Head Plate Research Articles

Assessment of Intra-articular Screw Penetration During Radial Head and Olecranon Locking Plate Fixation

The purpose of this study is to evaluate the role of radiographic and clinical exams in predicting screw penetration into the proximal radioulnar joint and ulnohumeral joint during open reduction and internal fixation of the radial head and proximal ulna. Olecranon and radial head plates were applied to 15 cadaveric elbows. Screws were assessed for intra-articular joint penetration using both clinical exam and radiographic evaluation. Clinical exam consisted of evaluation for crepitus. Radiographs demonstrating screws positioned near the joint surface were evaluated for penetration by 3 fellowship trained hand surgeons. Elbows were disarticulated and screw prominence was determined and recorded using standardized calipers. The ability of clinical and radiographic exams to correctly predict a breach in the articular surface was determined by calculating sensitivity, specificity, and predictive values. Consideration was given to screw position. The sensitivity of crepitus was 81.1% for screws in the radial head plate and 72.6% for screws in the olecranon plate. The sensitivity of radiographs was 72.4% for the screws in the radial head plate and 55.0% for screws in the olecranon plate. Correct radiographic assessment of penetration varied but position o-2 on the olecranon plate consistently resulted in the lowest sensitivity of 30.3%. The study evaluates sensitivity and specificity of clinical and radiographic means when assessing for articular penetration of screws during olecranon and radial head locking plate fixation. Certain screw locations are more difficult to evaluate than others and may go undetected by standard means of assessment used in a surgical setting.

An optimized surgical approach for obtaining stable extracellular single-unit recordings from the cerebellum of head-fixed behaving mice

BackgroundElectrophysiological recording approaches are essential for understanding brain function. Among these approaches are various methods of performing single-unit recordings. However, a major hurdle to overcome when recording single units in vivo is stability. Poor stability results in a low signal-to-noise ratio, which makes it challenging to isolate neuronal signals. Proper isolation is needed for differentiating a signal from neighboring cells or the noise inherent to electrophysiology. Insufficient isolation makes it impossible to analyze full action potential waveforms. A common source of instability is an inadequate surgery. Problems during surgery cause blood loss, tissue damage and poor healing of the surrounding tissue, limited access to the target brain region, and, importantly, unreliable fixation points for holding the mouse's head. New methodWe describe an optimized surgical procedure that ensures limited tissue damage and delineate a method for implanting head plates to hold the animal firmly in place. ResultsUsing the cerebellum as a model, we implement an extracellular recording technique to acquire single units from Purkinje cells and cerebellar nuclear neurons in behaving mice. We validate the stability of our method by holding single units after injecting the powerful tremorgenic drug harmaline. We performed multiple structural analyses after recording. Comparison with existing methodsOur approach is ideal for studying neuronal function in active mice and valuable for recording single-neuron activity when considerable motion is unavoidable. ConclusionsThe surgical principles we present for accessing the cerebellum can be easily adapted to examine the function of neurons in other brain regions.

The feather louse genus Mulcticola Clay et Meinertzhagen, 1938 (Phthiraptera: Philopteridae) from Brazil, with descriptions of five new species and catalogue for species described in the genus.

Five new species of Mulcticola Clay et Meinertzhagen, 1938 are described and illustrated from Brazil. These new species and their hosts are: Mulcticola sicki sp. n. from the sand-coloured nighthawk, Chordeiles rupestris rupestris (Spix), Mulcticola bacurau sp. n. from the common pauraque, Nyctidromus albicollis (Gmelin), Mulcticola tendeiroi sp. n. from the long-trained nightjar, Macropsalis forcipata (Nitzsch), Mulcticola piacentinii sp. n. from the short-tailed nighthawk, Lurocalis semitorquatus semitorquatus (Gmelin) (type-host) and L. s. nattereri (Temminck), and Mulcticola parvulus sp. n. from the little nightjar, Setopagis parvula (Gould). These species were compared primarily with Mulcticola nacunda Carriker, 1945 from the nacunda nighthawk, Chordeiles nacunda nacunda (Vieillot), which is one of the species of Mulcticola previously recorded in the Neotropical region. All the five new species described herein differ from their congeners by exclusive characters such as the shape of anterior dorsal head plate, metasternal plate, subvulvar plates in females and genitalia in males. We increased the number of species in Mulcticola to 18 in total, with seven of them now known from the Neotropics. We present the main morphological characters to distinguish Mulcticola from other species of the Philopteridae parasitising Caprimulgiformes and also compile a detailed catalogue for species included in this louse genus.

