Orthopaedics Resident Wins National Research Award

She earned the award for her manuscript “Hemolysis Is a Diagnostic Adjuvant for Propionibacterium acnes Orthopaedic Shoulder Infection,” which she presented at the ASES Specialty Day meeting March 18 in San Diego.

The research was published in the May 2017 issue of the Journal of Shoulder and Elbow Surgery.

Infection after orthopaedic shoulder procedures, especially shoulder replacement (total shoulder arthroplasty), is a devastating complication with significant diagnostic and therapeutic challenges, Boyle notes. Treatment often requires prolonged intravenous antibiotics and the potential for multiple surgical procedures.

There is a considerable need for improved diagnostic and treatment algorithms to optimize successful patient outcomes after orthopaedic shoulder infections as there has been a rapid increase in the number of orthopaedic shoulder procedures performed in the United States. Total shoulder arthroplasty rates are projected to increase by more than 150 percent by the year 2020. 

The accurate diagnosis of infection and identification of the offending organisms continues to be a challenge, according to Boyle, which is particularly true for Propionibacterium acnes (P. acnes), one of the most common infecting organisms after orthopaedic shoulder procedures.  

Diagnosing infection with P. acnes is a challenge due to the indolent clinical presentation and unreliable nature of blood tests and other common diagnostic tests for infection. 

Diagnosing true infection with P. acnes relies largely on intraoperative findings and the cultures that are taken in the operating room at time of surgery. When those cultures from the operating room do become positive for P. acnes, there is controversy on distinguishing true infection from contamination, Boyle says.

Hemolysis, defined as 2 mm of clearance around bacterial colonies when cultured, has been noted in certain strains of P. acnes and may be directly correlated with the bacteria’s pathogenicity. 

“The purpose of this study was to further evaluate orthopaedic patients with and without hemolytic strains of P. acnes,” Boyle says.

“We hypothesized that patients identified with hemolytic strains of P. acnes would demonstrate a more prominent systemic inflammatory response, greater antibiotic resistance and exhibit a higher rate of definite clinical infection than non-hemolytic strains of P. acnes,” she says.

Indeed, the study found that hemolytic strains of P. acnes demonstrate enhanced pathogenicity in their host and hemolysis serves as a marker for true P. acnes infection.

Boyle says the significance of the study is that hemolysis can be used as a diagnostic adjuvant for determining infection versus contamination in P. acnes positive cultures.

The increased antibiotic resistance profiles seen in hemolytic strains should be carefully considered when choosing antimicrobial therapy for prophylactic and therapeutic courses of treatment, she says.

UB’s microbiology laboratory has been collecting and storing P. acnes isolates since 2010. The basic science portion of the study consisted of the research team plating the P. acnes samples and evaluating for hemolysis as well as identifying the various antibiotic resistance patterns.

The clinical aspect of the study involved retrospectively reviewing the records of 31 patients who had a positive P. acnes shoulder culture for demographics, preoperative labs, intraoperative information, use of postoperative antibiotics and clinical course, including determining whether these patients required a return trip to the operating room for suspected persistent infection.

Co-authors on the paper are:

• Scott R. Nodzo, MD, an orthopaedic surgeon at Nellis Air Force base in Las Vegas, Nevada. He graduated from the orthopaedic surgery residency program at UB in 2015.
• Thomas R. Duquin, MD, clinical assistant professor of orthopaedics
• John K. Crane, MD, PhD, professor of medicine
• Travis Wright, a third-year medical student

Boyle says she had the opportunity to interview at many orthopaedic surgery programs throughout the country, but she was attracted to UB’s because she felt it offered one of the most diverse and robust training programs with a solid foundation for learning the principles of orthopaedics.

“This program has a strong focus not only on operative experience and providing autonomy but also on developing a young surgeon’s diagnostic and clinical acumen,” she says.

Boyle notes the program’s leadership is very supportive of resident research aspirations and novel ideas.

“I was given the opportunity to complete a three-month research rotation in my PGY-2 year at the Hospital for Special Surgery in New York City, where we evaluated current treatment protocols, outcomes and economic burden of orthopaedic infections after total knee and hip replacement.”