Clinical and diagnostic challenges of metal implant allergy using the example of orthopaedic surgical implants: Part 15 of the Series Molecular Allergology

Are Allergy-Induced Implant Failures Actually Hypersensitivity Reactions to Titanium? A Literature Review

PURPOSE

This literature review was performed to assess whether implant failures are associated with titanium allergy.

MATERIALS AND METHODS

An electronic search of the MEDLINE/PubMed, Cochrane Library, and Scopus databases up to April 2021 was conducted, and the obtained articles were independently assessed by two reviewers. Articles describing cases of implant failure in which the cause of implant failure was only identified as allergy were included.

RESULTS

Twelve studies were included. Eight studies identified Ti allergy by clinical examinations, of which four used patch tests, three used the lymphocyte transformation test (LTT)/memory lymphocyte immunostimulation assay (MELISA), and one used both tests. Nine studies reported cases of titanium hypersensitivity in combination with other systemic allergy-related disorders, with eight cases also showing positive results for Ni, Hg, Cr, and Co hypersensitivity. Ten papers reported the improvement of symptoms after the removal of the Ti implants and their replacement with zirconia implants, and two of these papers showed good results.

CONCLUSION

Cases of probable titanium allergy included those with true titanium allergies and those with a potentially different cause. However, the differentiation of these cases is difficult. Since no definitive method has been established for diagnosing titanium allergy, a comprehensive diagnosis based on the clinical course and clinical examination using a patch test/LTT/MELISA is necessary. Implant treatment should be performed with caution in patients with any preoperative allergies.

Hyaluronic acid-British anti-Lewisite as a safer chelation therapy for the treatment of arthroplasty-related metallosis

Cobalt-containing alloys are useful for orthopedic applications due to their low volumetric wear rates, corrosion resistance, high mechanical strength, hardness, and fatigue resistance. Unfortunately, these prosthetics release significant levels of cobalt ions, which was only discovered after their widespread implantation into patients requiring hip replacements. These cobalt ions can result in local toxic effects-including peri-implant toxicity, aseptic loosening, and pseudotumor-as well as systemic toxic effects-including neurological, cardiovascular, and endocrine disorders. Failing metal-on-metal (MoM) implants usually necessitate painful, risky, and costly revision surgeries. To treat metallosis arising from failing MoM implants, a synovial fluid-mimicking chelator was designed to remove these metal ions. Hyaluronic acid (HA), the major chemical component of synovial fluid, was functionalized with British anti-Lewisite (BAL) to create a chelator (BAL-HA). BAL-HA effectively binds cobalt and rescues in vitro cell vitality (up to 370% of cells exposed to IC50 levels of cobalt) and enhances the rate of clearance of cobalt in vivo (t1/2 from 48 h to 6 h). A metallosis model was also created to investigate our therapy. Results demonstrate that BAL-HA chelator system is biocompatible and capable of capturing significant amounts of cobalt ions from the hip joint within 30 min, with no risk of kidney failure. This chelation therapy has the potential to mitigate cobalt toxicity from failing MoM implants through noninvasive injections into the joint.

Hypersensitivity Reactions to Components of Cardiac Implantable Electronic Devices and Their Treatment: A Systematic Review

Background: Hypersensitivity reactions (HSRs) to components of cardiac implantable electronic devices (CIEDs) are rare but difficult to differentiate from device infection. Data on best management strategies of HSRs to CIEDs are lacking. The aims of this systematic review are to summarise the available literature on the aetiology, diagnosis and management of HSR in CIED patients and to provide guidance on best management strategies for these patients. Methods and results: A systematic search for publications on HSR to CIED in PubMed from January 1970 to November 2022 was conducted, resulting in 43 publications reporting on 57 individual cases. The quality of data was low. The mean age was 57 ± 21 years, and 48% of patients were women. The mean time from implant to diagnosis was 29 ± 59 months. Multiple allergens were identified in 11 patients (19%). In 14 cases (25%) no allergen was identified. Blood tests were mostly normal (55%), but eosinophilia (23%), raised inflammatory markers (18%) and raised immunoglobulin E (5%) were also encountered. Symptoms included local reactions, systemic reactions or both in 77%, 21% and 7% of patients, respectively. Explantation of CIED and reimplantation of another CIED coated with a non-allergenic material was usually successful. Use of topical or systemic steroids was associated with high failure rates. Conclusion: Based on the limited data available, the treatment of choice for HSRs to CIEDs is full CIED removal, reassessment of CIED indication and reimplantation of devices coated in non-allergenic materials. Steroids (topical/systemic) have limited efficiency and should not be used. There is an urgent need for further research in this field.

