Search results for "fixation"
showing 10 items of 482 documents
A Locked Intraosseous Nail for Transverse Patellar Fractures: A Biomechanical Comparison with Tension Band Wiring Through Cannulated Screws.
2018
Background Displaced transverse patellar fractures require open reduction and internal fixation. State-of-the-art stabilization techniques are tension band wiring (TBW) using Kirschner wires or cannulated screws. These techniques are associated with high rates of secondary fracture displacement, implant migration, implant prominence, wound-healing disturbances, and the need for implant removal. Recently, a locked intraosseous patellar nail prototype was developed. The aim of the present study was to investigate the biomechanical performance of this nail compared with TBW using cannulated screws. Methods Seven paired fresh-frozen human cadaveric knees were stripped of all soft tissues except…
Preliminary Experience with a Novel System of Facet Fixation to Treat Patients with Lumbar Degenerative Disease. A New Perspective in Minimally Invas…
2017
Purpose We report our experience with a novel surgical device for the treatment of lumbar degenerative microinstability. Facet Wedge (DePuy Synthes, Raynham, Massachusetts, United States) is a novel technique of intra-articular lumbar facet fixation that provides a minimally invasive alternative to standard posterior fixation. Materials and Methods From November 2014 to July 2015, 38 patients underwent single-level Facet Wedge implantation. The main surgical indications included herniated disk (18 patients), spinal canal and foraminal stenosis (14 patients), and Meyerding grade I degenerative spondylolisthesis (6 patients). All the patients showed radiologic signs of microinstability: hype…
Vergleich radiologischer Verfahren zur präoperativen Beurteilung der Verankerungsfestigkeit von Wirbelsäulenimplantaten
1997
PURPOSE To compare three techniques with regards to their ability to estimate pull out strength of spinal fusion hardware. MATERIAL AND METHODS VDS-screw fixation strength in 50 human cadaveric vertebral bodies was approximated by means of pull out force measurement. Bone quality was assessed by Dual X-ray Absorptiometry (DXA). Quantitative Computed Tomography (QCT) and T2*-relaxation time. For each of these techniques, correlation with axial pull out force strength was investigated. RESULTS Highest correlation was found for cancellous bone density measured by QCT (r = 0.72; p < 0.001). Immediately followed by DXA (r = 0.70; p < 0.001), which involves all bone components. Inverted T2*-relax…
Iliosacral Screw Osteosynthesis
2017
Fragility fractures of the anterior pelvic ring are very often combined with fractures of the posterior pelvic ring. The large majority of the posterior fractures is situated in the sacral ala. Non-operative therapy may be cumbersome in patients with a combination of an anterior with a posterior pelvic ring fracture. Any surgical therapy should be as less invasive as possible. Iliosacral screw fixation is a minimal invasive technique. Variations of the upper sacral anatomy make optimal iliosacral screw placement challenging. The vestibule or isthmus is the narrowest part of the bony corridor from the lateral ilium to the S1 sacral body. It always points towards anterior and superior. The wh…
In Silico Analysis of Bone Tension During Fixation of the Medial Malleolus Fracture After Ankle Joint Endoprosthesis
2020
Total ankle arthroplasty (TAR) is a procedure alternative to arthrodesis which enables the biomechanical stabilization of the ankle joint. The procedure is associated with a high risk of complications, including fractures of the medial malleolus. In this study, the finite element method (FEM), based on CT examinations, was used to model the ankle fracture fixation after TAR. Three types of fracture stabilization were considered: screw, Blount staple, and both screw and Blount staple. In the in silico model, the maximum stress tension was found at prosthetic junctions with the base, cone, and talar components of the tibial prosthesis. When the fracture was stabilized with the Blount staple, …
(i) Comminuted patellar fractures
2006
Summary Purpose of review This article reviews current best practice for the diagnosis and treatment of comminuted patellar fractures. Recent findings Patellar fractures make up about 1% of all fractures. As a rule, fractures of the patella are caused by direct trauma to the knee. A transverse fracture is the most common fracture type. Open reduction and internal fixation is the treatment of choice for the majority of displaced patellar fractures. Treatment must achieve anatomic reduction of the articular surface and reestablish the continuity of the extensor mechanism. Tension-band wiring, interfragmentary screw fixation and a combination of cerclage wiring and screw fixation are the most …
Screw‐in‐screw fixation of fragility sacrum fractures provides high stability without loosening—biomechanical evaluation of a new concept
2020
Surgical treatment of fragility sacrum fractures with percutaneous sacroiliac (SI) screw fixation is associated with high failure rates. Turn-out is detected in up to 20% of the patients. The aim of this study was to evaluate a new screw-in-screw implant prototype for fragility sacrum fracture fixation. Twenty-seven artificial hemipelvises were assigned to three groups (n = 9) for instrumentation of an SI screw, the new screw-in-screw implant prototype, ora transsacral screw. Before implantation, a vertical osteotomy was set in zone 1 after Denis. All specimens were biomechanically tested to failure in upright position. Validated setup and test protocol were used for complex axial and torsi…
A new tool to improve pedicle screw placement accuracy in navigated spine surgery: A monocentric study
2021
Objective Navigated instrumented spine surgery is burden by a low but significant screw mispositioning risks, respectively, for the 2D imaging system from 15 to 40% and, for the 3D imaging system, ranging from 4.1 to 11.5%. The primary objective of this study was to demonstrate the efficacy of a new "screw-like" tool in order to further decrease pedicle screws mispositioning rate during vertebral navigated spine surgery. Materials and methods Between January and June 2019 an initial case series of 18 patients were enrolled. All patients underwent a pedicle screw fixation, both in thoracic (Th10-Th12) and lumbosacral (L1-S1) spine, using O-arm (Medtronic Navigation, Louisville, Colorado) and…
Reaction of the bone structure to methotrexate-Palacos flow y. Experimental investigations in animals.
1989
With the combined osteosynthesis of pathological fractures in association with tumors and/or metastases in mind, E. Merck (Darmstadt, FRG) developed a bone cement containing a cytostatic agent, methotrexate-Palacos flow y (MTX-Pf). The animal-experimental study presented here investigates the tolerability of MTX-Pf in the femurs of rabbits with lateral comparison. In these investigations we used both the concentration of 0.63% MTX, as is currently used in standard clinical surgery, as well as a much higher concentration of 2.5% MTX. The histological sections were investigated using microradiographic methods and provided no indication of any significant differences between the femora with th…
Treatment of distal intraarticular tibial fractures: A biomechanical evaluation of intramedullary nailing vs. angle-stable plate osteosynthesis
2015
In factures of the distal tibia with simple articular extension, the optimal surgical treatment remains debatable. In clinical practice, minimally invasive plate osteosynthesis and intramedullary nailing are both routinely performed. Comparative biomechanical studies of different types of osteosynthesis of intraarticular distal tibial fractures are missing due to the lack of an established model. The goal of this study was first to establish a biomechanical model and second to investigate, which are the biomechanical advantages of angle-stable plate osteosynthesis and intramedullary nailing of distal intraarticular tibial fractures. Seven 4(th) generation biomechanical composite tibiae feat…