title: Delayed onset porous polyethylene implant-related inflammation after orbital blowout fracture repair: four case reports.
abstract: BACKGROUND
  Porous polyethylene implants are commonly used in orbital blowout fracture repair because of purported biocompatibility, durability, and low frequency of complications. Delayed inflammation related to porous polyethylene sheet implants is very rare and no case series of this condition have been reported.
  
  
  METHODS
  This is a retrospective review of clinical presentations, radiographic findings, histopathological findings, treatments, and outcomes of patients who developed delayed complications in orbital blowout fracture repair using porous polyethylene sheets. Four male patients were included with a mean age of 49 years (range 35-69 years). Blowout fracture repair was complicated with implant-related inflammation 10 months, 2 years, 3 years, and 8 years after surgery. Chronic and subacute orbital inflammatory signs were noted in two patients and acute fulminant orbital inflammation was found in two patients. Three patients developed peri-implant abscesses and one patient had a soft tissue mass around the implant. All patients underwent implant removal and two of these patients with paranasal sinusitis had sinus surgery. Histopathological findings revealed chronic inflammatory changes with fibrosis, and one patient had foreign body granuloma with culture positive Staphylococcus aureus.
  
  
  CONCLUSIONS
  Delayed complications with porous polyethylene sheets used in orbital blowout fracture repair may occur many years following the initial surgery in immunocompetent patients. Low-grade or fulminant inflammation could complicate blowout fracture repair related with the implant.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
authors.forename: Orapan
authors.initials: O
authors.lastname: Aryasit
authors.affiliation: Department of Ophthalmology and Visual Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Kowloon, Hong Kong.
authors.forename: Danny S
authors.initials: DS
authors.lastname: Ng
authors.affiliation: International Specialist Eye Center (ISEC), Kuala Lumpur, Malaysia.
authors.forename: Alice S C
authors.initials: ASC
authors.lastname: Goh
authors.affiliation: Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea. eyeminded@skku.edu.
authors.forename: Kyung In
authors.initials: KI
authors.lastname: Woo
authors.affiliation: Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Yoon-Duck
authors.initials: YD
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D020878:Device Removal; D004487:Edema / Q000209:etiology; D005128:Eye Diseases / Q000209:etiology*; D015818:Eye Infections, Bacterial / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009917:Orbital Fractures / Q000601:surgery*; D020273:Orbital Implants / Q000009:adverse effects*; D020959:Polyethylene / Q000009:adverse effects / Q000627:therapeutic use; D011183:Postoperative Complications / Q000209:etiology*; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000209:etiology; D013211:Staphylococcus aureus / Q000302:isolation & purification
chemical_list: D020959:Polyethylene
keywords: Delayed inflammation; Orbital fracture; Porous polyethylene