Pin Position Research Articles

A Revised Capsule Design for the Accelerated Testing of Advanced Reactor Fuels

The Advanced Test Reactor (ATR) has been used successfully for the testing of fast reactor fuel for nearly two decades. These successes have been in spite of numerous challenges for testing fast reactor fuel in the ATR (a thermal spectrum reactor), but the solutions to those challenges have resulted in excessively long irradiation times (~10 years) for high-burnup targets as well as experiments that are highly sensitive to fabrication tolerances and eccentricities. This paper presents a solution to the problems of extended irradiation times and fabrication sensitivities. Thermal and neutronic analyses were performed to show that a reduced-diameter fuel pin with an equivalent linear heat generation rate can provide a prototypic thermal profile (peak centerline and inner clad temperature) along with a near-prototypic power profile within the ATR thermal spectrum. This allows the experiment to reach a high burnup in an expeditious timeframe compared to traditional ATR fast fuel irradiations. In addition, problems with fabrication sensitivities were addressed by introducing a double-encapsulated experiment that pushes the high heat flux helium gap farther away from the fuel pin. Fuel pin position eccentricities are also mitigated by using a large sodium bond between the pin and capsule fuel. The advantages and potential pitfalls of this revised design are discussed, including the effect of length scales on fuel system behavior.

Temperature based spindle speed controller during friction stir welding of aluminium metal matrix composites

PurposeThis paper aims to investigate two control mechanisms on the two parameters, namely, spindle speed and tool pin position, while performing friction stir welding (FSW) for aluminium metal matrix composites (Al-MMC) using the concept of system identification.Design/methodology/approachFSW is a feasible choice for joining of Al-MMC over the fusion welding due to the formation of the narrow heat-affected zone and minimizing the formation of intermetallic compounds at weld interface. The goal in FSW is to generate enough thermal energy by friction between the workpiece and rotating tool. Heat energy is generated due to mechanical interaction because of the difference in velocity between the workpiece and rotating tool. The generated heat is proportional to the tool pin position and the spindle speed. In the present work, a Smith Predictor Control scheme and adaptive control scheme are developed during joining of Al6061/SiC/B4C Al-MMC by FSW. Adaptive controller is developed to control the tool pin position while Smith Predictor control is developed to control the spindle speed. Initially, the Al-MMC plates are prepared at five combinations of SiC and B4C reinforcements and welded at three level parameter settings followed by tensile testing. The experimental data are used in estimating the plant transfer function model using system identification. The control schemes are then developed for the estimated plant model and the same are validated using a standard PID controller. In both the control schemes, PID controller results in a sluggish response. Experimental validations are performed for the developed control schemes followed by microscopic studies of the weldments.FindingsIn both the control schemes, PID controller results in a sluggish response. Experimental validations are performed for the developed control schemes followed by microscopic studies of the weldments.Research limitations/implicationsResults from the study concluded that the developed MRAC and Smith predictor scheme effectively controlled the vibrations and spindle speed effectively.Originality/valueIt is observed that the scanning electron microscopy micrographs of the Al-MMC’s welded using developed control schemes resulted in good boding with homogenous distribution of reinforcement particles.

Optimal hydrothermal design of microchannel heat sink using trapezoidal cavities and solid/slotted oval pins

A new design of plate-fin microchannel heat sink (MCHS) with trapezoidal cavities and oval pins with and without slots is proposed. Heat transfer and fluid flow characteristics are numerically studied and analyzed for Reynolds number ranging from 100 to 1200. Three geometric parameters have been considered in this study including; the aspect ratio of the oval pins, pin position from cavity center toward the inlet, and lastly thickness of the two inclined slots of the pins. The finite volume method (FVM) is adopted for solving the governing equations, and the SIMPLE algorithm is utilized for the computations. The overall performance of the present design is evaluated based on friction factor, Nusselt number and hydrothermal performance factor (PEC). The results indicate that the optimal design of the proposed design is at a pin aspect ratio of (AR = 1.25), pin distance from cavity center of (x = 0.03 mm) and slot thickness of (t = 0.008 mm) which gives a maximum PEC of 1.37.

