Streamlined Surgery May Improve Treatment of Periprosthetic Joint Infection, Study Finds

By Hillary Eames
Friday, December 7, 2018

A one-stage surgical approach could be as effective in treating prosthetic joint infection (PJI) as the more common two-stage method, a recent British study found.

More than 2.5 million Americans have artificial hips, and the surgery is generally successful in enhancing mobility. While the likelihood of prosthetic hip joint infection is low — affecting approximately 1 percent of patients, according to the American Academy of Orthopaedic Surgeons — when such infections do occur, they can lead to intense pain, restricted movement, disability or death.

Biofilm formation usually makes treatment with antibiotics alone ineffective, according to Andrew Beswick, BSc, Research Fellow in Systematic Reviews at the University of Bristol, where the study was conducted. More than 50 percent of patients who develop a PJI require surgery to address the infection and replace the prosthetic.

These surgeries are performed in either one or two stages. In the two-stage approach, physicians remove the infected joint during the initial operation, after which patients are prescribed a course of antibiotics for several months. During the second stage, a surgeon implants a new joint. In the single-stage approach, infected prosthetic joints are removed and replaced with new joints in one operation.

The antibiotic regimen and the opportunity to monitor for complete clearance of infection have led most hospitals in the U.S. and the U.K. to favor the two-stage approach. However, findings from the University of Bristol study suggest one-stage surgery may be just as effective, if not more so.

“For several decades, the commonly used two-stage procedure has been presumed to be more effective than the one-stage procedure,” says Setor Kunutsor, PhD (Cantab.), MBChB (Legon), MA (Cantab.), BA (Legon), Research Fellow in Evidence Synthesis at the University of Bristol. “The one-stage strategy is less commonly used because of limited evidence on its effectiveness. It, however, has potential advantages, which include having only one major surgery, a shorter overall stay in the hospital, reduced functional impairment and less expense. With these new findings and subsequent adoption of the one-stage strategy by surgeons and hospitals, quality of life could be improved, unnecessary deaths averted, and this could all be achieved at a lower cost.”

The Findings

The study, in the European Journal of Epidemiology, analyzed re-infection rates among 1,856 participants across four continents who underwent surgery for prosthetic hip joint infections. At median follow-up of 3.7 years, 16.8 percent of one-stage surgery patients experienced re-infection, compared with 32.3 percent of two-stage surgery patients. Further research is underway to measure outcomes of both approaches. (See sidebar “INFORM Program and Clinical Trial.”)

While Kunutsor believes additional research will provide valuable perspective, he recommends surgeons consider the one-stage strategy to treat PJI, due to a range of potential advantages — the most obvious being that patients undergo only one major surgery.

Beswick urges caution in interpreting the data, as patient characteristics and other factors besides choice of revision strategy may have affected the findings. Nonetheless, he sees significant potential for the one-stage approach.

“In a two-stage revision, patients do not have a fully functioning hip joint for between two weeks and 12 months,” Beswick says. “A temporary spacer may be fitted, but patients experience considerable physical and psychological difficulties during this period, and spacers are associated with a high incidence of complications ... . While the operation in a one-stage revision may be of longer duration, rehabilitation and recovery can commence immediately.”

Infection Development in Prosthetic Joints

Prosthetic joint infection (PJI) may occur within the wound or around the implant itself. It can develop anytime after surgery, and an infection in a patient’s body can also spread to a prosthetic joint. However, a PJI in the implant itself poses greater risk to patients than typical infections.

“The primary reason [for the increased risk] is there is no blood flow to the prosthesis and the materials that we use,” says Richard A. Berg, MD, a physician at Life Bridge Health in Baltimore who was involved in research published in The Lancet in 2015 regarding PJI. “The bacteria can become adherent and make a layer of nondiffusible material around themselves. We call it slime. It impedes one’s immune system from effectively attacking the bacteria ... [and] makes it more difficult for them to be cleared.”

With regard to single- or two-stage surgical treatment of PJI, Dr. Berg believes each case must be approached individually.

“I think it altogether depends on what the situation is,” he says. “Case selection is absolutely vital for deciding. We can’t be sure that we’re putting a prosthetic joint in a sterile field.”

Dr. Berg highlights the importance of preventing infection to begin with, particularly among patients who have diabetes or are obese.

“What anybody can do is to optimize the chances of their doing well by making sure they don’t have an active rash at the area of the skin, no infection at the place where the wound is going to be placed, and [they are] in the best metabolic shape at the surgery,” he says. “This is what you do for any surgery, and if somebody does get an infection, it does often lead to a prolonged course of antibiotics and several more surgeries ... so optimizing the initial surgery lessens the chance of infection.”