A preliminary study of the novel antibiotic-loaded cement computer-aided design-articulating spacer for the treatment of periprosthetic knee infection

Abstract

Background In comparison to static spacers, articulating spacers have been shown to result in a similar infection eradication rate in two-stage revision of periprosthetic knee infections. However, the optimal construct for articulating spacers has not been identified yet. The aim of this study was to present a preliminary result of treatment for periprosthetic knee infection using a novel computer-aided design (CAD)-articulating spacer. Methods We retrospectively reviewed 32 consecutive cases of chronic periprosthetic knee infection occurring from January 2015 to December 2015. In these cases, we used an antibiotic-loaded, optimized CAD-articulating spacer based on the retrieved knee prosthesis. Evaluation included infection eradication rate, the Hospital of Special Surgery (HSS) knee score, range of motion (ROM), and spacer-related mechanical complications. All cases were regularly followed-up for 2 years minimum. Results Twenty-eight of 32 patients (87.5%) had infection eradication; 18 patients (56.3%) received reimplantation successfully. The mean interval between spacer insertion and reimplantation was 8.8 months (range 4.0–12.5 months). The mean HSS knee score and ROM significantly increased during each interval ( p < 0.0001 for both). The mean HSS knee scores were 31.2 (range 20–48) at initial visit, 65.4 (range 60–78.8) at 1 month after spacer insertion, and 84.2 (range 78–90) at 3 months after reimplantation ( p < 0.0001). The mean ROM were 72.0° (range 15–100°), 85.6° (range 35–110°), and 102.0° (range 80–122°), respectively ( p = 0.002). Two (6.3%) spacer-related mechanical complications occurred. Conclusions The CAD-articulating spacer in two-staged revision of periprosthetic knee infection significantly controlled infection, improved clinical outcomes, increased ROM, and decreased mechanical complications in the preliminary study. Further larger clinical studies are needed to confirm the findings presented here.

Release Characteristics of Enoxaparin Sodium Loaded Polymethylmethacrylate Bone Cement

“…[20][21][22][23][24] . As the drug carrier, the most mature and largest scale commercial application of PMMA bone cement is antibiotic loaded PMMA bone cement [25][26][27][28] . From the experience of antibiotic loaded bone cement, certain physical and chemical properties are required to facilitate the effective release of drug from bone cement and act on the body.…”

“…From the experience of antibiotic loaded bone cement, certain physical and chemical properties are required to facilitate the effective release of drug from bone cement and act on the body. These properties include high water solubility, resistance to radiation disinfection or epoxy ethane sterilization, stability when stored with bone cement powder before use, inactivity during bone cement polymerization, high temperature resistance, little or no effect on mechanical strength of bone cement, and good release from solid bone cement [29][30][31][32][33][34] .…”

Cruciate-Retaining vs Posterior-Stabilized Antibiotic Cement Articulating Spacers for Two-Stage Revision of Prosthetic Knee Infection: A Retrospective Cohort Study

“…The fabrication techniques for articulating spacers can be classified as prefabricated, handmade, molded, and sterilized [10]. The constraint characteristics of articulating spacers can be broadly classified as either cruciate-retaining (CR) or posterior-stabilized (PS) types [6,[11][12][13][14][15][16][17][18]. Most spacers are CR without a post-cam design [6,[13][14][15].…”

“…Most spacers are CR without a post-cam design [6,[13][14][15]. Some PS spacers only have a post design [16,17], although a post-cam design has been used in metal-on-polyethylene [18,19] and cement-on-cement spacers [11,12]. Despite the success of articulating spacers, the optimal construct has not yet been identified [20].…”

“…Despite the success of articulating spacers, the optimal construct has not yet been identified [20]. Moreover, heterogeneous spacer mechanical complications, such as spacer loosening or fracture, joint dislocation, and extensor apparatus problems [12][13][14], have been reported.…”