Metal hypersensitivity in total hip and knee arthroplasty: Current concepts

Metal hypersensitivity in foot & ankle orthopaedic surgery: A systematic review

Introduction

Metal hypersensitivity affects 10-15% of individuals. Orthopaedic implants contain various metals and, therefore, metal hypersensitivity may impact patient outcomes.

Purpose

We report a systematic review of the literature on metal hypersensitivity in patients undergoing foot and ankle (F&A) surgery. Our goal is to provide an overview presenting symptoms, diagnostic methods, treatment, and clinical outcomes.

Methods

A comprehensive literature search of Ovid MEDLINE and EMBASE was performed from its inception (01-Jan 1966) to 23-Nov 2021. MeSH search terms on F&A were used including orthopaedic surgeries, metal types, and hypersensitivity. All full-text, English, experimental and observational studies reporting on metal hypersensitivity in the context of foot and/or ankle surgeries using metallic orthopaedic devices were included. Article screening, critical appraisal, and data extraction was performed by two reviewers. Disagreements were resolved by a third reviewer.

Results

Fifteen studies were identified, reporting on 45 patients (18 male and 27 female). Median age was 58 years and mean follow-up was 20.8 months. 42 static and three arthroplasty implants were included. In total, 19 patients (42.2%) were diagnosed with metal hypersensitivity to a constituent of their implant, including two (4.4%) patients diagnosed without metal hypersensitivity testing. Twenty-six patients (57.8%) tested negative to their metal implant components. Of the 19 patients allergic to a constituent of their implant, 14 underwent hardware removal and improved. Four patients were asymptomatic and the last was symptomatic, but not revised. Of these, 23 patients retained their hardware (eight with skin reactions) and two symptomatic patients underwent hardware removal.

Conclusion

Metal hypersensitivity in the context of F&A surgery is not widely reported. It should be a differential diagnosis in patients who present with hypersensitivity-type symptoms once infection and mechanical failure are ruled out. This data informs a comprehensive algorithm for identifying and treating metal hypersensitivity in F&A patients.

Level of evidence

Level IV.

Difficult Preoperative Diagnosis of Suspected Metal Hypersensitivity in a Case with Early Failure of Bipolar Hemiarthroplasty

Background

Metal hypersensitivity is a rare complication after total hip arthroplasty (THA), and no reliable diagnostic method for metal hypersensitivity to orthopedic metal implants has yet been established. Case report. A 57-year-old woman underwent hemiarthroplasty using a metal implant despite a skin allergy to metal jewelry. Two years after surgery, the patient developed early hemiarthroplasty failure and refractory erythema. Although the patient was clinically suspected to have a hypersensitivity to metal, the preoperative screening test was negative, and patient underwent revision surgery with cemented THA. Postoperatively, the erythema as well as her hip pain disappeared completely.

Conclusion

Patients with clinically suspected metal hypersensitivity should undergo primary and revision total hip arthroplasty using hypoallergenic implants regardless of preoperative screening results.

Hypersensitivity reactions to metals in spine surgery

Hypersensitivity to orthopedic devices is a rare condition with an underestimated incidence due to the lack of diagnostic guideline and ambiguous clinical manifestations. Although hypersensitivity to metal is common, a few cases of hypersensitivity reactions have been reported after spinal instrumentation. Spinal fusion and stabilization require a wide range of devices such as screws, wires, bands, and artificial disk replacement devices. Spinal instrumented surgeries are different from total joint arthroplasty in several aspects such as degree and pattern of motion, loading environment, and adjacent tissues with distinct characteristics. The interval for hypersensitivity reactions to occur after spinal metallic implantation is usually weeks to months. The present review covers the topic of hypersensitivity reactions that have been reported after spinal surgeries with the focus on cutaneous presentations.

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.

Poor Correlation Among Metal Hypersensitivity Testing Modalities and Inferior Patient-Reported Outcomes After Primary and Revision Total Knee Arthroplasties

Background

Metal allergy testing may influence clinical decision-making for patients undergoing a total knee arthroplasty (TKA). Limited data were found to examine the consistency of available testing modalities. This study compares different metal allergy test results and clinical outcomes after primary and revision TKAs in patients with and without metal hypersensitivity.

Methods

Primary (n = 28) and revision (n = 20) TKA patients receiving hypoallergenic implants for metal allergies diagnosed by skin patch testing (SPT), lymphocyte proliferation testing (LPT), or lymphocyte transformation testing (LTT) were retrospectively reviewed. The agreement between tests was assessed by percentage and kappa statistic within patients who used multiple testing modalities. Postoperative clinical outcomes of these patients were compared to those of patients without metal hypersensitivity matched by age (±5 years), body mass index (±5), gender, and follow-up duration (±2 years).

Results

SPT and LPT showed weak agreement for nickel and minimal agreement for cobalt. SPT and LTT showed minimal agreement for nickel; weak agreement for titanium, bone cement, vanadium, and zirconium; but strong agreement for chromium and cobalt. LPT and LTT agreement was weak. Compared to matched controls, metal hypersensitivity patients undergoing primary TKAs with hypoallergenic implants experienced less improvement in Knee Society Scores, Veterans RAND 12 physical component scores, and range of motion. Patients undergoing revision TKAs for multiple indications including metal hypersensitivity had worse clinical outcomes with significantly worse improvements in Knee Society functional scores compared to matched controls.

