Insertion Hole Research Articles

Laser cladding of nickel base hardfacing material: Material analyses and manufacturing process evaluation on a scale one demonstrator

In fast neutron reactors, contact areas of moving parts usually require cobalt-free hardfacing coatings, as cobalt is highly activated under neutron flux. This is particularly critical for the insert holes of the diagrid for the positioning of the hexagonal fuel tubes that have to be internally coated. In this article, we propose to present the development of the cobalt-free hardfacing material up to the manufacturing of the inner clads with a specific deep laser cladding nozzle. In previous presentations, laser cladding has been identified as a deposition process that could increase the performances of the hardfacing materials compared to the standard process (Plasma Transferred Arc Welding). In parallel, the potential interest of some nickel base materials such as Colmonoy® 52 or Tribaloy® T700 has been demonstrated. Unfortunately, the deposition of these fragile alloys requires a preheating of the substrate over 450 °C. More recently, Nucalloy® 453, a new hardfacing nickel base alloy has been evaluated and demonstrated simpler deposition conditions that requires lower preheating temperature (<300 °C). The article presents the evaluation of Nucalloy® 453 with material analysis and wear tests. The microstructural characterization is compared to Colmonoy® 52, which is a similar NiFeCrSiBC alloy. Finally, the laser cladding of a scale one demonstrator is presented: two inner zones of a 1 m cylinder of 100 mm diameter are laser cladded, thanks to a deep cladding nozzle. The advantage of the laser cladding process is compared to Plasma Arc Transferred Welding.

A novel approach to embed eye shields in customized bolus on nasal dorsum treatment for electron radiotherapy

We aim to demonstrate the unique use of embedded lead eye shields in an electron wax bolus when treating the nasal dorsum. A patient presented to the clinic with squamous cell carcinoma of the nasal dorsum requiring treatment with en face electrons. A 3D customized wax bolus was designed and imported into the treatment planning system (TPS) to calculate the dose distribution. Due to high lens dose, the bolus was customized further to create 2 milled open slots in the wax, over the lens of eye, to allow lead sheets totaling 4 mm to be slid into the wax. The patient was brought back to the clinic to be scanned with the wax bolus fitting snugly over the nose, eyes, and cheek regions. The 3D milled insert holes were contoured on the CT in the TPS, assigned HU of 2758, to mimic the lead insertion. The lens dose with lead inserts was compared to the plan without lead insert. To further confirm the lens dose, EBT3 films were placed on the right and left eye under the bolus, and nose dorsum on the first day of treatment. The maximum dose of right lens, as calculated in the TPS with the simulated lead shields in place, decreased from 989.5cGy to 457cGy. The maximum dose of left lens decreased from 1085.4cGy to 501cGy. The dose readings from EBT3 films were in good agreement with the TPS, with deviation of 3.32%, 0.26%, and 3.44% for right lens, left lens, and nose, respectively. Daily positioning deviations compared to the plan were 0.65 ± 0.16cm and 0.63 ± 0.29cm for right eye and left eye, respectively. This novel device demonstrated the feasibility, in terms of dose calculation accuracy in the TPS and fabrication, of using customized bolus with lead inserts to conveniently shield the lens of the eyes in an electron treatment for the nose, enabling a streamlined daily setup.

Evaluation of a new bi-valve vaginal speculum applicator design for gynecologic interstitial brachytherapy.

PurposeWe designed a bi-valve vaginal speculum high-dose-rate (HDR) interstitial gynecologic brachytherapy applicator. This allows for both a direct view of the cervix and image-guided brachytherapy applicator placement. The purpose of this study was to assess the validity of the new applicator.Material and methodsThe applicator was designed to have a 25-mm arc, which can be spread transversely to 35-mm wide, with 10 insertion holes; it was produced using a stereolithographic printer with biocompatible Dental SG resin. For resin radiodensity was measured in Hounsfield units (HU) using computed tomography (CT). Comparing the new applicator with a conventional intracavitary applicator, we evaluated the treated volume (including dimensions of 100% isodose volume at the central axis), V100/D90/D98 for a hypothetical cervix (a 2-cm-long and 4-cm-diameter cylinder), and dose points of organs at risk (OARs) (at 25 and 30 mm from the tandem). Based on dose-volume histogram (DVH) analysis of the cervix and dose points of OARs, the range of tolerance for the percent dose difference in the prescription dose was set at 5%.ResultsThe mean radiodensity of the Dental SG resin, which was magnetic resonance imaging compatible, was 118 HU. Dimensions of the 100% isodose volume measured at the central axis were 4.4 × 6.6 × 7.4 cm for the new applicator and 4.3 × 6.0 × 7.7 cm for the intracavitary applicator. The 100% prescription dose volumes were 110 cc and 113 cc for the new and conventional applicator, respectively. The percent difference in the hypothetical cervix V100, D90, and D98 between the new and intracavitary applicator were within 5%. The percent differences in dose points of OARs at 25 and 30 mm between the new and conventional applicators were within 5%.ConclusionsOur speculum applicator can reproduce a conventional pear-shaped dose distribution. Our current clinical practice will use this applicator, which can improve the patient’s treatment results.

