failure rate regardless of when they are done, so that is usually not a good option. It is certainly an option that we all want to work and the patient wants it to work, unfortunately it does not work well,” Thomas K. Fehring, MD, co-director at the OrthoCarolina Hip and Knee center, told Orthopedics Today. “That puts us in the category of having to remove the implants to get better results [and] if you can do it in one stage rather than two stages with similar success rates, then that certainly would be a real advantage.”

There is controversy about whether a two-stage exchange, which is considered the gold standard for the treatment of periprosthetic joint infection (PJI), according to Thorsten Gehrke, MD, medical director at ENDO Klinik Hamburg, Germany, is the better technique for patients compared with one-stage exchange.

Thomas K. Fehring, MD
Thomas K. Fehring, MD, from OrthoCarolina, expressed optimism regarding research presently being conducted that compares outcomes between one- and two-stage exchanges in the treatment of periprosthetic hip and knee infection. He said if the outcomes prove to be similar, it could be a game-changer for patients and orthopedic surgeons.

Image: Stephanie Chesson Photography

“I would say the golden standard all over the world is the two-stage exchange, which aims to remove the implant, remove all infected tissue and remove all foreign bodies, like screws and cables and so on, and clear and debride the wound. Then give the patient about 6 [weeks] to 8 weeks of antibiotics, leave the patient in the bed or on a wheelchair without the joint and after 8 weeks you stop with the antibiotic therapy, and everything seems to be okay,” Gehrke said.

Advantages, disadvantages

According to Fehring, although two-stage exchange to treat PJI has a higher success rate compared with one-stage exchange, it requires two operations with a 2-month to 3-month period in which the patient has a temporary prosthesis or spacer in place. By definition, this leads to significantly more morbidity for the patient, he said.

“The one-stage involves one surgical procedure, one hospital admission, and the patient gets the old implant removed and the new implant put in at the same time so they do not have to suffer the disability and the pain in the interim,” Javad Parvizi, MD, FRCS, of the Rothman Institute and Editorial Board member for Orthopedics Today, said.

One-stage exchange also is more cost-effective, according to Gehrke, with only one load of anesthesia being used. He also noted functional and quality of life results have been found to be better with one-stage exchange.

“Normally the functional results are also better after one-stage because it is only one surgery and not two where you always destroy muscles and ligaments,” Gehrke said.

Some surgeons may find one-stage exchange offers inherent safety benefits. However, other surgeons contend two-stage exchange is the safer option as there is time to let the tissue and bone heal, and surgeons have the opportunity to check for additional infected soft tissue during reimplantation.

David G. Lewallen, MD, professor of orthopedic surgery and consultant in the Department of Orthopedic Surgery at the Mayo Clinic, noted two-stage exchange allows surgeons to “try to achieve control and eradication of the infection before putting a new implant back in place, and this allows a discontinuance of antibiotics and hopefully [an] infection-free, more durable survival of the device moving forward.”


Craig J. Della Valle, MD, professor of orthopedic surgery at Rush University Medical Center, said North American orthopedic surgeons may not be comfortable with performing a one-stage exchange.

“Some surgeons in Europe routinely utilize a one-stage exchange. They are adamant that a radical resection or radical debridement of the infected tissue is important and that includes excision of, in some cases, the collateral ligament. Then, they go ahead and use a hinged knee replacement,” Della Valle said. “In general, our philosophy has been to avoid hinged devices unless we have to and I just would not feel good about, in a 50-year-old patient with an infected total knee, excising medial and lateral collateral ligaments as part of the surgical debridement.”

Gehrke also noted treatment of an infected knee joint with one-stage exchange requires an orthopedic surgeon and staff with more experience and higher specialization.

“The one-stage exchange procedure requires a lot of experience and that means not only the surgical experience,” Gehrke said. “It is also the entire environment: diagnostics, the support of a microbiologist, experienced surgeons who can decide during the surgery which part of the tissue or the bone is infected and which part is not infected. You also need experienced staff on the ward, including the nurses.”

According to Lewallen, surgeons can look at multiple factors to see whether the patient is a good candidate for either a one- or two-stage exchange.

David G. Lewallen, MD
David G. Lewallen

“Success is influenced by the individual patient and their comorbidities and also the status of the limb,” Lewallen said. “Regardless of the technique chosen, there are some patients who we know at the outset are going to have a high chance of failure compared to others and then others who are healthy and have an intact limb with good soft tissue where the success rate may actually be higher than the average for some of these clinical series.”

