Polyetheretherketone (PEEK) is a versatile material and is used increasingly for the correction of facial deformity. We have used bespoke implants with an interlocking mechanism to add stability and to facilitate ease of insertion in areas with difficult access. The interlocking mechanism also reduces the need for fixation to segments that are difficult to access.
Polyetheretherketone (PEEK) is a semi-crystalline linear aromatic polymer. PEEK is a biocompatible material, favourable for craniofacial reconstruction: it is translucent to X-rays and non-magnetic so it does not create artefacts in computed tomography (CT) or magnetic resonance (MR) images. It is non-allergenic, strong, light in weight, resistant to fatigue and to chemicals, and can be sterilized repeatedly without the degradation of its mechanical properties. PEEK can be contoured with high speed burs and fixed to bone with the use of a conventional plating system.
PEEK implants have gained popularity in recent years for the correction of facial deformity, due to these characteristics. Multiple-piece implants can be useful when the access is narrow and reconstruction of a large area is desired. Various joints between the fragments have been used in the past and these are stabilized to the bone using screws. The use of bespoke interlocking PEEK implants for added stability and ease of insertion into sub-periosteal pockets around the facial skeleton is described herein.
The first case involved the reconstruction of a chin deformity with a three-piece PEEK implant (designed and manufactured by Materialise, Leuven, Belgium), stabilized using an interlocking mechanism. The implant was designed as a three-part ‘jigsaw’ to facilitate easy insertion through a minimal access.
The implant was inserted through a lower labial sulcus incision in the sub-periosteal pocket created. The pieces were inserted individually commencing with the first lateral fragment, which was inserted through the soft tissue tunnel and locked in place with the custom-made interlocking mechanism. The central fragment was fixed to the mandible with two 2.0-mm × 12-mm Synthes Matrix mandibular screws ( Fig. 1 ).
The second case involved the reconstruction of an untreated zygomatic complex injury defect. The implant was inserted through an intraoral upper sulcus incision and a sub-periosteal pocket that was created along the zygomatic arch, body, orbital rim, and the frontozygomatic process. The distal implant was inserted first, followed by the proximal fragment, and these were locked in place using the interlocking mechanism ( Fig. 2 ).