Distal Targeting Research Articles

Stereotactic Radiosurgery for Trigeminal Neuralgia: A Comparison of Proximal and Distal Isocenter Outcomes

Trigeminal neuralgia is a chronic pain condition of the trigeminal nerve affecting 12 per 100,000 people. Stereotactic radiosurgery (SRS) delivered by both a non-invasive stereotactic radiosurgery instrument and linear accelerators (LINAC) is a non-invasive alternative to surgical approaches. Although SRS in this setting is commonly performed, there lacks a consensus and comparative data on the optimal anatomical target with the two most common targets being the dorsal root entry zone (proximal) and retrogasserian zone (distal). This study aims to evaluate treatment outcomes in patients based on these two target locations. This multi-center, retrospective analysis included patients treated for trigeminal neuralgia between 2017 and 2021 with GK and LINAC-based SRS who were followed for at least 1 year. All patients received a dose of 85 Gy prescribed to the isocenter, set at the dorsal root entry zone (proximal) or the retrogasserian zone (distal). Isocenter location was based on the preference of the radiation oncologist and neurosurgeon. Patient reported clinical pain relief was recorded as full, partial, or no pain relief after SRS. Among patients with full and partial pain relief duration of pain relief was recorded. Ability to achieve full or partial medication de-escalation was also recorded. Outcomes of patients in the proximal and distal target cohort were compared using time based univariate analyses using log rank hazards model. We identified 86 eligible patients, of whom 54 patients (63%; median age 63, 72% female) were treated using a proximal target, and 32 (37%; median age 66, 71% female) were prescribed to a distal target. In the proximal and distal cohorts, patients experienced pain relief (either partial or full relief) at a rate of 74% and 90% and full pain relief at a rate of 46% and 31%, respectively (p = 0.011). The duration of pain relief was not significantly different amongst the two groups (p = 0.18). Partial medication de-escalation was more frequent in the distal target (75%) vs proximal (33%), while full medication de-escalation was more frequent with proximal (39%) vs distal (13%), p = 0.001. This study contributes to the limited data evaluating the differences in outcomes between proximal and distal targeting for treatment of trigeminal neuralgia with stereotactic radiosurgery. Overall, this study confirms that both approaches achieve a high rate of response in a difficult to control disease process. Our study suggests that a distal isocenter may be associated with higher rates of any type of pain improvement while a proximal isocenter may be associated with higher rates of complete pain relief. This data is hypothesis-generating and warrants further investigation into the effectiveness/toxicity differences of two approaches.

Osteolysis Around the Distal Targeting Screw after Using Proximal Femoral Nail Anti-Rotation for Intertrochanteric Fractures

Osteolysis Around the Distal Targeting Screw after Using Proximal Femoral Nail Anti-Rotation for Intertrochanteric Fractures

Observational prospective unblinded case-control study to evaluate the effect of the Gamma3® distal targeting system for long nails on radiation exposure and time for distal screw placement

PurposeTo determine if the DTS decreases radiation exposure (primary outcome measure), fluoroscopy time (secondary outcome measure), and time to distal screw placement (secondary outcome measure) compared to the freehand “perfect circles” method when used for locking of cephalomedullary nails in the treatment of femur fractures MethodsFifty-eight patients with hip or femoral shaft fractures that were treated with a long cephalomedullary nail were enrolled in this study. Cohorts were determined based on the method of distal interlocking screw placement into either the “Perfect Circles” or “Distal Targeting” cohort. Time from cephalad screw placement to placement of final distal interlocking screw (seconds), radiation exposure (mGy), and fluoroscopy time (seconds) were compared between groups. Hospital quality measures were compared between cohorts. ResultsUse of the DTS resulted in 77% (4.3x) lower radiation exposure (p < 0.001), 64% (2.7x) lower fluoroscopy time (p < 0.001), and 60% (1.7x) lower intraoperative time from end of cephalad screw placement to end of distal interlocking screw placement (p < 0.001) compared to the freehand “perfect circles” method. There was no difference in 30-day or 90-day complication rates between cohorts. ConclusionThe Stryker Gamma3® Distal Targeting System is a safe, effective and efficient alternative to the freehand “perfect circles” method.

Direct Observation of Compartment-Specific Localization and Dynamics of Voltage-Gated Sodium Channels.

