Academic literature on the topic 'Volar Plate'

Avaliar as propriedades mecânicas em dois sistemas de osteossíntese com o emprego de placa volar de rádio distal, alterando-se o tipo de parafuso utilizado quais sejam: bloqueados ou corticais, na fileira distal da placa bem como a colocação ou não de enxerto ósseo em modelos ósseos Sawbone(TM). Trata-se de um estudo experimental de fraturas do rádio distal extra articular, consideradas instáveis, com dois fragmentos e com uma cunha dorsal de 11 mm (classificação AO 23 A3) e também com modelo de osteotomia de cunha aberta, frequentemente empregado por cirurgiões ortopédicos, na prática clínica. Foram usados 10 (dez) ossos rádios Sawbone(TM) esquerdos (Código: 3407), validados para estudo biomecânico, os quais foram divididos em dois grupos de cinco ossos cada. Os grupos foram submetidos a dois sistemas de osteossíntese: sistema de fixação 1, placa volar de ângulo variável esquerda VA-LCP, dupla coluna, seis/três furos, com quatro parafusos bloqueados distais, dois parafusos bloqueados proximais e mais um parafuso cortical proximal e o sistema de fixação 2, utilizou a mesma placa volar de rádio, porém apenas trocou na fileira distal os quatros parafusos corticais. Os modelos foram submetidos a testes mecânicos de flexão dorsal de 30 N e compressão axial de 250 N para avaliar a deflexão e a rigidez dos sistemas, alternando a colocação do enxerto ósseo. A seguir, houve o ensaio de carregamento cíclico de compressão de 250 N por 1000 HZ, simulando-se um pós-operatório de 6 semanas. Na segunda parte do estudo, foram realizados os mesmos testes de compressão axial e flexão dorsal, usando as mesmas forças de carregamento empregadas na primeira fase dos ensaios mecânicos, para avaliar as possíveis alterações na deflexão e rigidez. Para se comparar as medidas aferidas entre os testes de flexão dorsal e compressão axial antes e depois do carregamento cíclico foi empregado o teste de U de Mann-Whitney, considerando-se um nível de significância de 5%. Ao analisar os resultados obtidos, o sistema de fixação com parafuso cortical com enxerto (CC) se mostrou mais rigído, tanto na deflexão quanto na compressão ao ser comparado com os demais sistemas de fixação, principalmente com o bloqueado sem enxerto (BS). Quanto a relevância clínica do estudo placas volar de rádio distal são comumente usadas nos tratamentos das fraturas do rádio distal, porém a configuração ideal dos parafusos distais não foi determinada. O sistema de fixação com quatro parafusos corticais com enxerto ósseo do ponto de vista biomecânico in vitro, os resultados se mostraram bastante confiáveis como uma proposta de tratamento.<br>Evaluating the biomechanical properties in two osteosynthesis systems using a volar distal radius plate by changing the type of screw used, whether locked or cortical, in the distal row of the plate, with or without bone grafting in Sawbone (TM) models. This is an experimental study of fractures of the extra articular distal radius, considered to be unstable, with two fragments and a dorsal wedge of 11 mm (AO 23 A3 classification), as well as the open-wedge osteotomy model frequently used by Orthopedic surgeons, in clinical practice. Ten left-hand radios bones, Sawbone (TM) (Code: 3407), validated for biomechanical studies were used. These were then divided into two groups of 5 bones each. The groups were submitted to two osteosynthesis systems: fixation system 1, VA-LCP left variable-angle volar plate, double-column, 6/3 holes, with four distal locked screws, two proximal locked screws and one proximal cortical screw. The fixation system 2 used the same volar plate, but only the four cortical screws were changed in the distal row. The models were submitted to mechanical tests of dorsal flexion of 30 N and axial compression of 250 N to evaluate the deflection and stiffness of the systems, changing the placement of the bone graft. Next, there was the cyclic loading test of 250 N per 1000 HZ, simulating a 6-week post-op. In the second part of the study, the same tests of axial compression and dorsal flexion were performed, using the same loading forces used in the first phase of the mechanical tests to evaluate the possible changes in deflection and stiffness. In order to compare the results between the dorsal flexion tests and axial compression before and after the cyclic loading, the Mann-Whitney U test was used, considering a level of significance of 5%. When analyzing the results obtained, the cortical screw fixation system with graft was shown to be more rigid, both in deflection and in compression when compared to the other fixation systems, especially with the locked system without graft. Regarding the clinical relevance of the study, the volar distal radius plate is commonly used in the treatments of distal radius fractures, however the ideal configuration of the distal screws has not yet been determined. The results of the fixation system with four cortical screws with bone graft, from a biomechanical point of view in vitro, proved to be a reliable form of treatment.

