A Unique Case of Extra-articular Extravasation of Metal Into the Lower Leg Resulting From Oxidized Zirconium Wear Particles From Total Knee Arthroplasty

Abstract

With an increasing number of joint replacements and the evolution of orthopaedic implants and hardware, there is increased occurrence and awareness of metal-related sensitivity. This has resulted in the development of devices using a variety of different materials to coat the implant. One popular option is to cover the metallic surface with a ceramic. One commercially available ceramic-coated prosthesis is coated with oxidized zirconium, with the trade name Oxinium. Although pseudotumor and metallosis resulting from ceramic joint arthroplasty implants have been documented, there is limited information on the occurrence of metallosis resulting from ceramic-coated knee implants. The purpose of this case report is to discuss a potential differential diagnosis for lower leg mass after total knee arthroplasty and to present a novel case of catastrophic failure of an Oxinium-coated total knee prosthesis (Smith and Nephew) that resulted in metallosis with extra-articular extravasation along the extensor digitorum longus tendon.

The Oxinium Arthrogram: A Sign of Oxidized Zirconium Implant Failure

“…A recent article by Purcell et al. [ 18 ] described extra-articular extravasation of oxidized zirconium particles after a failed TKA. This article differs in that there was only small articular sided wear on the femoral condyles and no failure of the polyethylene.…”

“…Greco and Berend published a case of a dissociated polyethylene from a medial unicompartmental knee arthroplasty that resulted in rapid wear of the oxidized zirconium femoral component and demonstrated a large Oxinium arthrogram [17]. A recent article by Purcell et al [18] described extra-articular extravasation of oxidized zirconium particles after a failed TKA. This article differs in that there was only small articular sided wear on the femoral condyles and no failure of the polyethylene.…”

Equally low blood metal ion levels at 10-years follow up of total hip arthroplasties with Oxinium, CoCrMo and stainless steel femoral heads. Data from a randomized clinical trial

“…There are reports that Oxinium femoral heads are susceptible to damage upon hip dislocation with subsequent increased polyethylene wear (Gibon et al 2013). A recent case report showed catastrophic failure of an Oxinium-coated total knee prosthesis (Smith and Nephew) that resulted in metallosis with extra-articular extravasation (Purcell et al 2020). In a systematic review and meta-analysis, Oxinium femoral heads did not lead to lower polyethylene wear rate or higher survival rate, when compared with CoCr femoral heads in patients treated with THA (Malahias et al 2019).…”

Similarly low blood metal ion levels at 10‐years follow‐up of total hip arthroplasties with Oxinium, CoCrMo, and stainless steel femoral heads. Data from a randomized clinical trial

“…There are reports that Oxinium femoral heads are susceptible to damage upon hip dislocation with subsequent increased polyethylene wear 25 . A recent case report showed catastrophic failure of an Oxinium‐coated total knee prosthesis (Smith and Nephew) that resulted in metallosis with extra‐articular extravasation 26 . In a systematic review and meta‐analysis, Oxinium femoral heads did not lead to lower polyethylene wear rate or higher survival rate, when compared with CoCrMo femoral heads in patients treated with THA 27 .…”