Is an extension of the safe zone possible without jeopardizing the proximal radioulnar joint when performing a radial head plate osteosynthesis?

Proximal radial fractures are common elbow injuries. Because of the fracture pattern, stability criteria, or plate configuration, a plate position outside the "safe zone" (SZ) may be required in some cases when performing a radial head plate osteosynthesis. We examined the gross anatomy of the radial head and analyzed different so-called low-profile and precontoured radial head and neck plates with respect to the SZ. Macroscopic measurements of the radial head and neck of 22 formalin-fixed human cadaveric upper extremities were obtained. The SZ was determined by maximum forearm rotation. If the edge of a plate could be extended beyond the respective SZ boundary without jeopardizing the proximal radioulnar joint (PRUJ) in maximum forearm rotation, a new plate-specific SZ boundary was set. The mean SZ was 133° (SD, 14°). Among the 5 plates studied, only the 2 radial neck designs allowed the anterior edge of the plate to partially pass the lesser sigmoid notch of the ulna and consequently afforded a significant extension of the SZ in maximum pronation. All 3 radial head designs had to remain within the SZ to avoid interference with the PRUJ. A safe plate position depends on individual plate dimensions, particularly the proximal plate width, and the diameter of the radial head. The smaller the head diameter, the more accurately a plate must be placed within the SZ. If an extension of the SZ in radial head plate osteosynthesis is not essential, we recommend respecting the SZ to minimize the possibility of interference with the PRUJ.

Discussion of “Plugging effect of open-ended piles in sandy soil”

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Balance workshop: synchronized head and force plate measurements. The potential for diagnostic yields

s / International Journal of Surgery 12 (2014) S13eS117 S43 of endoscopy-related oral mucosal injuries was 31.6%(24/76). Of these, 21 were recorded from the wet gauze subgroup, and 3 were from dental dam. The comparative mucosal injuries rate for wet gauze and dental dam was 37.5%(21/56) and 15%(3/20) respectively. No teeth trauma recorded. Conclusions: Alveolar ridge mucosal and gingival injuries remain a significant complication during rigid endoscopies. The routinely used wet gauzes appear inadequate in providing optimal protection. With the newly devised appliance, the dental dam may provide an alternative for oral protection during rigid endoscopies, although further studies are required. 1247: BALANCE WORKSHOP: SYNCHRONIZED HEAD AND FORCE PLATE MEASUREMENTS. THE POTENTIAL FOR DIAGNOSTIC YIELDS Cian O. Hughes, David D. Pothier, Paul Ranalli, John A. Rutka. Toronto General Hospital, Toronto, ON, Canada. Introduction: Currently only force-plate measurements are used in posturography. Given that the vestibular end-organs are situated within the temporal bone, recording movement of the head can provide additional information compared to body sway alone. We describe the synchronously recording of head position during posturography and investigate its potential additional value. Methods: A device was designed to capture information from headmountedaccelerometersandgyroscopes, allowingmovements andposition to be accuratelymeasured in three dimensions. Ten normal participants, ten patients with bilateral vestibular loss(BVL) and ten patients who were instructed tomalingerwere testedusing themodified clinical test of sensory interaction on balance(mCTSIB). Results: Our device accurately synchronized with the force-plate and allowed sway data to be calculated for the head. Normal controls showed a strong correlation between head and foot measurements: path length mean r-score1⁄40.57(p<0.001). This correlation became negative in BVL patients (mean r-score1⁄4-0.48(p<0.001)). Conclusions: This study suggests that head data are related to footplate data, but in pathologic conditions also provide different information from which diagnoses can be made. Given the small size of the device, it has the potential to be used over long periods. This allows for the telemetry of longitudinal data on sway. 1255: A PROSPECTIVE AUDIT OF CHRONIC RHINOSINUSITIS (CRS) MANAGEMENT AT A TEACHING HOSPITAL: BEFORE AND AFTER THE 2012 EUROPEAN POSITION PAPER GUIDELINES ON CHRONIC RHINOSINUSITIS (EPOS) Lulu Ritchie, Anna Slovick, Shilpy Ojha, Romana Kuchai. St Marys Hospital,

Imaging neuronal population activity in awake and anesthetized rodents.

