Orthopaedic Implant Surgery or Trauma as a Trigger for Necrobiosis Lipoidica: A Manifestation of an Immunocompromised Cutaneous District?

Necrobiosis lipoidica (NL) is a rare chronic granulomatous skin disorder most commonly associated with diabetes mellitus, typically presenting in middle-aged women. We report an unusual case of NL in a young, non-diabetic male following orthopedic surgery involving a metallic implant. The patient developed characteristic well demarcated, atrophic, violaceous-brown plaques with violaceous borders localized over shin area of his left lower leg. Histopathological examination confirmed the diagnosis of NL, showing palisading granulomas with necrobiosis and lipid-laden macrophages. Notably, there was no history of diabetes, hypothyroidism, glucose intolerance, or autoimmune disease. This case highlights a rare presentation of NL potentially triggered by local immune dysregulation by trauma, surgery and the presence of a metallic implant. The report underscores the importance of considering NL in the differential diagnosis of persistent postsurgical cutaneous lesions, even in non-diabetic individuals, and raises questions about trauma, implant-related immune dysregulation, or microvascular changes as possible pathophysiological mechanisms.