Multiphysics Analysis of Pin-Socket Electrical Dynamic Contact Susceptibility Under Vibration Stress

The pin-socket connector susceptibility under vibration stress constitutes one of the electrical engineer breakthroughs. Only single electrical engineering is not enough to treat this challenging issue. The Multiphysics analysis is expected to be a solution to analyze this electromechanical dynamic pin-socket structure. This paper develops a dynamic contact Multiphysics analysis with the tensorial analysis of networks (TAN) formalism. The Multiphysics model integrates the pin relative velocity and position coupled with the instantaneous contact resistance implemented in an RC -network. An innovative method enabling to determine the vibration stress signature via the signal-to-noise (SNR) amplitude is established. The relevance of the Multiphysics TAN model is illustrated with an example of a 10-mm-length pin-socket under arbitrary waveform uniaxial vibration stress with 20-kHz bandwidth. It was shown that the contact resistance may fluctuate with more than thousand-time relative variation. More importantly, the vibration stressed pin-socket SNR in function of the RC -network parameters is discussed. The proposed Multiphysics analysis can be potentially applied to the electromagnetic compatibility and signal integrity investigation of assembled electronic equipment and printed circuit boards under vibration stress.

Do fluoroscopic and radiographic images underestimate pin protrusion in paediatric supracondylar humerus and distal radius fractures? A synthetic bone model analysis.

PurposeFluoroscopy is commonly used to confirm acceptable position of percutaneously placed pins when treating paediatric fractures. There is a paucity of literature investigating the accuracy of fluoroscopic imaging when determining pin position relative to the far cortex of the fixated bone. The purpose of this study was to evaluate the accuracy of fluoroscopic and radiographic imaging in measuring smooth pin protrusion from the far cortex of a bone model.MethodsEight bone models were implanted with smooth pins and anteroposterior fluoroscopic and radiographic studies were obtained. All images were evaluated by orthopaedic attending physicians, residents and medical students. The length of pin protrusion from the model surface was estimated on fluoroscopic imaging and measured on radiographs and compared with actual lengths measured on the bone models.Results20 evaluators took a total of 320 pin measurements on images of 8 models. There was a significant difference between fluoroscopic measurements compared to radiographic measurements and actual pin lengths. There was no significant difference between radiographic measurements and actual pin lengths. Level of training of examiner was not statistically significant. On average, fluoroscopic estimations of pin protrusion were 1.53 mm shorter than the actual measured length.ConclusionFluoroscopic images underestimate the length of smooth pins protruding from a bone model surface when compared with radiographs and actual measurements. Orthopaedic surgeons using fluoroscopy should be aware of this discrepancy when assessing intraoperative fluoroscopic images to decide on acceptable implant position.Level of Evidence:Level V

Design and Analysis of Ejection Pin System for 1500T Press

In manufacturing industries hydraulic press are used to produce different parts required for automobile and other industries. To produce different parts by stamping process dies and position patterns of cushion pins are changed. Depending upon the shape of part to be produced respective die and the position pattern of cushion pins in the bolster plate is selected. Before the production starts position of this cushion pins is tasted to secure the safety of die and parts to be produced. But the testing consumes more time and effects production rate. In this project the time required for the testing is reduced by automating the cushion pin ejection system. A separate hydraulic system is used for the required automation in order to reduce the idle of the hydraulic press. AUTOCAD and ANSYS software are used for design and analysis of the automation.

Percutaneous Pinning of Pediatric Proximal Humeral Fractures.

