Metal Hypersensitivity and Total Knee Arthroplasty.

Area of Science:

• Orthopedic Surgery
• Allergy and Immunology
• Biomaterials Science

Background:

• Metal hypersensitivity is a controversial complication following total knee arthroplasty (TKA).
• Diagnosing metal hypersensitivity is challenging due to a lack of validated diagnostic tests.
• It is a rare condition, considered only after excluding other causes of TKA pain and swelling.

Purpose of the Study:

• To review the current understanding and diagnostic challenges of metal hypersensitivity after TKA.
• To discuss potential clinical presentations and diagnostic testing limitations.
• To provide insights into management strategies, including revision arthroplasty.

Main Methods:

• Review of existing literature on metal hypersensitivity following TKA.
• Analysis of diagnostic challenges, including cutaneous and in vitro testing.
• Discussion of clinical presentations and potential treatment outcomes.

Main Results:

• Metal hypersensitivity after TKA is uncommon, presenting as dermatitis or synovitis.
• Standard laboratory tests are typically negative; allergy testing lacks defined accuracy.
• Revision surgery with alternative materials may relieve symptoms but is a last resort.

Conclusions:

• Metal hypersensitivity is a rare diagnosis in TKA patients, requiring exclusion of other pathologies.
• Current diagnostic tests for metal allergy lack validation, complicating clinical decisions.
• Widespread pre-operative screening for metal allergies is not recommended due to testing limitations.