Training simulation for oral and maxillofacial surgeons based on the techniques of arthroscopy in the temporomandibular joint

Arthroscopy is a diagnostic-therapeutic technique used in the treatment of disorders of the temporomandibular joint (TMJ). The difficulties of arthroscopy lie in the manipulation of the tools, which is why training in the technique of triangulation in artificial models is essential. We developed a training system based on the techniques of arthroscopy in the TMJ, using simulators. The first simulator was a metal box containing three holes for insertion of the instruments, and the second was a human artificial model made of polymers. We found that they facilitated training in the techniques of arthroscopy, which subsequently reduced operating time and led to a better execution of skills in reality.

Locking Hole Inserts: Effect of Insertion Torque on Fatigue Performance and Insert Loosening in Locking Plates.

To evaluate the effect of locking hole inserts (LHIs) and their insertion torque on locking plate fatigue life. Eighteen standard 3.5-mm locking plates were instrumented with LHIs (Smith & Nephew, Memphis, TN) of 1.70 or 3.96 Nm insertion torque, or without LHIs, whereas eleven 4.5-mm locking plates were instrumented with LHIs at 3.96 Nm insertion torque or without LHIs. Plates were cyclically loaded to failure (ie, plate fracture) in four-point bending. Number of cycles to plate failure were measured. The 3.5-mm plates with 1.70 Nm LHI insertion torque had a 52% increase in cycles to failure compared with plates without LHIs (114,300 ± 23,680 vs. 75,487 ± 15,746 cycles; P = 0.01). Increasing insertion torque to 3.96 Nm led to a further increase of 36% in fatigue life (155,177 ± 32,493 cycles; P = 0.02) and a 106% increase compared with plates without LHIs (P = 0.001). The 4.5-mm plates with 3.96 Nm insertion torque had a 48% increase in cycles to failure when compared with plates without LHIs (74,369 ± 10,181 vs. 50,214 ± 5544 cycles; P = 0.001). LHIs significantly extend plate fatigue length, which would be advantageous in the setting of delayed fracture healing. We recommend the use of LHIs in round locking holes over bony gaps whenever possible; however, we recognize that these findings are limited to implants manufactured by Smith & Nephew.

Hardware/engineering battery-operated drills are more cost-effective as compared to orthopedic drills

Background: Drilling of the bone is common to produce holes for screws and pin insertion, to fix the fractured parts for immobilization. For this purpose, we need a power drill machine. Power drills used in orthopedic surgery can be categorized into two types: electrical and battery operated. Battery-operated drills could be orthopedic drills or hardware engineering drills. Commercial orthopedic battery drills (OBDs) are very costly. However, the same purpose can be subserved by hardware/engineering battery drill (HBD or EBD), with some additional practical advantages. Purpose: The purpose of this study is to aware the orthopedic surgeons who are working at resource constraint places about the advantages of EBD which is available at a very low price and serves the same purpose. Methods: We are using these battery operated hardware/engineering drills from quite a period of time and we have immense experiences with these EBD. The present article discusses in details about both the OBD and EBD. We assessed both drills by our own practical experience and compared both drills' specifications. Research Performance Place: The present study was conducted at Amandeep Hospital, G. T. Road, Model Town, Amritsar, Punjab, India. +91-98760-02746, 9876046778, E-mail: ah.admin@amandeephospital.org. It is a research institute with super specialty and multispecialty offering postgraduation courses and residency with national and international fellowships and observerships. Results: After comparing both the drills, we found that EBD is a very good substitute for OBD in orthopedic surgery in various aspects, namely availability, procurement, functionalities, servicing, and maintenance and is very cost-effective too. Conclusion: Hardware / engineering battery drills are very good and practical alternative to orthopedic drills in orthopedic surgeries. Hence, EBD is recommended for hospitals with limited resources and where treatment cost is an issue. Level of Evidence: 5.