Proximal humeral fractures are relatively common in pediatric patients. These injuries are usually treated nonoperatively in younger children or children with minimally displaced fractures. However, closed reduction or open reduction followed by percutaneous pinning is recommended for older children with displaced fractures. Percutaneous pinning has several advantages, but there are limited reports of a safe and reliable surgical technique in the literature. Patients are positioned in a modified beach-chair position to allow orthogonal imaging. The injured extremity is draped free from the remainder of the body. Closed reduction, which comprises a combination of traction, abduction, and rotation, is attempted. Internal or external rotation may be required, depending on the fracture line and deforming forces. If an anatomic closed reduction cannot be obtained, a block to reduction should be suspected and open reduction should be performed via a deltopectoral approach. Once the fracture is reduced, two 2.5-mm threaded Kirschner wires from the small external fixator set are used to percutaneously fix the fracture. Any small external fixator set can be used, and if not available, individual threaded wires of similar size can be used. Alternatively, Kirschner wires can be advanced to the fracture site prior to reduction and then advanced into the humeral epiphysis once the fracture is reduced. Care is taken to avoid the axillary nerve, which is reliably within 6 cm of the anterolateral aspect of the acromion, and wires are placed distal to this site. Once pin position has been confirmed radiographically, the construct is secured with pin-to-pin clamps to improve rigidity and further decrease the risk of pin migration. A soft dressing and shoulder immobilizer are placed postoperatively. Patients are followed with biweekly radiographs, and pins are removed in the outpatient office or under conscious sedation at 4 weeks. Leaving pins for a longer period may increase the risk of skin irritation and potentially infection. Alternatives to closed reduction or open reduction and percutaneous pinning include nonoperative management and elastic intramedullary nailing. Nonoperative treatment is a reliable option for most patients. However, it is not suitable for older children with severely displaced fractures because of diminished remodeling potential. Elastic intramedullary nailing is a good option for distal fractures. However, it is not suitable for proximal fractures, and it has been associated with longer operative times and more blood loss than percutaneous pinning. It also requires a second procedure. This procedure allows for anatomic fixation of proximal humeral fractures and provides a rigid construct to maintain reduction. It is not technically challenging, requires limited postoperative immobilization, and decreases the risk of a second general anesthetic.

An implanted pH sensor read using radiography.

A biomedical sensor was developed to measure local pH near orthopedic implants to detect and study implant-associated infection. The sensor is read using plain radiography, a technique which is noninvasive, inexpensive, ubiquitously available in medical facilities, and routinely used in diagnosis and follow-up. The sensor comprises a radiopaque tungsten indicator pin embedded within a chemically responsive hydrogel that exhibits a pH-dependent swelling. A stainless steel well holds this hydrogel and attaches to an orthopedic plate. The local pH may be determined from the extent of hydrogel swelling by radiographically measuring the indicator position relative to the well. We calibrated the sensor in a series of standard pH buffers and tested it during bacterial growth in culture. The sensor was robust: its response was negligibly affected by changes in temperature, ionic strength within the normal physiological range, or long-term incubation with reactive oxygen species generated from hydrogen peroxide and copper. Pooled data from several sensors fabricated at different times and tested in different conditions had a root-mean-square deviation from a pH electrode reading of 0.24 pH units. Radiographic measurements were also performed in cadaveric tissue with the sensor attached to an orthopedic plate fixed to a tibia. Pin position readings varied by 100 μm between observers surveying the same radiographs, corresponding to 0.065 pH units precision in the range pH 4-8. The sensor was designed to augment standard radiographs of tissue, bony anatomy, and hardware by also indicating local chemical concentrations.

