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Rigid Fixation (rigid + fixation)

Distribution by Scientific Domains

Medical Sciences	75%

Selected Abstracts

The conservative treatment of pediatric mandibular fracture with prefabricated surgical splint: a case report

DENTAL TRAUMATOLOGY, Issue 4 2007
Ceyda Kocabay
Abstract,,, The use of rigid fixation in children is controversial and may cause growth retardation along cranial suture lines. Intermaxillary fixation for mandibular fractures should be used cautiously as bony ankylosis in the temporomandibular joint (TMJ) and trismus may develop. The high osteogenic potential of the pediatric mandible allows non-surgical management to be successful in younger patients with conservative approaches. In this case, successful conservative treatment of mandibular fracture of a 3-year-old patient is presented. [source]

Conservative treatment of paediatric mandibular fracture by the use of orthodontic appliance and rubber elastics: report of a case

DENTAL TRAUMATOLOGY, Issue 1 2005
Petter J. E. Gawelin
Abstract,,, Treatment principles of paediatric mandibular fractures may differ from the treatment of the adult population in that a conservative approach is in most cases advocated before the use of internal rigid fixation with plates and screws. This is because of a relative high risk of disturbed facial skeletal growth and risk of damaging unerupted teeth. Knowledge of conservative treatment options is essential in order to minimize these risks and one option is presented in this paper. This case report describes a 5-year-old girl that sustained an open fracture of the mandible and who was successfully treated by the means of applying orthodontic brackets and an arch bar combined with ligatures and rubber elastics. [source]

Induction of a neoarthrosis by precisely controlled motion in an experimental mid-femoral defect

JOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2002
Dennis M. Cullinane
Bone regeneration during fracture healing has been demonstrated repeatedly, yet the regeneration of articular cartilage and joints has not yet been achieved. It has been recognized however that the mechanical environment during fracture healing can be correlated to the contributions of either the endochondral or intramembranous processes of bone formation, and to resultant tissue architecture. Using this information, the goal of this study was to test the hypothesis that induced motion can directly regulate osteogenic and chondrogenic tissue formation in a rat mid-femoral bone defect and thereby influence the anatomical result. Sixteen male Sprague Dawley rats (400 ± 20 g) underwent production of a mid-diaphyseal, non-critical sized 3.0 mm segmental femoral defect with rigid external fixation using a custom designed four pin fixator. One group of eight animals represented the controls and underwent surgery and constant rigid fixation. In the treatment group the custom external fixator was used to introduce daily interfragmentary bending strain in the eight treatment animals (12°s angular excursion), with a hypothetical symmetrical bending load centered within the gap. The eight animals in the treatment group received motion at 1.0 Hz, for 10 min a day, with a 3 days on, one day off loading protocol for the first two weeks, and 2 days on, one day off for the remaining three weeks. Data collection included histological and immunohistological identification of tissue types, and mean collagen fiber angles and angular conformity between individual fibers in superficial, intermediate, and deep zones within the cartilage. These parameters were compared between the treatment group, rat knee articular cartilage, and the control group as a structural outcome assessment. After 35 days the control animals demonstrated varying degrees of osseous union of the defect with some animals showing partial union. In every individual within the mechanical treatment group the defect completely failed to unite. Bony arcades developed in the experimental group, capping the termini of the bone segments on both sides of the defect in four out of six animals completing the study. These new structures were typically covered with cartilage, as identified by specific histological staining for Type II collagen and proteoglycans. The distribution of collagen within analogous superficial, intermediate, and deep zones of the newly formed cartilage tissue demonstrated preferred fiber angles consistent with those seen in articular cartilage. Although not resulting in complete joint development, these neoarthroses show that the induced motion selectively controlled the formation of cartilage and bone during fracture repair, and that it can be specifically directed. They further demonstrate that the spatial organization of molecular components within the newly formed tissue, at both microanatomical and gross levels, are influenced by their local mechanical environment, confirming previous theoretical models. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source]

Transcriptional profiling and biochemical analysis of mechanically induced cartilaginous tissues in a rat model

ARTHRITIS & RHEUMATISM, Issue 4 2010
Kristy T. Salisbury Palomares
Objective To characterize patterns of molecular expression that lead to cartilage formation in vivo in a postnatal setting, by profiling messenger RNA expression across the time course of mechanically induced chondrogenesis. Methods Retired breeder Sprague-Dawley rats underwent a noncritical-sized transverse femoral osteotomy. Experimental animals (n = 45) were subjected to bending stimulation (60° cyclic motion in the sagittal plane for 15 minutes/day) of the osteotomy gap beginning on day 10 after the operation. Control animals (n = 32) experienced continuous rigid fixation. Messenger RNA isolated on days 10, 17, 24, and 38 after surgery was analyzed using a microarray containing 608 genes involved in skeletal development, tissue differentiation, fracture healing, and mechanotransduction. The glycosaminoglycan (GAG) content in the stimulated tissues was compared with that in native articular cartilage as a means of assessing the progression of chondrogenic development of the tissues. Results The majority of the 100 genes that were differentially expressed were up-regulated in response to mechanical stimulation. Many of these genes are associated with articular cartilage development and maintenance, diarthrodial joint development, cell adhesion, extracellular matrix synthesis, signal transduction, and skeletal development. Quantitative real-time polymerase chain reaction results were consistent with the microarray findings. The GAG content of the stimulated tissues increased over time and was no different from that of articular cartilage on day 38 after surgery. Conclusion Our findings indicate that mechanical stimulation causes up-regulation of genes that are principally involved in joint cavity morphogenesis and critical to articular cartilage function. Further study of this type of stimulation may identify key signaling events required for postnatal hyaline cartilage formation. [source]