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Thomas K. Fehring, MD

When One Joint Replacement Turns to Three

Thomas K. Fehring, MD OREF Clinical Research Grant in Hip and Knee Arthroplasty Infection in Collaboration with the American Association Of Hip And Knee Surgeons, The Hip Society, The Knee Society, Zimmer Biomet And Depuy Synthes
Research Summary
Research topic: Investigating the success of one-stage versus two-stage exchange arthroplasty for patients with chronic periprosthetic joint infections

Research results: Understanding of whether one-stage exchange arthroplasty is as effective as two-stage in treating patients with periprosthetic join infections, and evidence that guides orthopaedic surgeons in selecting the patients best suited for one-stage-exchange

Patient care application of results: Evidence to guide orthopaedic surgeons in selecting appropriate patients for one-stage exchange of infected hip and knee prostheses, which could decrease patient morbidity between stages and reduce direct and indirect health care costs

Simplified patient care application: Some patients with periprosthetic joint infections may be eligible to receive one-stage revision surgery, reducing patient morbidity between stages as well as the direct and indirect health care costs associated with traditional 2-stage surgery.

When One Joint Replacement Turns to Three

OREF grant recipient researches viability of one-stage exchange arthroplasty
Sharon Johnson

Patients in the United States whose hip or knee replacements have become chronically infected may soon have new choices thanks to research now underway.

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, Hip Society, Knee Society, Zimmer Inc., DePuy Synthes Joint Reconstruction, and Biomet.

Current two-stage protocol
When severe infection persists following a hip or knee replacement, standard treatment protocol in North America is two surgical procedures. In the first stage, the infected implant is removed and infected soft tissue and bone is debrided. Following debridement, the infected prosthesis is replaced with a temporary implant that delivers antibiotics and helps restore the patient’s mobility. About two to three months later, a second revision surgery is performed to replace the temporary implant with a new permanent prosthesis.

The reported rate of PJI is low, about 1–3% and 1–2%, respectively, for primary knee and hip arthroplasty. However, those rates are going up exponentially and are associated with sharp increases in patient morbidity and mortality.1–4

The promise of one-stage treatment
Increasingly the norm in Europe, one-stage exchange treatment offers a multitude of benefits. A one-stage remedy to PJI eliminates an entire cycle of surgical interventions.

Dr. Fehring knows well what’s at stake. PJI patients represent about 10-15% 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 three or four years. Helping them is very rewarding.”

Moving to one-stage treatment would benefit providers and payers, too. Health care resources consumed in the treatment of PJI totaled $1 billion in 2013. That figure is projected to reach $1.62 billion by 2020 and still does not account for lost wages, patient disability and other indirect costs.3

Big, broad, highly collaborative
Dr. Fehring’s research is structured as a multicenter, prospective, clinical randomized trial (CRT). Considered the gold standard for research that seeks to explore alternatives to accepted treatment protocols, a multicenter CRT requires substantial time and resources and a high degree of collaboration among distant teams.

The study is in progress at 12 orthopaedic centers and, ultimately, will include 350 participants in 10 states.5 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 tissues defects are excluded.

Half of study participants will receive two-stage treatment, half one-stage treatment. Which patient receives which procedure is determined randomly, by computer. Care teams learn the day before surgery which procedure each patient will receive; patients are informed following surgery.

Results worth waiting for
If first-year rates of recruitment hold, the study will be fully subscribed some time in 2018. Each participant will contribute follow-up data for two years. That means it will be 2020 before complete clinical, psychosocial, and financial information can be analyzed.

Dr. Fehring is confident the study will provide clear evidence to guide orthopaedic surgeons in selecting appropriate patients for one-stage exchange of infected hip and knee prostheses, and could have a significant impact on health care 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% infection is a huge volume of patients. The economic burden of two stage treatment is significant.”

Research that benefits the entire specialty
Dr. Fehring said that the OREF grant is essential to conducting this study.

“I’m in a private practice group with a self-funded research department, meaning, unless there’s funding from industry, the surgeons in the group pay for the research department’s expenses. It’s unlikely that industry would support a clinical research project on infection, so we’re grateful for the OREF funding. It allowed us to hire a research coordinator, which is essential with prospective, randomized double-blinded studies.”

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,” Dr. Fehring 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, to the benefit of many more patients and payers.

Sharon Johnson is a contributing writer for OREF. She can be reached at

1  Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am 2007; 89:780–5. doi:10.2106/JBJS.F.00222.
2  Aggarwal VK, Rasouli MR, Parvizi J. Periprosthetic joint infection: Current Concepts in J Orthop 2013;47:10–7. doi:10.4103/0019-5413.106884.
3  Kurtz SM, Lau E, Watson H, Schmier JK, Parvizi J. Economic burden of periprosthetic joint infection in the United States. J Arthroplasty 2012;27:61–5.e1. doi:10.1016/j.arth.2012.02.022.
4  Kurtz SM, Ong KL, Schmier J, Mowat F, Saleh K, Dybvik E, et al. Future clinical and economic impact of revision total hip and knee arthroplasty. J Bone Joint Surg Am 2007;89 Suppl 3:144–51. doi:10.2106/JBJS/G/00587.
5  California, Georgia, Illinois, Iowa, Michigan, North Carolina, New York, Ohio, South Carolina, Virginia

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