Plate Device Research Articles

Different Role of CA1 5HT3 Serotonin Receptors on Memory Acquisition Deficit Induced by Total (TSD) and REM Sleep Deprivation (RSD).

Serotonin receptors such as 5-HT3 plays critical role in regulation of sleep, wake cycle and cognitive process. Thus, we investigated the role of CA1 5HT3 serotonin receptors in memory acquisition deficit induced by total sleep deprivation (TSD; for 24 hour) and REM sleep deprivation (RSD; for 24 hour). Pain perception and locomotor activity were also assessed as factors that may affect the memory process. Modified water box and multi-platform apparatus were used to induce TSD or RSD, respectively. Passive avoidance, hot plate and open field devices were used for assessment of memory acquisition, pain and locomotor activity, respectively. Totally, 152 male Wistar rats were used in the study. Pre-training, intra-CA1 injection of 5-HT3 receptor agonist Chlorophenylbiguanide (Mchl; 0.01 and 0.001 µg/rat; P < 0.001) and antagonist Y-25130 (0.1 µg/rat; P < 0.001) reduced memory acquisition and did not alter pain response, while higher dose of both drugs increased locomotor activity in normal rats. Both TSD and RSD reduced memory acquisition (P < 0.001) and did not alter locomotor activity, while TSD (P < 0.001) but not RSD induced analgesia effect. The amnesia induced by TSD was restored by subthreshold dose of Y25130 (0.001 µg/rat; P < 0.001) but not Mchl (0.0001 µg/rat), while both drugs reversed TSD-induced analgesia effect (P < 0.01 for Mchl and P < 0.05 for Y25130), and Y25130 increased locomotor activity in TSD rats (P < 0.05). In RSD rats, subthreshold dose of both drugs did not alter memory acquisition deficit and increased locomotor activity (P < 0.001 for Mchl and P < 0.01 for Y25130), while the Y25130 (P < 0.001), but not Mchl induced analgesia in the RSD rats. Based on the above data, CA1 5HT3 receptors seem to play a critical role in cognitive and non-cognitive behaviors induced by TSD and RSD.

Comparison and analysis of reoperations in two different treatment protocols for trochanteric hip fractures \u2013 postoperative technical complications with dynamic hip screw, intramedullary nail and Medoff sliding plate

BackgroundIn treatment of unstable trochanteric fractures dynamic hip screw and Medoff sliding plate devices are designed to allow secondary fracture impaction, whereas intramedullary nails aim to maintain fracture alignment. Different treatment protocols are used by two similar Swedish regional emergency care hospitals. Dynamic hip screw is used for fractures considered as stable within the respective treatment protocol, whereas one treatment protocol (Medoff sliding plate/dynamic hip screw) uses biaxial Medoff sliding plate for unstable pertrochanteric fractures and uniaxial Medoff sliding plate for subtrochanteric fractures, the second (intramedullary nail/dynamic hip screw) uses intramedullary nail for subtrochanteric fractures and for pertrochanteric fractures with intertrochanteric comminution or subtrochanteric extension. All orthopedic surgeries are registered in a regional database.MethodsAll consecutive trochanteric fracture operations during 2011–2012 (n = 856) and subsequent technical reoperations (n = 40) were derived from the database. Reoperations were analysed and classified into the categories adjustment (percutaneous removal of the locking screw of the Medoff sliding plate or the intramedullary nail, followed by fracture healing) or minor, intermediate (reosteosynthesis) or major (hip joint replacement, Girdlestone or persistent nonunion) technical complications.ResultsThe relative risk of intermediate or major technical complications was 4.2 (1.2–14) times higher in unstable pertrochanteric fractures and 4.6 (1.1–19) times higher in subtrochanteric fractures with treatment protocol: intramedullary nail/dynamic hip screw, compared to treatment protocol: Medoff sliding plate/dynamic hip screw. Overall rates of intermediate and major technical complications in unstable pertrochanteric and subtrochanteric fractures were with biaxial Medoff sliding plate 0.68%, with uniaxial Medoff sliding plate 1.4%, with dynamic hip screw 3.4% and with intramedullary nail 7.2%.ConclusionsThe treatment protocol based on use of biaxial Medoff sliding plate for unstable pertrochanteric and uniaxial Medoff sliding plate for subtrochanteric fractures reduced the risk of severe technical complications compared to using the treatment protocol based on dynamic hip screw and intramedullary nail.