Conclusions

Metal allergy tests produce conflicting results. Hypersensitivity patients may experience inferior clinical outcomes even with hypoallergenic implants. Clinician awareness may influence the choice of testing and improve preoperative counseling of this patient population.

The effect of Nickel hypersensitivity on the outcome of total knee arthroplasty and the value of skin patch testing: a systematic review

Background

To assess the Nickel sensitizing potential of total knee arthroplasty (TKA), explore the relationship between hypersensitivity and clinical outcomes, and evaluate the utility of skin patch testing pre- and/or postoperatively.

Materials and methods

A literature search was performed through EMBASE, Medline and PubMed databases. Articles were screened independently by two investigators. The level of evidence of studies was assessed using the Oxford Centre for Evidence-Based Medicine Criteria and the quality evaluated using the Methodological Index for Non-randomized Studies and Cochrane risk-of-bias tools.

Results

Twenty studies met the eligibility criteria, reporting on 1354 knee arthroplasties. Studies included patients undergoing primary or revision TKA, pre- and/or postoperatively, and used patch testing to identify Nickel hypersensitivity. Prevalence of Nickel hypersensitivity ranged from 0% to 87.5%. One study compared the prevalence of Nickel hypersensitivity in the same patient group before and after surgery and noted newly positive patch test reactions in three patients (4.2%). Three studies reported lower prevalence of Nickel hypersensitivity in postoperative patients compared to preoperative ones. Seven studies suggested that hypersensitivity might cause adverse clinical outcomes, but six did not support any relationship. Seven studies recommended preoperative patch testing in patients with history of metal allergy, and nine concluded that testing may be valuable postoperatively.

Conclusions

Patients undergoing TKA with no prior history of metal hypersensitivity do not seem to be at an increased risk of developing Nickel hypersensitivity, and there is conflicting evidence that patients with pre-existing hypersensitivity are more likely to experience adverse outcomes. Patch testing remains the most commonly used method for diagnosing hypersensitivity, and evidence suggests preoperative testing in patients with history of metal allergy to aid prosthesis selection, and postoperatively in patients with suspected hypersensitivity once common causes of implant failure have been excluded, since revision with hypoallergenic implants may alleviate symptoms.

A rare case of oxidized zirconium - All polyethylene tibia unicompartmental arthroplasty failure: A case report

Oxidized zirconium (Oxinium) implants has been claimed as the best material in terms of wear reduction. However, longevity of an all polyethylene uni knee arthroplasty (UKA) has been a long debate. We reported a rare case of 74 year old female who was performed all polyethylene UKA 6 years prior and fell 3 months prior. After the incident, patient was wheel-chair ridden afterwards. There was no evidence of fracture upon conventional radiography examination. Conversion of UKA to total knee replacement (TKA) was performed and patient was able to walk with aid after the surgery. The failed Oxinium all polyethylene UKA failure in this case is suspected due osteoarthritis progression.

Metal Hypersensitivity or Missed Periprosthetic Joint Infection? A Critical Review

The World Association Against Infection in Orthopedics And Trauma (W.A.I.O.T.) Study Group on Bone And Joint Infection Definitions Metal hypersensitivity (MHS) has been investigated by several authors as a possible reason for painful total joint arthroplasty, with controversial results. Periprosthetic joint infection (PJI) is another possible source of unexplained pain and implant failure that may be difficult to diagnose if not properly investigated. We performed this critical review to assess whether the current literature on MHS includes an adequate diagnostic workup to discern metal allergy from PJI. The results of this review highlight the importance of assessing patients for PJI before making a diagnosis of MHS and emphasize that the methods currently used to exclude PJI are substantially inadequate. Therefore, well-designed clinical trials with adequate diagnostic protocols and definitions of PJI that can differentiate MHS from low-grade PJI are needed. [Orthopedics. 2022;45(2):e73-e78.].

THE METHOD OF ATOMIC FORCE MICROSCOPY AS A POSSIBLE TOOL FOR TESTING THE BIOCOMPATIBILITY OF IMPLANTS IN TRAUMATOLOGY AND ORTHOPEDICS PRACTICE

OBJECTIVE

The aim: To establish the possibility of using the atomic force microscope (AFM) to predict the body's reaction to the implant.

PATIENTS AND METHODS

Materials and methods: A total of 32 patients, 22 men and 10 women, the average age of the patients was 55±6 years, were included in the study. They performed pre- and post-operative testing of the biocompatibility of orthopedic implant materials with the patient's body with the help of AFM.

RESULTS

Results: According to the research, an increase in pro-inflammatory factors was found, which may indicate a constant inflammatory process, which is probably related to the presence of the implant.

CONCLUSION

Conclusions: On the basis of atomic force spectroscopy, an express method of testing biomaterials for compatibility with the body of a specific recipient and studying the effect of the reactions of recipient tissues on the surface of various implants has been developed. The obtained results can be useful in planning further clinical studies.

Reconstruction or replacement? A challenging question in surgical treatment of complex humeral head fractures in the elderly

INTRODUCTION

Surgical treatment of complex humeral head fractures in the elderly is challenging due to osteoporotic bone, comorbidities and reduced compliance. The treatment strategy (reconstruction versus replacement) should allow for a functional aftercare and result in a high patient satisfaction. Major complications leading to surgical revision are crucial and should be avoided. The purpose of this study was to analyse the major complication rate leading to surgical revision and the patient-based outcome in complex humeral head fractures of the elderly population treated either using locking plate fixation (LCP) or reversed total shoulder arthroplasty (rTSA).