Full-Wave Modal Analysis of a Novel Dielectrometer for Accurate Measurement of Complex Permittivity of High-Loss Liquids at Microwave Frequencies

A novel dielectrometer to measure the complex permittivity of high-loss liquids is presented. The geometry consists of a reentrant cavity with insertion holes, where the holder filled with liquid can be introduced readily. Radii of the insertion holes are large enough for a convenient pouring of the liquid. The electromagnetic analysis has been performed by a mixed mode-matching and circuit technique with the purpose of taking the high accuracy and fast convergence of the mode-matching and the flexibility and versatility of the circuit method. The convergence of the method is studied, and a procedure to estimate the result for an infinite number of modes is proposed. A calibration procedure is presented to minimize the error introduced by the numerical method. Mode charts are shown to analyze the behavior of resonant parameters for every mode. Some reference liquids are measured at different resonant frequencies, and the results are compared with those provided by other models of the literature.

Nutrient foramen location on the laminae provides a landmark for pedicle screw entry: a cadaveric study

BackgroundNutrient foramina are often encountered around the entry point of pedicle screws. Further, while probing the pedicle for pedicle screw insertion around the nutrient foramen, bleeding from the probe insertion hole is often observed. The purpose of this study was to investigate the frequency of occurrence of nutrient foramina, the association between the nutrient foramen and pedicle, and the safety and accuracy of cervical and thoracic pedicle screw placement using the nutrient foramen as the entry point.MethodsWe identified the location of the nutrient foramina for the dorsal branches of the segmental artery and their anatomical association to the pedicles and bony landmarks in the vertebrae for C3–T12 in seven cadavers. We also determined the frequency with which the nutrient foramina were present in 119 cadaveric vertebrae. We identified the pedicle location, base of the superior articular facet, and lateral border of laminae with respect to the nutrient foramen.ResultsThe overall presence of the nutrient foramina was 63% (150/238) in the specimens, with 60% (42/70) and 64% (108/168) identifiable in the cervical and thoracic vertebrae, respectively. In the cervical vertebrae, the nutrient foramen was located on the outer wall of the pedicle and was positioned between the cephalad and caudal walls. In the thoracic spine, 98% (106/108) nutrient foramina were located inside the pedicle walls.ConclusionsOur study findings confirm that the location of the nutrient foramen can be used for identifying the entry point for pedicle screws. In the cervical vertebrae, the nutrient foramina are located lateral to pedicle but within the cranial and caudal margins. In the thoracic vertebrae, the nutrient foramina are located in the medial and caudal regions of the pedicle. Thus, to decrease the risk of overshoot, the entry point for thoracic pedicle screws should be positioned a few millimeters cephalad and lateral to the nutrient foramen.

Human Subcutaneous Tissue Response to Glucose Sensors: Macrophages Accumulation Impact on Sensor Accuracy.

Subcutaneous (s.c.) glucose sensors have become a key component in type 1 diabetes management. However, their usability is limited by the impact of foreign body response (FBR) on their duration, reliability, and accuracy. Our study gives the first description of human acute and subacute s.c. response to glucose sensors, showing the changes observed in the sensor surface, the inflammatory cells involved in the FBR and their relationship with sensor performance. Twelve obese patients (seven type 2 diabetes) underwent two abdominal biopsies comprising the surrounding area where they had worn two glucose sensors: the first one inserted 7 days before and the second one 24 h before biopsy procedure. Samples were processed and studied to describe tissue changes by two independent pathologists (blind regarding sensor duration). Macrophages quantification was studied by immunohistochemistry methods in the area surrounding the sensor (CD68, CD163). Sensor surface changes were studied by scanning electron microscopy. Seven-day continuous glucose monitoring records were considered inaccurate when mean absolute relative difference was higher than 10%. Pathologists were able to correctly classify all the biopsies regarding sensor duration. Acute response (24 h) was characterized by the presence of neutrophils while macrophages were the main cell involved in subacute inflammation. The number of macrophages around the insertion hole was higher for less accurate sensors compared with those performing more accurately (32.6 ± 14 vs. 10.6 ± 1 cells/0.01 mm2; P < 0.05). The accumulation of macrophages at the sensor-tissue interface is related with decrease in accuracy of the glucose measure.

