Purpose: To describe previously unreported histologic findings in two patients who developed chronic implant exposure and abscess formation within hydroxyapatite orbital implants.
Methods: Surgically removed implant specimens were processed for histopathologic examination and stained for microorganisms. Each patient's clinical course, socket appearance, and exposure management were reviewed.
Results: Histopathologic examination of case 1 showed a channel of necrosis leading from the anterior surface of the implant to its center. Hair shafts were discovered embedded within this channel. Histopathologic examination of the site of chronic exposure in case 2 showed epithelial ingrowth into the pores of the implant. Both spheres in this report indicated limited fibrovascular ingrowth and abscess formation.
Conclusions: Chronic exposure of hydroxyapatite implants allows a portal of entry for extraneous hair shafts and also can lead to epithelial downgrowth. Both of these may be contributing factors in the development of serious implant infections.