Every surgical stage is critical in treatment of periprosthetic hip infection

U.K. investigators are involved in a head-to-head study of one- vs two-stage revision for infected hip arthroplasty to collect outcomes data.

Some orthopaedic hip arthroplasty surgeons in Europe are now performing more one-stage revision procedures to treat periprosthetic hip infections. Others, however, remain committed to two-stage revisions as the best approach to eradicate the infection, provide patients with better hip function and greatly reduce the chances of re-infection.

“We feel this is a thorny question, ‘Should you do one stage or two stages?’ There are no great data out there,” Jonathan R. Howell, MBBS, MSc, FRCS (Tr&Orh), of Exeter, United Kingdom, told Orthopaedics Today Europe.

For this Cover Story, Howell and other orthopaedic surgeons told Orthopaedics Today Europe about their preferences for one- or two-stage revision for periprosthetic joint infection (PJI) of the hip and discussed the indications. They agreed that in hip PJI cases, infection eradication is always more important than the number of surgical stages needed.

“Successful treatment of PJI is difficult,” Howell said, noting this surgery has multiple challenges, and should be done in specialist centers that have appropriate surgical services that can deal with it.

“It is almost akin to cancer surgery in my view. Many of the surgical techniques, the radical debridement, etc., are similar,” he said.

Case for one-stage treatment

Ten years to 15 years ago, Howell and colleagues at Devon and Exeter NHS Trust standardly used two-stage revisions and implanted a custom articulated spacer. The spacer consisted of relatively small primary components with large mantles of cement impregnated with antibiotics that were temporarily fixed. As such, it served as a temporary hip replacement until the second stage procedure could be performed.

Before that time, they performed a Girdlestone procedure during stage one and then closed the incision. They usually waited 2 months to 3 months between both stages, after which they implanted the revision hip components during a second stage procedure.

This rationale changed in the last decade, Howell said, after patients who with the so-called temporary hip replacement did not want to have another surgery. In fact, many of them did not need another operation.

“In many cases now, we will try to fix a so-called temporary hip replacement, but fix it well and the patients may never come to need another operation,” he said. “Now whether you call that a one-stage or two-stage is difficult; but it is difficult, to be sure, which is best.”

Algorithm associated with success

Rihard Trebe, MD, PhD, associate professor and consultant orthopaedic surgeon who is head of service for bone infections at Orthopaedic Hospital Valdoltra, in Ankaran, Slovenia, told Orthopaedics Today Europe, “We do not have one preferred approach, but we built an algorithm in 1998.”

The algorithm guides him and his colleagues in the appropriate procedure to perform based on the type of infection, as well as whether it occurs early or late in relation to when the primary total hip arthroplasty (THA) was done.

“The aim is to perform the least invasive treatment for PJI without compromising the microbiological results, and to have the best functional treatment result,” Trebe said.

The early infection protocol involves debridement and component retention, which is done when the pathogen is known and proven to be susceptible to anti-biofilm antibiotics, such as rifampicin for gram-positive and quinolones for gram-negative bacteria. For the rest of the patients, a one-stage or two-stage revision is performed depending “on the presence of the fistula, pathogen type and systemic factors, particularly immunocompetence of the patient,” Trebe said.

He noted a PJI registry established a few years ago helps track results with these PJI techniques. For debridement and retention alone, the success rates for eradication of infection and not needing a second-stage surgery are 79%, based on registry data. Using the algorithm, he estimates the rates at his hospital of a cured infection are slightly more than 90% at more than 15-year follow-up, Trebe said.

One-stage revision trend not new

Dieter C. Wirtz, MD, of University Hospital, Bonn, Germany, told Orthopaedics Today Europe, the trend toward more orthopaedists performing more one-stage revisions for PJI is not new.

“The one-stage revision is not in contrast to the two-stage revision. It is complementary,” he said, noting the soft tissue quality, extent and location of any inflammation, and type of bacteria help the surgeon decide whether a one-stage or two-stage revision is best.

