Supplementary Material for: Clinical presentation and causes of prosthesis-related hypersensitivity reactions: An analysis of 225 patients

Introduction: Between 10-20% of all prosthesis patients experience implant-related complications within 1-2 years following surgery. Hypersensitivity to components within the prosthesis is a possible cause of these complications. Results: 225 patients, who underwent patch testing to investigate a PRH between 2011 and 2021 were included. The mean age was 72 with 34% being male and 65% being female. Knee pain was the most common symptom (85%), followed by eczematous skin lesions and joint instability (both around 20%) and redness/swelling (13-16%). In 67 % of the patients undergoing patch testing, an allergy was diagnosed, with Nickel being the most common allergen (31.5%), followed by vanadium chloride (13.7%) and gentamycin (an antibiotic often added to bone cement). 60 % of the PRH patients had a previously known contact allergy to metals (25.7%) or other substances (34.6%). Among metals, Nickel was the most common allergen (19.5%), followed by Silver (3.1%). This was significantly higher than in patients without a metal allergy diagnosis. There was no significant difference regarding overall and individual atopic comorbidities (about 40%). Conclusion: A previous contact allergy may be an indicator of a PRH. In contrast, the clinical presentation or consideration of atopic/non-atopic comorbidities of prosthesis patients with suspected PRH do not seem to provide helpful clues for the diagnosis. Given our findings PRH might be an underestimated cause of postoperative complaints.