A load measuring anchor plate for rock bolt using fiber optic sensor

Rock bolts are the devices that used to reinforce the rock masses in mining tunnels and underground excavation structures. The loading level of the rock bolt indicates the reinforcing efficiency and is able to ensure safe underground operation by giving warnings to the underground miners prior to any accidents. Therefore, it is very important to monitor the load level of the rock bolts. In this short communication, we propose a smart anchor plate, a simple but effective device that uses fiber Bragg gratings (FBG) type optic sensor, to monitor the load level of the rock bolt. Instead of measuring the stress/strain on the rock bolt, which adds more complexity, the proposed method monitors the rock bolt load by measuring the load experience on the rock bolt anchor plate. Such a configuration has the advantages of simple structure and flexible implementation. In experimental observation, the FBG instrumented anchor plate is able to observe the load of the plate with good repeatability. This test will lead to further in-depth studies involving finite element analysis as well as more complex applications.

Using an anatomically preshaped low-profile locking plate system leads to reliable results in comminuted radial head fractures.

For comminuted and displaced fractures of the radial head open reduction and internal fixation (ORIF) is recommended nowadays as the treatment of choice. Due to the development of locking plates the possibilities of ORIF in complex fracture types were extended. The purpose of this retrospective survey therefore was to review the preliminary subjective and objective results in patients treated by anatomically preshaped locked plating. A reliable fracture healing for these recently introduced plating devices was hypothesized. Subjective and objective criteria included patient's satisfaction, pain rating on a visual analogue scale (VAS) and active range of motion (ROM) compared to the contralateral armside. Functional scoring included the Morrey elbow performance score (MEPS), the QuickDASH and the elbow self-assessment score (ESAS). Furthermore, follow-up radiographs were reviewed. Between 2011 and 2014 a total of 24 patients were managed with ORIF using anatomically preshaped low-profile locking plates. All patients had suffered from comminuted radial head fractures (type III-IV according to Mason classification). Twenty of 24 patients returned for follow-up examination after a mean of 30months (range 18-53months). Patients' satisfaction was rated as highly satisfied in 17 cases and satisfied in 3 cases. An unrestricted ROM for extension-flexion arc and pronation-supination arc was rated in 10 cases. Minor ROM deficiencies with a 5° limited extension compared to the contralateral side was evaluated in 6 cases. Only four patients were rated with and extension and supination deficiency of 10°, one of whom with an additional pronation deficiency of 10°. The calculated MEPS was Ø 98±4 (range 85-100), and the QuickDASH was Ø 3±6 (range 0-21). The ESAS was completed by 18 patients with a mean of Ø 96.54±2.95 (range 94-100) indicating a non-restricted elbow function. The treatment of comminuted radial head fractures using anatomically preshaped locking radial head plates represents a reliable and safe surgical approach, leading to good to excellent functional results. Being aware of the importance of the radial head for elbow stability, open reduction and internal fixation should be preferred prior to radial head resection or replacement in complex radial head fractures. Further trials with a higher number of patients are needed to confirm the advantages of preshaped radial head plates.

Precision electronics for a system of custom MCPs in the TORCH Time of Flight detector

The TORCH detector will provide charged particle pi/K/p identification up to 10 GeV/c, combining Time-of-Flight and Cherenkov techniques to achieve a timing resolution of 70 ps for single photons. Based on a scalable design, a Time-of-Flight electronics readout system has been developed to instrument a novel customized 512-channel Micro Channel Plate (MCP) device. A Gigabit Ethernet-based readout scheme that operates the TORCH demonstration unit consisting of ten such MCPs will be reported. The trigger and clock distribution will also be discussed.

Modelling and experimental determination of thermal properties of local wet building materials

One of the greatest challenges in the construction sector throughout the world is the development of appropriate building materials that can reduce energy consumption. In this work, an investigation on the thermophysical properties of three wet composite building materials was carried out: the black pouzzolan, the red pouzzolan and sand cinder blocks. Experimental measurements were carried out on these three materials each with a water contentranging between 0 and 5%.Using an asymmetrical hot plate device, a transient method, the thermal effusivity and volumetric heat capacity were estimated experimentally with respect to water content. With the values of the mass specific heat capacity of pouzzolans, sand and cement separately measured by the Differential Scanning Calorimeter (DSC) method, the values of the volumetric heat capacity of these composite materials were evaluated according to their water content calculated from the theoretical developed model. The results obtained are in good agreement with those determined experimentally with the asymmetrical hot plate method (maximum standard deviations 5%). Results reveal that the thermal conductivity of red pouzzolan cinder blocks (e.g. λ=0.503Wm−1K−1 at 0% water content) and of black pouzzolan cinder blocks (e.g. λ=0.549Wm−1K−1 at 0% water content) are lower than that of sand cinder blocks (e.g. λ=0.875Wm−1K−1 at 0% water content). Results also show that pouzzolans cinder blocks have higher volumetric heat capacity than sand cinder blocks. These results further confirm that blocks based on pouzzolans are better insulator materials than sand blocks (usually uses) and can contribute significantly to the energy saving and thus reduce the GHG emission in the air-conditioning building.