Ceramic Coating in Cemented Primary Total Knee Arthroplasty is Not Associated With Decreased Risk of Revision due to Early Prosthetic Joint Infection

BACKGROUND

Prosthetic joint infection (PJI) is one of the most frequent and devastating causes of short-term revision total knee arthroplasty (TKA). In vitro evidence suggests ceramic surfaces demonstrate resistance to biofilm, but the clinical effect of bearing surface modifications on the risk of PJI remains unclear. This premier registry-based study examines the influence of ceramic bearing surface coatings on the outcome in cemented primary TKA.

METHODS

In total, 117,660 cemented primary TKAs in patients with primary osteoarthritis recorded in the German arthroplasty registry since 2012 were followed up for a maximum of 3 years. The primary endpoint was risk of revision for PJI on ceramic coated and uncoated cobalt-chromium-molybdenum femoral components. Propensity score matching for age, gender, obesity, diabetes mellitus, depression and Elixhauser comorbidity index, and substratification on common design twins with and without coating was performed.

RESULTS

In total, 4637 TKAs (85.1% female) with a ceramic-coated femoral component were identified, 42 had been revised for PJI and 122 for other reasons at 3 years. No survival advantage due to the risk of revision for PJI could be determined for ceramic-coated components. Revision for all other reasons demonstrated a significant higher rate for TKAs with ceramic-coated components. However, the results of this were confounded by a strong prevalence (20.7% vs 0.3%) of metal sensitivity in the ceramic-coated group.

CONCLUSION

No evidence of reduced risk for PJI due to ceramic-coated implants in cemented primary TKA was found. Further analysis for revision reasons other than PJI is required.

Fatigue Crack Growth and Fracture of Internal Fixation Materials in In Vivo Environments-A Review

The development of crack patterns is a serious problem affecting the durability of orthopedic implants and the prognosis of patients. This issue has gained considerable attention in the medical community in recent years. This literature focuses on the five primary aspects relevant to the evaluation of the surface cracking patterns, i.e., inappropriate use, design flaws, inconsistent elastic modulus, allergic reaction, poor compatibility, and anti-corrosiveness. The hope is that increased understanding will open doors to optimize fabrication for biomedical applications. The latest technological issues and potential capabilities of implants that combine absorbable materials and shape memory alloys are also discussed. This article will act as a roadmap to be employed in the realm of orthopedic. Fatigue crack growth and the challenges associated with materials must be recognized to help make new implant technologies viable for wider clinical adoption. This review presents a summary of recent findings on the fatigue mechanisms and fracture of implant in the initial period after surgery. We propose solutions to common problems. The recognition of essential complications and technical problems related to various approaches and material choices while satisfying clinical requirements is crucial. Additional investigation will be needed to surmount these challenges and reduce the likelihood of fatigue crack growth after implantation.

A systematic review of cranioplasty material toxicity in human subjects

PURPOSE

Local and systemic toxic reactions to implanted materials can result in morbidities. However, little is reported about cranioplasty implants. Therefore, we performed a systematic review on the toxicity of different materials used for cranioplasty implants.

MATERIALS AND METHODS

A systematic search was conducted by browsing the Pubmed, Embase, and Cochrane Library databases. All human studies that identified toxic (aseptic) reactions to any types of material used as cranioplasty implants or onplants, published up to January 1, 2019, were included in the review.

RESULTS

Nineteen studies were identified. Collectively, 36 patients endured some type of toxic reaction to an implanted material. Eleven studies presented several types of toxicity for PMMA cranioplasties in several tissue types. One article highlighted the risk of neurotoxicity for PMMA cranioplasty. Three articles presented toxic reactions to calcium phosphate and titanium implants. Three additional articles presented toxic reactions to PEEK, polypropylene-polyester, and polyethylene.

CONCLUSION

All materials currently used for cranioplasty showed occasional toxicity and morbidities. Therefore, none can be considered completely biologically inert. We found that aseptic inflammatory reactions have been underreported in the literature due to a high incidence of infections with questionable evidence.

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.