A broadband variable-temperature test system for complex permittivity measurements of solid and powder materials

A microwave test system to measure the complex permittivity of solid and powder materials as a function of temperature has been developed. The system is based on a TM0n0 multi-mode cylindrical cavity with a slotting structure, which provides purer test modes compared to a traditional cavity. To ensure the safety, effectiveness, and longevity, heating and testing are carried out separately and the sample can move between two functional areas through an Alundum tube. Induction heating and a pneumatic platform are employed to, respectively, shorten the heating and cooling time of the sample. The single trigger function of the vector network analyzer is added to test software to suppress the drift of the resonance peak during testing. Complex permittivity is calculated by the rigorous field theoretical solution considering multilayer media loading. The variation of the cavity equivalent radius caused by the sample insertion holes is discussed in detail, and its influence to the test result is analyzed. The calibration method for the complex permittivity of the Alundum tube and quartz vial (for loading powder sample), which vary with the temperature, is given. The feasibility of the system has been verified by measuring different samples in a wide range of relative permittivity and loss tangent, and variable-temperature test results of fused quartz and SiO2 powder up to 1500 °C are compared with published data. The results indicate that the presented system is reliable and accurate. The stability of the system is verified by repeated and long-term tests, and error analysis is presented to estimate the error incurred due to the uncertainties in different error sources.

Experimental investigation of friction stir blind riveting process for similar and dissimilar alloy sheets

Friction stir blind riveting (FSBR) is a new joining method which eliminates the need to predrill a hole for rivet insertion. A new one-sided mechanical joining process, friction stir blind riveting (FSBR) was developed to form lap-shear joints for similar and dissimilar alloy sheets in different combinations. The similar and dissimilar joints are made from copper, Al 5052-H32, Al 6061-T6 metals. The process window was investigated of CNC machines using only three spindle speeds: 1110, 1750 and 2750 rpm. FSBR joints were observed and discussed during tensile testing. All the similar and dissimilar joints are well fabricated at 1750 rpm. Tensile testing results show that any material with copper combinations (copper used as a top plate) at 1750 rpm as riveting speed gives the appreciable ultimate tensile strength. Further study revealed micro structure of the joint interfaces, when compared with different combinations.

Inversely designed, 3D-printed personalized template-guided interstitial brachytherapy for vaginal tumors.

PurposeIn this paper, we report cases of two patients with vaginal tumor who underwent interstitial brachytherapy (ISBT), using three-dimensional (3D)-printed personalized templates designed inversely from computed tomography (CT) or magnetic resonance (MR) images.Material and methodsPatient 1 presenting with vaginal vault recurrence was planned to receive whole pelvis external beam radiotherapy (EBRT) followed by ISBT. The tumor invaded the paracolpium; thus, we planned to administer ISBT to include the tumor and vaginal membrane. A template was designed with holes for plastic needle applicator insertion considering the appropriate direction based on pre-treatment medical images. Patient 2 presenting with vaginal cancer was scheduled to receive EBRT and ISBT because of a paracolpium invasion. Before ISBT, MR imaging was performed with vaginal cylinder inserted in the patient’s vagina. By measuring the length of the tumor manually and projecting the tumor orthogonally to a plane parallel to the bottom surface of the cylinder applicator, a template was designed. Computer-aided design software was used for planning both templates. Polycarbonate/acrylonitrile-butadiene-styrene resin was selected as material of the templates.ResultsPatient 1 received 4-fraction ISBT one week apart. A mean of 10 applicators were inserted through the holes of the template in an average of 9 minutes (range, 5-15 minutes). All applicators were inserted toward the planned directions. Median minimum dose covering 90% (D90%) of the clinical target volume (CTV) was 634 cGy. Patient 2 underwent three-fraction irradiation twice daily at 6-hour interval. All applicators were inserted through the inside of the template. The median D90% of the CTV was 703 cGy. No grade 3 or higher toxicity were found in both series.Conclusions3D-printed templates designed using medical images are useful, especially for ISBT of vaginal tumors. Further verification of clinical indications, design of templates, and manufacturing process are needed.

Reevaluation of Classic Posterior Ventricular Puncture Sites Using a 3-Dimensional Brain Simulation Model.

