Despite all the advances in hip and knee arthroplasty in recent decades, key aspects of the surgeries have remained unchanged: the incidence of periprosthetic joint infections (PJIs) and success rates for treating them.
Almost 3 million total hip and knee operations are performed each year in the United States – and that number is rapidly growing. With an estimated 2% of these surgeries complicated by infection, that means tens of thousands of patients face devastating consequences that may include weeks, months or even years of antibiotic treatment, limited mobility and, at times, overwhelming wounds. For some people, death is a possibility, as well. Mortality rates in patients who develop PJIs can be as high as 12% in the first year and as high as 30-35% in the first five years. These death rates have the same prognosis that’s seen in patients with all forms of colon cancer.
Those who survive may face economic burdens, including loss of income. And with treatment-related expenses for these infections often exceeding $100,000 per patient, the overall costs to the health care system are staggering.
At The Ohio State University Wexner Medical Center, experts are addressing these challenges with a multidisciplinary approach to patient care, dedicated facilities and innovative research that may transform the way PJIs are treated.
A multidisciplinary team
Recognizing the growing need to better deal with PJI, orthopedic surgeon Andrew Glassman, MD, chair of the Department of Orthopaedics at The Ohio State University College of Medicine, has developed more systematic tactics for treating these infections.
He began by assembling a team of administrators; physicians, including orthopedists, plastic surgeons and infectious disease specialists; and ancillary staff. Key recruits included Douglas Chonko, DO, MS, an orthopedic surgeon with a special interest in infection, and plastic surgeon Rajiv Chandawarkar, MBBS, who treats infection-related soft tissue wounds.
Together, they established a plan whereby trained and knowledgeable professionals would filter all PJI-related calls received at the Ohio State Wexner Medical Center from doctors’ offices and outside emergency departments. Their role is to ensure patients get the right care at the right time.
A better approach to patient care
To deliver the right care, the team:
- Created a nurse practitioner position to coordinate care among providers for inpatients undergoing care for PJI.
- Developed new protocols for antibiotic administration.
- Engaged specialists, such as interventional radiologists who provide timely, image-guided fluid and tissue sampling, as well as venous access experts, who help patients receive long-term antibiotics.
- Ensured appropriate instrumentation is available to remove well-fixed implants.
- Established a separate inpatient floor for infectious patients, where they receive care from experts trained to address their unique needs.
- Introduced processes to ensure that an orthopedist evaluates emergency department patients with efforts to obtain appropriate cultures prior to antibiotic administration.
- Streamlined admissions processes and established plans to eliminate unnecessary admissions.
Team members are available at a moment’s notice to address any patient’s needs.
The Ohio State Wexner Medical Center is now a regional leader in PJIs, managing more than 400 cases each year. We accept even the most complex patients and have created greater efficiencies in getting them admitted when necessary and treated. Team members are accessible around the clock, every day of the year. The program is one of only a few in the country that has a joint replacement surgeon on call seven days a week to respond specifically to periprosthetic joint infections.
As valuable as this undertaking has been for patients and referring physicians in easing access to high-level care, it doesn’t change outcomes for the significant percentage of patients who experience treatment failure. That’s where research comes in.
A powerful peptide
Dr. Glassman is one of several principal investigators in two multicenter clinical trials evaluating new treatments for PJIs. Both hold the promise of transforming PJI care.
The first is a phase Ib multicenter trial with seven participating sites. The trial is evaluating a novel, one-time peptide antibiotic for acute infections of total knees treated with debridement, antibiotics and implant retention (DAIR). Early results suggest it’s safe and not inferior to traditional treatment.
“The unique thing about this peptide is that it will kill any bacteria. That’s number one,” Dr. Glassman says. “Number two is that bacteria do not develop resistance to this particular antibiotic. And number three — and perhaps this is most important — is that the peptide has shown the ability to disrupt biofilm, which is earth-shattering.”
Because biofilm isn’t typically penetrated by antibiotics, it’s believed to be the reason for high rates of treatment failure using traditional methods for managing PJIs.
The possibility that doctors could someday eradicate PJIs and retain the prosthesis without traditional implant removal and spacer placement is groundbreaking.
Faster, easier antibiotic delivery
The second trial is a phase II clinical trial comparing two-stage exchange arthroplasty with a new treatment that makes rapid exchange possible. The trial involves an investigational titanium spacer with perforations that’s inserted into the joint space during stage-one surgery. “There are catheters that allow us to connect the device to an IV pump, and on an hourly basis, we’re instilling vancomycin and tobramycin, on an alternating basis, into the patient’s hip or knee,” Dr. Chonko says.
The openings in the spacer make it somewhat like a sprinkler. As antibiotics are instilled, the spacer “pushes” them from the knee space up the femur and down the tibia. From the hip, the drugs go down the femur and up into the acetabulum. It uses a soak and vacuum procedure.
“The device allows the whole area to be bathed in antibiotics,” Dr. Chonko says.
This trial, which will be presented at the American Academy of Orthopaedic Surgeons’ annual meeting in February, enrolled patients at 17 U.S. centers. Thirty-nine patients in the control group received standard two-stage exchange arthroplasty; 37 received treatment with the new spacer. After just seven days of intra-articular antibiotic irrigation, those in the experimental group safely underwent reimplantation surgery with results equivalent to those of patients receiving a standard two-stage exchange procedure. Time to reimplantation in the control group averaged 120 days, versus only seven to eight days in the study group.
Making things better
“These two approaches, alone or in combination, would be transformational,” Dr. Glassman says, referring to the clinical trials. “They would further elevate what are already life-changing procedures into truly amazing and much safer, more predictable procedures.”
Together, with the care model established at the Ohio State Wexner Medical Center, this research could help positively influence outcomes for patients nationwide with PJIs and improve the bottom line for the health care system.
“At the Ohio State Wexner Medical Center, we’re looking at the problems that have yet to be solved,” Dr. Glassman says.
While providing exceptional care is always the top priority, continually improving that care is viewed as essential.
“We’re focused on the downsides of hip and knee replacements and how we can make them better,” Dr. Glassman says.