Comparison of planetary bearing load-sharing characteristics in wind turbine gearboxes

Abstract. In this paper, the planetary load-sharing behavior and fatigue life of different wind turbine gearboxes when subjected to rotor moments are examined. Two planetary bearing designs are compared – one design using cylindrical roller bearings with clearance and the other design using preloaded tapered roller bearings to support both the carrier and planet gears. Each design was developed and integrated into a 750 kW dynamometer tests, the loads on each planet bearing row were measured and compared to finite-element models. Bearing loads were not equally shared between the set of cylindrical roller bearings supporting the planets even in pure torque conditions, with one bearing supporting up to 46 % more load than expected. A significant improvement in planetary bearing load sharing was demonstrated in the gearbox with preloaded tapered roller bearings with maximum loads 20 % lower than the gearbox with cylindrical roller bearings. Bearing life was calculated with a representative duty cycle measured from field tests. The predicted fatigue life of the eight combined planet and carrier bearings for the gearbox with preloaded tapered roller bearings is 3.5 times greater than for the gearbox with cylindrical roller bearings. The influence of other factors, such as carrier and planet bearing clearance, gravity, and tangential pin position error, is also investigated. The combined effect of gravity and carrier bearing clearance was primarily responsible for unequal load sharing. Reducing carrier bearing clearance significantly improved load sharing, while reducing planet clearance did not. Normal tangential pin position error did not impact load sharing due to the floating sun design of this three-planet gearbox.

Surgical technique and outcomes for bilateral humeral lengthening for achondroplasia: 26-year experience.

Elongation in patients with achondroplasia provides better overall skeletal proportionality and significantly improves such individuals' access to their perineal region to self-manage personal hygiene. This paper describes our surgical technique and outcomes for bilateral humeral lengthening in achondroplasia patients over 26years. Ours was a retrospective study of 55 patients with achondroplasia-related short stature, in whom bilateral humeral lengthening was performed from 1990 to 2016. We describe the surgical technique and analyze mean gain in humeral length, days using an external fixator, mean percentage of lengthening, external fixation index, type of callus, and complications. Pre- and postoperative radiographic measurements were obtained. Patients also were contacted by telephone and asked about their ability to perform peri-anal self-hygiene and about their overall satisfaction. In total, 110 humeri were lengthened (28 males and 27 females) with medium elongation of 9.5cm on the right and 9.6cm on the left, while averaging 220days in an external fixator. We observed 14 minor complications. There was no significant association between pin position and type of callus, and elongation most often external and in the presence of a straight callus. Before elongation, 77.1% of patients reported difficulties with perineal hygiene and 85.4% could not put their hands in their pockets. Upon completion of lengthening, 100% could perform both tasks and 94.5% were very satisfied. Bilateral humeral elongation yields significant improvements in patient autonomy, with a relatively low complication rate and very high patient satisfaction.

Distal Biceps Repair With Flexible Instrumentation and Risk of Posterior Interosseous Nerve Injury: A Cadaveric Analysis.

Background:Current repair techniques using cortical button fixation cannot achieve anatomic reconstruction of the distal biceps when performed through a single-incision anterior approach. We recently introduced a single-incision technique that uses flexible guide pins and flexible reamers to allow for an insertion point on the tuberosity that more closely approximates the anatomic footprint of the distal biceps.Purpose:To investigate the safety of this technique with regard to nerve injury by comparing the guide pin position relative to the posterior interosseous nerve in 16 cadaveric elbows through use of a flexible versus rigid reamer.Study Design:Descriptive laboratory study.Methods:A standard single-incision anterior approach was performed in all cadaveric specimens, and the biceps tendon was dissected off the tuberosity. In 8 specimens, a traditional straight guide pin was used with a cortical button repair inserted through the bicipital tuberosity as close to the anatomic tendon footprint as possible. In the remaining 8 specimens, a curved guide was used to insert a flexible guide wire through the tuberosity within the native footprint. Dissection was carried out to measure the distance from the exit point of the guide pin to the posterior interosseous nerve. The 2 groups were compared by use of nonparametric Wilcoxon rank-sum test (significance threshold, P < .05).Results:The mean distance of the guide wire to the posterior interosseous nerve was 11.6 mm (SD, 3.4 mm; range, 6.5-16.9 mm) in the standard rigid instrument group compared with 8.6 mm (SD, 4.2 mm; range, 1.0-13.9 mm) in the flexible instrumentation group; the difference between groups was not statistically different (P = .19; 95% CI, –1.1 to 7.1).Conclusion:Based on our cadaveric testing, the use of flexible instrumentation in a single-incision repair of the distal biceps presents with no significant difference in risk of damage to the posterior interosseous nerve compared with standard rigid instruments. In view of the relatively small number of specimens, however, some caution should be observed when applying these results clinically.Clinical Relevance:As contemporary techniques in sports medicine strive to re-create each patient’s native anatomic characteristics, the use of flexible instruments allows for a more anatomic repair of the distal biceps, and our study demonstrates that it is a safe option. The next step is to evaluate its safety in vivo.