Antibiotics are an essential component of a hip successfully revised for PJI, regardless of the number of stages of surgery performed, he said.

Treatment of bone loss

The approach used for revision may differ when there is extensive bone loss that requires bone grafting or metal augments, he said.

“You are not allowed to do a one-stage revision. That means, in severe bone deficiency situations, you have to do a second revision procedure. Having these points in mind — soft tissue situation, bacteria situation, bone defect situation — you have to decide,” Wirtz said.

Wirtz and his colleagues at University Hospital Bonn, which is one of three referral centers in Germany for infected hip arthroplasty, prefer the second-stage revision in severe cases. It provides a second chance to do surgical debridement and evaluate the patient’s anatomy in situ.

“This way seems, in our hands and in our studies we have done, the more safe way for patients,” Wirtz said.

Early infection

Only in cases of an early infection that occurs within about 6 weeks to 8 weeks of a primary total hip arthroplasty (THA) does Luigi Zagra, MD, of Milan, perform a one-stage revision for PJI.

He noted other surgeons in Europe have revisited one-stage revision because it involves a shortened period of illness for the patients and, since a second surgical procedure is avoided, it costs less to perform.

“If we are sure the total infection can be solved with one-stage, of course it is better — one operation than two. But, from my point of view at the moment, with the risk of reinfection, especially with complications, which in some patients are so high, it is safer to use two-stage,” Zagra, who is an Orthopaedics Today Europe Editorial Board member, said.

Two stages: Gold standard care

Two-stage hip revision for PJI is still the gold standard, Zagra said. However, he noted a minority of surgeons mainly perform one-stage hip revisions for PJI, but their numbers are increasing.

“I do not think one-stage is a better option. It is a good option, but in our hands, with our experience, two-stage is still a better solution for our patients,” he said.

The emphasis, regardless of the number of surgical stages used, should be on stopping the initial infection and preventing re-infection.

Test to identify organisms

Howell, Trebe, Wirtz and Zagra agreed that knowing the exact organism associated with a patient’s hip PJI is critical to a successful revision of any kind, with puncture or aspiration being the first step in identification.

Trebe recommends performing an aspiration in conjunction with any THA revision done within the first 10 years of a primary THA and, if the hip is suspected of being infected, then possibly performing another aspiration.

“Then, we have different other possibilities to try to rule out infection before a so-called aseptic loosening is diagnosed, like bone scans,” he said, noting particularly that leukocyte-labelled bone scans combined with a bone marrow scan also helpful, particularly if the aspiration is dry or results are inconclusive.

Those investigations, as well as routine intraoperative sampling for histological and microbiological evaluation, are essential to the preoperative evaluation for any THA revision, except perhaps for a periprosthetic fracture, according to Trebe.

“We have too many patients who have undergone several revisions without being thoroughly examined for infection” and may have missed the opportunity to be revised with a relatively easy two-stage approach, he said.

Cultures, appropriate antibiotics

During the first stage of a one-stage revision, Howell and colleagues take and send five tissue specimens to be cultured.

“We generally like to get identification of the organism before we do the surgery,” he said, noting multiple aspirations are sometimes done prior to the start of the first surgical stage.

“We will discuss the antibiotics to go into the cement and consult with a microbiologist before the operation,” Howell said.

Should a patient require special antibiotics, for a fungal infection for example, Howell may mix the necessary antibiotics into dissolvable Stimulan (Biocomposites) beads right in the OR and not place a prosthesis of any kind during the first stage of a two-stage procedure. The Stimulan is implanted at the time he performs a Girdlestone procedure.

“I have used those to mix a whole range of antimicrobials,” he said.

In the rare case the infective organism is unknown at the time of surgery, Howell uses broad spectrum IV antibiotics until results of the extended cultures come back. He also monitors the patient’s C-reactive protein (CRP) level postoperatively. Once the CRP is below 50 and stays there for a few days, Howell switches the patient to oral antibiotics for about 6 weeks.