Intramedullary Tibial Nail Fixation of Simple Intraarticular Distal Tibia Fractures.

The optimal treatment strategy for distal tibia fractures, especially those with intraarticular extension, remains controversial. Although open reduction and internal fixation with a plate and screw device is commonly performed for these injuries, the risk of soft tissue complications using this approach is significant. Staged treatment protocols and alternative means of fixation have been proposed to address these undesired events. Although potentially more technically demanding than fixation of diaphyseal or extraarticular tibial fractures, intramedullary nail (IMN) fixation of simple intraarticular distal tibia fractures is a viable treatment alternative with unique advantages. This article presents a review of the literature and rationale for intramedullary tibial nail fixation of simple intraarticular distal tibia fractures and a surgical approach commonly utilized for successful implementation.

Transapical Coaptation Plate for Functional Mitral Regurgitation: An In Vitro Study.

A novel transapical coaptation plate (TCP) device was developed and anchored by sutures in the mitral valve to treat functional mitral regurgitation. The objective of this study was to test efficacy of the TCP in an in vitro model. Eight fresh porcine mitral valves were mounted in a left heart simulator to simulate functional mitral regurgitation by means of annular dilatation and asymmetrical or symmetrical papillary muscle (PM) displacement. Six polyurethane TCPs in thickness of 6.4(#1), 4.8(#2), 3.2(#3) mm and hardness of durometer 30 A (H) and 30 OO(S),were fabricated and labeled as H1, H2, H3 and S1, S2, S3, respectively. These TCPs were anchored by the sutures in the mitral annulus and left ventricle apex, and tested. Steady backward flow leakage in a hydrostatic condition and regurgitant volume in a pulsatile flow were measured before and after implantation of the TCPs. Mean regurgitant volume fractions in the asymmetric PM displacement were reduced significantly from 59.1 to 37.2% for H1, 43.2% for H2, 35.9% for S1 and 34.2% for S2 (p<0.021), after implantation of the TCPs. No significant reduction in mitral regurgitation was seen for H3 and S3 (p>0.067). Mitral regurgitation was mild in the symmetric PM displacement, and was not significantly reduced after implantation of the TCPs. In conclusion, the TCP anchored by the sutures in the mitral annulus and left ventricle apex functions successfully as a plug in the mitral valve leaflet gap. The TCP with thickness equal to or greater than 4.8mm is effective to reduce functional mitral regurgitation. The TCP hardness has no effect on difference in reduction of functional mitral regurgitation.

Outcomes Evaluation of Zero-Profile Devices Compared to Stand-Alone PEEK Cages for the Treatment of Three- and Four-Level Cervical Disc Disease

Background: Anterior cervical discectomy and fusion (ACDF) is a well-accepted treatment option for patients with cervical spine disease. Three- and four-level discectomies are known to be associated with a higher complication rate and lower fusion rate than single-level surgery. This study was performed to evaluate and compare zero-profile fixation and stand-alone PEEK cages for three- and four-level ACDF.Methods: Two cohorts of patients who underwent ACDF for the treatment of three- and four-level disease were compared. Thirty-three patients underwent implantation of zero-profile devices that included titanium screw fixation (Group A). Thirty-five patients underwent implantation of stand-alone PEEK cages without any form of screw fixation (Group B).Results: In Group A, twenty-seven patients underwent a three-level and six patients a four-level ACDF, with a total of 105 levels. In Group B, thirty patients underwent a three-level and five patients underwent a four-level ACDF, with a total number of 110 levels. In Group A, the mean preoperative visual analog scale score (VAS) for arm pain was 6.4 (range 3-8), and the mean postoperative VAS for arm pain decreased to 2.5 (range 1-7). In group B, the mean preoperative VAS of arm pain was 7.1 (range 3-10), and the mean postoperative VAS of arm pain decreased to 2 (range 0-4). In Group A, four patients (12%) developed dysphagia, and in Group B, three patients (9%) developed dysphagia. Conclusions: This study found zero-profile instrumentation and PEEK cages to be both safe and effective for patients who underwent three- and four-level ACDF, comparable to reported series using plate devices. Rates of dysphagia for the cohort were much lower than reports using plate devices. Zero-profile segmental fixation devices and PEEK cages may be considered as viable alternatives over plate fixation for patients requiring multi-level anterior cervical fusion surgery.

