Allergy to orthopedic metal implants - a prospective study

Area of Science:

• Orthopedic Surgery
• Dermatology
• Toxicology

Background:

• Metal-on-metal hip and knee implants are widely used.
• Metal allergies are a growing concern in orthopedic patient populations.
• Understanding the link between metal allergy and implant failure is crucial for patient outcomes.

Purpose of the Study:

• To evaluate the allergenic potential of metal knee and hip implants.
• To assess the relationship between metal allergy and orthopedic implant failure.
• To determine the prevalence of metal hypersensitivity before and after joint replacement surgery.

Main Methods:

• Prospective study involving two stages: pre-implantation and 24-month post-surgery.
• Patch testing with various metal allergens (nickel, cobalt, chromium, palladium, etc.).
• Clinical evaluation including personal interviews and dermatological examinations.

Main Results:

• Pre-implantation, 21.7% of subjects showed "metal dermatitis" symptoms, with positive patch tests for nickel, palladium, cobalt, and chromium.
• Post-surgery, 10.4% reported implant intolerance and 4.2% experienced skin lesions.
• Statistical analysis indicated chromium and cobalt as potential allergens in implants, with post-surgery allergies found in 25% of patients.

Conclusions:

• Metal orthopedic implants can be a primary cause of allergies, potentially leading to implant failure.
• Mandatory patch testing for metal allergies is advised before implanting devices in patients with dermatitis.
• Patients with confirmed metal allergies should receive implants free of specific allergenic metals.