TCM treatment of allergy induced by stainless steel implants for tibiofibular fracture: A case report

Background: Metal allergy is frequently seen. Orthopedic metal implants, such as external fixators or other stainless implants, contain chromium, nickel, and molybdenum, which can cause type IV hypersensitivity. Case summary: A patient diagnosed with open comminuted tibiofibular fracture was treated with external fixation surgery, and she showed contact dermatitis and eczema-like symptoms 2 weeks postoperatively. She was then diagnosed as allergic to several metals by patch test and subsequently treated with traditional Chinese medicine (TCM), both orally and externally for 1 month. TCM treatment significantly alleviated the hypersensitive symptoms and made the patient bear the external fixator for 2 months until bone union. Conclusion: TCM therapy may be an effective treatment for external fixation-induced metal allergy and contact dermatitis.

Neuropathy Caused by Metal Hypersensitivity after Placement of Stainless Steel Plate

Metal hypersensitivity is a rare complication for implants especially with neuropathy involvement. There was not any previous report suggesting metal hypersensitivity manifested in the form of neuropathy or tendinopathy from metal plate implantation. Here, we present a case of a 42-year-old female with chronic ulnar wrist pain and unremarkable physical and radiological findings. Ulna shortening osteotomy with small stainless steel-made DCP and screw fixation was done. On the third day postoperative, the patient developed pain, swelling, ulnar neuropathy, and flexor tendon contracture. Severe adhesion was found around the implant and the ulnar nerve. Minimal skin patch testing reaction and pathological study suggest a cell-mediated delayed type IV hypersensitivity reaction. A titanium-made LCP was later implanted in place of the stainless steel-made DCP. The patient's clinical status significantly improved after the operation. Metal hypersensitivity in this patient was unprecedented and unique. The severity of the reaction and its location close to the ulnar nerve may predispose to the intensity of the reaction.

Long-term outcome after implantation of a nickel-containing cemented hip stem on the right in a patient with type IV sensitization to nickel sulphate

Type IV allergies to nickel sulfate, potassium dichromate and/or cobalt chloride are supposed to be associated with aseptic loosening, pain or infections in patients with hip arthroplasty. However, there is debate on any causal relation between type IV sensitization to metals and any of these complications. We report on a patient with suspicion of pre-existing type IV sensitization to nickel sulfate and potassium dichromate who did not show any complications after hip arthroplasty.

Incidence of Metal Hypersensitivity in Orthopedic Surgical Patients Who Self-Report Hypersensitivity History

INTRODUCTION

Metallic implants are integral to the practice of orthopedic surgery. Delayed-onset T-cell-mediated metal hypersensitivity (diagnosed by patch testing) is reported in 10% to 17% of the general population. Inconclusive evidence exists about the role of metal hypersensitivity in persistently painful or aseptic loosening of arthroplasties. Literature suggests that preoperative patch testing may influence surgical practice.

OBJECTIVE

To determine the incidence of metal hypersensitivity in orthopedic surgical patients who self-report hypersensitivity and to characterize which metals are most commonly implicated.

METHODS

A retrospective chart review of patients from a single surgeon's practice was conducted during a 1-year period. All patients were questioned about metal hypersensitivity history; all patients who responded affirmatively were sent for patch testing for specific metals.

RESULTS

Only 41 (4.9%) of 840 patients self-reported any metal hypersensitivity. Of these, 34 (83%) were patch-test positive to 1 or more metals. There were 27 whose test results were positive for nickel, 4 each to cobalt or gold thiosulfate, and 1 each to tin or titanium. Seven patients had positive results to multiple metals, all of whom were also nickel hypersensitive. Six patients had metal orthopedic implants before patch testing, and 4 (67%) tested positively to a metal in their implant.

CONCLUSION

Metal hypersensitivity can be concerning for treating surgeons and patients. Greater awareness of a history to hypersensitivity may prevent patient exposure to implants containing metals that may cause hypersensitivity. Non-metal-containing or nonreactive metal implants are an option for patients in whom metal hypersensitivity is suspected or confirmed.

Exploring the Incidence, Implications, and Relevance of Metal Allergy to Orthopaedic Surgeons

Introduction:

Allergic reactions to metal implants are increasingly recognized, but its relevance to the orthopaedic surgeon remains unclear. We evaluate the prevalence of metal allergies in a subset of the population and review the significance through a survey of the current literature.

Methods:

Preoperative and postoperative patients referred for metal allergy testing were divided into two groups; those with a history of dermatitis and those without. Patients with a history of dermatitis were offered skin patch testing that included the North American Contact Dermatitis core allergen panels in addition to our metal screening series. Patients without dermatitis were tested to the more limited patch testing metal screening series. Some patients with dermatitis opted for the more limited screening, whereas some patients without dermatitis underwent more extensive testing at their request or at the request of the referring clinician. Patch tests were evaluated at 2 and 4 days after placement.