To revalidate the craniometric dimensions of classic posterior burr holes for ventricular catheter insertion in hydrocephalic patients, based on ideal catheter position on a 3-dimensional simulated computed tomography (CT) reconstruction model of the ventricles. Fifteen patients with hydrocephaly underwent multislice, thin-cut CT to geometrically determine the Cartesian coordinates of a new point for optimal posterior ventricular catheterization. The success rate for ventricular puncture and the thickness of brain traversed by the catheter with 3 approaches (Frazier, Keen, and the suggested point) were compared. The suggested burr hole point for posterior ventricular catheterization is 51 and 57 mm posterior and 58 and 60 mm above the external auditory meatus parallel to the orbitomeatal plane on the right and left sides, respectively, significantly different from the classical Frazier and Keen points. The success rate was 100% for approaches using the suggested point and the Frazier point, compared with 83% using the Keen point. This 17% difference was marginally significant (P= 0.052). The parenchymal mantle for the Frazier point was thicker than that of the suggested point on both sides, although the difference was statistically significant only on the right side (P= 0.006). The parenchymal mantle was thinner in the Keen approach compared with the suggested approach, but the difference was not statistically significant. The use of a suggested burr hole point for posterior ventricular catheterization may decrease the amount of parenchymal mantle of the brain transgressed by the catheter, and may marginally improve the chance of successful posterior ventricular catheterization.

Experimental Study on the Effect of Point Angle on Force and Temperature in Ultrasonically Assisted Bone Drilling

Drilling of bone is a common surgical procedure in orthopedics to produce holes for screw insertion. The force and temperature rise in bone drilling are two important factors affecting the outcome of the process. The present work attempts to investigate the effect of drill point angle on the level of force and temperature in bone in the presence of ultrasonic vibrations imposed on the drill along the drilling direction. The effect of drill speed on the drilling force and bone temperature was studied using two types of drills with different point angles. The influence of a range of ultrasonic frequencies and amplitudes of vibrations on drilling force, torque and surface temperature of bone was also investigated. The drilling force and bone temperature were found to be strongly influenced by the drill point angle in the presence of ultrasonic vibrations. The drill with larger point angle caused more force and temperature compared to the drill with smaller point angle. Ultrasonic frequency above 15 kHz was observed to produce more temperature in bone for both types of drill geometries. This study found drill with smaller point angle favorable for safe and efficient drilling in bone.

Proton radiography and computed tomography with dynamic water range shifter

We introduce a novel dynamic water range shifter (DWRS) that enables range shifting of a mono-energetic proton beam for the purpose of obtaining a water equivalent path length (WEPL). A scintillation screen and a charge-coupled device (CCD) camera were assembled with a mirror for a detecting system. We acquired two sets of proton radiographs with and without the scanned object, and calculated 2D distribution of the WEPL. We first optimized measurement conditions, i.e., the sampling interval and the nearest sampling point from the surface. Then we evaluated the performance of the proton radiography system by use of the step phantoms and a patient-specific range compensator. The step phantom measurement was designed to evaluate WEPL accuracy and standard deviation, and the patient-specific compensator was utilized to evaluate image quality dependency on the shifting motions of the DWRS. Based on the optimization and evaluation in the radiographic setting, a cylindrical phantom having multiple insert holes was used to obtain proton CT and the image contrasts of the holes were evaluated. This study successfully demonstrates the feasibility of using the DWRS for proton radiography and CT.

The clinical application research of Utrecht applicator in three-dimensional image guided brachytherapy (3D-IGBT) for cervical cancer