MATERIALS AND METHODS

All patients older than 65 years surgically treated due to a four-part fracture of the proximal humerus between 2003 and 2015 were enrolled in our retrospective study. Major complications and revision rates were recorded and functional outcome was assessed using the Munich Shoulder Questionnaire (MSQ) allowing for qualitative self-assessment of the Shoulder Pain and Disability Index (SPADI), of the Disability of the Arm, Shoulder and Hand (DASH) score and of the Constant Score.

RESULTS

A cohort of 103 patients with a mean age of 73.4 ± 6.2 years suffering from four-part fractures of the humeral head were enrolled. 63 patients were treated using the LCP fixation compared to 40 rTSAs. There were no significant differences in the patient-reported functional outcome. The revision rate was significantly higher in the LCP group (10/63; 15.9%) compared to the rTSA group (1/40; 2.5%). Reasons for revision were avascular head necrosis, cut-out of screws, secondary dislocation of the greater tuberosity and hypersensitivity to metal.

CONCLUSIONS

Reversed total shoulder arthroplasty and locking plate fixation are both established surgical procedures for the management of complex proximal humerus fractures in the elderly leading to similar functional results. However the revision rate in the rTSA group was significantly lower. Primary rTSA should, therefore, be favoured in multimorbid elderly patients with an increased complication risk to avoid repeated anaesthesia.

Nickel hypersensitivity and skin patch testing in total hip replacement surgery: a systematic review

Approximately 60,000 cemented femoral stems are implanted in the UK each year with the majority being manufactured from stainless steel containing 10–15% nickel. Nickel hypersensitivity has been reported in up to 13% of the general population and there is a concern that nickel hypersensitivity might adversely affect the outcome of total hip replacement (THR). We reviewed the current literature on the potential link between nickel hypersensitivity and THR complications, and the usefulness of patch testing.

We conducted a literature search in PubMed, MEDLINE and EMBASE databases. The level of evidence and the quality of the selected studies were assessed using the Oxford Centre for Evidence-Based Medicine Criteria and the Methodological Index for Non-Randomised Studies tool, respectively.

Twenty-six studies met the inclusion criteria, reporting on 1852 patients who underwent primary or revision THR. All studies detailed skin patch testing and recorded prevalence of nickel hypersensitivity from 1.5% to 33.3%. Five studies reported a rise in Nickel hypersensitivity following THR, while four reported a decreased prevalence post-operatively. Eight studies concluded that metal hypersensitivity could have developed following THR, while seven studies did not support a link between metal hypersensitivity and THR complications. Four of the studies recommended routine patch testing pre-operatively, but three others concluded that routine patch testing was not indicated.

We have not identified a link between nickel hypersensitivity and THR complications, and the role of patch testing remains unclear. Further large-scale studies would be required to investigate this relationship and to clarify the role of patch testing in facilitating implant selection.

Cite this article: EFORT Open Rev 2021;6:825-838. DOI: 10.1302/2058-5241.6.210051

Prospective Mid-Term Results of a Completely Metal-Free Ceramic Total Knee Endoprosthesis: A Concise Follow-Up of a Previous Report

BACKGROUND

Hypersensitivity reactions are suspected to cause premature aseptic loosening in susceptible patients after total knee arthroplasty. In response, metal-free implants have been developed. The aim of this prospective, observational midterm study was the assessment of a completely metal-free ceramic knee replacement system as a concise follow-up of a previous report.

METHODS

Thirty-eight patients, with anamnestic suspected or documented allergy to the metal used in prosthetic alloys, participated in this 4-year follow-up of the metal-free BPK-S (Peter Brehm) total knee replacement system with ceramic femoral and tibial components. Clinical assessment included Knee Society Score (KSS), Oxford Knee Score, Euro Quol-5D-Visual Analogue Scale (EQ-5D-VAS), and perioperative or postoperative complications and need for revision. The position of the implant, signs of loosening, and leg alignment were assessed radiographically.

RESULTS

All postoperative clinical scores improved significantly from baseline to 48-month follow-up examination. The Oxford Knee Score improved from 39 to 15 points. The KSS improved from 99 to 195 points (the KSS knee score 42.5 to 96 and the KSS function score 60 to 100). The EQ-5D improved from 12 to 7 points; the EQ-VAS improved from 52.5 to 97 points. No allergic reactions could be detected. Radiologically, a median preoperative varus deformity of 5° improved to 0° at 4-year follow-up. Radiolucent lines appeared around uncemented areas with no clinical symptoms.

CONCLUSION

The fully metal-free BPK-S Integration ceramic knee replacement system exhibits excellent immuno-allergological compatibility, offering a safe option for patients with prior hypersensitivity reactions to metallic materials. Full cementation of all components is recommended to avoid radiolucent lines around the implant.