Recent advances in in vivo two-photon imaging have extended the technique to permit the detection of action potentials (APs) in populations of spatially resolved neurons in awake animals. Although experimentally demanding, this technique's potential applications include experiments to investigate perception, behavior, and other awake states. Here we outline experimental procedures for imaging neuronal populations in awake and anesthetized rodents. Details are provided on habituation to head fixation, surgery, head plate design, and dye injection. Determination of AP detection accuracy through simultaneous optical and electrophysiological recordings is also discussed. Basic problems of data analysis are considered, such as correction of signal background and baseline drift, AP detection, and motion correction. As an application of the method, the comparison of neuronal activity across arousal states is considered in detail, and some future directions are discussed.

Finite Element Analysis of Split Type Header in Air Cooled Heat Exchanger

Split type header is a part of tube bundle of an Air-cooled heat exchanger, used in refinery and oil & gas production. Typically, header can be considered as a pressure vessel subjected to uniform internal pressure. Hence the header and nozzle in various design and operating conditions needs to be checked and verified for soundness of participating components. Top plate due to uniform internal pressure in the nozzle & header plate can produce high-localized stress and deformation. If the components are not designed for these conditions, safety of the equipment is at stake. Hence check for the stress and displacement of the header during operating condition is carried out using finite element analysis software and observed that header nozzle is free from collapse and serviceability failure. I. Introduction (1) Heat exchangers are systems that transfer heat between fluid mediums. The fluids or gases in a heat exchanger can be mixed or the energy transference can go through a conductive wall that keeps them separate. Air-cooled heat exchangers typically have rectangular bundles containing several rows of tubes. The hot fluid enters at the top of the bundle through nozzle pipe. While air is blown by fans vertically upwards across the tube bank, i.e. counter current flow. Structural integrity of the header box can be checked by using (12) Appendix 13 of ASME Sec VIII Div I and other parts of the exchanger header box with the respective clauses of ASME code. For installing the nozzle on the header box opening is made on it, this opening of the vessel must be reinforced with an equal amount of metal which has been cut out for the opening. The reinforcement may be an integral part of the vessel and nozzle or may be an additional reinforcing pad. In addition the compensation must account for the bending strength as well as the membrane strength. The reinforcement calculations for nozzle openings according to UG-39 are in addition to bending & membrane strength. However, the calculation of Area required, according to UG-39, requires that the required thickness(tr) be substituted for in the formula, and it has not been calculated, since the method used in Appendix 13 is by assuming a and calculating stresses then comparing with allowable stresses and yield stress. This means that required thickness (tr) cannot be directly calculated. Accordingly, the area A cannot be directly calculated however in this case nozzle opening is larger than ½ of the header opening hence is beyond the scope of UG-39 of ASME Sec VIII Div-I and therefore the calculation has to done by finite element method.

Evaluation of functional results of CWD surgery with ossicular replacement prosthesis due to cholesteatoma using computed tomography

With the use of high-resolution computed tomography, this retrospective clinical study evaluated the factors affecting hearing in patients who were operated on due to chronic otitis media with cholesteatoma and underwent ossiculoplasty with titanium total ossicular replacement prosthesis (TORP). Fifteen patients with postoperative hearing results of 20 dB or less air-bone gap, and thirteen patients with postoperative hearing results of 21 dB or more air-bone gap were the subjects of this study. All patients were operated on due to chronic otitis media and underwent ossiculoplasty with titanium TORP. High-Resolution Computed Tomography (HRCT) and pure-tone audiometry were performed on each patient after an average of 17 months, postoperatively. Three-dimensional oblique CT cross-sections were analyzed with Vitrea 2(®) software. The presence of soft tissue in the middle ear and contact between the prosthesis head plate and the bone had an adverse effect on hearing (p < 0.05). The angle between the TORP and the oval window did not seem to affect the hearing results (p > 0.05). The study results indicate that an examination of the patients with poor postoperative hearing with HRCT may help find the possible cause and allow for the determination of the prosthesis location.

