title: Clinicopathologic analysis of 15 explanted hydroxyapatite implants.
abstract: OBJECTIVE
  To report the clinical findings, treatment, outcomes, and histopathologic findings in patients with suspected orbital implant infection requiring implant removal.
  
  
  METHODS
  Retrospective, observational case series of 14 patients (15 hydroxyapatite orbital implants) undergoing implant removal from September 1994 through December 2002. Patient age, type of surgery, implant type, symptoms, treatment, histopathology of implant, and follow-up course were analyzed.
  
  
  RESULTS
  Of the 14 patients, 7 were female and 7 were male. The mean age at explantation was 42 years. The most common symptoms were discharge and socket tenderness. The most common signs were conjunctival inflammation (edema, hyperemia), discharge, and recurrent pyogenic granuloma. Clinical evidence of infection was documented in 13 patients. Histopathologic assessment of the 15 explanted implants showed acute inflammation and necrosis (abscess) with identification of microorganisms (5 patients), acute inflammation and necrosis without identification of microorganisms (4 patients), chronic inflammation with identification of microorganisms (1 patient), chronic inflammation without identification of microorganisms (3 patients), and a predominant foreign body granulomatous response without identification of microorganisms (2 patients). Osseous metaplasia was seen in 10 implants. Prompt resolution of symptoms and signs occurred in all but one case.
  
  
  CONCLUSIONS
  The clinical course of porous orbital implant infection may be prolonged, and the early symptom of recurrent discharge, a common problem for implant recipients, may delay diagnosis. Implant infection should be suspected when there is persistent conjunctival inflammation and discharge after implant placement despite antibiotic therapy, discomfort on implant palpation, and recurrent pyogenic granuloma (indicative of implant exposure). Implant removal is usually required in these cases. If orbital pain (not necessarily related to implant palpation) is the main complaint, without signs of conjunctival inflammation and with or without discharge, one should consider other reasons for the symptoms.
authors.affiliation: Department of Ophthalmology, University of Ottawa Eye Institute, 340 McLeon Street, Suite 104, Ottawa, Ontario K2P 1A4, Canada.
authors.forename: David R
authors.initials: DR
authors.lastname: Jordan
authors.forename: Seymour
authors.initials: S
authors.lastname: Brownstein
authors.forename: Hamid
authors.initials: H
authors.lastname: Faraji
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000853:Anophthalmos / Q000601:surgery*; D001672:Biocompatible Materials; D003231:Conjunctivitis / Q000175:diagnosis / Q000382:microbiology; D020878:Device Removal; D017886:Durapatite; D015353:Eye Enucleation; D017234:Eye Evisceration; D015818:Eye Infections, Bacterial / Q000175:diagnosis / Q000382:microbiology; D005260:Female; D015745:Granuloma, Foreign-Body / Q000175:diagnosis / Q000382:microbiology; D017789:Granuloma, Pyogenic / Q000175:diagnosis / Q000382:microbiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009915:Orbit / Q000601:surgery*; D020273:Orbital Implants; D019919:Prosthesis Implantation; D016459:Prosthesis-Related Infections / Q000175:diagnosis / Q000382:microbiology; D012086:Reoperation
chemical_list: D001672:Biocompatible Materials; D017886:Durapatite