Sonication to identify infective organism

Wirtz has sonication performed on explanted hip components in PJI cases for a better indication of the cause of the infection.

“The sonication is a much more sensitive and specific method to prove the bacteria than if you do it only by puncture and the fluid, and so on,” he said.

Based on the sonication results, Wirtz gives the patient a specific antibiotic for that organism for the next few weeks, after which he repeats the surgical debridement during the second stage surgery.

“If you do it in one stage, you do not have the result from the sonication. You have only the result from the puncture preoperatively. That means the specificity and sensitivity of the sonication is completely lost in the one-stage procedure,” Wirtz said.

Instead of sonication, Zagra uses dithiothreitol (DTT), a biofilm-dissolving substance developed at his hospital by microbiologist Lorenzo Drago. DTT uses a sulphydryl compound to remove microorganisms from biofilm so they can be analyzed more quickly in the laboratory. Its use helps reduce the rates of false positives and false negatives during the analyses.

Teamwork needed

“From my point of view, the most important thing to approaching this patient is teamwork with the radiologist, pathologist, infectious disease team and, especially, with the specialized laboratory,” Zagra said. “Intraoperatively during revision, we need to rule out the presence or persistence of an infection, especially during the second stage, for a successful eradication.”

He also said special bags are used at his hospital, together with DTT, to transfer any PJI-suspected tissues from the OR to the laboratory for direct analysis.

“This system avoids all the risk of contamination of the sonication,” Zagra said.

Howell said he and other U.K. surgeons have enrolled 42 patients to date in a multicenter study in which patients are randomized to undergo one- or two-stage THA revision for infection, unless they absolutely require a one- or two-stage revision. He noted it has been challenging to be required to do the type of revision to which the patient was randomized.

“That has included one or two patients who have been randomized to a one-stage who have required bone graft in order to fix components. We have gone ahead and done a one-stage with bone graft, which is controversial and feels a bit odd,” he said.

However, “We will only get the answer, if we are rigorous about it,” according to Howell.

Trebe said, “Intra-articular antibiotics, instead of systemic, may have a role in future treatment,” and noted only a few groups have published results on their use to date.

According to Zagra, surgeons must communicate with their patients about PJI and use all available methods to prevent infection, because it presents a real trauma for patients.

“There are studies demonstrating the mortality in infection for joint replacement is similar to cancer, so it is important to prevent an infection. This comes from education, and this comes from good prophylaxis and it comes with good surgical practice from all our community, also,” Zagra said. – by Susan M. Rapp

• References:
• Duncan WW, et al. J Bone Joint Surg Br. 2009;doi:10.1302/0301-620X.91B5.21621.
• Morley JR, et al. J Bone Joint Surg Br. 2012;doi:10.1302/0301-620X.94B3.28256.
• Tsung JD, et al. J Arthroplasty. 2014;doi:10.1016/j.arth.2014.04.013. Epub 2014 Apr 18.

• For more information:
• Jonathan R. Howell, MBBS, MSc, FRCS (Tr&Orh), can be reached at Royal Devon and Exeter NHS Foundation Trust, RD&E, Barrack Rd., Exeter, EX2 5DW, United Kingdom; email: jrhowell@dooctors.org.uk.
• Rihard Trebe, MD, PhD, can be reached at Valdoltra Orthopaedic Hospital, Jadranska cesta 31, 6280 Ankaran, Slovenia; email: rihard.trebse@ob-valdoltra.si.
• Dieter C. Wirtz, MD, can be reached at Clinic of Orthopaedics and Traumatology, University Hospital, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany; email: dieter.wirtz@ukb.uni-bonn.de.
• Luigi Zagra, MD, can be reached at Hip Department, Istituto Ortopedico Galeazzi IRCCS, via R. Galeazzi 4, Milan, Italy; email: luigi.zagra@fastwebnet.it.

Disclosures: Howell reports he is a designer surgeon for the Exeter hip, for which he receives royalties from Stryker. Trebe, Wirtz and Zagra report no relevant financial disclosures.