Level of Sagittal Plane Fit of Plates on the Radial Shaft: A Cadaveric Study Comparing Precontoured and Straight Titanium Plates

Background: During radial shaft fracture fixation, it is important to contour the plate appropriately to restore the radial bow in order to maintain normal forearm mechanics and motion. The aim of this study was to investigate the fit of precontoured radial shaft plates versus surgeon-contoured plates. Methods: Six 10-hole Acumed® precontoured volar and dorsolateral radius plates and twelve 10-hole Synthes straight titanium 3.5 mm LC-DCP plates were drilled with arrays of 1.5 mm diameter holes to permit measurement of the plate distance off bone. Plates were applied to 6 cadaver radii and secured with a screw on each end. Three plate conditions were tested: precontoured plates, precontoured plates with further surgeon contouring, and straight plates with surgeon contouring. Surgeon contouring time for each plate was recorded. Each plate was divided into 3 equal regions, and the average distance gaps for each region and the entire plate were calculated. Results: For the volar side, precontoured plates had a larger total gap compared to that plate with additional surgeon contouring (1.4 mm difference) and the straight surgeon-contoured plates (1.2 mm difference). On the dorsal side, there was no difference in fit between the 3 plate conditions at any location. No differences were found in plate contouring times. Conclusions: The precontoured dorsal plate fit was as good as the surgeon-contoured plates indicating this plate could potentially be used in fracture surgery without further bending. The precontoured volar plate was under-contoured, on average, and would likely require further bending to restore the radial bow.

The Use of Starch Matrix-banana Fiber Composites for Biodegradable Maxillofacial Bone Plates

Starch based green composites have been studied as potential materials to be used in several biomedical applications. This paper explores utilizing starch based composites reinforced with pseudostem banana fibers in fabricating biodegradable maxillofacial bone plates. Corn starch plasticized by 30 wt.% glycerin and 20 wt.% distilled water was used as a matrix. The produced thermoplastic starch (TPS) matrix is reinforced with pseudostem banana fibers at different weight fractions using hot pressing at 5 MPa and 160ºC for 30 minutes. Our experimental results showed that increasing the banana fibers weight fraction progressively improved the mechanical properties reaching a maximum at 50 wt.% fibers. The improvement in the mechanical properties of starch/banana fibers composite was attributable to the strong interaction between fibers and the starch matrix, as evidenced by a series of scanning electron micrographs of the fracture surface. Furthermore, experiments investigating thermal properties and water uptake also showed that the best results are achieved at the 50 wt.% banana fibers. The experimental results show that the starch matrix-banana fiber composites satisfy the maxillofacial bone fixation requirements.

The Mechanical Properties and Fatigue Prediction of a New Generation of Osteosynthesis Devices

The aim of the study was to predict the fatigue life of metallic bone plates employing SIMULIA fe-safe software. Two materials commonly used for surgical implants were subjected to investigation: 1.4441 (ASTM F138) stainless steel for implants and Ti6Al4V ELI (ASTM F136) titanium alloy. The material parameters of the two materials were determined from experimental research. Four-point bending fatigue testing was conducted on two generations of bone plates in order to allow for the comparison of the prediction results with the measured data from the experiments.

A review of biomechanical studies for mandibular angle fracture internal fixation

Mandible fractures correspond to 19-40% of all facial fractures. Among all mandible fractures, 12-30% are fractures of the mandibular angle. These fractures are mainly caused by sports activities, interpersonal violence and car accidents. The presence of the third molar and the thin transverse bone area seem to be responsible for the frequent involvement of the mandibular angle in facial fractures. Before the advent of antibiotics, a high frequency of infection was always associated after an open reduction in mandibular angle fractures. Wired osteosynthesis and maxillomandibular fixation (MMF) were traditional methods for fixing mandibular angle fractures. The limitation of both methods has influenced the development of new approaches for the treatment of mandibular angle fractures. Currently, osteosynthesis of mandibular angle fractures with plates and screws has become an effective treatment option. Several forms are described in the literature as: fixation of bone segments with a miniplate on the upper edge of the mandible, fixation with two miniplates, lag screw or by a single rigid plate on the lower edge of the mandible. The purpose of this study was to summarize the main characteristics of biomechanical studies such as the type of mandible source used, the plating techniques employed, the plate material, and the loading protocols used to evaluate the stability of the fixation methods. The Medline (PubMed) database was searched combining relevant terms and pertinent articles in English were included. Articles had to meet the following inclusion criteria: be in vitro biomechanical studies evaluating fixation methods for mandibular angle fractures. A total of 27 articles fulfilled the inclusion criteria. Synthetic mandibles (n=12), animal mandibles (n=9), and human cadaveric mandibles (n=5) were used as the sample source to perform the biomechanical analysis. One article used both synthetic and human cadaveric mandibles. Also, a variety of fixation techniques was described such as mini-plates, lag-screws, reconstruction plates, and three-dimensional plates. The materials of the bone plates used were: stainless steel, commercially pure titanium, titanium alloy or bioresorbable. However, there was inconsistency in reporting the materials and not all studies clearly stated the material of the bone plates. For the biomechanical analysis, there was a high variation among all studies regarding the loading protocols used. The same side of fixation, the anterior part of the mandible (central incisors) or the contralateral side were reported as the dentate regions in which the force was applied. For more than 2 decades, in vitro biomechanical studies have been used to help researchers and clinicians in the field of Oral and Maxillofacial Surgery to properly evaluate and compare the different devices and techniques available for the treatment of mandibular angle fractures. Also, biomechanical studies are important to answer questions on fatigue performance and fracture strength on the gross level.

Alveolar Cleft Reconstruction Using Double Iliac Corticocancellous Bone Plates Grafting Technique in Mixed Dentition Phase

Objective The primary goal of maxillary alveolar cleft reconstruction in patients with cleft lip/palate at the phase of mixed dentition is to build bone in the cleft area which in turn allows closure of the oronasal fistula, establishes arch continuity, and improve maxillary stability. This study aimed to evaluate the double iliac corticocancellous bone plates grafting technique for initial alveolar cleft grafting. Design This prospective study was conducted on 12 consecutive patients with unilateral complete alveolar cleft and previous cleft lip and palate corrective surgery. Intervention For all patients, the iliac crest graft was harvested and cut into 2 cortical bone plates and adapted labially and palatally. Both plates were fixed with screws then the gap between the 2 plates was filled with cancellous bone. The grafted side was compared to the contralateral side 9 months postoperatively regarding labio-palatal alveolar width and bone density, while the 9 months postoperative graft height was compared to the immediate postoperative height using computed tomography scans. Results All grafted sides showed similarity to the contralateral sides regarding both alveolar width and bone density with minimal crestal bone resorption. Conclusion The double iliac corticocancellous bone plate grafting technique seems to be a reliable method for alveolar cleft reconstruction with adequate bone quality and contour.