Brain enriched voltage-gated sodium channel (VGSC) Nav1.2 and Nav1.6 are critical for electrical signaling in the CNS. Previous studies have extensively characterized cell-type-specific expression and electrophysiological properties of these two VGSCs and how their differences contribute to fine-tuning of neuronal excitability. However, because of a lack of reliable labeling and imaging methods, the subcellular localization and dynamics of these homologous Nav1.2 and Nav1.6 channels remain understudied. To overcome this challenge, we combined genome editing, super-resolution, and live-cell single-molecule imaging to probe subcellular composition, relative abundances, and trafficking dynamics of Nav1.2 and Nav1.6 in cultured mouse and rat neurons and in male and female mouse brain. We discovered a previously uncharacterized trafficking pathway that targets Nav1.2 to the distal axon of unmyelinated neurons. This pathway uses distinct signals residing in the intracellular loop 1 between transmembrane domain I and II to suppress the retention of Nav1.2 in the axon initial segment and facilitate its membrane loading at the distal axon. As mouse pyramidal neurons undergo myelination, Nav1.2 is gradually excluded from the distal axon as Nav1.6 becomes the dominant VGSC in the axon initial segment and nodes of Ranvier. In addition, we revealed exquisite developmental regulation of Nav1.2 and Nav1.6 localizations in the axon initial segment and dendrites, clarifying the molecular identity of sodium channels in these subcellular compartments. Together, these results unveiled compartment-specific localizations and trafficking mechanisms for VGSCs, which could be regulated separately to modulate membrane excitability in the brain.SIGNIFICANCE STATEMENT Direct observation of endogenous voltage-gated sodium channels reveals a previously uncharacterized distal axon targeting mechanism and the molecular identity of sodium channels in distinct subcellular compartments.

Evaluation of the accuracy of the Sureshot® electromagnetic targeting system in distal locking of long-nailed humeral diaphyseal fractures

IntroductionOsteosynthesis of humeral diaphyseal fractures by long intramedullary nailing is a widespread practice. Distal interlocking is a delicate and uncertain step in the procedure, and the free-hand method is adopted by most surgeons. We evaluated the accuracy of a magnetic field-guided system for distal interlocking of long intramedullary nailed humeral diaphyseal fractures. HypothesisThe field magnetic method to interlock distal screws procured satisfying success rates at first attempt in each hole. Study designSingle center, retrospective, descriptive and continuous. Material and methodsWe used the Sureshot® Distal Targeting System (DTS) and the Trigen® (Smith & Nephew) nail. All patients who presented to our center for osteosynthesis of a fracture of the humeral diaphysis by long intramedullary nailing between April 1, 2016 and June 30, 2018 were retrospectively included. ResultsThe analyses included 32 of the 34 patients who presented during this period (mean age, 64 years). There were 51 attempts to install distal interlocking screws. The screws were interlocked successfully in 40 cases (78.4%), and there were 11 failures (21.6%). There was an average of 29 fluoroscopic views and an average cumulative dose area product of 36.90 cGcm2. DiscussionWe found a lower success rate than that found in the literature for the accuracy of Sureshot® DTS in long humeral nailing. We found also a lower success rate than for tibial and femoral centromedullary nailing with this system. Our study showed a success rate of only 78.4% at the first attempt for distal interlocking of Trigen® humeral long nails. Level of evidenceIV; retrospective study without control group.

Robotized Catheter With Enhanced Distal Targeting for Peripheral Pulmonary Biopsy

Transbronchial biopsy with a lung catheter is more appealing with lower complication risks for peripheral pulmonary biopsy. The distal tips of the current lung catheters lack targeting capabilities, however, which prevents a physician from guiding the biopsy tools to lesions, especially those in a peribronchial location. In this study, we investigated if a robotized catheter could enhance distal targeting after passing through tortuous bronchi. We experimentally evaluated targeting accuracy and the spatial dispersion of targeting with attention to catheter shape constraints by utilizing the bronchi of a patient-derived lung phantom. This newly developed robotized catheter has an outer diameter of 3 mm and a total length of 800 mm and comprises two bending sections at the distal 30 mm length. With these two bending sections, the distal tip can be steered to peribronchial lesions followed by the targeting of multiple locations inside the lesion with controlled dispersion to improve opportunities for tissue sampling. In the experimental results, the targeting position error for a peribronchial lesion ranged from 4.6 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 1.2 to 7.2 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 3.3 mm (mean <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> STD) among the different shape constraints. As for the targeting dispersion, the shape constraints reduced dispersion ability by a maximum of 50% compared to straight reference constraints, while the dispersion was still larger than the expected minimum requirement of 1 mm. One-way analysis of variance concluded that targeting accuracy and targeting dispersion included a significant dependence on shape constraints (p <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$&lt; $</tex-math></inline-formula> .05). This study demonstrates the feasibility of enhancing distal targeting with the proposed robotized catheter and found that bronchi shape constraints significantly affect targeting capability.

Reduced Surgical Time and Higher Accuracy of Distal Locking with the Electromagnetic Targeting System in Humeral Shaft Intramedullary Nailing.