A copper electroplating formula for BVHs and THs filling at one process

Purpose The purpose of this paper is to introduce a new copper electroplating formula which is able to fill blind microvias (BVHs) and through holes (THs) at one process through a direct current (DC) plating method. Design/methodology/approach Test boards of printed circuit board (PCB) fragments with BVHs and THs for filling plating are designed. The filling plating is conducted in a DC plating device, and the filling processes and influence factors on filling effect of BVHs and THs are investigated. Dimple depths, surface copper thickness, thermal shock and thermal cycle test are applied to characterize filling effect and reliability. In addition, to overcome thickness, increase of copper on board surface during filling plating of BVHs and THs, a simple process called pattern plating, is put forwarded; a four-layered PCB with surface copper thickness less than 12 μm is successfully produced. Findings The filling plating with the new copper electroplating formula is potential to replace the conventional filling process of BVHs and THs of PCB and, most importantly, the problem of thickness increase of copper on board surface after filling process is overcome if a pattern plating process is applied. Research limitations/implications The dimple depth of BVHs and THs after filling plating is not small enough, though it meets the requirements, and the smallest diameter and largest depth of holes studied are 75 and 200 μm, respectively. Hence, the possibility for filling holes of much more small in diameter and large in depth with the plating formula should be further studied. Originality/value The paper introduces a new copper electroplating formula which achieves BVHs and THs filling at one process through a DC plating method. It overall reduces production processes and improved reliability of products resulting in production cost saving and production efficiency improvement.

Modeling and estimation of the thermal properties of clusters aggregates for construction materials: The case of clusters aggregates of lateritic soil, sand and pouzzolan

Most of the composite materials are manufactured by mixing several aggregates such as sand, cement, gravel and others. The aim of this paper was to present a method dedicated to the determination of the thermal effusivity and porosity for building material that is in aggregates granular form. A transient asymmetrical hot plate device was constructed to characterize the thermal effusivity. Experimental measurement of the specific heat capacity using the Differential Scanning Calorimeter (DSC) and measurement of apparent density enabled the estimation of the volumetric heat capacity of the aggregates. With these values and that of the thermal effusivity pre-estimated using the simplified 1D model, the study of the reduced sensitivity of the experimental temperature to parameter Eag and ρCag and ρCh is carried out. The thermal effusivity is then estimated from a complete 1D model by minimization of the quadratics errors between the experimental temperature curve and simulated one. Experimental results applied on clusters with maximum diameter aggregates 1.6mm; 1mm; 0.8mm, 0.4mm and 0.2mm show that for the same diameter, the black pouzzolan have higher thermal effusivity and thermal conductivity than the red pouzzolan (e.g. for D=1mm, EBPZ=418Jm-2K-1s-1/2, λBPZ=0.166Wm-1K-1, ERPZ=418Jm-2K-1s-1/2, λRPZ=0.135Wm-1K-1). Pouzzolan has the smaller value of porosity and lateritic the greater one.

Continuous intra-sinus bone regeneration after nongrafted sinus lift with a PLLA mesh plate device and dental implant placement in an atrophic posterior maxilla: a case report.

BackgroundSinus lift is a bone augmentation procedure that improves the alveolar crest height in an atrophic posterior maxilla. However, the regenerated bone volume can vary and generally has a tendency to decrease after sinus operation. This article describes nongrafted maxillary sinus lift using a bioresorbable unsintered hydroxyapatite combined with poly l-lactide (HA/PLLA) mesh plate device and dental implant placement in an atrophic posterior maxilla, after which continuous bone gain was observed around the implant apex during a postoperative follow-up period of 3 years.Case presentationA 60-year-old healthy female was referred to our department for dental implant therapy in the right posterior maxilla. Clinical examination revealed that the maxilla was edentulous from the right first premolar to the second molar region. Radiographically, atrophy of the maxillary alveolar ridge in the same tooth site was observed. Sinus membrane elevation and simultaneous implant placement were performed through the lateral approach. HA/PLLA mesh was utilized to maintain space under the elevated sinus membrane and as a fixation device to replace the bone window. Six months later, new bone was generated in the secluded space maintained under the elevated sinus membrane. When observed 42 months after the implant insertion, bone volume around the implant apex had increased in vertical direction under the HA/PLLA mesh plate device, and there was continuous bone formation in the sinus over time.ConclusionThis nongrafted sinus lift procedure using an HA/PLLA mesh device attained predictable bone formation. Stable membrane elevation by an HA/PLLA device might induce long-term, continuous bone formation in the sinus.

