What role does metal allergy sensitization play in total knee arthroplasty revision?

Hypoallergenic Knee Implant Usage and Clinical Outcomes: Are They Safe and Effective?

Background

One of the most debated topics in modern total knee arthroplasty (TKA) is the impact of metal hypersensitivity (MH) as a potential cause of prosthesis failure. Implanting hypoallergenic prostheses to avoid potential problems in suspected cases of MH is one treatment option that can be used in such cases. However, their long-term clinical safety and efficacy are not well proven.

Methods

All literature relevant to modern hypoallergenic implants were reviewed and summarized to provide a comprehensive synopsis. In addition, a detailed literature search was performed on PUBMED, MEDLINE, and Google Scholar to identify all the clinical studies reporting outcomes for hypoallergenic knee implants. Our search was confined to those studies published as full manuscripts in the English language from July 2018 to July 2023.

Results

To minimize the risk of MH, new implant variants have been developed which are either under clinical evaluation or in routine clinical use. These include conventional metal implants with protective coatings (mono- or multilayer) and metal-free implants. However, there is insufficient clinical data to confirm the rationale and effectiveness of using these "hypoallergenic" TKA implants.

Conclusions

Published studies and arthroplasty registry data analyses indicate no significant differences between hypoallergenic and standard TKAs with overall good survival rates. In the future, further high-quality studies are needed to better understand the complexity of this subject.

Hypersensitivity and lymphocyte activation after total hip arthroplasty

In the last decades total hip arthroplasty (THA) has become a standard procedure with many benefits but also a few still unsolved complications, which can lead to surgical revision in 19-23% of cases. Thus, aseptic loosening and metal hypersensitivity remain challenges. The phenomenon of wear debris causes chronic inflammation, which produces osteolysis and aseptic loosening. Wear debris promotes osteoclast production and inhibits osteoblasts by secretion of pro-inflammatory cytokines. Micro-abrasions can be induced by abrasive, adhesive and fatigue wear and cause a liberation of metal ions, which lead to another immune response elicited mostly by macrophages. Another reaction in the neocapsule can be a type IV hypersensitivity reaction to various alloys, containing metals such as nickel, cobalt and chromium. Patch testing and the lymphocyte transformation test (LTT) are not the best diagnostic possibilities to exclude a postoperative hypersensitivity reaction, because of the different alignment of the epicutaneous cells compared to the periprosthetic deep tissue. This hypersensitivity reaction is mostly induced by cytokines, which are secreted by macrophages rather than lymphocytes. In cell cultures and in animal studies, multipotent mesenchymal stem cells (MSC) have been shown to play a role in improving initial implant integration, to limit periprosthetic osteolysis and also to reconstitute peri-implant bone stock during implant revision. Thus, MSC might be used in the future to prolong the durability of THA. A better understanding of the interactions between primary chronic inflammation, corrosion, osteolysis and hypersensitivity is mandatory to develop new therapeutic strategies, aiming at the reduction of the incidence of implant failures. In this article the underlying immunological mechanisms to aseptic loosening are presented.

Titanium niobium nitride knee implants are not inferior to chrome cobalt components for primary total knee arthroplasty at medium-term follow-up

BACKGROUND

Oxidized zirconium (Oxinium), titanium nitride (TiN) or titanium niobium nitride (TiNbN) coated implants became in recent years available for an increasing amount of total knee arthroplasty (TKA) systems. The hypothesis of this study was that the use of TiNbN-coated components would not lead to inferior results compared to conventional implants and that none of the metal hypersensitivity patients receiving TiNbN-coated implants would require revision for metal allergy.

MATERIALS AND METHODS

This retrospective study compared 53 Titanium Niobium Nitride coated TKA with 103 conventional chrome cobalt implants of the same design. Patients were evaluated at a minimal follow-up of 3 years.

RESULTS

No differences in clinical, radiological or patient-reported outcome measurements were observed between these groups. A survivorship of 96% without differences in revision rates was observed at medium-term follow-up of 6.5 years.