Cobalt ions induce metabolic stress in synovial fibroblasts and secretion of cytokines/chemokines that may be diagnostic markers for adverse local tissue reactions to hip implants

Adverse local tissue reactions (ALTRs) are a prominent cause of hip implant failure. ALTRs are characterized by aseptic necrosis and leukocyte infiltration of synovial tissue. The prevalence of ALTRs in hips with failing metal implants, with highest rates occurring in patients with metal-on-metal articulations, suggests a role for CoCrMo corrosion in ALTR formation. Although hypersensitivity reactions are the most accepted etiology, the precise cellular mechanism driving ALTR pathogenesis remains enigmatic. Here we show that cobalt ions released by failing hip implants induce mitochondrial stress and cytokine secretion by synovial fibroblasts: the presumptive initiators of ALTR pathogenesis. We found that in-vitro treatment of synovial fibroblasts with cobalt, but not chromium, generated gene expression changes indicative of hypoxia and mitophagy responses also observed in ALTRs biopsies. Inflammatory factors secreted by cobalt-exposed synovial fibroblasts were among those most concentrated in ALTR synovial fluid. Furthermore, both conditioned media from cobalt-exposed synovial fibroblasts, and synovial fluid from ALTRs patients, elicit endothelial activation and monocyte migration. Finally, we identify the IL16/CTACK ratio in synovial fluid as a possible diagnostic marker of ALTRs. Our results provide evidence suggesting that metal ions induce cell stress in synovial fibroblasts that promote an inflammatory response consistent with initiating ALTR formation. STATEMENT OF SIGNIFICANCE: We demonstrate that the cytotoxic effects of cobalt ions on the synovial cells (fibroblast) is sufficient to trigger inflammation on hip joints with metal implants. Cobalt ions affect mitochondrial function, leading to the auto phagocytosis of mitochondria and trigger a hypoxic response. The cell's hypoxic response includes secretion of cytokines that are capable of trigger inflammation by activating blood vessels and enhancing leukocyte migration. Among the secreted cytokines is IL-16, which is highly concentrated in the synovial fluid of the patients with adverse local tissue reactions and could be use as diagnostic marker. In conclusion we define the cells of the hip joint as key players in triggering the adverse reactions to hip implants and providing biomarkers for early diagnosis of adverse reactions to hip implants.

Hypersensitivity in patients receiving metal implants: a scoping review protocol

OBJECTIVE

The objective of this scoping review is to gather the available evidence on metal hypersensitivity to determine the extent of the problem and identify gaps in the evidence about screening practices.

INTRODUCTION

Hypersensitivity to metal was first reported in 1966. Since this time, the use of metal in prosthetic devices has increased with an associated rise in reported hypersensitivity reaction to other metals. Symptoms of metal hypersensitivity can be subtle, and it is unclear whether clinicians are aware of or routinely ask patients about metal hypersensitivity when documenting allergies. This can lead to a delay in diagnosis, which puts patients at risk of poor outcomes. Hence, there is a need to map the available evidence on hypersensitivity reaction in people who receive metallic device implantation.

INCLUSION CRITERIA

The review will consider studies that include patients who undergo procedures involving metal implantation. The concept to be explored is hypersensitivity following a procedure that involves the implementation of a device with metal components. Implementation is defined as permanent integration of a foreign (non-biological) object into the human body to restore function.

METHODS

The proposed scoping review will be conducted in accordance with JBI methodology for scoping reviews. Searches will be generated in multiple databases and updated as needed. Gray literature and organizational websites will also be searched. Titles, abstracts, and full articles will be screened according to the inclusion criteria. Studies published in English from 1960 to the present will be included. Data will be extracted and findings will be presented in tabular form with a narrative summary.

The Oxinium Arthrogram: A Sign of Oxidized Zirconium Implant Failure

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.

Sensitization to Implant Components Is Associated with Joint Replacement Failure: Identification and Revision to Nonallergenic Hardware Improves Outcomes

BACKGROUND

Over 90% of one million annual US joint replacements are highly successful. Nonetheless, 10% do poorly owing to infection or mechanical issues. Many implant components are sensitizers, and sensitization could also contribute to implant failure.

OBJECTIVE

To determine the prevalence of implant sensitization in joint failure patients, their clinical characteristics, and implant revision outcomes. We hypothesized that sensitized patients would improve when revised with nonallergenic materials.

METHODS

We prospectively enrolled 105 joint failure patients referred by orthopedic surgeons who had already excluded infection or mechanical causes. Patients provided informed consent, completed a history and physical examination, patch testing to metals and bone cement, and a nickel lymphocyte proliferation test. A study coordinator was able to contact 64% of patients (n = 67) 9 to 12 months later to evaluate outcomes.

RESULTS

A total of 59% were sensitized to an implant component: 32% to metal and 37% to bone cement. The nickel lymphocyte proliferation test was 60% sensitive and 96% specific in diagnosing nickel sensitization. Most sensitized subjects reported no or uncertain histories of reactions to a specific material. Implant sensitized patients were younger and reported previous eczema, joint itching, and implant loosening. By 9 to 12 months later, most patients with a revised implant (revised) described significant improvement (16 of 22 revised for sensitization [P = .0003] vs 9 of 13 revised without sensitization [P = .047]) compared with patients without implant revision). All revised patients with sensitization used components to which they were not sensitized. Pain (P = .001), swelling (P = .035), and instability (P = .006) were significantly reduced in the revised sensitized group.