Slotted plate device to measure the yield stress of biofluids

AbstractThe slotted plate device by Zhu et al.1,2 was redesigned to allow for the measurement of very low yield stress values that occur with complex biofluids. The newly built apparatus improves the force measurement with a balance of fine resolution and smooths the vertical motion via a lab jack. The slotted plate geometry was optimized to further reduce wall slip as well as pressure drag via computational fluid dynamics (CFD). To improve on the yield stress measurement accuracy, the new design has a large slot area ratio and a large number of slots, as well as sharp front and rear edges. Test results for a few structured fluids, including blood, are compared with yield stress values determined via a TA Instruments AR‐2000 rheometer.

Reconstruction of Monteggia-like proximal ulna fractures using different fixation devices: A biomechanical study

BackgroundComminuted proximal ulna fractures are rare and reconstruction of these fractures is discussed controversially. The aim of this study was to test three currently available plate devices in a standardized comminuted four-part fracture model created in proximal ulna sawbones. Material and methodsA standardized four-part fracture of the proximal ulna was created in 80 sawbones. Reconstruction was performed by five experienced test surgeons according to a standardized reconstruction protocol. Each surgeon reconstructed 4 fractures with a 3.5mm eight-hole reconstruction plate, 4 fractures with seven-hole third-tubular double plates and 4 fractures with a 3.5mm anatomical seven-hole locked angle proximal ulna plate. 4 more fractures were reconstructed with simple K-wires as a reference construct for further experiments. Outcome measurements were time for reconstruction, quality of reconstruction and stability of the reconstruction. Stability testing was done in 90° and 30° flexion of the elbow. Testing in 30° flexion was done to test the anteroposterior stability regarding the fixed coronoid process. ResultsTime for reconstruction was significantly less for K-wire fixation than for the plate devices. Time for reconstruction plating and locked angle plating was significantly lower than for double plating (p<0.005). Quality of reduction did not differ between the three plate systems (p<0.05). K-wire fixation showed the best quality of reduction (p<0.005). In 90° of elbow flexion the anatomic locked angle olecranon plate showed a significantly higher stability compared to the other devices. Furthermore the tubular double plating was significantly more stable than reconstruction plating or K-wire fixation (p<0.05). In anteroposterior loading at 30°, the stability did not differ between the 4 different fixation techniques (p>0.05). For all devices the testing in 30° flexion showed a significantly higher rigidity compared to 90° flexion. ConclusionThe locked angle plate system showed the highest stability in 90° of elbow flexion. Each implant was more stable in 30° flexion than in 90° flexion. Testing of the anterior stability of the elbow did not show any differences between the different implants. Because of the superior stability of this device, we conclude that locked angle plating should be preferred for reconstruction of monteggia like complex proximal ulna fractures.

Generation of vector beams at 1550 nm telecommunications wavelength using a segmented q -plate

We present the use of a q -plate device operating at the 1550 nm telecommunications wavelength. A prototype liquid-crystal device from Citizen Holdings Co. is demonstrated to be useful for the generation of vector beams and orbital angular momentum transfer at this important wavelength.

Stabilisation of infected peri-articular nonunions with an antibiotic impregnated cement coated locking plate: Technique and indications

Management of fracture nonunion in the setting of subacute or chronic bacterial infection is a clinical challenge. Treatment must concurrently manage fracture instability and bacterial contamination. When acute infection occurs following fracture fixation, surgical debridement, antibiotic suppression and retention of stable fracture fixation hardware have been shown to be successful [1]. When fracture healing has not occurred alongside deep infection, alternative tactics must be explored. A general approach involves implant removal, thorough excisional debridement and irrigation, fracture stabilisation and focused systemic antibiotic therapy with or without additional local antibiosis. The use of antibiotic impregnated poly-methylmethacrylate (PMMA) as a nonbiodegradable drug delivery vehicle is well described in the orthopaedic literature [2,3]. Antibiotic impregnated PMMA can be placed in open fractures, areas of bone loss, soft tissue wounds, as well as in the setting of acute and chronic orthopaedic infections. Multiple authors have also reported the success of antibiotic impregnated PMMA intramedullary (IM) implants to stabilise and treat infected long bone nonunions [4–6]. The stabilisation and management of infected peri-articular nonunions remains a clinical challenge. In some clinical scenarios, limb stability is best achieved with a plate and screw device. We describe the creation and use of an antibiotic impregnated PMMA cement covered periarticular plate for this problem. This approach is highly effective in the provisional or definitive treatment of infected periarticular nonunions. It provides local delivery of antibiotics, immediate osseous stability, complete soft tissue closure and early range of motion.

