Porous polyethylene channel implants: A modified porous polyethylene sheetimplant designed for repairs of large and complex orbital wall fractures

Purpose: To evaluate the effectiveness of a modified porous polyethylene im plant in orbital fracture repair. A porous polyethylene channel implant (PP CI) has internal channels that accept mini- or microplates from conventiona l plating systems, facilitating fixation to bone in the reconstruction of l arge, complex orbital fractures. Methods: The authors used 29 PPCIs to repair 25 orbits. Seventeen cases inv olved repair of an acute (less than two weeks after injury) fracture of one or more orbital walls. Eight cases represented delayed reconstruction of o rbital walls for late enophthalmos; or for residual defects after previous operations. Results: A PPCI provides a stable platform. for orbital soft tissue. Excell ent results were obtained in all patients with acute orbital fractures, whe reas good or excellent corrections of enophthalmos and hypoglobus were achi eved in all patients who underwent late repair. There were no instances of orbital infection, implant exposure or migration, worsening diplopia, visua l loss, or loss of structural support during 31 months of follow-up. Conclusions: A PPCI allows controlled placement of a porous polyethylene sh eet 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 fract ures are too large to support the implant in the posterior orbit. PPCIs are ideally suited for reconstruction of defects resulting from displacement o f orbital walls and for repair of posterior floor fractures, medial wall fr actures, and combined floor and medial wall defects.