CFRP Anchor for Preventing Premature Debonding of Externally Bonded FRP Laminates from Concrete

AbstractTo delay or prevent debonding of externally bonded fiber-reinforced polymer (FRP) laminate from concrete substrate, a new carbon FRP (CFRP) anchor is developed. The monolithically built anchor comprises two legs and a wide head plate, with the legs inserted into adhesive-filled drilled holes in the concrete and the head plate bonded to the surface of the FRP laminate and the adjacent concrete. Full-scale reinforced concrete T-beams were strengthened in flexure with different amounts of CFRP laminate and tested in four-point bending. The anchor number and spacing were varied to find the most effective configuration. It was determined that the configuration involving nearly uniform spacing of the anchors along the laminate and the placement of the laminate strips between the anchor legs were most effective to allow beams with up to eight plies of the laminate to fail by rupture of FRP rather than debonding. When comparing the efficiency factor of the proposed anchor with those of other anchors repor...

A numerical study of the behavior of fully grouted rockbolts under dynamic loading

The widespread preference for rockbolts in providing adequate rock stability in underground mines and man-made cavities make it necessary to obtain a better understanding of the response of these support systems. It is widely accepted that the fully grouted rockbolts provide better roof stability in areas of very poor roof condition which may be caused by high ground stress conditions. There is little information about the in situ behavior of these systems especially under dynamic loading. Hence, to study the behavior of fully grouted rockbolts under dynamic loading, a numerical modeling study was conducted using the FLAC3D code. In this study the behavior of three types of fully grouted rockbolts were compared with each other including rockbolts with and without head plate and a yielding type one. The results of analyses indicated that under dynamic loading the fully grouted rockbolts without the head plate are incapable of controlling the rock mass movement. Although fully grouted rockbolts with head plate damp a considerable amount of the dynamic energy through friction as these bolts slide within the grout, but the elongation of the rockbolt is not possible due to the rapid breakage of the rockbolt–grout interface. Yielding rockbolts are the best choice for the absorption of the dynamic stress wave and controlling of the rock mass movement. The obtained results show that the optimal design of yielding rockbolt should be in such a way that after dynamic loading, anchoring part of bolt has a limited movement to prevent stress concentration in the shaft of rockbolt and its breakage.

Determination of the Fundamental Frequency of Perforated Rectangular Plates: Concentrated Negative Mass Approach for the Perforation

This paper is concerned with a vibration analysis of perforated rectangular plates with rectangular perforation pattern of circular holes. The study is particularly useful in the understanding of the vibration of sound absorbing screens, head plates, end covers, or supports for tube bundles typically including tube sheets and support plates used in the mechanical devices. An energy method is developed to obtain analytical frequencies of the perforated plates with clamped edge, support conditions. Perforated plate is considered as plate with uniformly distributed mass. Holes are considered as concentrated negative masses. The analytical procedure using the Galerkin method is adopted. The deflected surface of the plate is approximated by the cosine series which satisfies the boundary conditions. Finite element method (FEM) results have been used to illustrate the validity of the analytical model. The comparisons show that the analytical model predicts natural frequencies reasonably well for holes of small size.

Treatment of a femoral fracture with a titanium locking compression plate distal femur (LCP-DF) in a young donkey

A closed complete mid-diaphyseal spiral fracture of the left femur in a one-year-old donkey was treated with a 4.5 mm titanium locking compression plate distal femur (LCP-DF)1. This plate was originally manufactured for human orthopaedics, primarily for femoral osteosynthesis. The LCP-DF1 has a distal head plate that was advantageous in this case because the distal fragment was smaller. Post operative radiographs showed optimal femoral reconstruction and a callus was present 3 weeks after surgery. The donkey was sound at the walk and trot 2 months after surgery. Radiographs taken 5 months after surgery showed stable implants and complete healing without complications.

