Metallosis following a clip breakage in a total knee arthroplasty implant: A case report

Abstract

BACKGROUNDMetallosis describes the build-up of metal debris in the soft tissues after a period of metal on metal articulation. This debris can be asymptomatic or lead to catastrophic implant failure, which can present acutely, as in this case, or over a period of time. This report highlights how a metal clip used to hold the polyethylene liner to the tibial base plate broke 5 years after implantation, dislodged from its original position and went on to cause post-operative knee metallosis.CASE SUMMARYWe present a case of a 63 year old lady admitted to our unit with an acute onset of right knee pain on top of a previous right total knee replacement. There was no associated trauma and examination revealed an erythematous, swollen and tender right knee. Blood investigations went on to display significantly raised inflammatory markers, raising the suspicion of a septic joint. This patient was taken to theatre for a knee arthrotomy and lavage of what was thought to be a septic joint when she was found to have extensive knee metallosis. On further inspection the metal clip, normally used to secure the polyethylene insert to the tibial base plate, had broken, dislodged, and had triggered this response. After the initial washout, this lady went back to theatre, once the appropriate implants were in stock, for an exchange of liner and metal clip.CONCLUSIONThis case highlights this very rare complication which has never been reported in the literature and the success of this patient’s management.

Metallosis After Oxinium Total Knee Arthroplasty in a Patient With Rheumatoid Arthritis: A Case Report

“…Usually, the breakdown and loosening of components are inevitable because of progressive metal and polyethylene degradation [ 6 ]. However, deterioration of the opposite compartment and polyethylene tibial insert wear may occur early causing metal-on-metal articulation, aseptic loosening, and metallosis [ 9 ]. A major cause of loosening is attributed to the failure of the polyethylene locking mechanism which impairs the control of the interface micromotion and causes a dissociation of the polyethylene insert from the tibial base plate and an unintended articulation of metal components [ 10 ].…”

“…Some designs use a metal clip to hold the polyethylene liner to the tibial base plate to provide more stability. Nevertheless, it has been reported that the breakage of this component is a potential trigger for prosthesis loosening and post-operative knee metallosis [ 9 ].…”

“…This Oxinium Genesis II prosthesis has three major components: a femoral made of zirconium and niobium (oxidized surface into zirconium oxide ceramic), a patellar made of polyethylene, and a modular tibial one with a UHMWP (ultrahigh molecular weight polyethylene) insert in a titanium-aluminium-vanadium alloy base plate [ 1 ]. Hypersensitivity to metal is common in up to 15% of the population [ 9 ]. Metallic implants may trigger a type IV hypersensitivity reaction in which implant debris causes macrophage activation with subsequent release of interleukin (IL)-1b, tumour necrosis factor (TNF), IL-6, and IL-8 activating osteoclasts leading to cutaneous eczematous eruptions, device failure, chronic inflammation and pain, loosening of joint prostheses, osteolysis, metallosis, excessive periprosthetic fibrosis, and muscular necrosis [ 1 , 10 ].…”

Potentially toxic metallic wear nanoparticles and trace metal ions release from metal-on-metal orthopedic implants in the human biological specimens: An Overview of in vivo and ex vivo clinical studies

“…The eventual outcome of this condition is local tissue damage and changes in tissue characteristics as a result of direct toxic effects and biologic reactions to metallic nanoparticles [29,30]. Lately, cases were diagnosed patients after total knee replacement [31][32][33][34][35][36][37], knee joint load absorber [38], and total hip replacement [39][40][41][42][43][44]. Although, metallosis is a well-established complication of MoM implants, emerging data reveal that it also may be a problem in non-MoM implants such as either metal-on-polyethylene (MoP) or ceramic-on-polyethylene (CoP) implants, perhaps related to modular corrosion [45,46].…”

Late Onset Metallosis after Revision Total Knee Arthroplasty with Metal-Backed Patellar Component In Situ

“…Metallosis can cause a wide variety of local and systemic symptoms, including pseudotumours and neurocognitive disorders [1,2]. Metallosis in TKA has been described in a few case reports with different causes, including clip breakage of the insert, insert wear, and failure of the metal-backed patellar components [3][4][5].…”