He added, “There is a need for individualized treatment and that goes for a lot of the decisions involved, including the difficult choice between whether to try one-stage or two-stage exchange.”

Reinfection risk

Regardless of whether patients undergo one-stage or two-stage exchange, there is a risk for reinfection. Although the reinfection risk is not fully known, a systematic review published in 2013 in BMC Musculoskeletal Disorders, James PM Masters and his colleagues noted a reinfection rate between 0% and 41% for two-stage exchange and between 0% and 11% in one-stage exchange.

“There is a risk of reinfection following both procedures, the question is: Is it higher or lower with one technique or the other?” Della Valle said. “Although I think that we believe that two-stage exchange is associated with a higher cure rate but, 1) we do not know for sure if that is true and; 2) we do not know how big the difference is.”

Fehring said the risk for reinfection in both one-stage and two-stage exchange tends to be higher in patients who have several comorbidities.

“There is chance of reinfection for both because the people who get reinfected frequently have lot of comorbidities,” Fehring said. “They are either diabetic or they are obese, they are what we call compromised hosts, so they have a lot of medical problems that predispose them to infection from the start. In fact, many patients who get reinfected after a one- or two-stage frequently get reinfected with a different organism and that speaks to them being compromised hosts and more susceptible.”

Regardless of the differences between the two techniques, Lewallen noted both have been proven to have high success rates.

“There are overall numbers which would suggest that the batting average is pretty good. For example, two-stage exchange with claimed cure rates in the literature sometimes is around 85% to even 90% or higher in some series,” Lewallen said. “But, the cure rate varies depending on the length of follow-up. As with many things, the longer the follow-up, the lower the success rate, the higher the chance of reinfection and that goes for one-stage exchange also.”



Patient contraindications play a role in deciding whether they are the appropriate candidates for either a one-stage or two-stage exchange.

“Not everybody is felt to be a candidate for one-stage exchange, even by the most enthusiastic supporters,” Lewallen told Orthopedics Today.

Parvizi agreed, noting “patients who are extremely sick, systemically sick, who have to be operated on fast to remove the infection and they cannot undergo a long operation, they usually have to be operated on by two-stage exchange.”

Gehrke noted one-stage exchange is easier to perform when the organism causing infection is known, its susceptibility is known and when the organism does not have a high resistance against antibiotics.

Thorsten Gehrke, MD
Thorsten Gehrke

“The one-stage is a tailored surgery, so that means every mix of antibiotics to the bone cement is tailored to the susceptibility of the bacteria,” he said. “It means if you do not know the bacteria before susceptibility. It does not make any sense to do the one-stage.”

Other factors, such as soft tissue state, can make a one-stage exchange unlikely.

“There are some [surgeons] who will not do the one-stage exchange if [the patient has] severe soft tissue problems, or if it is not clear whether you can get healing of the soft tissues over the knee,” Lewallen said. “If the wound fails to heal, everything gets reinfected and if you have an implant that is securely fixed, it could be more destructive getting that out again.”

Cultural differences also may affect the decision for a one- or two-stage exchange. According to Della Valle, although North American surgeons may also be concerned about performing a one-stage exchange on a patient with a sinus tract infection, European surgeons may not consider that a contraindication. He noted surgeons also may be hesitant to perform a one-stage exchange on patients with severe bony defects.

“The flip side to that would be, say you have someone with an infected tumor prosthesis, you know where it would be difficult to manage them between the two stages of the two-stage exchange,” Della Valle said. “Even though that is kind of the ultimate in bone loss, a one-stage exchange might be preferred because you do not have that problem of how do you manage them with a spacer between the two stages.”

Most importantly, patients should be optimized prior to primary surgery to reduce the postoperative infection risk. This would include having obese patients lose weight, have patients go through a smoking-cessation program and enhance patient nutrition, Fehring said.

“Another way to diminish infection [is] diminish the traffic in the OR. Make sure there are not many people going in and out of the room,” Fehring told Orthopedics Today.

Advice for orthopedic surgeons

According to Gehrke, any septic exchange should only be performed by experienced surgeons.

“It does not make any sense if a surgeon is doing only two or three surgeries like this in a year,” Gehrke said. “It is not good for [the surgeon] and not good for the patient.”