Wide range control of Schottky barrier heights at metal/Ge interfaces with nitrogen-contained amorphous interlayers formed during ZrN sputter deposition

A ZrN contact on a Ge substrate can alleviate the intrinsic Fermi-level pinning (FLP) position toward conduction band edge, which is induced by an amorphous interlayer (a-IL) containing nitrogen atoms at the interfaces. Since the a-IL could be retained on the Ge surface, we demonstrated a wide range Schottky barrier height (SBH) control for metal/a-IL/Ge contacts. The sputtering power for ZrN affects the SBH, pinning factor (S), and effective charge neutral level. A high S value of 0.26 was achieved, which is comparable to that of metal/Si contacts. A model was proposed for explaining the mechanism of this effective FLP alleviation.

Slip Detection With a Biomimetic Tactile Sensor

Slip detection helps to prevent robotic hands from dropping grasped objects and would thus enable complex object manipulation. Here we present a method of detecting slip with a biomimetic optical tactile sensor-the TacTip-that operates by measuring the positions of internal pins embedded in its compliant skin. We investigate whether local pin movement is a strong signal of slip. Accurate and robust discrimination between static and slipping objects is obtained with a support vector machine (accuracy 99.88%). We then demonstrate performance on a task in which a slipping object must be caught. For fast reaction times, a modified TacTip is made for high-speed data collection. Performance of the slip detection method is then validated under several test conditions, including varying the speed at which slip onset occurs and using novel shaped objects. The proposed methods should apply to tactile sensors that can detect the local velocities of surface movement. The sensor and slip detection methods are also well-suited for integration onto robotic hands for deploying slip control under manipulation.

Advantages and disadvantages of the prone position in the surgical treatment of supracondylar humerus fractures in children. A literature review

IntroductionSupracondylar humerus fractures are the most common elbow injuries in children. The widely adopted approach for Gartland III extension type consists of closed reduction and percutaneous pinning; the pin configuration can be lateral or crossed in relationship with the habit of the surgeons. Iatrogenic injury of the ulnar nerve is the most common risk during the insertion of the medial pin. The aim of this study was to analyze advantages and disadvantages of percutaneous pinning with the patient in prone position. Materials and MethodsA literature review of the period 2005–2017 was carried out; four medical search engine (Pubmed, Cochrane Library, ISI Web of Science and Scopus) were consulted using the review’s filter and the key words “Ulnar nerve AND supracondylar humerus fractures”. The total number of patients were analyzed for: ulnar nerve injuries, anesthesiologic management, time of surgery. ResultsTwenty-nine papers were read, 23 regarding cross pinning in supine position and 6 in prone position. On one hand, 1529 children were treated with closed reduction and cross pinning in supine position; 69 of these patients (4.5%) suffered from iatrogenic ulnar nerve injury. On the other hand, 579 patients underwent the same treatment in prone position; no ulnar nerve lesions were reported in this group. Only one article compared both groups of children in supine and prone position regarding time of anesthesia which is slightly higher in the prone group. There were no differences between supine and prone positions regarding x-ray exposition, time of surgery, closed reduction manoeuvers, pin positioning, x-ray results, clinical and functional results. Discussion and ConclusionsThe ulnar nerve in children is hypermobile in the cubital tunnel and tends to dislocate anteriorly over the medial epicondyle, especially when the elbow is in hyperflexion. This may be the reason of the increased risk of nerve injury during the insertion of the medial pin in supine position and, instead, an advantage of the prone position. The insertion of both pins from the lateral side could reduce this complication. Larger studies need to be carried out regarding the reported higher duration of anesthesia in prone position.