DISCUSSION

Metal allergy leading to contact or generalized dermatitis after TKA is very rare and usually linked to chrome or cobalt hypersensitivity. Nickel release from knee implants has not been shown to lead to cutaneous symptoms, but unexplained pain and swelling, peri-prosthetic osteolysis and component loosening remain potential issues not fully understood. The use of coated implants eliminates this factor from the diagnostic equation in case of postoperative dissatisfaction.

CONCLUSION

The use of titanium niobium nitride coated implants for primary knee osteoarthritis in self-reported metal hypersensitivity patients shows similar outcomes and survivorship rates as conventional chrome cobalt TKA, with no revisions for allergy at medium-term follow-up.

Metal allergy in primary and revision total knee arthroplasty : a scoping review and evidence-based practical approach

Aims

Metal allergy in knee arthroplasty patients is a controversial topic. We aimed to conduct a scoping review to clarify the management of metal allergy in primary and revision total knee arthroplasty (TKA).

Methods

Studies were identified by searching electronic databases: Cochrane Central Register of Controlled Trials, Ovid MEDLINE, and Embase, from their inception to November 2020, for studies evaluating TKA patients with metal hypersensitivity/allergy. All studies reporting on diagnosing or managing metal hypersensitivity in TKA were included. Data were extracted and summarized based on study design, study population, interventions and outcomes. A practical guide is then formulated based on the available evidence.

Results

We included 38 heterogeneous studies (two randomized controlled trials, six comparative studies, 19 case series, and 11 case reports). The evidence indicates that metal hypersensitivity is a rare complication with some histopathological features leading to pain and dissatisfaction with no reliable screening tests preoperatively. Hypoallergenic implants are viable alternatives for patients with self-reported/confirmed metal hypersensitivity if declared preoperatively; however, concerns remain over their long-term outcomes with ceramic implants outperforming titanium nitride-coated implants and informed consent is paramount. For patients presenting with painful TKA, metal hypersensitivity is a diagnosis of exclusion where patch skin testing, lymphocyte transformation test, and synovial biopsies are useful adjuncts before revision surgery is undertaken to hypoallergenic implants with shared decision-making and informed consent.

Conclusion

Using the limited available evidence in the literature, we provide a practical approach to metal hypersensitivity in TKA patients. Future national/registry-based studies are needed to identify the scale of metal hypersensitivity, agreed diagnostic criteria, and management strategies.

Cite this article: Bone Jt Open 2021;2(10):785–795.

Association of Lumbar Degenerative Disease and Revision Rate following Total Knee Arthroplasty

Recently, a variety of studies have analyzed the potential correlation between lumbar degenerative disease (LDD) and inferior clinical outcomes after total hip arthroplasty. However, there has been limited data concerning the role of LDD as a risk factor for failure after total knee arthroplasty (TKA). The aim of our study was to determine: (1) what is the association of LDDs with TKA failure (all-cause revision) within 2 years of index arthroplasty and (2) if patients with LDD and lumbar fusion are at increased risk of TKA revision within 2 years compared with LDD patients without fusion. Data were collected from the Humana insurance database using the PearlDiver database from 2007 to 2017. To assess aim 1, patients were stratified into two groups based on a prior history of LDD (International Classification of Diseases [ICD]-9 or -10 diagnostic codes). To analyze aim 2, patients within the LDD cohort were stratified based on the presence of lumbar fusion (lumbar fusion Current Procedural Terminology code). All-cause revision rate was 3.4% among LDD patients versus 2.4% of patients with non-LDD (p < 0.001) at 2 years. Following multivariate analysis, LDD patients were at increased risk of all-cause revision surgery at 2 years (odds ratio [OR]: 1.361; 95% confidence interval [CI]: 1.238-1.498; p < 0.001) as well as aseptic loosening (OR: 1.533; 95% CI: 1.328-1.768; p < 0.001), periprosthetic joint infection (OR: 1.245; 95% CI: 1.129-1.373; p < 0.001), and periprosthetic fracture (OR: 1.521; 95% CI: 1.229-1.884; p < 0.001). Among LDD patients, patients who have a lumbar fusion had an all-cause revision rate of 5.0%, compared with 3.2% among LDD with no lumbar fusion patients at 2 years (p = 0.021). Following multivariate analysis, lumbar fusion patients were at increased risk of all-cause revision surgery (OR: 1.402; 95% CI: 1.362-1.445; p = 0.028), aseptic loosening (OR: 1.432; 95% CI: 1.376-1.489; p = 0.042), and periprosthetic fracture (OR: 1.302; 95% CI: 1.218-1.392; p = 0.037). Based on these findings, TKA candidates with preoperative LDD should be counseled that TKA outcome may be impaired by the coexistence of lumbar spine degenerative disease. This is Level III therapeutic study.

