Implant infection in porous orbital implants.

Purpose: To analyze implant infection in patients with porous orbital implants.

Methods: A retrospective analysis of 212 patients with one of five types of porous orbital implants (bone-derived hydroxyapatite [HA], coralline HA, synthetic HA, porous polyethylene, and aluminium oxide) was conducted. Reasons for surgery, type of surgery, type of implant, peg system used, time of pegging, problems before and after pegging, treatment, and follow-up duration were recorded for all patients, along with additional data including time of onset of infection, microorganism cultured, antibiotics used, patient response to antibiotic therapy, additional interventions, and final status for patients with infection.

Results: Of the 212 patients with porous orbital implants, 116 (54.72%) were pegged. Implant infection was observed in 11 of 116 patients (9.48%) with pegs, whereas 0% of unpegged implants was infected (p = 0.001). The interval between pegging and the onset of infection was 3 to 83 months (average, 36.27 +/- 29.12 months). Implant exposure was noted in 5 of the 11 patients with infection. Symptoms resolved completely with antibiotic treatment in 7 patients. One patient required implant removal as the result of frequent exacerbations. The remaining 3 patients presented with hemorrhagic, purulent discharge and/or pyogenic granuloma on their last visits after being free of symptoms for 5 to 6 months.

Conclusions: Implant infection is a serious problem that requires additional patient visits, intensive antibiotic therapy, surgery, or some combination of these. Existence of a peg system appears to play a role in implant infection. Infection may develop as late as 6 to 7 years after pegging, and the patient should be cautioned about potential late-onset problems. It is possible to control the infection with appropriate antibiotic therapy; removal should be reserved for refractory cases.