Fracture of the distal radius is one of the most frequent injuries, and it represents about 20% of all adults taken into emergency rooms. A number of studies suggest various methods to reduce the dislocation and to secure fragments of the distal radius. In this study, the Non-Bridging External Wrist Fixator System (NBX), a pre-market-released product manufactured by NUTEK Inc. was biomechanically assessed by comparing with the Universal Distal Radius System (Volar Plate Fixator: VPF), a market-released product manufactured by Stryker Co. The comparison was performed in several parameters, which were wrist motion, radial tilt angle, radial length, volar tilt angle, stiffness, and failure load. Five pairs of fresh human cadaver arms were used for this study. The wrists were tested to obtain x-ray images for 1 normal and 2 injury conditions (intact, fractured, and fixed), 2 load conditions (gravity only and torque applied), and 4 postural conditions (volar flexion, dorsiflexion, ulnar deviation, and radial deviation). These tests yielded 24 (3×2×4) x-ray images for each wrist, and the images were analyzed to obtain the data for each parameter. Although the results were not statistically significant in some conditions, NBX fixation limited wrist motion more than VPF fixation. This result can be explained not only by the difference in the ability of fixation, but also by the difference in the surgical trauma (NBX is less invasive than VPF). Furthermore, in the measurement of radial tilt angle, radial length, and volar tilt angle, NBX was more effective than VPF to reduce and secure the bone fragments of the distal radius. In destructive test, the NBX is less strong than VPF. However, NBX is strong enough to sustain the expected forces of daily activity.

Background and aims The advent of volar locking plates designed specifically for fractures of the distal radius has resulted in a major shift away from percutaneous fixation of these injuries. However, comparative studies have not always demonstrated better outcomes than those achieved with less invasive and potentially less expensive established techniques. The present study was a randomized controlled trial comparing the outcome of displaced distal radius fractures when treated with a volar locking plate or closed reduction and percutaneous wire fixation, with supplemental bridging external fixation when required. The primary research objective was to ascertain whether the use of volar locking plates improves functional outcome in the short and medium term. The secondary objective was to determine, through economic evaluation, whether the use of volar locking plates for distal radius fractures is of financial benefit to the health service. Methods A single-centre randomized controlled trial of pragmatic design, conducted in a tertiary care institution, with accompanying economic evaluation. 130 patients with displaced distal radius fractures were randomised to either volar locking plate (n=66) or conventional percutaneous fixation methods (n=64). Outcome assessments were conducted at 6 weeks, 12 weeks and 1 year. The primary outcome measure was the PEM score at one year. Secondary outcomes included the QuickDASH, PRWE, EQ-5D and SF-12 scores, range of motion, grip strength, radiographic and cost parameters. A cost-effectiveness analysis was performed from the perspective of the NHS, and in line with NICE guidance on the methods of technology appraisal. “Bottom up” micro-costing methods were used to calculate costs for each treatment pathway, prospectively collecting information on consumables, inpatient and outpatient resource use, complications and additional procedures up to a year post surgery. Main findings Patients in the volar locking plate group had significantly better PEM, QuickDASH, PRWE scores and range of motion at 6 weeks, with no differences at 12 weeks and 1 year. Grip strength was better for the plate group at all time points. The volar locking plate was better at restoring the radiographic parameters of palmar tilt and radial height. Despite the early functional advantage, patients did not return to work sooner. Quality of life scores were marginally, but not significantly, better for the plate group at early follow-up. Both groups returned to baseline at one year. NHS costs for the plate group were significantly higher. For an additional £713, VLP fixation offered 0.018 additional QALYs in the year post surgery. The incremental cost effectiveness ratio (ICER) for VLP fixation at NHS list price was £40,068. Conclusion The current study showed that use of a volar locking plate resulted in better early post-operative function. However, there was no significant difference at, or after 12 weeks. The volar locking plate achieved better radiographic reduction and measured grip strength, but this did not translate to a difference in function at 12 weeks and 1 year. The earlier recovery of function may be of advantage to some patients. However, in spite of their increasing use and popularity, volar locking plates were cost-ineffective according to NICE threshold criteria.