Solution of Leakage Problem in a Guarded Hot Plate Device

The conduction heat transfer coefficients of the fibrous insulation materials depend on temperature, especially under high temperature conditions. In this study, the device, called guarded hot plate (GHP), measuring the heat transfer performance of insulation materials under high temperature conditions is improved. Circulation of the cooling fluid inside aluminum cold plates is optimized by numerical results. To prevent leakage of the fluid, metal pipes are inserted into the conduits aiming the fluid to circulate throughout these pipes. Following the design, the cold plates are manufactured and the computational results are validated by the experimental ones. By the new designed cold plate, the system operates and achieves validated measurements for the thermal conductivity of the fibrous insulation materials, under high temperature conditions.

Impact of multi-task on symptomatic patient affected by chronical vestibular disorders.

After a vestibular deficit some patients may be affected by chronical postural instability. The aim of this study was to identify the emotional and cognitive factors of these symptomatic patients. In particular, the double cognitive task and the anxiety disorder were identified by our patients. Through a retrospective study, 14 patients (65.4 ± 18 years) participated in the experiment. The experimentation consists in the study of the standing position of our patients through the aggregate of the trajectories of the center of pressure (COP) using a force plate device. With the aim of isolating the emotional and cognitive influence, this experimentation was defined in two conditions. In the first one, the patients were asked to maintain their balance without additional tasks. In the second one, the patients were submitted to an additional cognitive arithmetic task. The stabilogram surface, length (the forward and backward displacement distance during deviations in COP), lateral and the antero-posterior deviations were assessed. Our results showed an increase of postural instability of patients affected by chronical vestibular disorders when submitted to the double task. The patients submitted to the cognitive task present a larger surface of activity in comparison with the free-task one (Wilcoxon test p-value equals p = 0.0453). In addition, their displacements inside this area are more important (p = 0.0338). The COP of all our patients deviated forward in the presence of the double task. The increase in instability during the double cognitive task could be explained by an additional stress caused by the desire to make a success of the cognitive task.

Thermal Conductivity of Foam Glass Gravels: A Comparison between Experimental Data and Numerical Results

In this study the equivalent thermal conductivity of foam glass gravels is investigated by means of measurements with guarded hot plate devices. Firstly the thermal conductivity of the foam glass corns is determined. Following experiments are performed on random generated gravel beds varying the mean temperature, the temperature difference between hot and cold plate, the gravel compression degree and the heat flux direction. The influence of these parameters on the effective thermal conductivity is investigated. An empirical model based on the Krischer approach for determination of thermal conductivity in porous media is proposed and validated against the experimental data. In addition, results from numerical simulations are presented.

Mechanical testing of internal fixation devices: A theoretical and practical examination of current methods

Successful healing of long bone fractures is dependent on the mechanical environment created within the fracture, which in turn is dependent on the fixation strategy. Recent literature reports have suggested that locked plating devices are too stiff to reliably promote healing. However, in vitro testing of these devices has been inconsistent in both method of constraint and reported outcomes, making comparisons between studies and the assessment of construct stiffness problematic. Each of the methods previously used in the literature were assessed for their effect on the bending of the sample and concordant stiffness. The choice of outcome measures used in in vitro fracture studies was also assessed. Mechanical testing was conducted on seven hole locked plated constructs in each method for comparison. Based on the assessment of each method the use of spherical bearings, ball joints or similar is suggested at both ends of the sample. The use of near and far cortex movement was found to be more comprehensive and more accurate than traditional centrally calculated interfragmentary movement values; stiffness was found to be highly susceptible to the accuracy of deformation measurements and constraint method, and should only be used as a within study comparison method. The reported stiffness values of locked plate constructs from in vitro mechanical testing is highly susceptible to testing constraints and output measures, with many standard techniques overestimating the stiffness of the construct. This raises the need for further investigation into the actual mechanical behaviour within the fracture gap of these devices.