Similarly, Parvizi noted if an orthopedic surgeon sees a patient with an infected knee joint and does not have the best means to treat the patient, the best solution is to send the patient to a larger surgical center that has the appropriate staff and tools for optimum treatment.

“When you encounter a patient with infection and you feel you do not have the infrastructure at your institution to treat them, you might want to refer them to specialized authority surgical centers where they have multidisciplinary team, including microbiologist, infectious disease specialist, nurse practitioners, intravenous infusion therapy, etc.,” Parvizi said. “Some of these cases are challenging to be treated in the smaller centers, but I think it is important for us to consider these like patients with cancer and refer them on to centers that have these structures.”


He added all orthopedic surgeons should practice the appropriate protocols proven to reduce the risk of infection, including looking for infections prior to, during and after surgery.

“We should focus our efforts on prevention of PJI at this point because that is probably the most effective method to try to reduce the economic and psychologic burden of the disease, both on society and on the patients,” Parvizi said.

Gehrke noted diagnostic tools, such as alpha-defensin Synovasure (CD Diagnostics) and leukocyte esterase, should be used to help detect infection. Della Valle said appropriate dosage and timing of antibiotics before the skin incision of the primary surgery also can help reduce the risk of infection.

Javad Parvizi, MD, FRCS
Javad Parvizi

According to Lewallen, more research is needed, including understanding how European orthopedic surgeons perform one-stage exchange and what their results show.

“I do not think we have the complete picture yet. We need to better understand some of the European data,” Lewallen said. “[I] think if [one-stage exchange] is going to be attempted, it needs to be done following the principles that have been laid out by those who have had success. I think there is further work to be done on refining who is a good candidate for one-stage exchange and who should never have a one-sage exchange, [and] always have a two-stage exchange, and then the grey zone in the middle which may be patients who might be managed successfully either way.”

The Orthopedic Research and Education Foundation awarded a grant to help answer the question of whether one-stage or two-stage exchange is more appropriate for treating deep infection, and whether one-stage exchange can be performed with techniques comfortable for orthopedic surgeons in North America.

“This is a big deal for the orthopedic community and if we can show there is not much difference between the two [exchanges], I think that would be huge,” Fehring said. “That is the most important research question that needs to be answered.” – by Casey Tingle

Disclosure: Della Valle reports he is a consultant for DePuy, Zimmer Biomet and Smith & Nephew; receives royalties from Zimmer Biomet; and is on the scientific advisory board and has stock options for CD Diagnostics. Gehrke reports he is an advisor and stock options owner for CD Diagnostics. Fehring, Lewallen and Parvizi report no relevant financial disclosures.



Is two-stage exchange better than one-stage exchange in total knee arthroplasty?


Treatment of infection

Management of the infected total knee replacement remains a major challenge to orthopedic joint surgeons. Many factors must be considered in the decision process when planning treatment. These include the infecting organism, host immunity and duration of the infection. It has been shown in vivo that Staphylococci form a robust biofilm on the implant within 2 weeks — making cure difficult. A compromised host may have great difficulty clearing an infection with retained implants. Multi-drug resistant organisms are also difficult to treat from a pharmacologic standpoint. These complex factors prevent a single easy solution to infected total knee replacement.

Stephen L. Kates, MD
Stephen L. Kates

An algorithmic approach is needed that considers the organism, host immunity, implant stability and duration of infection. For short duration infections with simpler organisms and a competent host, debridement and polyethylene exchange is a reasonable treatment. For short duration infections with more virulent organisms and a good host, single-stage exchange or short interval two-stage exchange is reasonable. For virulent organisms and poor hosts, two-stage exchange remains the best treatment choice. Chronic infection with virulent organisms, poor host immunity and loosened implants may require multiple procedures to control the infection.

In addition to choosing the optimal procedure to teat the infection, co-management of the infection with an infectious diseases consultant is essential. The main limiting factor in treatment decision-making is the lack of a quantitative method to measure host immunity. The concept of A, B and C host is subjective and lacks a quantitative measure. As immune system diagnostics become available, arthroplasty surgeons will have additional tools to use when planning their treatment.

Stephen L. Kates, MD, is a professor and chairman of the Department of Orthopaedic Surgery at Virginia Commonwealth University, Richmond, Va.
Disclosure: Kates reports no relevant financial disclosures.