Stipinkaulio distalinės dalies lūžiai yra vienas iš dažniausių kaulų ir raumenų sistemos pažeidimų. Literatūroje nurodoma, kad distalinės stipinkaulio dalies lūžiai yra 1/10 visų lūžių, kuriuos patiria vyresni nei 35 metų amžiaus asmenys. Apie 3 % pacientų, po šios traumos išlieka ilgalaikė negalia. Siekiant optimizuoti stipinkaulio distalinės dalies lūžių gydymą, buvo atliktas tyrimas, kuriame buvo iškelti trys uždaviniai. Vertinome 2 savaičių imobilizacijos įtaką rankos funkcijai, po stipinkaulio distalinės dalies lūžio ir osteosintezės delnine rakinama plokštele. Taip pat vertinome,radiologinio lūžio tipo, pagal AO klasifikaciją, įtaką rankos funkcijai. Sugijus kaului, tirta metalinių konstrukcijų pašalinimo įtaka rankos funkcijai. Vertinant rezultatus, nustatyta, kad riešo judesių amplitudė ir rankos funkcija tarp pacientų, patyrusių stipinkaulio distalinės dalies lūžį su poslinkiu ir operuotų delnine rakinama plokštele, kuriems buvo taikyta pooperacinė 2 savaičių riešo imobilizacija ir kuriems pooperacinė riešo imobilizacija nebuvo taikyta, nesiskyrė. Tiriamiesiems, patyrusiems C tipo lūžį pagal AO radiologinę klasifikaciją nustatyta prastesnė funkcija. Riešo judesių amplitudė ir rankos funkcija po delninės rakinamos plokštelės pašalinimo nepakito.<br>Distal radius fracture is one of the most common injuries of the skeletal and muscular system. It has been reported in literature that distal radius fractures account for one-tenth of all the fractures experienced by people older than 35 years. Long-term disability remains in approximately 3% of patients after a distal radius fracture. In order to optimise treatment of distal radius fractures, a study with three objectives was performed. We evaluated the effect of immobilisation for the period of 2 weeks on the hand function after a distal radius fracture and osteosynthesis with a volar locking plate. The effect of the fracture type according to the AO classification on the hand function was also assessed. After the bone has healed, the effect of the removal of metal constructions on the hand function was evaluated. The analysis of the results demonstrated that there were no differences in the range of wrist motions and the hand functionbetween the patients after a displaced distal radius fracture operated with a volar locking plate and post-surgery immobilisation of the wrist applied for the period of 2 weeks and the patients who did not have post-surgery wrist immobilisation applied. A worse function was determined in the patients after type C fracture according to the AO radiological classification. The range of wrist motions and the hand function after the removal of a volar locking plate did not differ.

碩士<br>正修科技大學<br>機電工程研究所<br>100<br>Wrist is an important joint of high activity rate. A distal radius fracture is a common bone fracture of the radius in the forearm. Because of its proximity to the wrist joint, this injury is often called a wrist fracture. Improper treatment of wrist fracture will cause stiffness, pain, and affect the quality of life seriously. The key of success surgery is to create nice joint restoration. Precise radial bone plate can help doctors to conduct accurate and effective reduction surgery. According to different type of radial cracking for each patient, radius bone plate shape with a fixed position is planned in order to shorten the operation time and increase the success rate of surgery. The main objective of this paper is the geometry design and machining of a radius bone plate. First, reverse engineering equipment is used to capture the important parameters of the geometric shape and curvature of the wrist bones. Those parameters are employed to design the radius bone plate geometry and locking. Three-dimensional model of the radius bone plate is constructed by CAD, the radius bone plate holder fixture is manufactured, and the 3D model of the radius bone plate is imported into Unigraphics NX software. After drawing a reference plane, projection curve, establishing of appropriate tool path, and verifying the correct tool path, the NX processor will export NC codes, the solid cutting simulation software VERICUT will verify that it is the correct cutting tool path. Then, multi-axis NC machine is used to process the work piece, and non-contact 3D optical scanner and contact 3D coordinate measuring machine are employed to verify machining results.

碩士<br>正修科技大學<br>機電工程研究所<br>102<br>When people fell down, the body will make a natural reaction with palm to support on the ground floor. If excessive bending or force was applied on the supporting hands, it will cause the damage or fracture of distal radial.Fracture of distal radius are occurring frequently and accounting for approximately 20% of bone fractures. The traditional treatment of bone fractures often used plaster to fix the parts of fracture. But the fixation stability of plaster treatment is not always satisfied and the activity of elbow is limited.In this study, how the choices of T-type volar plate to affect the treatment of bone injury is addressed. By using the three-dimensional non-contact scanners SmartSCAN 3D, a perfect distal radial model of human bone can be obtained through reverse engineering method. With Geomagic Studio and SolidWorks software, the distal radial model can be further edited to simulate the damage of radial bone fractures.The mismatch problem of T–type volar radial plate and distal radius can be further performed by using NX CAD software to create various contact conditions. Through finite element analysis, the effect of mismatch degree of T–type volar radial plate and distal radius on loading conditions can be further investigated. The results show that the maximum stress of T–type volar radial plate will increase 20 % with 25 % contact surface mismatch of T–type volar radial plate and distal radius.

The current standard post-operative X-rays for patients who have had volar locking plate fixation for a distal radius fracture may give the impression of intra-articular screw placement due to the normal anatomic inclination of the radiocarpal joint. Aim: To determine: 1. If anatomically tilted post-operative radiographs increased the observer’s confidence with regard to assessment of screw position. 2. The intra- and inter-observer reliability of these X-rays. Materials and Methods: 30 patients’ standard and tilted (11° PA and 22° lateral) post-operative radiographs were assessed by an orthopaedic intern, registrar, consultant, and a radiologist on two occasions. Single and combined views were analysed. Results: There was no difference in confidence of assessment, but there was a significant change of assessment with fewer intra-articular penetrations reported with the tilted PA view. There was low intra-observer reliability except for the consultant orthopaedic surgeon. Inter-observer reliability was good when the intern’s observations were excluded. Conclusion: The routine acquisition of the tilted PA radiograph can assist senior health professionals with important patient management decisions.