Clinical Presentation and Causes of Prosthesis-Related Hypersensitivity Reactions: An Analysis of 225 Patients.

Introduction: Between 10% and 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.

Methods: This study aimed to investigate the characteristics of prosthesis-related hypersensitivity (PRH) and identify possible associated risk factors. A retrospective, monocentric study was conducted at the University Hospital Zurich.

Results: A total of 225 patients who underwent patch testing for suspected PRH between 2011 and 2021 were included. The mean age was 72 years; 34% were male and 65% were female. Knee pain was the most commonly reported symptom (85%), followed by eczematous skin lesions and joint instability (each around 20%), as well as redness or swelling (13-16%). In 67% of the patients undergoing patch testing, an allergy was diagnosed. Nickel was the most frequently identified 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 - 25.7% to metals and 34.6% to other substances. Among the metals, nickel was the most prevalent (19.5%), followed by silver (3.1%). This prevalence was significantly higher than in patients without a metal allergy diagnosis. No significant differences were observed between the groups regarding overall or individual atopic comorbidities (present in approximately 40% of patients).

Conclusion: A history of contact allergy may be an indicator of PRH. In contrast, clinical presentation and the consideration of atopic or non-atopic comorbidities in prosthesis patients with suspected PRH do not appear to provide helpful diagnostic clues. Based on our findings, PRH may represent an underestimated cause of postoperative complaints.