Porous polyethylene channel implants: a modified porous polyethylene sheet implant designed for repairs of large and complex orbital wall fractures.

Purpose: To evaluate the effectiveness of a modified porous polyethylene implant in orbital fracture repair. A porous polyethylene channel implant (PPCI) has internal channels that accept mini- or microplates from conventional plating systems, facilitating fixation to bone in the reconstruction of large, complex orbital fractures.
Methods: The authors used 29 PPCIs to repair 25 orbits. Seventeen cases involved repair of an acute (less than two weeks after injury) fracture of one or more orbital walls. Eight cases represented delayed reconstruction of orbital walls for late enophthalmos or for residual defects after previous operations.
Results: A PPCI provides a stable platform for orbital soft tissue. Excellent results were obtained in all patients with acute orbital fractures, whereas good or excellent corrections of enophthalmos and hypoglobus were achieved in all patients who underwent late repair. There were no instances of orbital infection, implant exposure or migration, worsening diplopia, visual loss, or loss of structural support during 31 months of follow-up.
Conclusions: A PPCI allows controlled placement of a porous polyethylene sheet with secure fixation to stable bone. The implant design allows it to be cantilevered from the orbital rim to serve as a stable platform when fractures are too large to support the implant in the posterior orbit. PPCIs are ideally suited for reconstruction of defects resulting from displacement of orbital walls and for repair of posterior floor fractures, medial wall fractures, and combined floor and medial wall defects.