Objective To investigate the clinical application of Utrecht applicator in three-dimensional image-guided brachytherapy (3D-IGBT) for locally advanced cervical cancer, as well as its application discipline in intracavitary/interstitial (IC/IS) therapy. Methods A retrospective analysis was performed for the clinical data of 45 patients with locally advanced cervical cancer who received radical radiotherapy, and the patients received external beam radiotherapy followed by 3D-IGBT. A total of 130 times (n=45) of IC/IS therapy were performed, and the patients who received such therapy were all enrolled. The patients who met the target dose fractionation defined in the plan were enrolled as group A (n=37, 86 times), and the other patients were enrolled as group B (n=22, 44 times). Two groups difference was analyzed with Group t-test. Results The frequencies of use of 15-, 20-, and 25-mm ovoids by the applicator were 50.0%, 20.0%, and 30.0%, respectively, and the 30-mm ovoid was not used. A total of 499 needles were used, and the frequencies of use of 6, 7, 10, and 11 insertion holes were 23.1%, 21.2%, 21.2%, and 24.1%, respectively. Group A had a significantly lower mean number of the needles than group B (3.7 vs. 4.2, P=0.008). Compared with group B, group A had a significantly lower mean high-risk clinical target volume (CTV)(40.71±18.43 cm3vs. 51.81±14.74 cm3, P=0.001), as well significantly lower width and height of high-risk CTV (P=0.011 and 0.006), but the thickness of high-risk CTV was similar between the two groups (P=0.595). The difference between height and insertion depth (DH) was similar between the two groups (P=0.366). Group A had a smaller difference between width and pinhole distance Dw than group B (P=0.007). Conclusions When IC/IS therapy is performed for locally advanced cervical cancer, the 15-, 20-, and 25-mm ovoids of Utrecht applicator and 6, 7, 10, and 11 insertion holes are frequently used. When the number of needles is no less than 4 and the depth is no less than 3 cm, width is the major factor which affects the planned dose. Key words: Cervical neoplasms/brachytherapy; Brachytherapy, three-dimentional image quided; Utrecht applicator; Interstitial /interstitial; Planning aim dose

Percutaneous Fixation for Scaphoid Nonunion with Bone Grafting Through the Distal Insertion Hole of a Fully Threaded Headless Screw.

Percutaneous scaphoid screw fixation is a popular treatment for acute scaphoid fractures with no or minimal displacement. For treating scaphoid nonunions, however, open reduction and internal fixation with bone grafting is still the most popular treatment. Percutaneous fixation with bone grafting through the screw insertion hole has received little attention, although it minimizes damage to the surrounding tissues. We report excellent results of six scaphoid nonunions treated by retrograde percutaneous fixation with curettage and bone grafting through the distal insertion hole of a fully threaded headless screw. Six scaphoid nonunions with substantial bone loss were treated, including one revision case. All nonunions were located at the middle third of the scaphoid. The mean patient age at operation was 26 years, and the mean interval between fracture and surgery was 7 months. In the revision case, the interval between the primary and revision surgery was 6 months. In one case, curettage alone was performed before retrograde insertion of the headless screw. In the other cases including the revision, curettage and bone grafting with a bone biopsy needle was required through a distal insertion hole. The mean follow-up was 11.3 months. Radiologically, union was achieved at averaged 12 weeks postoperatively. At the final follow-up, there was significant improvement in the wrist extension range of movement (from 65.8° to 80.8°) and grip strength (from 69.5% to 93.0% of the unaffected side). Five patients were free of pain, and one experienced mild pain only during heavy manual labor. The mean VAS, DASH, and Cooney wrist scores were 0.3, 1 and 99, respectively. All patients returned to their work or athletic activities. Retrograde percutaneous fixation with bone grafting through the distal insertion hole of a fully threaded headless screw is a promising option for surgical treatment of scaphoid nonunions.

Percutaneous Fixation for Scaphoid Nonunion With Bone Grafting Through the Distal Insertion Hole of a Fully Threaded Headless Screw

