Greenwich Hospital partners with ONSF to conduct research on surgical site infections

Research on surgical site infections conducted at Greenwich Hospital in alliance with the ONS Foundation for Clinical Research and Education (ONSF) examined why a certain bacteria is so common in post-surgical shoulder infections and are helping to develop tactics to control it.

The research project, Understanding and Preventing Surgical Site Infection, garnered ONSF a second place award at the recent meeting of the American Orthopedic Society for Sports Medicine (AOSSM).

The research included 57 patients scheduled to undergo arthroscopic shoulder surgery to repair injuries such as rotator cuff tears or to implant prosthetic shoulder joint structures. The surgical team collected swabs and tissue samples for analysis pre-, during and post-surgery to evaluate the potential for post-operative infection that can cause chronic pain and, potentially, additional surgeries.

Participating in this research project conducted at Greenwich Hospital were Sports Medicine Specialists and Orthopedic Surgeons Paul Sethi, MD, Orthopedic Surgeon and president of ONSF Timothy Greene, MD, Katie Vadasdi, MD, director of the ONS Women's Sports Medicine Center, and James Sabetta, MD, GH Infectious Disease Specialist.

"The bacterium (Proprionibacter Acnes,) most commonly attributed to shoulder infection, is a very unusual organism," said Dr. Sethi. "Until recently, however, it was not properly recognized because it was so difficult to identify."

The Greenwich Hospital/ONSF team sought to understand why this bacterium is so common in post-surgical shoulder infections, where and how the exposure happens, and how to control it. The research provided evidence that Proprionibacter Acnes, which resides deep within the skin pores surrounding hair follicles, resists the most stringent skin sterilization procedures undertaken prior to surgery.

Interestingly, the study also found that the bacterium is present at surgical sites in men more frequently than in women because men have more body hair.

"After careful analysis, we were able to identify when (during surgery) patients are most susceptible to this bacterial infection and were able to determine just how frequently this bacteria is present. Now that we know when this bacterium may gain its access to patients, we are developing ways to attack it at the patient's point of vulnerability," Dr. Sethi said.

The Greenwich Hospital/ONSF team in the conclusion of their study recommended that current procedures for pre-surgical skin preparation be evaluated for effectiveness and possible revision, and noted that intraoperative exposure could occur if instruments or prosthetic devices come in contact with the patient's skin during the procedure.

"As the field of shoulder surgery and, particularly, shoulder replacement grows, the risk of developing shoulder infection increases. When treated imperfectly, infection may cause devastating complications. Our goal is to help develop a universal measure to absolutely minimize post-surgical infection," Dr. Sethi said.