CONCLUSIONS

Sensitization to implant components is an important cause of unexplained joint replacement failure. Joint revisions based on sensitization information resulted in significant improvements.

Metal Hypersensitivity in Joint Arthroplasty

Metal hypersensitivity in joint arthroplasty is a very controversial topic with limited evidence. With increasing numbers of joint replacements being done annually, a clear understanding of the pathogenesis, clinical picture, preimplant screening, postimplant workup, and treatment plan is crucial. This review article looked at all the available evidence regarding metal hypersensitivity and summarized the key findings. An algorithm was also proposed for preimplant screening, postimplant workup, and management.

Metal hypersensitivity screening among frontline healthcare workers-A descriptive study

AIMS AND OBJECTIVES

The study aims were to (a) assess allergy screening practices, (b) determine the awareness of metal hypersensitivity among frontline healthcare workers and (c) examine perceived barriers to implementing metal hypersensitivity screening into clinical practice.

BACKGROUND

Adverse device-related events, such as hypersensitivity to metals, are well documented in the literature. Hypersensitivity to metal is a type IV T-cell-mediated reaction that can occur after cardiac, orthopaedic, dental, gynaecological and neurosurgical procedures where a device with metal components is implanted into the body. Patients with hypersensitivity to metal are likely to experience delayed healing, implant failure and stent restenosis. Identifying patients with a history of metal hypersensitivity reaction could mitigate the risk of poor outcomes following device implant. Yet in clinical practice, healthcare workers do not routinely ask about the history of metal hypersensitivity when documenting allergies. The existing literature does not report why this is not included in allergy assessment.

DESIGN

Following the STROBE checklist, a cross-sectional, descriptive study was conducted.

METHODS

Frontline healthcare workers were recruited using professional contacts and social online media to complete an online questionnaire. Quantitative data were summarised descriptively while thematic analysis was used to examine barriers to implementation.

RESULTS

Three hundred forty-five participants from 14 countries completed the questionnaire, with the majority (187/54%) practicing in Canada, in general medicine and intensive care units. Ninety per cent of the participants did not routinely ask about metal hypersensitivity when evaluating allergy history. Of the respondents, 86% were unaware of the association between metal hypersensitivity and poor patient outcomes. After presented with the evidence, 81% indicated they were likely or very likely to incorporate the evidence into their clinical practice. Common themes about barriers to implementing were 'Standards of Practice', 'Knowledge' and 'Futility of Screening'.

CONCLUSION

The findings suggest lack of awareness as the main reason for not including metal in routine allergy assessment.

Ten-year outcomes of a nitrided Ti-6Al-4V titanium alloy fixed-bearing total knee replacement with a highly crosslinked polyethylene-bearing in patients with metal allergy

BACKGROUND

Metal hypersensitivity in patients with a total knee arthroplasty (TKA) is a rare condition and a very controversial topic. Despite the lack of data concerning the real effective impact of allergy on TKA failures, most of the manufactures offer the choice of 'non-allergenic' implants both for primary and revision TKA, some of which provide the same designs and surgical techniques as the conventional ones. Only a few studies are available on outcomes on these 'hypersensitivity-friendly' implants and even fewer specifically on allergic patients with a mid- to long-term follow-up.

METHODS

Between 2007 and 2015, we enrolled 72 patients (57 females, 15 males), who underwent TKA treated with a non-allergenic posterior-stabilized (PS) total knee implant for a declared and proven metal allergy. Patients were followed clinically and radiographically for a mean 10 years of follow-up.

RESULTS

With revision as an endpoint the Kaplan-Meier survival estimate showed a survival rate of 97.2% at five years and 95.1% at 10 years. Significant improvements in range of motion (ROM), Knee Society Scoring (KSS) and Hospital for Special Surgery (HSS) knee scores were registered at final follow-up (P < 0.0001). At final follow-up validated Patient-Reported Outcome Measures (PROMs) showed the following scores: Oxford Knee Score (OKS) 42.1, EQ5D 0.80, EQ VAS 80.1, Forgotten Joint Score 71.2.

CONCLUSIONS

This nitrided Ti-6Al-4V titanium alloy fixed-bearing total knee replacement with a highly crosslinked polyethylene-bearing showed interesting results and survival rates in patients with metal allergy at mid- to long-term follow-up.

Systemic Effects of Metals Released from Arthroplasty Implants – a Brief Summary

In recent years, increasing concern has been raised regarding potential systemic toxicity of metals released from arthroplasty implants. A lack of valid metal thresholds for human (organ) toxicity and the prospect of multi-decade survival of modern hip and knee replacements pose special challenges. Indeed, evidence of systemic effects of metals released from such implants is largely missing. Systemic cobalt exposure has repeatedly been associated with cardiotoxic and neurotoxic effects, and also with thyroid dysfunction. The toxic potential of chromium is considered less pronounced. Yet, in arthroplasty there is usually a co-exposure to chromium and cobalt which complicates evaluation of element-specific effects. Toxicity of titanium dioxide nanoparticles has been subject to debate among international regulatory authorities. Their wide use in a variety of products in everyday life, such as toothpaste, cosmetics and food colorants, hampers the assessment of an arthroplasty-induced systemic titanium exposure. To date there is no clear evidence for systemic complications due to titanium dioxide released from arthroplasty implants. Release of further metals such as tantalum, niobium, nickel, vanadium and zirconium from hip and knee replacement implants has been described occasionally, but systemic effects of respective long-term exposure scenarios are unknown. Generally, the characterization of all released metals regarding their chemical and physical specifications is critical for the evaluation of potential systemic risks. Systematic studies investigating the accumulation of metals relevant in arthroplasty in different organs/organ systems and the biological consequences of such accumulations are urgently needed.

