Level 1 Randomized Control Trial Conducted by Hoag Orthopedics Shows Reduction in Bacterial Contamination Risk Following Shoulder Replacement

Hoag Orthopedics today announced the publication of a Level 1 randomized controlled trial (RCTs) led by its physicians in the Journal of Shoulder and Elbow Surgery. The study demonstrates that using chlorhexidine gluconate (CHG) irrigation during total shoulder arthroplasty (TSA) can cut deep Cutibacterium acnes contamination rates by more than half compared with standard saline irrigation.

“Our findings support subcutaneous CHG irrigation as a low‑cost, high‑impact strategy to reduce the risk of deep C. acnes contamination in shoulder replacements,” said Hafiz Kassam, MD, medical director of shoulder surgery at Hoag Orthopedic Institute and lead author of the trial. “Adopting CHG into intraoperative protocols could potentially enhance patient safety and surgical outcomes.”

CHG is already a mainstay of preoperative skin preparation, but C. acnes reside in the deeper dermal layer, where surface antisepsis alone may fall short. To address this gap, the trial enrolled 126 patients undergoing TSA, randomly assigning them to receive either standard saline irrigation or 0.05 percent CHG irrigation before implantation. Results showed that the saline group faced more than double the risk of deep C. acnes contamination compared with the CHG group.

“The reduction in contamination we have shown is statistically significant, and hopefully clinically meaningful,” added Dr. Kassam. “This trial underscores the importance of targeted intraoperative measures to prevent periprosthetic joint infections and just how seriously we take this at Hoag Orthopedic Institute.”

Hoag Orthopedics is a research, education and outreach not-for-profit organization founded by Hoag Orthopedic Institute physicians. Hoag Orthopedics’ 2024-2025 Sports Medicine Surgical Fellows, Abhay Mathur, MD and Patrick Saunders, MD, were co-authors of the study.

“As a nationally and internationally recognized expert in total shoulder replacement, Dr. Kassam has brought our shoulder division to new academic heights,” shared Hoag Orthopedics Medical Director Vance Gardner, MD. “His expertise, enthusiasm, innovation, and hard work have contributed immensely to our research and teaching efforts.”

Dr. Kassam is the program director for shoulder reconstruction at HOI.