Results:

Hundred patients were referred for metal allergy testing, 46 of whom were for reasons related to planned orthopaedic surgery. Of those tested, 60 patients had a history of dermatitis and 40 did not. Some patients were nonreactive to all tested allergens, whereas others demonstrated one or more positive skin patch test reactions. The number of positive reactions to each metal in patients with a history of dermatitis was the following: nickel 19, amalgam 10, palladium 10, copper 8, cobalt 5, mercury 5, tin 2, gold 1, titanium 1, and vanadium 1. The number of positive reactions to metals in patients without a history of dermatitis was the following: nickel 4, amalgam 5, palladium 4, mercury 4, cobalt 4, tin 2, copper 2, gold 1, vanadium 1, and molybdenum 1.

Discussion:

Metal allergy was common in the individuals referred for testing, with reactions to nickel and amalgam being the most commonly encountered. Some individuals experience more notable allergic reactions to implanted devices than others. Localized and generalized skin reactions have been reported, along with implant failure and loosening. Surgeons should be aware of the incidence of metal allergies and the potential consequences.

Nanoglass-based balloon expandable stents

Here, a prototypical metallic nanoglass is proposed as a new alloy for balloon expandable stents. Traditionally, the stainless steel SS 316L alloy has been used as a preferred material for this application due to its proper combination of mechanical properties, corrosion resistance, and biocompatibility. Recently, metallic glasses (MGs) have been considered as promising materials for biodevice applications. MGs often display outstanding mechanical properties superior to those of conventional metallic alloys and overcome some of the weaknesses of SS 316L, such as radiopacity, stainless steel allergy, and thrombosis-induced restenosis. However, commonly used monolithic MGs, which have an amorphous homogeneous microstructure, suffer from lack of ductility that is necessary for deployment of balloon expandable stents. In contrast, nanoglasses, that is, amorphous alloys with heterogeneous microstructure, exhibit enhanced ductility which makes them promising materials for balloon expandable stents. We evaluate the feasibility of a prototypical Zr₆₄ Cu₃₆ nanoglass with a grain size of 5 nm for balloon expandable stents by performing finite element method modeling of the stent deployment process in a coronary artery. We consider the BX-Velocity stent design and the nanoglass mechanical properties calculated from atomistic simulations. The results suggest that nanoglasses are suitable materials for balloon expandable stent applications. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:73-79, 2020.

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.

Skin Complications of Orthopedic Procedures and Devices

BACKGROUND

Knowledge of skin complications and contributing factors in orthopedic patients is important for design and development of preventive approaches. Therefore, this study was designed to assess skin complications in orthopedic patients.

METHODS

In this case-series study, 126 orthopedic patients referred to Rasoul-e-Akram and Bahman hospitals from 2012 to 2016 with skin complications were analyzed. The adverse effects were assessed with respect to type and contributing factors. Fisher's exact test, Chi-square, and independent sample t-test were performed to assess the associations between skin complications and other variables.

RESULTS

Skin complications in orthopedic patients included infections in 33 (26.1%) cases and hypersensitivity reactions in 88 (40%) cases. In total, 66 (55%) cases of fracture and 35 (29.2%) cases of cellulitis were detected, while the remaining cases involved complications such as disc herniation, nerve involvement, and osteoarthritis-related arthroplasty. Severe reactions presenting as toxic epidermal necrolysis were observed in 3 patients, 2 of whom died eventually. Age and gender were not related to the type of skin complications (P>0.05).

CONCLUSION

Complications due to orthopedic treatments were not common. However, since the disease may become fatal on certain occasions, patients should receive more attention from physicians and nurses.

Failure of facet replacement system with metal-on-metal bearing surface and subsequent discovery of cobalt allergy: report of 2 cases

The aim of this study was to report on 2 patients in whom metal-on-metal (MOM) facet replacements failed, with subsequent positive findings on allergy testing. Motion-preserving devices have been used with limited success when instrumentation is indicated in the mobile spine. MOM-bearing surfaces in orthopedics were developed to increase implant longevity, yet have been associated with numerous adverse outcomes, including local tissue reactions, pseudotumors, metallosis, and the need for revision surgery. Five patients with spinal stenosis and low-grade spondylolisthesis were randomized to undergo facet replacement surgery with the ACADIA facet replacement system at the authors’ institution. Two patients experienced a return of neurological symptoms after a pain-free interval (< 2 years) with development of local tissue reaction and positive findings on allergy testing to cobalt, the metal in the MOM-bearing surface. Both patients underwent successful removal of the implant and revision to titanium posterior spinal fusion and interbody fusion without further complication.