Remains controversial

Although periprosthetic joint infection is a major clinical problem, the optimal treatment remains controversial. It is not clear whether a direct exchange or staged approach provides the best chance for clinical success and eradication of infection.

Paul A. Manner, MD, FRCSC
Paul A. Manner

In the Americas, the two-stage method, in which components are removed at the outset with placement of a temporary spacer, followed by eventual placement of a permanent device, is considered the gold standard. In Europe, a single procedure, typically incorporating a complete change of OR dress and instrumentation, is more commonly preferred.

Because a one-stage exchange requires only one operative procedure, it provides several logistical advantages. These include lower cumulative operative risk, a shorter total hospitalization, lower cost and the chance to avoid prolonged impairment of patient function. What is the downside? Unless debridement is meticulous and thorough, a single procedure by definition will increase the chance of leaving substantial infectious material behind. Historically, reinfection rates have been higher in a single procedure than with a staged method.

The advantages of the staged approach are the opposite of those for one-stage. The majority of studies show a better chance of eradication of infection. This is true even in the face of more virulent organisms. In addition, a two-staged approach allows treating physicians to tailor antimicrobial treatment to the offending organism, which is essential in the many cases where the microbe is unknown at the time of initial surgery. It is also logical to assume that two attempts at vigorous debridement will be more fruitful than one.

For periprosthetic joint infection (PJI) of the knee, I will stick with the staged approach for the time being. However, I would certainly consider a one-stage in the following scenario: a reasonably healthy patient, without evidence of systemic sepsis, with a clearly identified, low-virulence microbe. What would help here? A systematic review, with comparable patient groups and consideration of patient-related outcome measures. We have done this for PJI of the hip, but I have to admit that I find knee infections more challenging.

Paul A. Manner, MD, FRCSC, is a professor in the Department of Orthopaedics and Sports Medicine at the University of Washington, Seattle.
Disclosure: Manner reports he is the senior editor for
Clinical Orthopedics and Related Research.



Distinct contraindications

Perhaps the most devastating complication of total joint arthroplasty is infection. Severe pain and compromise of function are the hallmarks of this complication, which is associated with significant morbidities and mortality. Treatment of an established arthroplasty infection remains somewhat controversial. Historically in the United States, the gold standard for treatment has been a two-stage exchange, which is dramatically different than the single-stage exchange, that is advocated in certain centers throughout the world. It is intuitively obvious that a single-stage exchange will allow for more rapid return to life as it was prior to infection.

Adolph V. Lombardi Jr., MD, FACS
Adolph V. Lombardi Jr.

At the recent International Consensus Meeting on Periprosthetic Joint Infection, it was concluded that single-stage exchange is a reasonable option for the treatment of arthroplasty infection in situations where effective antibiotics are available. Knowledge of the offending organism prior to the procedure is a requisite since appropriate antibiotics can be administered perioperatively and incorporated into the polymethylmethacrylate. There are distinct contraindications to performing a single-stage exchange which include lack of identification of the offending organism preoperatively, inadequate soft tissue coverage or presence of a sinus tract. Therefore, it is the impression of this author that the number of patients in whom a single-stage exchange is appropriate is limited. It is relegated to the healthy host with excellent soft tissue and with an identifiable organism readily treatable by available antibiotics. Hence, in the United States, two-stage exchange represents the gold standard. Certainly, the indications for two-stage exchange are the compromised host with compromised soft tissue. Any patient who presents with systemic manifestation of infection, that is sepsis, is a candidate for two-stage exchange. Patients who appear to be infected but no organism can be identified, or patients with difficult or resistant of organisms, should also be treated with a two-stage exchange.

As a result, the majority of patients in my practice are treated with two-stage exchange. The optimal interval between the two stages has yet to be defined in the literature. Reports indicate anywhere from 2 weeks to several months is appropriate. I have historically used 6 weeks and continue to do so. When performing a two-stage exchange, there is also controversy about whether a static or articulating spacer should be utilized. Until further studies are performed, two-stage exchange will remain the most appropriate form of treatment for an established arthroplasty infection.

Adolph V. Lombardi Jr., MD, FACS, is president of Joint Implant Surgeons Inc., New Albany, Ohio.
Disclosure: Lombardi reports he receives consulting fees, royalty payments and institutional research support from Zimmer Biomet and Orthosensor; consulting fees and institutional research support from Pacira Pharmaceuticals; royalty payments from Innomed Inc.; and institutional research support from Stryker and Kinamed.