Objective: Percutaneous scaphoid screw fixation is a popular treatment for acute scaphoid fractures with no or minimal displacement. For treating scaphoid nonunions, however, open reduction and internal fixation with bone grafting is still the most popular treatment. Percutaneous fixation with bone grafting through the screw insertion hole has received little attention, although it minimizes damage to the surrounding tissues. We report excellent results of 10 scaphoid nonunions treated by retrograde percutaneous fixation with curettage and bone grafting through the distal insertion hole of a fully threaded headless screw. Materials and Methods: Ten scaphoid nonunions with substantial bone loss were treated, including 1 revision case. All nonunions were located at the middle third of the scaphoid. The mean patient age at operation was 24.7 years, and the mean interval between fracture and surgery was 8.8 months. In the revision case, the interval between the primary and revision surgery was 6 months. Surgery was performed under general anesthesia or an axillary brachial plexus block with local anesthesia at the iliac crest donor site. A 1.1-mm guidewire was percutaneously inserted into the scaphoid tuberosity and advanced to the proximal pole of the scaphoid with the wrist in an extended and ulnar-deviated position. A 1.2-mm second derotation wire was also inserted radial or ulnar to the original guidewire. A 2.0-mm cannulated drill was passed over the guidewire, stopping at the distal end of the cystic lesion. The guidewire was then removed. The 1.2-mm second derotation wire maintained the reduction of the scaphoid. Curettage inside the cystic lesion was performed using a small curette inserted through the distal insertion hole. Bone graft was harvested percutaneously from the iliac crest with an 11-gauge bone biopsy needle and inserted into the cystic lesion through the drill hole of the distal scaphoid fragment. The removed guidewire was reinserted into the previously drilled hole followed by insertion of a selected fully threaded headless screw (Acutrak 2 mini; Acumed, Hillsboro, OR, USA). After the operation, the wrist was immobilized in a thumb spica cast for the initial 6 weeks, followed by splinting until bone union was confirmed. In one case, curettage alone was performed before retrograde insertion of the headless screw. In the other cases including the revision, curettage and bone grafting with a bone biopsy needle was required through a distal insertion hole. Results: The mean follow-up was 12.1 months. Radiologically, union was achieved at averaged 12 weeks postoperatively. At the final follow-up, there was significant improvement in the wrist extension range of movement (from 65.8° to 80.8°) and grip strength (from 65.5% to 87.8% of the unaffected side). Nine patients were free of pain, and 1 experienced mild pain only during heavy manual labor. The mean visual analogue scale (VAS), Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH), and Cooney wrist scores were 0.1, 1.75, and 98.5, respectively. All patients returned to their work or athletic activities. Conclusions: Retrograde percutaneous fixation with bone grafting through the distal insertion hole of a fully threaded headless screw is a promising option for surgical treatment of scaphoid nonunions.

Evaluación de la efectividad y satisfacción del apósito con Gluconato de Clorhexidina 3M Tegaderm™ en el cuidado del catéter central tunelizado para hemodiálisis

Introducción: Son múltiples los métodos y materiales utilizados para el manejo del orificio de inserción del catéter venoso central tunelizado para hemodiálisis con el fin de prevenir infecciones asociadas a su uso. El objetivo de este estudio es analizar el uso del Apósito con Gluconato de Clorhexidina 3M™ Tegaderm™ con respeto al Apósito formado por gasa y esparadrapo en la cura del orificio de inserción del catéter tunelizado para hemodiálisis. Material y método: Se ha llevado a cabo un estudio prospectivo durante 32 semanas en el que se han incluido 9 pacientes portadores de catéter venoso central tunelizado. Se han recogido datos referentes al estado del orificio de inserción del catéter, del túnel, de la zonza colindante, aplicabilidad del material, satisfacción del paciente, percepción del profesional y costes. Resultados: No se ha evidenciado diferencias en la eficacia para la prevención de infecciones entre ambos apósitos. En el análisis de satisfacción, se constata una mayor percepción de seguridad con el uso del apósito con clorhexidina además de una reducción de coste de la técnica. Discusión: Basándonos en los costes, satisfacción del paciente y en la percepción del personal de enfermería responsable de la técnica, el Apósito con Gluconato de Clorhexidina es una buena alternativa para el cuidado del orificio de inserción del catéter tunelizado para hemodiálisis.

1F11 大腿骨頚部骨折治療支援のための歩行を模擬した動的条件下における有限要素解析

Femoral neck fracture is one of serious healthcare problems in aging societies. Osteosynthesis with implants is widely used for femoral neck fracture treatment, however, complications such as bone refracture around implant insertion holes may occur during postoperative rehabilitation period. Authors had already numerically analyzed osteosynthesis with implant under a static loading condition. In order to resolve the mechanics of the complications, we should analyze under the dynamic loading condition corresponding to gait motion. The purpose of this study is to evaluate not only time dependent stress distribution but also maximum stress concentration around proximal femur by using finite element analysis under the dynamic loading condition. First, three-dimensional hip joint finite element model was reconstructed from CT image. This model consists of the pelvis, proximal femur and implants (Hansson pin and Dual SC Screw). Then, dynamic loading and boundary conditions were applied to the model for simulating a gait motion. The dynamic loading around the hip joint was obtained from inverse dynamic analysis of a human gait using in-house musculoskeletal model Time varying stress distribution during a gait cycle was analyzed by using dynamic explicit method (AB AQUS ver.6.13-5). We examined the time varying von Mises stress distribution at the representative points located on the cortical surface. These simulation results successfully demonstrated the excessive stress concentration around the insertion holes induced by the gait motion. It is proofed that the proposed dynamic analysis has the capability of the refracture risk assessment of the osteosynthesis of femoral neck fractures.