Allergic complications from orthopaedic joint implants: the role of delayed hypersensitivity to benzoyl peroxide in bone cement.

BACKGROUND

Orthopaedic implants and osteosynthesis materials are increasingly being used. Complications include mainly physical-mechanical problems and infections. Uncommonly, an allergic reaction towards an alloy metal or a bone cement component has been implicated. Potential bone cement allergens include acrylates, benzoyl peroxide, N,N-dimethyl-p-toluidine, and gentamicin. Typical symptoms are pain, swelling, inflammatory skin reactions, implant loosening, and fistula formation.

OBJECTIVES

To report on 5 patients with complications from a knee or a shoulder joint implant in whom a relevant sensitization to benzoyl peroxide was shown.

METHODS

Patch tests were performed with the European baseline series, an extended metal series, and a bone cement series. Patch tests with benzoyl peroxide were performed twice in all patients. A bone cement-free replacement was chosen in sensitized patients.

RESULTS

In 4 patients sensitized to benzoyl peroxide, a bone cement-free replacement resulted in a considerable decrease or disappearance of pain and swelling, and complete clearing of cutaneous symptoms.

CONCLUSIONS

Components of bone cement, such as benzoyl peroxide, may rarely cause allergic complications. However, because of the irritant potential of these substances, careful performance, reading and interpretation of the patch tests is required.