Machine vision based in-process light-emitting diode chip mounting system

Background: In this study, a machine vision–based method was developed for automated in-process light-emitting diode chip mounting lines with position uncertainty. In order to place the tiny light-emitting diode chips on the pattern of a printed circuit board, a highly accurate mounting process is achieved with online feedback of the visual assistance. Methods: The system consists of a charge-coupled device camera, a six-axis robot arm, and a delta robot. The lighting system is a critical point for the in-process machine vision problem. Hence, designing the optimal lighting solution is one of the most difficult parts of a machine vision system, and several lighting techniques and experiments are examined in this study. In order to commence the mounting process, the light-emitting diode chip targets inside the camera field were identified and used to guide the delta robot to the grabbing zone based on the calibrated homography transformation. Efforts have been focused on the field of machine vision–based feature extraction of the chip pins and the holes on the printed circuit board. The correspondence of each other is determined by the position of the chip pins and the printed circuit board circuit pattern. The image acquisition is achieved directly online in real time. The image analysis algorithm must be sufficiently fast to follow the production rate. In order to compensate for the uncertainty of the light-emitting diode chip mounting process, a visual feedback strategy in conjunction with an uncertainty compensation strategy is employed. Results: Finally, the light-emitting diode chip was automatically grabbed and accurately placed at the desired positions. Conclusion: On-line and off-line experiments were conducted to investigate the performance of the vision system with respect to detecting and mounting light-emitting diode chips.

Dual-Band High-Gain Differentially Fed Circular Patch Antenna Working in TM11 and TM12 Modes

A differentially fed circular patch antenna working in TM11 and TM12 modes is proposed for dual-band high-gain and stable radiation patterns. A set of shorting pins are loaded in circular contours underneath the circular patch to substantially increase the resonant frequency of TM11 mode, and the radiation gain in lower band can be hence effectively enhanced due to the enlarged patch size at resonance. Meanwhile, a narrow slot is introduced to the center of patch, in order to interrupt the out-of-phase current of TM12 mode on patch for sidelobe reduction. As the electric current distribution on patch is significantly reshaped by the slot, the antennas act like a full-wave dipole in this case, so both high gain and low sidelobe level are realized in upper band. Besides, by properly adjusting the shorting positions of pins and length of slot, the antenna can be well matched in the desired 3.6 and 5.9 GHz wireless local area network bands. Simulated and measured results show that at least 10 dBi realized gain can be obtained in both the lower and upper bands, and the patterns in the two bands show agreeable beamwidths.

Challenges in Circumferential Entry Blades for Structural Integrity of Closing Blade in Steam Turbines

The bladed disc of an LP last stage rotor assembly in a steam turbine often employs circumferential entry blades. The closing blade is fastened with the aid of a pin type locking mechanism, which locks the closing blade onto the disc. Radial entry blade root design demands for a groove in the disc through which blades are inserted and guided to their respective final positions which alters the stiffness in the disc. Closing blade is the most highly stressed weak link zone in the circumferential entry rotor disc achieving mechanical integrity for in-service condition is a challenge. Location of pin and its insertion is the key to achieve the desired in-service life with good material model. The present research work focus on emphasis of pin positioning to lock the T-root blade at operating range. Various material model configurations and pin positions are considered in both blade and disc to improve the reliability in design. Customized methodology is developed to address the elasto-plastic kinematic hardening in pin, disc and blade grove during in-service life. Finite element approach along with classical design equations followed by API 616 standards is employed to achieve the mechanical integrity in bladed disc assembly.