Early Outcomes of an Alternative Bearing Surface in Primary Total Knee Arthroplasty in Patients with Self-reported Metal Allergy

Background

Most implants for total knee arthroplasty (TKA) are comprised of alloys that contain nickel. Controversy exists whether metal allergies produce negative effects and affect clinical outcomes. The purpose of this study was to retrospectively review a minimum 2-year follow-up with an ion-bombarded titanium TKA implant in patients with reported metal sensitivity.

Methods

A retrospective review of patients who underwent primary TKA with the ion-bombarded titanium Vanguard (Zimmer Biomet, Warsaw, IN) implant with 2-year minimum follow-up was performed from 2008 through 2017. The query revealed 346 patients (451 knees) with minimum 2-year follow-up. The mean age was 64.7 years, the mean body mass index was 35.1 kg/m², and 95% of patients were women.

Results

The mean follow-up was 4.6 years. The mean range of motion improved from 109° to 112° (P = .03), University of California Los Angeles activity scale from 4.1 to 5.1 (P < .001), Knee Society Clinical scores from 36 to 89 (P < .001), and Knee Society Functional scores from 48 to 73 (P < .001). There were 5 (1.1%) revisions: 2 infections (2-staged exchange), 1 tibial revision for aseptic loosening after a fall, and 2 bearing exchanges for instability. Other surgeries were open reduction internal fixation of periprosthetic fracture, 1 arthroscopic release of snapping popliteus, and 4 local wound incision and debridement (2 superficial infections and 2 nonhealing wounds). Manipulation under anesthesia was required in 27 (6%) patients.

Conclusions

These early results are encouraging for the use of alternative metal titanium alloy implants in metal-sensitive patients undergoing primary TKA. At 4.6 years of mean follow-up, patients had substantial improvement in the range of motion and clinical outcomes with a low frequency of revision.

Prevalence of metal hypersensitivity in patients with shoulder pathologies

BACKGROUND

To date, medical history and dedicated questionnaires are the fastest and easiest way to assess risks of joint metal hypersensitivity. No published studies determined the overall prevalence of hypersensitivity to metals in patients with shoulder pathologies. The purpose of this study was therefore to estimate the prevalence of metal hypersensitivity reported by patients with shoulder pathologies, and to identify patients at risk of joint metal hypersensitivity based on a dedicated questionnaire.

METHODS

The authors prospectively asked all adult patients consulting for shoulder pathologies between September 2018 and February 2019 at 10 centers to fill in a form. The main outcome was "reported hypersensitivity to metals," comprising belt buckles, coins, earrings, fancy jewelry, keys, leather, metallic buttons, piercings, spectacles, watch bracelets, or zips.

RESULTS

A total of 3217 patients agreed to fill in the survey, aged 55 ± 16 (range, 18-101) with equal proportions of men (51%) and women (49%), and a majority of patients consulting for cuff pathology (55%). A total of 891 (28%) patients had professions considered at risk for metal hypersensitivity. The most frequently reported metal hypersensitivities were fancy jewelry (15%), earrings (13%), and watch bracelets (9%). A total of 629 (20%) patients, of which the vast majority were women, reported hypersensitivity to 1 or more metals.

CONCLUSIONS

This survey of 3217 patients identified 20% who reported metal hypersensitivities, though only 2.2% had done patch tests. Matching profiles of those with positive patch tests to those with no patch tests revealed that 9.4% of the total cohort had similar sex and self-reported metal hypersensitivities. Factors associated with a positive patch test were female sex, self-reported cutaneous allergy, and self-reported metal hypersensitivity. The clinical applicability of these estimates remains uncertain as there is insufficient evidence that allergy to metal implants can be predicted by questionnaires or patch tests.

A rare case of delayed hypersensitivity reaction to metal ions secondary to a remnant pedicle screw fragment after spinal arthrodesis

Delayed hypersensitivity reaction to metal ions is rare and has been mostly documented among patients undergoing total joint arthroplasty with metal-on-metal bearing surfaces. Nonetheless, to our knowledge, only a few cases associated with spinal arthrodesis have been reported in the literature. The aim of this case report was to describe the clinical features of a rare case of delayed-type hypersensitivity reaction to nickel that occurred after an extraordinarily long period of time (approximately 15 years) after spinal arthrodesis. Here, we present a 38-year-old patient who was referred to us with a diagnosis of delayed-type hypersensitivity reaction to nickel that was established by a skin patch test. The chief sign and symptoms of the patient were allergic contact dermatitis along with intractable, generalized itching that started several months ago. The medical history revealed that the patient had undergone spinal arthrodesis using rods and pedicle screws approximately 15 years ago, followed by revision surgery to remove the implants. Radiological examination showed a remnant pedicle screw fragment at the third lumbar vertebra that had broken off during the removal of implants nine years ago. However, the signs and symptoms of metal hypersensitivity started shortly before the patient was referred to our hospital. We decided to remove the screw fragment as allergic contact dermatitis was refractory to medical treatment. On postoperative day one, the itching was completely resolved, although the skin patch test remained positive.

