A novel knee spacer designed to deliver antibiotics directly to the site of an artificial joint infection has received 510(k) clearance from the U.S. Food and Drug Administration (FDA). The device, developed by Mass General Brigham researchers, incorporates the antibiotic gentamicin into a durable medical-grade plastic, allowing it to release the medication into the infected area while providing structural support during treatment for knee replacement infections.

The device is intended for patients who develop an infection around an artificial knee implant. After an infected implant is removed, the spacer temporarily maintains the joint space and provides structural support until a new artificial joint can be placed.

“Our goal was to create a spacer that can deliver antibiotics directly to the affected joint while remaining strong enough to support patients during treatment,” said Orhun K. Muratoglu, PhD, director of the Harris Orthopaedics Laboratory and the vice chair of clinical innovation in the Department of Orthopedic Surgery at Mass General Brigham. “This clearance is an important step toward making that technology available for patient care.” Infection occurs after approximately 2% of knee replacement surgeries and is among the most difficult complications to treat. Standard treatment typically requires multiple operations and a temporary spacer made from antibiotic-loaded bone cement, which may provide limited support and release antibiotics inconsistently.

The new spacer was designed to address these limitations by combining load-bearing support with sustained antibiotic delivery directly to the infected joint. The technology grew out of research led by Muratoglu, investigating how to incorporate gentamicin into ultra-high-molecular-weight polyethylene (UHMWPE) without weakening the material. UHMWPE is well-established as a durable, wear-resistant polymer commonly used in artificial joints.

In a 2025 study published in The Journal of Bone & Joint Surgery, the researchers reported that using very small gentamicin particles produced higher, more sustained antibiotic release while preserving more than 90% of the polymer’s originalmechanical strength.

In addition to Muratoglu, the Mass General Brigham research was led by Harris Orthopaedics Laboratory deputy director Ebru Oral, PhD, and investigator Mehmet Asik, PhD.

Mass General Brigham Innovation worked with Muratoglu and his laboratory over several years to help advance the technology from research toward commercialization. Mass General Brigham Innovation is the system’s business development arm for technologies and capabilities that are developed within Mass General Brigham.  The team engaged industry partners with the expertise to develop and bring the product to market and secured patent protection, and is also in the process of licensing the intellectual property rights to a large implant manufacturer.

Muratoglu previously played a key role in the discovery of highly crosslinked UHMWPE and pioneered the use of vitamin E for further stabilization. Medical implants fabricated using these technologies have been in clinical use since 1998 with more than 25 million implantations worldwide in total hip, knee and shoulder replacements.

“The path from a promising laboratory discovery to an FDA-cleared product is long, and relatively few technologies complete that journey,” said Chris Coburn, Chief Innovation Officer at Mass General Brigham. “This research team’s earlier generation implantsare among the technologies that have had the greatest impact on patients in Mass General Brigham’s history, and the next-generation technology also stands to benefit millions of patients worldwide.”