Catastrophic Failure of Regenerex Tibial Components: A Case Series

Abstract

The aim of this study was to analyze short-term metal failures in well-placed Signature-guided Regenerex (Zimmer Biomet, Warsaw, IN) tibial components in a limited patient series. A retrospective, consecutive, nonrandomized, unblinded study from a limited cohort of young active osteoarthritis patients was conducted. All cases received a Regenerex tibial component which we evaluated for metal failure. Patients met the then current indications from the Center for Medicare and Medicaid Services Guidelines for knee replacement. Age, body mass index (BMI),and gender were compared between Regenerex and concurrent non-Regenerex knee arthroplasties. We identified a 4.7% (2 of 43) fracture rate in our Regenerex tibia replacements. Fractures occurred after 17 and 37 months, with a mean follow-up of 65 months (44-77). No statistical difference was seen in age or BMI between the fracture and nonfracture groups. Regenerex compared with standard arthroplasty patients were younger and predominantly male. Our inability to identify our fractures in the Food and Drug Administration (FDA) reporting site is concerning, suggesting additional cases may be unreported. A short-term Regenerex tibial fracture rate of 4.7% is unacceptably high. Inability to identify our fractures on the FDA Web site is a system failure, suggesting additional component fractures may be unreported.

Component migration, bone mineral density changes, and bone turnover markers in cementless and cemented total knee arthroplasty: a prospective randomized RSA study in 53 patients with 2-year follow-up

“…However, in the annual report from the Australian Orthopedic Association National Joint Replacement Registry, there have been reports of a higher than anticipated revision rate of the Regenerex tibial component with a cumulative percent revision of 5.3% at 5‐year follow‐up (3.4% in other TKA’s) [20]. Furthermore, there have been reports of cases with implant fractures of the Regenerex tibial baseplate, which was not seen in the current study [21, 22]. The main difference characteristics of the Regenerex cementless tibial component compared to the cemented Vanguard component in the current study are the porous titanium coating, the modular stem design with a finned stem, and four additional fixation pegs, but as discussed in other studies, the fixation pegs probably do not make a difference [17, 23].…”

A review of the bio-tribology of medical devices

“…Aseptic loosening remains the most common indication for revision [30]. Clinical problems such as sinking [31], fibrous tissue wrapping, and even breakage of the prosthesis were also observed [32,33], as shown in Fig. 6.…”

Review of Electric Cracking of Hydrocarbons

“…Literature indicates that large-scale electric furnaces are typically electric arc furnaces (up to 175 MW) or induction furnaces (up to 42 MW). Resistance heating furnaces have been built with power up to about 8 MW, while microwave or other technologies are typically below 1 MW. Furthermore, compressors are built over a wide range of powers, the largest having powers up to 100 MW, indicating a large upscaling potential for the RDR concept.…”