Thomas K. Fehring, MD


Published 12/1/2017
Sharon Johnson

Researcher Evaluates Treatment for PJI Following Lower Extremity TJA

Grant recipient researches viability of one-stage exchange arthroplasty
Patients in the United States whose hip or knee replacements have become chronically infected may soon have access to treatment options currently utilized mainly in Europe.

With a $500,000 grant from the Orthopaedic Research and Education Foundation (OREF), Thomas K. Fehring, MD, is leading a prospective, randomized clinical trial to assess the relative success of one-stage versus two-stage exchange arthroplasty for patients with chronic periprosthetic joint infection (PJI) following a primary knee or hip replacement. This research will be among the first to assess how economic and quality of life factors contribute to clinical decision making.

The grant that supports the study is the first awarded under OREF's collaborative research agenda (CRA) program. Introduced in 2014, the program engages major orthopaedic stakeholders to identify and fund the research that is most critical to improving clinical practice and patient care.

In the case of Dr. Fehring's grant, OREF collaborated on study design and funding with the American Association of Hip and Knee Surgeons, The Hip Society, The Knee Society, Zimmer Inc., DePuy Synthes Joint Reconstruction, and Biomet.

Current two-stage protocol
In North America, two-stage exchange arthroplasty is the standard treatment for PJI following lower extremity total joint arthroplasty (TJA). In the first stage, the infected implant is removed and infected soft tissue and bone is débrided. Following débridement, the infected prosthesis is replaced with a temporary implant that delivers antibiotics and helps restore the patient's mobility. About 2 to 3 months later, a second revision surgery is performed to replace the temporary implant with a new permanent prosthesis.

The reported rate of PJI is about 1 percent to 3 percent and 1 percent to 2 percent for primary knee and hip arthroplasty, respectively. However, those rates are increasing exponentially and are associated with sharp increases in patient morbidity and mortality.

The promise of one-stage treatment
Increasingly common in Europe, one-stage exchange arthroplasty offers several potential benefits, especially the elimination of a third surgery.

Dr. Fehring knows well what's at stake. PJI patients represent about 10 percent to 15 percent of his practice, and he's had a joint replacement himself. "Patients are devastated by this. If I had an infection I'd be devastated, too. Sometimes, my patients haven't walked for 3 or 4 years. Helping them is very rewarding," he said.

Moving to one-stage treatment would benefit providers and payers, too. Healthcare resources consumed in the treatment of PJI totaled $1 billion in 2013. That figure is projected to reach $1.62 billion by 2020 and does not account for lost wages, patient disability, and other indirect costs.

Thomas K. Fehring, MD
Anterior wound breakdown after flap placement over an infected TKA was performed at outside facility where amputation or fusion was recommended.
Courtesy of Dr. Fehring's patient
Leg appearance after two-stage procedure including lateral gastrocnemius flap.
Courtesy of Dr. Fehring's patient

Big, broad, highly collaborative
Dr. Fehring's research is structured as a multicenter, prospective, clinical randomized trial. The study is in progress at 12 orthopaedic centers and, ultimately, will include 350 participants in 10 states. Beyond geography, the study is highly inclusive. The study is open to patients regardless of comorbidities, organism, age, ethnicity, or socioeconomic factors. Only patients with fungal infection, suppressed immune systems, or severe soft-tissue defects are excluded.

Study participants will be equally and randomly assigned to either two- or one-stage treatment. Care teams learn the day before surgery which procedure each patient will receive; patients are informed following surgery.

If first-year recruitment rates hold, the study will be fully subscribed in 2018. Each participant will contribute follow-up data for 2 years. Complete clinical, psychosocial, and financial information will therefore be analyzed during or after 2020.

Dr. Fehring is confident the study will provide clear evidence to guide orthopaedic surgeons in selecting appropriate patients for one-stage exchange arthroplasty and could have a significant impact on healthcare costs. Ultimately, he sees the research as leading to improvements in treatment and outcomes.

"I'd like to know the answer to this, and I think many other orthopaedic surgeons would as well," Dr. Fehring said. "With the number of joint replacements being done each year, even a .5 percent infection rate is a huge volume of patients. The economic burden of two-stage treatment is significant."

Research that benefits the entire specialty
Although Dr. Fehring acknowledges some of the challenges research presents, such as designing a perfect protocol and the amount of time it can take to conduct a sound study, he enjoys being active as a clinician, teacher, and researcher.

"What I like about research is it helps people beyond your local sphere of influence. I can help a lot more patients doing research than I ever can doing piecework," he said.

That is clearly the case with this study since findings may also be applicable to infections associated with shoulder, elbow, ankle, wrist, or spine arthroplasty.

Sharon Johnson is a contributing writer for OREF. She can be reached at
© Orthopaedic Research and Education Foundation (OREF)


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  5. California, Georgia, Illinois, Iowa, Michigan, North Carolina, New York, Ohio, South Carolina, Virginia