Nickel allergy to orthopaedic implants: A review and case series

Many of the metals used in orthopaedic surgical implants are immunologically active and can cause hypersensitivity reactions. Most of these metal hypersensitivity (MHS) reactions are type IV/delayed-type hypersensitivity reactions. The most common form of all metal hypersensitivity reactions is allergic contact dermatitis (ACD) caused by nickel. The purpose of this review is to examine the evidence regarding hypersensitivity to orthopaedic implants and provide current recommendations for evaluating these patients. We report on four case examples of patients where it was determined that metal allergy led to complications related to surgery. The most common symptoms for patients with MHS-associated failures are localized soft tissue reaction including delayed wound healing and/or recurrent wound issues. The best way to avoid postoperative issues is to routinely ask patients prior to surgery if they have any known MHS including problems with cosmetic jewelry. If this is known before surgery, titanium or carbon fiber implants should be used for fracture fixation and arthroplasty implantation choice should be modified based on the specific arthroplasty performed. MHS-associated failures are a diagnosis of exclusion and must be contemplated after judicious workup of localized soft tissue reaction including delayed wound healing and/or recurrent wound issues.

Diagnosis of Metal Hypersensitivity in Total Knee Arthroplasty: A Case Report

Delayed type hypersensitivity (DTH) reactions are considered infrequent complications in arthroplasty, but have been recognized to be associated with devastating morbidity and substantial decrease in quality of life of affected patients. Chronic inflammation of artificial joints and associated loss of peri-implant bone often require revision surgery. Methods for the diagnosis of implant-related DTH are available but infrequently considered to the full extent. Sequential diagnostics based on exclusion of septic complications, local and systemic metal level determination, lymphocyte transformation testing (LTT), and local T cell subset analysis are required for an unequivocal DTH diagnosis. Here, we report on a patient with a history of chronic rheumatoid arthritis and an unfavorable outcome of unilateral knee arthroplasty. This case illustrates pitfalls and difficulties in the course of recurrent inflammation following joint replacement. In the early course, suspicion of low-grade bacterial infection led to three two-stage revisions. Afterwards, the joint was proven to be sterile. However, metal level quantification revealed release of especially cobalt and chromium from the joint, LTT indicated persisting cobalt and nickel sensitization and subset analysis of T cells from the synovium suggested DTH as a root cause for the inflammatory symptoms. This report aims to recommend the depicted diagnostic algorithm as an adequate tool for future DTH detection. Yet, systemic to local subset ratios for effector memory and regulatory T cells should be derived from sufficient patient numbers to establish it as a diagnostic marker. Moreover, future prospects regarding implant-related DTH diagnostics are discussed. Therapeutic options for the portrayed patient are proposed, considering pharmaceutical, cell-therapeutic and surgical aspects. Patients who experience peri-implant inflammation but do not have obvious mechanical or infectious problems remain a diagnostic challenge and are at high risk of being treated inadequately. Since potentially sensitizing materials are regularly used in arthroplasty, it is essential to detect cases of acute DTH-derived inflammation of an artificial joint at early postoperative stages. This would reduce the severity of inflammation-related long-term consequences for affected patients and may avoid unnecessary revision surgery.

Utility of Patch Testing and Lymphocyte Transformation Testing in the Evaluation of Metal Allergy in Patients with Orthopedic Implants

Total joint arthroplasties are increasingly common orthopedic procedures performed throughout the United States. Implant failure after these procedures occurs due to a number of causes such as infection or mechanical problems, with metal hypersensitivity being an area of growing interest. The nature and mechanism of a causative relationship between metal hypersensitivity and implant failure have been unclear as it is not known whether implant failure occurs due to a previous metal allergy or metal allergy results from secondary sensitization via metal exposure in existing failing implants. Overall, there appears to be growing support and evidence for metal-hypersensitive patients having worse outcomes with regard to total hip and knee arthroplasties. However, there are conflicting recommendations (outside of Nuss procedures) for pre-implant testing for metal hypersensitivity as testing has not consistently been shown to change patient outcomes.

The Migratory Cortical Button: A Rare Case of Hypersensitivity to Titanium after an Anterior Cruciate Ligament Reconstruction

Allergy to metal, especially to titanium, is a poorly known subject in orthopedic surgery and is mostly found after arthroplasty. Here, we describe an original case of titanium allergy that developed after an anterior cruciate ligament (ACL) reconstruction of the left knee in a patient with a history of severe atopic dermatitis. Three years after the surgery, he returned to the clinic with the femoral cortical button in his hand; he removed the device from the wound when the skin spontaneously opened at the lateral part of the thigh. The wound healed with dressings without use of any antibiotics. Clinical and functional results were favorable and magnetic resonance imaging signal of the graft was normal. We ruled out the possibility of infection and the final diagnosis was allergy to titanium. This case demonstrates the need to investigate the presence of allergy to metal, including titanium, before an ACL reconstruction.

Have the frequency of and reasons for revision total knee arthroplasty changed since 2000? Comparison of two cohorts from the same hospital: 255 cases (2013-2016) and 68 cases (1991-1998)

INTRODUCTION

The number of total knee arthroplasty (TKA) revisions is expected to increase 601% in the United States between 2005 and 2030. This type of information is not available in France, and the last national study on this topic was done in 2000. This led us to perform a comparative study to determine if 1) the frequency of TKA revisions has increased and 2) the reasons for reoperation have changed relative to data gathered in 2000 at a single hospital in France.

