AGH Researchers to study the impact of biofilm infections on the success of orthopaedic procedures

Researchers from Allegheny General Hospital's (AGH) Department of Orthopaedic Surgery and Center for Genomic Sciences have launched dual groundbreaking studies that may help determine the cause of two common, hard-to-treat problems experienced by patients who undergo orthopedic surgery: a joint replacement that becomes infected and a bone fracture that will not heal properly.

Both clinical trials will focus on the role of biofilms -- formidable, highly resistant communities of bacteria -- as a root cause of these surgical complications.

AGH's Center for Genomic Sciences is led by two of the world's foremost experts on biofilm bacteria, J. William Costerton, Ph.D., director of Biofilm Research, and Garth Ehrlich, Ph.D., executive director. Dr. Costerton is also director of Microbiology Research for AGH's Department of Orthopaedic Surgery.

Under the direction of principal investigators Dr. Costerton and Sandeep Kathju, M.D., Ph.D., director of the Center for Genomic Science's Wound Healing Program, the AGH team is the first in the country to explore the impact of biofilm infections on the success of orthopaedic procedures.

"This innovative research project addresses two fundamental surgical risks that healthcare professionals in our field confront on a daily basis. These complications not only cause a tremendous amount of suffering among patients, but they are also exceedingly costly to hospitals," said Patrick DeMeo, M.D., chairman of AGH's Department of Orthopaedic Surgery.

Infections occur in an estimated 2 percent of primary total joint replacements and as many as 15 percent of revision total joint replacements. The costs of treating such infections range from $15,000 to $100,000 per case.

AGH's Department of Orthopaedic Surgery is one of the state's largest and most comprehensive programs, performing more than 12,000 orthopaedic operations each year.

The first biofilm study examines how the presence of such bacteria affects the natural process of bone healing. The outcome could shed light not only on whether or not biofilms are found in the setting of non-healing -- or non-union -- bone fractures, but if so, how physicians might one day more effectively treat the condition and improve the healing process.

"It is well established that the healing of bone fractures is delayed or incomplete when bacteria are present near the trauma site," Dr. Costerton said. "We can use antibiotics to kill floating (planktonic) bacteria, in any infection, but it is usually necessary to surgically remove damaged tissues and biofilms when the infecting organisms have resorted to this strategy for survival and persistence."

Patients with open fractures of the femur (or tibia/fibula) are being recruited from AGH's Department of Orthopaedic Surgery for the non-union study.

The second study investigates the source of chronic infection in joint replacement procedures.

Evidence is growing that chronic and difficult-to-detect infections fueled by biofilms may be the primary cause of 'aseptic' loosening of joint replacements. In such cases, where failed joint replacements are not obviously infected, the optimum treatment is often unclear, frustrating both doctors and patients.

The study takes on increasing importance as the nation's population ages. Already, some 650,000 people undergo joint replacement surgery each year, and that number is expected to double by 2030.

While joint replacement surgery is generally a highly successful procedure that dramatically improves a patient's quality of life, infection can lead to increased morbidity and mortality, the need for additional surgeries, poor outcomes and economic loss.

"A small but growing body of evidence points to biofilm involvement in orthopedic implant infections," Dr. Costerton said. "Our goal is to establish definitively what role biofilms play in complications associated with artificial joint implants and hopefully take an important step towards improving our ability to prevent this vexing problem in the future."

For the study, AGH researchers will examine aspirated fluid collected from the following types of patients: those who have already undergone a joint replacement and are having problems, those who are undergoing surgery to remove a prosthesis and, as a control group, those who are having a first joint replacement surgery.