Suspected Metal Allergy and Femoral Loosening After Total Knee Arthroplasty: A Diagnostic Dilemma

Metal sensitivity is increasingly prevalent and is associated with negative outcomes after total knee arthroplasty (TKA). Currently, there is no consensus on diagnostic criteria for TKA failure from immune reaction. We present a patient who had pain and aseptic effusion 2 years after TKA. Radiographs were concerning femoral loosening. Lymphocyte transformation testing showed nickel sensitivity. During revision surgery, the femoral component was loose. The histologic aseptic lymphocyte-dominated vasculitis-associated lesion score was 4 with elevated CD4+ lymphocytes, consistent with sensitization. Nickel-free revision implants were used. One year after surgery, the patient is symptom-free. This case has features suggestive of an immune reaction, with femoral loosening, and is illustrative of the diagnostic dilemma. Using a hypoallergenic knee eliminates future concern for nickel sensitivity.

Early Failures of Total Knee Patients with Nickel Allergies Secondary to Carbon Fiber Debris

Aim:

Currently, there are not many studies on the long-term outcomes of the specific implants used in patients with metal hypersensitivities. The purpose of this study is to report a significant number of TKA revision failures with the CFR-PEEK prosthetic knee implant with an anatomic hinge.

Background:

Patients can experience multiple issues following a primary Total Knee Arthroplasty (TKA). A growing body of research is finding a correlation between primary TKA failure and metal hypersensitivity, most commonly with nickel and cobalt. Because of this, knee prosthetics are being made from hypoallergenic metals, such as zirconium nitride (ZrN), to minimize the number of failures due to metal allergy. Given the relatively new development of the hypoallergenic prostheses, there is sparse data about their overall success.

Objective:

The purpose of this study is to report a significant number of TKA revision failures with the CFR-PEEK prosthetic knee implant with an anatomic hinge.

Methods:

In this study, we analyzed the sequelae of 84 patients between May 2015 to June 2020 who received a total knee revision due to a failed primary TKA with metal hypersensitivity. These patients were revised with the rotating anatomic hinge knee system, which consisted of Carbon Fiber Reinforced Poly-Ether-Ether-Ketone (CFR-PEEK implant) coated with a ZrN, Zirconium, and Chrome Nitride multi-layer surface coating with 30% polyacrylonitrile fiber content. The patients requiring an additional revision operation presented with increasing pain that showed evidence of osteolysis on plain radiographs, CT imaging, positive indium labeled WBC scans and increased uptake on bone scan. Intraoperatively, an open incisional biopsy of the surgical bed was obtained, followed by radical debridement and implantation of porex knee prosthesis. In addition, intraoperative findings included black debris that grossly stained the surrounding synovial tissue black, indicative of wear and debris from carbon fiber bearings and the anatomic hinge. Histology of the intraoperative biopsy showed the accumulation of black debris in the histiocyte, fibrosis, and perivascular cuffing of lymphocytes and multinucleated giant cells stained with black debris.

Results:

Of the 84 patients, 22 failed, requiring an additional revision procedure, equating to a 26 percent failure rate of the CFR-PEEK implant, averaging 25 months to failure.

Conclusion:

This study was meant to report the extremely high failure rate of the anatomic hinge secondary to carbon fiber debris. Perhaps carbon fiber-laden implants are not as good an option for total knee revision prosthesis because of the high failure rate compared to those with polyethylene in their hinge mechanism.