A Study of Structural Performance of Self-Drilling Screw Connections

춤이 깊은 골형 데크는 그 단면의 형태가 개방형 단면(개단면(開斷面))으로 단면의 불안정성에 의한 휨비틀림 등의 구조적 문제를 일으킬 수 있다. 박판의 냉간성형강인 데크와 캡플레이트의 접합에 사용되는 연결재(파스너)는 볼트, 리벳, 용접 그리고 나사 접합이 있다. 이 연구는 냉간성형강을 사용한 춤이 깊은 데크와 보강용 캡플레이트간의 직결나사 접합부에 관한 실험적 연구로, 직결나사 접합부의 파괴거동과 최대내력에 영향을 주는 직결나사 배치방법, 직결나사 수, 직결나사 간격 그리고 직결나사 머리밑판의 두께변화를 실험변수로 하여 국외 설계기준식 비교 분석하고자 한다. As the deep deck plate has the shape of open cross section, It can cause structural problems such as bending torsions due to instability of the section. There are a number of fasteners types which are frequently used on light gage steel diaphragms such as bolts, rivets, welds, and screws. In this study, the structural capacity of the self drilling screw connection between the deep deck and the reinforced cap plate was evaluated by experimental variables such as the arrangement method, numbers of screw, pitch of screw, and head plate thickness.

Description of the immature stages of Glyphepomis spinosa Campos &amp;amp; Grazia (Hemiptera: Pentatomidae: Pentatominae: Carpocorini)

The study of immature stages is important in phylogeny, as well to the recognition and control of pest species. Glyphe-pomis Berg is included in the tribe Carpocorini. This paper describes the morphology of eggs and nymphs of Glyphepomis spinosa Campos &amp; Grazia. Adult specimens were collected on rice plants in Formoso do Araguaia, Tocantins, Brazil, and they were reared in the laboratory. The immatures obtained were analyzed with a light stereomicroscope and scanning electron microscope. Eggs and nymphs were measured and illustrated and/or photographed. Eggs are barrel-shaped, light green; operculum round and convex; chorion translucent, bright and granulated; aero-micropylar processes clubbed, 68 on average. All instars have oval body and obtuse tylus, surpassing jugae. In the 1st instar, head, thorax and abdominal plates are black, and abdomen is reddish brown; punctures are absent. From 2nd instar on, head and thorax are grayish with dark punctures, and the abdomen is whitish with dark-red punctures. In relation to other Carpocorini species that occur on rice, the eggs of G. spinosa resemble those of Oebalus poecilus (Dallas), a major rice pest in South America. However, nymphs of both species can be easily differentiated by their general color: in O. poecilus all instars have a dark head and thorax and red abdomen.

A major facilitator superfamily protein participates in the reddish brown pigmentation in Bombyx mori

MucK is a member of the major facilitator super family (MFS) and is within a subgroup involved in the uptake of organic acids. Here, we provide the first evidence that mucK is required for normal body color pattern in insect larvae. In the cts mutant strain of Bombyx mori (Linnaeus), the larval anal plates, prothoracic tergum, and the head are reddish brown, as opposed to the white color found in the wild type. Positional cloning of the cts gene was carried out and it was mapped within 90kb on the 16th chromosome. Two molecular markers, 182A4 and 242GA, were found co-segregated with the cts phenotype. Only one candidate gene in the region, BGIBMGA013242, which codes for a major facilitator super family protein named BmMucK, located between the two loci. Sequence analysis revealed that a ∼3kb deletion in the genome resulting in a 126bp deletion in the open reading frame (ORF) of BmmucK in the cts mutant. Fluorescence in situ hybridization (FISH) and quantitative reverse transcription PCR showed that BmmucK expression coincided with reddish brown pigmented regions in the cts mutant strain. BmmucK expression in the head and anal plates were markedly elevated at the molting stages. We performed RNA interference of the mucK homolog in Tribolium castaneum and observed brown coloration accompanied by lethality in ∼1/3 of the insects. The results suggest that MucK plays an important role in the pigmentation process of insect larvae.