HYPOTHESIS

The frequency of TKA revision has increased between the two studies, performed 15 years apart.

MATERIAL AND METHODS

In this retrospective observational single-center study (January 2013 to December 2016), all patients with a TKA who were reoperated with or without any component change were included. This cohort was compared to our historical cohort defined in 2000 of 68 TKA reoperations between January 1991 and January 1998. The reasons for revision were determined by consulting computerized patient records to find the disease history, clinical examinations, imaging findings, laboratory tests and the surgery report. Cases due to periprosthetic fractures, infection and skin-related complications were excluded in order to be consistent with the indications of the historical cohort.

RESULTS

Between 2013 and 2016, 349 TKA revisions were performed, and 255 met the inclusion criteria. Note that the historical cohort had 68 cases. The mean time elapsed between the primary TKA and revision procedure was 5.3 years [34 days to 31 years]. Eight reasons for reoperation were identified. Aseptic loosening (85 cases (33.3%)), stiffness (70 cases (27.5%)), tibiofemoral laxity (39 cases (15.3%)) and patellar complications (34 cases (13.3%)) were the four most common reasons for reoperation. The frequency has changed over time: relative to 2000, the annual frequency increased by a factor of 6.5. The reasons have also changed over time: there was an increase in revisions for aseptic loosening (33.3% vs. 23.5%), stiffness (27.5% vs. 20.6%) and knee joint laxity (15.3% vs. 10.3%). Conversely, there was a reduction in revisions for patellar complications (13.3% vs. 26.5%), unexplained pain (0.4% vs. 8.8%) and patellar clunk syndrome (1.2% vs. 4.4%).

DISCUSSION

The number of TKA revisions has increased by a factor of 6.5, with aseptic loosening still being the most common reason. The number of revisions performed for stiffness and knee joint laxity have increased. Fewer revisions are being done for unexplained pain because surgeons are now better able to determine the cause of TKA-related pain. There were fewer patella-related complications because of technical progress. The data generated from our single-center study are consistent with current published data.

LEVEL OF EVIDENCE

II, comparative study.

Allergy in total knee replacement surgery: Is it a real problem?

Total knee arthroplasty is a common procedure, with extremely good clinical results. Despite this success, it produces 20% unsatisfactory results. Among the causes of these failures is metal hypersensitivity. Metal sensitization is higher in patients with a knee arthroplasty than in the general population and is even higher in patients undergoing revision surgery. However, a clear correlation between metal sensitization and symptomatic knee after surgery has not been ascertained. Surely, patients with a clear history of metal allergy must be carefully examined through dermatological and laboratory testing before surgery. There is no globally accepted diagnostic algorithm or laboratory test to diagnose metal hypersensitivity or metal reactions. The patch test is the most common test to determine metal hypersensitivity, though presenting some limitations. Several laboratory assays have been developed, with a higher sensitivity compared to patch testing, yet their clinical availability is not widespread, due to high costs and technical complexity. Symptoms of a reaction to metal implants present across a wide spectrum, ranging from pain and cutaneous dermatitis to aseptic loosening of the arthroplasty. However, although cutaneous and systemic hypersensitivity reactions to metals have arisen, thereby increasing concern after joint arthroplasties, allergies against implant materials remain quite rare and not a well-known problem. The aim of the following paper is to provide an overview on diagnosis and management of metal hypersensitivity in patients who undergo a total knee arthroplasty in order clarify its real importance.

A case series of cementless revision total knee arthroplasty in patients with benzoyl peroxide allergy

PURPOSE

The contact allergens nickel, cobalt, and chromium are often discussed as possible triggers of allergic reactions to orthopedic implants. Additionally, acrylates and polymerization additives in bone cement (e.g., benzoyl peroxide (BPO)) have been implicated as triggers of eczema, wound healing disorders, and aseptic implant loosening. We report about six patients with aseptic loosening after total knee arthroplasty (TKA), who underwent revision surgery after testing positive for BPO hypersensitivity.

METHODS

After clarification of possible other causes of implant failure, epicutaneous testing had been performed and the implants were replaced in a two-stage procedure with cementless, diaphyseal anchoring, hypoallergenic (TiNb-coated) revision endoprostheses.

RESULTS

Epicutaneous testing revealed a BPO allergy in all six patients and an additional nickel allergy in three of the six patients. There was no histopathological or microbiological evidence for a periprosthetic infection. The clinical follow-up showed a low level of pain with good function, a stable knee joint, and proper implant position. The Knee Society Score (KSS) with its subscales Knee Score and Functional Score improved post-operatively from 43 to 70 points and from 47.5 to 68.3 points, respectively. Two implant-specific complications occurred: femoral stress shielding two years post-operatively with no further need for action and aseptic loosening of the tibial stem with the need of revision three years post-operatively.

CONCLUSIONS

The regression of complaints after replacement with cementless and nickel-free revision implants suggests allergic implant intolerance. Implantation of a cementless, hypoallergenic endoprosthesis might, therefore, be a surgical treatment strategy in patients with evidence of allergies.