# Allergic Reaction to Titanium Alloy Osteosynthesis Implants: A Case Report of Three Patients

## TL;DR

Three patients showed allergic reactions to titanium alloy implants used for bone fractures, highlighting the need for better diagnostic standards.

## Contribution

This case report provides evidence of titanium alloy hypersensitivity and emphasizes the importance of standardized diagnostic processes.

## Key findings

- Three patients exhibited persistent localized dermatitis after titanium-alloy implant surgery.
- Patch tests and histopathology confirmed hypersensitivity reactions in two patients.
- Symptoms improved significantly after implant removal, supporting an allergic cause.

## Abstract

Background: Titanium is commonly used for fracture fixation and is considered inert, but hypersensitivity reactions to titanium alloy still occur and are difficult to diagnose due to a lack of a universally accepted standard in post-orthopedic surgical patients, and other common diagnoses need to be differentiated. Case Presentation: This case report describes three patients with manifestations of allergic reactions to titanium-alloy implants after Open Reduction and Internal Fixation (ORIF) with Ti-6Al-4V plates. Three patients mainly presented with persistent localized dermatitis. During follow-up, radiographs confirmed bone unions, and there were no signs of purulent drainage, abscess formation, or systemic infection. Taken together, these findings reduce the possibility of fracture-related infection (FRI) and other etiologies. Conservative treatment was ineffective, and the patch test and histopathology in two patients respectively supported hypersensitivity reactions. After the implants were surgically removed, there were significant improvements in symptoms. Conclusion: Three cases of suspected titanium-alloy hypersensitivity were diagnosed by exclusion based on clinical history, laboratory results, and additional testing. The findings showed the importance of clinical history and the identification of signs and symptoms of allergic reactions, emphasizing the need for a standardized diagnostic process.