Type IV Cell-Mediated Hypersensitivity Reaction Caused by Titanium Implant Following Double Calcaneal Osteotomy and First Metatarsal-Cuneiform Arthrodesis: A Case Report and Review of the Literature

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.

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.

Titanium Allergy Caused by Dental Implants: A Systematic Literature Review and Case Report

(1) Background: Hypersensitivity reactions to metals may arise in predisposed patients chronically exposed to metallic materials, including dental implants made of titanium alloys. The purpose of this article was to systematically review titanium allergy manifestations in patients treated with dental implants and report a clinical case; (2) Methods: A systematic electronic search was performed for articles published in the English language until July 2021. The following eligibility criteria were adopted: (1) Population: individuals undergoing titanium and/or titanium alloy implant-supported rehabilitations; (2) Exposure: peri-implant soft tissue reactions attributable to implant insertion; (3) Outcome: evidence of titanium allergy, diagnostic methods, and forms of resolution; (3) Results: The included studies, in summary, presented evidence that titanium should not be considered an inert material, being able to trigger allergic reactions, and may be responsible for implant failure. A 55-year-old male patient received 3 implants in the posterior region of the left mandible and presented an epulis-like lesion developed from the peri-implant mucosa. The immunohistochemical analysis of the biopsy specimen confirmed the initial diagnosis of allergic reaction to titanium; (4) Conclusions: Although the evidence is weak, and titanium allergy has a low incidence, hypersensitivity reactions should not be underestimated. A rapid and conclusive diagnosis is mandatory to prevent further complications.