Newly defined fracture pattern specific to Mason III radial head fractures: fracture description, management and outcomes using screw fixation

Radial head fractures are the most common type of elbow fracture and are universally classified under the Mason classification system. Mason type III fractures are comminuted and are the most difficult to treat, generally requiring plating if possible, or more commonly arthroplasty or excision, which gives a variable outcome. We hypothesized that a new and specific fracture pattern of the radial head (Mason III) can be treated successfully with screw fixation. Six patients presented to the senior surgeon's clinic with this unusual Mason III fracture pattern. In these patients, the fracture was acute, requiring an open reduction and internal fixation with the use of three headless compression screws. Average follow-up time was 21 months. Using serial X-rays and the Broberg-Morrey elbow score, the six acute fractures were evaluated radiologically and functionally. All six patients had good to excellent results using the Broberg-Morrey scoring system. All patients showed radiological and clinical union within 3 months of injury. No patient required revision surgery or excision at a later date. We have recognized a specific type of comminuted and displaced Mason III radial head fracture that has not previously been described in the literature. This type of fracture is amenable to open reduction internal fixation with buried compression screws giving a good to excellent outcome, while avoiding the common consequences seen with a radial head excision, arthroplasty or plate fixation.

Two-Photon Imaging of Microglia in the Mouse Cortex In Vivo

Microglia are the primary immune effector cells of the brain parenchyma. They are distributed throughout the brain at various densities. Two-photon fluorescence microscopy, together with expression of fluorescent proteins in microglia, has enabled study of these fascinating cells in vivo. Imaging studies have shown, for example, that microglia continually survey their cellular environment and immediately respond to injury. However, we still know very little about their roles in various parts of the developing and adult brain or their diverse effector functions in aging and different disease states. Experimental procedures have been developed for minimally invasive short- and long-term two-photon imaging of microglial cells in cortical regions of the intact mouse brain. This protocol describes two-photon imaging of microglia in the mouse cortex in vivo, using mice which have had a head plate implanted and have been prepared with either a thinned skull or optical window. Technical pitfalls, limitations, and alternative approaches are also discussed.

Surgical Implantation of a Head Plate in Mice in Preparation for In Vivo Two-Photon Imaging of Microglia: Figure 1.

Microglia are the primary immune effector cells of the brain parenchyma. They are distributed throughout the brain at various densities. Two-photon fluorescence microscopy, together with expression of fluorescent proteins in microglia, has enabled study of these fascinating cells in vivo. Imaging studies have shown, for example, that microglia continually survey their cellular environment and immediately respond to injury. However, we still know very little about their roles in various parts of the developing and adult brain or their diverse effector functions in aging and different disease states. Experimental procedures have been developed for minimally invasive short- and long-term two-photon imaging of microglial cells in cortical regions of the intact mouse brain. This protocol describes the initial preparation of the mice by surgical implantation of a head plate.

Development of the ear, hearing capabilities and laterophysic connection in the spotfin butterflyfish (Chaetodon ocellatus)

The ontogeny of the ear, swim bladder and laterophysic connection was investigated in the spotfin butterflyfish, Chaetodon ocellatus in order to determine how the development of the laterophysic connection (a Chaetodon synapomorphy) is correlated with ontogenetic changes in the hearing capabilities in these abundant and ecologically important coral reef fishes. Histological and cleared and stained material revealed that the medial opening in the lateral line canal in the supracleithrum (which defines the laterophysic connection), an inflated physoclistous swim bladder, and the three otolithic organs are already present in the smallest individuals examined (7–15 mm SL). The medial opening in the supracleithrum increases in size and the cylindrical swim bladder horns form after the loss of the head plates characteristic of the tholichthys stage, in individuals ≥29 mm SL. The three sensory maculae of the ear increase in size, and the shape of the sacculus changes most dramatically with fish growth; hair cell density is highest in the utriculus. Physiological analysis of the reponse to sound pressure showed that larval and juvenile C. ocellatus had a hearing sensitivity peak at 100–200 Hz, which was ~30–40 dB more sensitive than that measured in larval coral reef fishes (e.g., damselfishes) that lack swim bladder horns. C. ocellatus did not show any ontogenetic changes in sensitivity to sound pressure, which may be explained by the fact that the growth of the swim bladder horns maintains the small distance between the swim bladder and ear that was established earlier during the larval stage. The timing of the development of the swim bladder horns suggests that if the laterophysic connection has a sensory acoustic function, its presence in individuals >29 mm SL suggests that its role is limited to post-settlement, reef-based behaviors.