Efficacy and complications of the use of Gardner-Wells Tongs: a systematic review.

We conducted a thorough review of the literature to examine the risks and complications associated with the use of Gardner-Wells Tongs (GWT). Twenty-three articles were included in this review for final analysis. One article reported a 37.5% (6/16) incidence rate of minor complications with the usage of GWTs, which included pin loosening, asymmetrical pin positioning, and superficial infections. Various cases reported more serious yet rare complications, including perforation of the skull, brain abscesses, and neurovascular damage. Overall, the complication rate is low, and often associated with only minor and transient complications, which can be easily managed. Therefore, we conclude that GWT are safe and effective, with only rare, more serious complications reported in the literature.

Design of Miniaturized Multiband Microstrip Patch Antenna using Defected Ground Structure

The recent developments in communication and antenna engineering demands compact and multiband antennas. Microstrip antenna is one of the most useful antennas for wireless communication because of its inherent features like low profile, light weight and easy fabrication. This design is aimed at miniaturized Microstrip Patch Antenna (MSA), without deteriorating its other parameters, such as gain, bandwidth, directivity and return loss. A significant amount of 89% miniaturization has been made possible by careful and meticulous investigation of slots insertion in patch and ground of MSA antenna. Dielectric substrate used in this design is polyester which has shown better result. As the focus of this design is to miniaturize the MSA, the technique used here is Defected Ground Structure (DGS), along with Defected Patch Structure (DPS) which actually shifted the resonant frequencies to the lower range without increasing its physical dimensions. Besides this shorting pin is also introduced between patch and ground, which also contributed in the enhancement of parameters like gain and return loss. The position of pin played an important role in the acquirement of better performance and radiation at desirable frequency band. Different shapes have been designed on Ground and Patch to obtain enhanced results. With the use of DGS, the designed antenna started radiation at multiple frequency bands. The frequency bands generated by this designed antenna are in the range of L band and S band of IEEE standard which made it apposite to use in variety of applications.

A 3-Dimensional Analysis of the Fracture Planes in Pediatric Lateral Humeral Condyle Fractures for Image-Based Pin Positioning During Fixation.

To determine the 3-dimensional morphology of pediatric lateral condylar physeal fractures using 3-dimensional computed tomography (3D-CT) and to identify optimal pin positions for percutaneous pinning. Prospective case series of consecutively treated patients. Tertiary university hospital setting. Preoperative 3D-CTs in pediatric surgical candidates diagnosed with lateral condylar physeal fractures. Closed reduction and percutaneous pinning was performed. Reconstructed images of the distal humerus were aligned accordingly to determine the coronal (α), sagittal (β), and axial tilt (γ) angles of the fracture plane. Both α and β were also measured on plain radiography. Image-based position of the 2 pins was calculated preoperatively using 3D-CT, based on anteroposterior and lateral views. Final angle of pins was measured on postoperative radiographs. A total of 29 fractures were assessed. 3D-CT reconstruction images of fractures showed a posterolateral fracture fragment with reference to the long axis of the humerus. The mean α, β, and γ were 62 degrees [95% confidence interval (CI), 59-64], 69 degrees (95% CI, 65-72), and 36 degrees (95% CI, 34-38). Both α and β measured on plain radiography were not significantly different from 3D-CT measurements (P = 0.6712, 0.6218). Average postoperative pin angles were 144 degrees (95% CI, 140-147) and 161 degrees (95% CI, 158-165) for the proximal pin, and 118 degrees (95% CI, 114-122) and 115 degrees (95% CI, 110-120) for the distal pin, on anteroposterior and lateral views, respectively, resulting in similar trajectories to the preoperatively calculated pin positions. Our study adds to the current knowledge by providing an image-based angular reference of the fracture configuration in pediatric lateral humeral condyle fractures, which may be used during percutaneous pinning. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.