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Oxidized zirconium was first introduced in total hip arthroplasty procedures to merge the strengths of metal and ceramic into one prosthetic. The subsequent adoption of oxidized zirconium (oxinium) for total knee arthroplasty is attributed to the theory of causing less wear on the tibial components compared to the alternative, cobalt chromium. However, the superficial layer of the femoral component is occasionally breached, exposing the softer zirconium substrate. Multiple mechanisms leading to zirconium substrate exposure have been explained, including collateral ligament instability and polyethylene wear. Such a failure may lead to damage to the periprosthetic tissues and often requires a revision procedure. In the current case report, we present a case of bilateral total knee arthroplasty with oxidized zirconium components that resulted in catastrophic failure and subsequent revision with hinged knee prostheses.

We present a case of a 72-year-old male with a history of a late 1980s metal-on-polyethylene total hip arthroplasty who presented with unilateral leg vascular compromise, joint pain, and stiffness and subsequently underwent revision for adverse local tissue reaction secondary to mechanically assisted crevice corrosion. His stable and extensively porous coated femoral implant had a legacy taper with no currently manufactured option for a non–Co-alloy femoral head. After shared decision-making with the patient, we opted to use an oxidized zirconium femoral head from another manufacturer with a similar taper during his revision surgery and documented that his vascular compromise resolved and his serum Co was undetectable 3 years after the revision.

Oxinium implants are composed of a zirconium alloy with a hard ceramic surface formed by oxidization of the outer layer. This material has been shown to be an effective bearing surface for total joint arthroplasty and an alternative material for use in patients with metal hypersensitivity. Reports exist of metallosis due to unintended wear of Oxinium components from multiple mechanisms including polyethylene liner dissociation and joint instability. This metallosis creates a distinct appearance on radiographic imaging similar to that of an arthrogram. We report 2 cases of metallosis and describe the characteristic radiographic appearance of failed oxidized zirconium implants.

Oxidized zirconium was introduced as an alternative bearing surface to decrease polyethylene wear and reduce aseptic mechanical failure of hip and knee arthroplasties. Oxidized zirconium combines the strength of a metal with wear properties of ceramic, proposing increased survivorship of implant components, and possible decreased rate of revision. Despite a harder surface than cobalt-chromium, the substrate of zirconium is a softer metal. Although uncommon, prior reports have described accelerated wear and severe metallosis after femoral head dislocation in oxidized zirconium total hip arthroplasty; however, this has not been described in total knee arthroplasty. We report a case of an oxidized zirconium total knee arthroplasty failure in a patient with knee instability. This is the first report of catastrophic failure of an oxidized zirconium total knee arthroplasty implant.

Background: Oxidized zirconium (OxZr) has demonstrated excellent mechanical properties in vitro when used against articular cartilage; less coefficient of friction and less chondral damage have been found when compared with cobalt-chromium (CoCr) implants. However, controversy exists as to whether implants with a zirconium femoral component articulate safely with a native patella in total knee arthroplasty (TKA). To answer this question, the clinical and radiographic results were analysed from a group of patients who underwent a TKA with patella retention; the OxZr versus CoCr femoral components were compared., Methods: The present study prospectively evaluated 83 knees of 74 patients from 2009 to 2010. Each patient was evaluated clinically (visual analogue scale, Knee Society score, patellar score) and radiographically (long leg standing radiograph, anterior-posterior and latero-lateral projections, axial view of the patella) pre-operatively and postoperatively with a mean follow-up of 4.47years. The patellar tilt and shift, and progression of patellofemoral osteoarthritis were calculated with the axial view., Results: There were no patient reported adverse reactions and none of the evaluated prostheses failed. Both the clinical and radiographic evaluations showed no statistically significant between-group differences., Conclusion: No adverse events were observed clinically or radiologically. These results justify pursuing the use of oxidized zirconium as an alternative bearing surface for a femoral component associated with patellar retention in TKA., (Published by Elsevier B.V.)

Background: New bearing surfaces for total knee replacement have been described in an attempt to reduce polyethylene wear and secondary osteolysis and improve longevity of implants. Oxidized zirconium is a new material that combines the strength of a metal with the wear properties of a ceramic. However, there are no reports as to who documents the long term results. We report a 10 year follow-up note of a selected series of TKAs with an oxidized zirconium femoral component., Methods: We prospectively follow 98 TKAs performed in 94 patients with an oxidized zirconium femoral component. Five patients (5 knees) had died and 6 (6 knees) were lost to follow-up at a minimum of 2 years (mean, 6.3 years; range, 2-9 years) after the operation. For the remaining 83 patients (87 knees), the minimum follow-up was 10 years (mean, 11.3 years; range, 10.0-12.6 years). In 51 cases (58.6%), a cruciate-retaining implant with a deep-dished, more conforming PE was used, and in 36 cases (41.4%), a posterior-stabilized design was used. The patellae were resurfaced in 32 cases (36.7%) and in 55 cases (63.3%) were left unresurfaced., Results: Survivorship was 97.8% at 10 years postoperatively. Two knees were revised for aseptic loosening of the femoral component. No major complication was observed clinically or radiologically. Mean Knee Society score improved from 36 to 84 and functional score from 37 to 83., Conclusions: Oxidized zirconium femoral component in TKA performs well over the first 10 years following implantation, with excellent survival rates and good clinical and radiological outcomes., Level of Evidence: Level IV, therapeutic study., (Copyright © 2014 Elsevier B.V. All rights reserved.)

The objective of this article is to provide an up-to-date overview of zirconia-toughened alumina (ZTA) components used in total hip arthroplasties. The structure, mechanical properties, and available data regarding the clinical performance of ZTA are summarized. The advancements that have been made in understanding the in vivo performance of ZTA are investigated. This article concludes with a discussion of gaps in the literature related to ceramic biomaterials and avenues for future research., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Background: The surface characteristics of the femoral component affect polyethylene wear in modular total knee replacements. In the present retrieval study, the surface characteristics of cobalt-chromium (CoCr) alloy and oxidized zirconium (OxZr) femoral components were assessed and compared., Methods: Twenty-six retrieved CoCr alloy femoral components were matched with twenty-six retrieved OxZr femoral components for implantation period, body-mass index, patient gender, implant type, and polyethylene insert thickness. The surface damage on the retrieved femoral components was evaluated using a semi-quantitative assessment method, scanning electron microscopy, and contact profilometry., Results: The retrieved CoCr alloy femoral components showed less posterior surface gouging than OxZr femoral components; however, at a higher magnification, the grooving damage features on the retrieved CoCr alloy femoral components confirmed an abrasive wear mechanism. The surface roughness values Rp, Rpm, and Rpk for the retrieved CoCr alloy femoral components were found to be significantly higher than those of the retrieved OxZr femoral components (p≤0.031). The surface roughness values were higher on the medial condyles than on the lateral condyles of the retrieved CoCr alloy femoral components; such a difference was not observed on the retrieved OxZr femoral components., Conclusions: The surface roughness of CoCr alloy femoral components increased while the surface roughness of the OxZr femoral components remained unchanged after in vivo service. Therefore, the OxZr femoral components' resistance to abrasive wear may enable lower polyethylene wear and ensure long-term durability in vivo., Level of Evidence: Level IV., (Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.)