Porous Polyethylene Implant for Cranioplasty and Skull Base Reconstruction

James K. Liu, MD; Oren N. Gottfried, MD; Chad D. Cole, MSc; William R. Dougherty, MD; William T. Couldwell, MD, PhD


Neurosurg Focus. 2004;16(3) 

In This Article

Abstract and Introduction


Object: Cranial reconstruction after skull base surgery is important for restoration of function and cosmesis. The authors describe their experience with the Medpor porous polyethylene implant for cosmetic cranioplasty and reconstruction after skull base surgery.
Methods: Medpor, a biocompatible implant, is flexible and can be contoured to facilitate surgical reconstruction of small to medium (< 8 cm) convexity or cranial base defects resulting from a variety of skull base approaches. This method provides similar cosmetic results to standard alloplast cranioplasty while decreasing operating time. The porous nature of the material allows ingrowth of soft tissue and bone to increase implant strength and decrease the risk of infection. This material can also be used safely in reconstruction of the cranium and skull base adjacent to the paranasal sinuses.
Conclusions: The authors have used the Medpor porous polyethylene implant in 611 standard cranial and skull base procedures and have achieved excellent cosmetic results and no implant-related complications.


Reconstruction of cranial base and craniofacial defects is an important goal after skull base surgery.[9] Although biocompatibility characteristics are optimal in autogenous grafts, the risk of donor site morbidity, difficulty with graft contouring, and prolonged operating time limit their use. The desire for immediate functional and aesthetic reconstruction after skull base surgery has led to increased use of alloplastic materials, including silicone, porous hydroxyapatite, titanium mesh, and methyl methacrylate.[1,4,7,11,13,20]

The Medpor porous polyethylene Flexblock implant (Porex Surgical, Inc., Newnan, GA) is a biocompatible material that is composed of high-density polyethylene microspheres that are sintered to create a framework of interconnected pores approximately 150 µm in diameter.[2,3,22] Its porous character allows for rapid fibrovascular and soft tissue ingrowth and eventual incorporation of bone, which strengthens the implant as well as decreases the risk of infection.[5,8,10,12,18,21] The Medpor Flexblock implant is flexible and can easily be contoured to accommodate a variety of skull defects. It has long been used as a standard reference material for biocompatibility testing and has been used in cranioplasty, craniofacial repair, and skull base reconstruction.[2,3,6,7,9,16–19,22] We have found the Medpor implant to be a useful material for cranioplasty and reconstruction after skull base surgery. We describe our surgical technique in which the Medpor Flexblock implant is used and report our experience with it in 598 patients.