Cranioplasty with individual XXXX fibre reinforced polymere (CFRP) medical grade implants based on CAD/CAM technique.

@entity1 @entity129 @entity11555 @entity990 @entity2103 @entity11757 @entity194 @entity505
BACKGROUND: The authors present a new method for the reconstruction of large or complex-formed cranial bone defects using prefabricated, computer-generated, individual CFRP ( @entity505 fibre reinforced plastics) medical grade implants. METHOD: CFRP is a composite material containing @entity505 fibres embedded in an @entity990 resin matrix. It is radiolucent, heat-resistant, extremely strong and light (its weight is 20% that of @entity11555 ), has a modulus of elasticity close to that of bone, and an established biocompatibility. The utilisation of a CAD/CAM (computer aided design/computer aided manufacture) technique based on digitised computed tomography (CT) data, with stereolithographic modelling as intermediate step, enabled the production of individual, prefabricated CFRP medical grade implants with an arithmetical maximum aberration in extension of less than +/-0.25 mm. Between 1995 and February 2002, 29 @entity1 (15 @entity1 and 14 @entity1 ; mean age, 39.9 years; range, 16 to 67 years) underwent cranioplasty with CFRP medical grade implants at the neurosurgical department of the University of Vienna. Twenty-four @entity1 were repaired secondarily (delayed cranioplasty) while 5 were repaired immediately following craniectomy (single stage cranioplasty). All cases were assessed for the accuracy of the intra-operative fit of the implant, restoration of the natural skull contour and aesthetics and adverse symptoms. FINDINGS: The intra-operative fit was excellent in 93.1% and good in 6.9% of the implants. In two cases minor adjustments of the bony margin of the defect were required. The operating time for insertion ranged from 16 to 38 minutes, median 21 minutes. Postoperatively, 86.2% of the @entity1 graded the restoration of their natural skull shape and symmetry as excellent while 13.8% termed it good. In one @entity1 a non-space occupying @entity11757 was found at the follow-up, but required no intervention. Two @entity1 experienced @entity194 of the frontal portion of the temporal muscle while one @entity1 had a transient @entity2103 . Over the mean follow-up period of 3.3 years (range, 0.08 to 6.8 years), there were no adverse reactions and no plate had to be removed. INTERPRETATION: Individual, prefabricated CFRP medical grade implants may be considered as an alternative to conventionally utilised materials for cranioplasty, in particular in the challenging group of @entity1 with extensive @entity129 or more complex-formed defects of the fronto-orbital or temporo-zygomatic region, guaranteeing short operating times and excellent functional and aesthetic results, which justifies the expense of their production.
