Developments in Craniomaxillofacial Surgery: Use of Self-Reinforced Bioabsorbable Osteofixation Devices

Abstract

Because of the problems associated with the conventional osteofixation devices used in craniomaxillofacial surgery, absorbable devices present an appealing alternative. Devices made of the polymers polylactide, polyglycolide, and their copolymers (PLGA and P[L/DL]LA) are currently the most commonly used. Ultrahigh-strength implants can be manufactured from these polymers with the self-reinforcing technique. Over the authors' almost two decades of study, both in experimental and clinical settings, self-reinforced devices have proved to be biocompatible, easy to handle, and mechanically strong, even for the fixation of femoral neck fractures. In craniomaxillofacial surgery, the authors have used self-reinforced devices for over 8 years without complications. Because of the more favored degradation characteristics, currently the copolymeric self-reinforced devices (P[L/DL]LA, Biosorb FX and PLGA, Biosorb PDX; Elite Performance Technologies, Solana Beach, Calif.) represent the advancing front in the application of absorbable devices in craniomaxillofacial surgery. The authors' share their experience and their studies of self-reinforced devices, which possess the highest strength and ductility of all bioabsorbable products.

The effect of cellulose nanowhiskers on the flexural properties of self-reinforced polylactic acid composites

“…The concept of self--reinforced composites was first developed by Capiati and Porter [3] who demonstrated that the orientation of aligned chains within the same polymer significantly improved their initial mechanical and fracture failure properties. In this process, fibres derived from the same polymer were heated above the glass transition (T g ) temperature but below their melting temperature (T m ) and compressed to produce composite plates using high pressure where the ultimate mechanical properties of the prepared composites depend on the molecular weight of the polymer and the fraction of aligned chains within the self--reinforced composites [4,5]. The selection of temperature, pressure and time are very important in order to maintain optimum reinforcing effect of the fibres in SRC processing [6].…”

Biomechanical Strength of Reconstruction Plates when Used for Medial Support of Med-El Cochlear Implants: Implications for Diagnostic MRI

“…An additional benefi t of the resorbable plate is that the plate facilitates new bone growth by providing a lattice for bone regrowth across the gap that exists between the craniotomy margin and the bone island beneath the CI internal device. In addition, the resorbable plates are temporary fi xtures, providing the additional support while the bone regrows before the plates are reabsorbed by the body, typically within 2 years [10] . The primary negative aspect of the resorbable plate is that when the resorbable plates fail, they fail catastrophically.…”

“…Based on clinical experience with removal or revision of CIs, this interval is anecdotally thought to be 6 months. There is a possibility, however, that given the osteoconductive behavior of demineralized bone matrix material such as the allograft-based DBX bone void fi ller (SynthesStratec Inc.), the combined use of this material with mesh fi xation may minimize the time necessary for bone to regrow across the gap at the edge of the craniotomy defect [10][11][12] .…”

“…However, even if the resorbable plates offer no additional advantage as far as the maximum force required for failure is concerned, they do offer the two additional benefi ts outlined above. First, they help fi x the CI internal device in place which may decrease the displacement due to torque effects, and second they help facilitate ingrowth of new bone, particularly if combined with a demineralized bone matrix material, through their osteoconductive properties [10] . For calvaria thick enough to accommodate the CI interval device by completing a craniectomy rather than a craniotomy and creation of a bone island, it is not necessary to use the resorbable or titanium reconstruction plates.…”

Self-reinforced bioresorbable polymer P (L/DL) LA 70:30 for the manufacture of craniofacial implant

“…occurs when the internal structure of the polymer is oriented at temperatures above glass transition temperature (T g ) and below melting temperature (T m ) in the case of semicrystalline polymers and above the (T g ) for amorphous polymers. Different forms of deformation can be used to promote the orientation, such as the uniaxial deformation, independent or in a matrix, the calendering and lamination, resulting in different types of microstructures such as microfibrils and fibers [7] . One of the principal methods used to produce self-reinforced samples is the so called "die-drawing", in which the sample is pulled through a heated die with dimensions smaller than the original.…”