Orthopedic implant hypersensitivity: Characterization of clinical presentation and effects of photobiomodulation therapy.

Objectives: Orthopedic implants have improved the quality of life in aging society but also induces several kinds of tissue reactions, referred to as orthopedic implant hypersensitivity (OIH). The aim of our study is to report the clinical characteristics of OIH and the effects of photobiomodulation therapy (PBMT) on these groups of patients.

Materials And Methods: We collected cases that complained of skin rashes with pruritus after orthopedic implants from January 2017 to June 2022 at the Dermatology clinic in Hualien Tzu Chi Hospital. We recorded the sites and material of orthopedic implants, skin lesions onset time, symptoms, location after implantation, and the disease duration. Laboratory tests were measured, including complete blood count, differential count, serum immunoglobulin E (IgE) level, as well as inflammatory and autoimmune markers. PBMT, including UVB311 nm or low-level laser therapy 808 nm, was performed. Dose, duration, and response were documented.

Results: Fourteen patients were diagnosed with OIH; twelve presented with localized eczema at the implant sites, and two with generalized eczema. Eleven patients (78.6%) had either elevated eosinophils percentage (>6%) or IgE level (>200 U/mL) or both. Seven patients (50%) had favorable outcome after PBMT and successfully withdrew from systemic steroid.

Conclusion: In our case series, localized eczema at implant sites was a common cutaneous presentation in OIH. Hence, a surgical scar at the eczema site or long-term waxing and waning generalized eczema should prompt physicians on the possibility of OIH. Blood eosinophils percentage and serum IgE level can be reference biomarkers for OIH. PBMT provides a noninvasive and effective treatment strategy for immune regulation and tissue regeneration.