Enhanced Antibiotic Release and Mechanical Strength in UHMWPE Antibiotic Blends: The Role of Submicron Gentamicin Sulfate Particles.

Abstract

Background: Periprosthetic joint infections (PJIs) are a major complication of total joint replacement surgeries. This study investigated the enhancement of mechanical properties and antibiotic release in ultra-high molecular weight polyethylene (UHMWPE) through the encapsulation of submicron gentamicin sulfate (GS) particles, addressing the critical need for improved implant materials in orthopaedic surgery, particularly in managing PJIs.

Methods: The present study involved embedding submicron GS particles into UHMWPE flakes at concentrations of 2% to 10% by weight. These particles were prepared and blended with UHMWPE flakes using a dual asymmetric centrifugal mixer, and the blends were consolidated. The present study compared the mechanical properties and antibiotic release rate of UHMWPE containing submicron, medium (as-received), and large (resolidified) GS particles.

Results: UHMWPE samples with submicron GS particles exhibited superior mechanical properties, including higher ultimate tensile and Izod impact strengths, compared with samples with larger particles. Additionally, the submicron GS UHMWPE blends demonstrated a markedly higher and more sustained antibiotic release rate.

Conclusions: This study highlights the potential of incorporating submicron GS particles into UHMWPE to drastically improve the feasibility of using these therapeutic and functional spacer implants in expanded indications.

Clinical relevance: By offering improved mechanical strength and effective, prolonged antibiotic release, this innovative material could be used as a spacer implant to reduce the considerably high morbidity and mortality associated with PJIs. This material has the potential to prevent PJIs not only in high-risk revision cases but also in primary total joint arthroplasty procedures.