Motion-preserving devices have been designed and trialed for specific indications in the mobile spine. Given the adverse results from MOM devices in hip arthroplasty and now the early reports with MOM facet replacements, caution is warranted when moving forward with any MOM joint–bearing surface. Both patients presented here had an unusual tissue reaction locally and subsequent positive allergy testing results to cobalt. These 2 patients appear to have developed a delayed hypersensitivity reaction to the metal, likely from fine debris at the MOM interface.

Hard Chrome-Coated and Fullerene-Doped Metal Surfaces in Orthopedic Bearings

Metal-on-metal bearings for total hip replacements have been introduced as an alternative to polyethylene in young and more active patients. These have, however, been shown to be prone to implant malpositioning and have been limited by some specific design features. In that context, coatings present an option to increase wear resistance by keeping the high fracture strength of the metal substrate. A custom-made electroplating setup was designed for the coating of CoCr substrates using (a) an industrial standard chromium electrolyte; (b) a custom-made hexavalent chromium (Cr⁶⁺) electrolyte with a reduced chromium trioxide (CrO₃) content, both without solid additives and (c) with the addition of fullerene (C₆₀) nanoparticles; and (d) a trivalent chromium (Cr³⁺) electrolyte with C₆₀ addition. All coatings showed an increase in microhardness compared with the metal substrate. Trivalent coatings were thinner (10 µm) than the hexavalent coatings (23–40 µm) and resulted in increased roughness and crack density. Wear was found to be reduced for the hexavalent chromium coatings by 70–84% compared with the CoCr–CoCr reference bearing while the trivalent chromium coating even increased wear by more than 300%. The addition of fullerenes to the electrolyte did not show any further tribological effect.

Allergic or Hypersensitivity Reactions to Orthopaedic Implants

Allergic or hypersensitivity reactions to orthopaedic implants can pose diagnostic and therapeutic challenges. Although 10% to 15% of the population exhibits cutaneous sensitivity to metals, deep-tissue reactions to metal implants are comparatively rare. Nevertheless, the link between cutaneous sensitivity and clinically relevant deep-tissue reactions is unclear. Most reactions to orthopaedic devices are type IV, or delayed-type hypersensitivity reactions. The most commonly implicated allergens are nickel, cobalt, and chromium; however, reactions to nonmetal compounds, such as polymethyl methacrylate, antibiotic spacers, and suture materials, have also been reported. Symptoms of hypersensitivity to implants are nonspecific and include pain, swelling, stiffness, and localized skin reactions. Following arthroplasty, internal fixation, or implantation of similarly allergenic devices, the persistence or early reappearance of inflammatory symptoms should raise suspicions for hypersensitivity. However, hypersensitivity is a diagnosis of exclusion. Infection, as well as aseptic loosening, particulate synovitis, instability, and other causes of failure must first be eliminated.

Hypersensitivity to Orthopedic Implants: A Review of the Literature

Awareness of rare etiologies for implant failure is becoming increasingly important. In addition to the overall increase in joint arthroplasties, revision surgeries are projected to increase dramatically in the coming years, with volume increasing up to seven-fold between 2005 and 2030. The literature regarding the relationship between metal allergy and implant failure is controversial. It has proven difficult to determine whether sensitization is a cause or a consequence of implant failure. Testing patients with functional implants is not a clinically useful approach, as the rate of hypersensitivity is higher in implant recipients than in the general population, regardless of the status of the implant. As a result of the ineffectiveness of preoperative patch testing for predicting adverse outcomes, as well as the high cost of implementing such patch testing as standard procedure, most orthopedists and dermatologists agree that an alternative prosthesis should only be considered for patients with a history of allergy to a metal in the standard implant. In patients with a failed implant requiring revision surgery, hypersensitivity to an implant component should be considered in the differential diagnosis. Because a metal allergy to implant components is currently not commonly considered in the differential for joint failure in the orthopedic literature, there should be improved communication and collaboration between orthopedists and dermatologists when evaluating joint replacement patients with a presentation suggestive of allergy.

[Modern allergy diagnostic procedures and their clinical application]

Due to the increasing incidence of allergies, the importance of allergy diagnostic procedures is growing. In addition to a patient's history and prick, intracutaneous and patch testing, serological testing is an important diagnostic procedure. In recent years, tremendous advances have been made in the area of in vitro allergy tests. In particular, it is possible to predict severity and risk management of food allergies with component-based IgE diagnostic procedures. Even new allergy syndromes have been elucidated at the molecular level.