ObjectiveTo evaluate the efficacy of the electromagnetic distal targeting system in the treatment of humeral shaft fractures.MethodsFrom January 2012 to December 2018, we retrospectively reviewed 60 patients with humeral shaft fractures treated by intramedullary nailing. Among 60 cases, 41 were men and 19 were women. The average age at surgery was 48.5 years (range, 21–81 years). We performed the same surgical procedure for all patients. According to the different distal locking technique used, all patients were divided into two groups. The standard fluoroscopic freehand technique was used for Group FH, while the electromagnetic real‐time targeting technique was used for Group EM. All procedures were performed by two senior surgeons. Overall surgical time, cases of complications, failure of distal locking, union time, and shoulder function assessment were recorded intraoperatively and during follow‐up.ResultsTwenty‐seven patients in Group FH and 33 patients in Group EM met the inclusion criteria. No significant difference was found in the demographic data of the two groups. The mean surgical time was 76.48 ± 10.73 min in Group FH and 65.61 ± 8.91 min in Group EM (P < 0.05), showing significant difference. Seven failures occurred in Group FH and two failures occurred in Group EM (P < 0.05). No relevant complications were noted. The average union time was 3.37 ± 0.49 months in Group FH and 3.39 ± 0.50 months in Group EM (P = 0.855). The mean follow‐up was 14.30 ± 2.28 months in Group FH and 15.27 ± 2.83 months in Group EM (P = 0.153). The disabilities of the arm, shoulder and hand score (DASH) score, the range of motion (checked with the constant score), and the degree of functionality were, respectively, 21.52 ± 3.23, 27.04 ± 1.84, and 81.31% ± 3.88% in Group FH and 19.09 ± 2.40, 26.18 ± 1.70, and 77.97% ± 3.91% in Group EM (P = 0.233, 0.971, and 0.607).ConclusionThe electromagnetic real‐time targeting system reduced surgical time and improved accuracy, and there was no radiation exposure in the distal locking procedure for humeral shaft fractures.

Trial of a Distal Targeting System for Cephalomedullary Nails as Part of Surgical Repair of Hip and Femoral Shaft Fractures

Trial of a Distal Targeting System for Cephalomedullary Nails as Part of Surgical Repair of Hip and Femoral Shaft Fractures

Development of piriform cortex interhemispheric connections via the anterior commissure: progressive and regressive strategies.

The anterior commissure (AC) is a phylogenetically conserved inter-hemispheric connection found among vertebrates with bilateral symmetry. The AC connects predominantly olfactory areas but many aspects of its development and structure are unknown. To fill this gap, we investigated the embryonic and postnatal development of the AC by tracing axons with DiI and the piggyback transposon multicolor system. With this strategy, we show that axon growth during establishment of the AC follows a strictly regulated timeline of events that include waiting periods ("regressive strategies") as well as periods of active axon outgrowth ("progressive strategies"). We also provide evidence that these processes may be regulated in the midline via overexpression of chondroitin sulfate proteoglycans. Additionally, we demonstrate that the ipsi- and contralateral innervation of piriform cortex occurs simultaneously. Morphologically, we found that 20% of axons were myelinated by postnatal day (P) 22, in a process that occurred fundamentally around P14. By immunohistochemistry, we described the presence of glial cells and two new subtypes of neurons: one expressing a calretinin (CR)-/MAP2+ phenotype, distributed homogeneously inside the AC; and the other expressing a CR+/MAP2+ phenotype that lies beneath the bed nucleus of the stria terminalis. Our results are consistent with the notion that the AC follows a strictly regulated program during the embryonic and postnatal development similarly to other distal targeting axonal tracts.

Electromagnetic distal targeting system does not reduce the overall operative time of the intramedullary nailing for humeral shaft fractures

IntroductionWe aimed to evaluate the efficacy of the use of the electromagnetic distal targeting system in treating humeral shaft fracture. MethodsPatients were divided in: Group 1) patients that received a distal locking screw placement following the free-hand technique; Group 2) patients in which the distal locking screw was performed using the SURESHOT device. ResultsNo differences were noted comparing Group 1 (freehand) [71,9 range 40–135 min] to Group 2 (SURESHOT)[70, range 25–125 min]. ConclusionThe use of the EM distal targeting system doesn't reduce the overall operative time of the humeral shaft fracture fixation using IMN.

The application of distal aiming system in humeral intramedullary nailing

Objective To investigate the value of electromagnetic field real-time system (EFRTS) in the distal locking of intramedullary nailing for humeral shaft fractures. Methods From April 2015 to January 2017, data of 32 consequent patients with humeral shaft fracture (22 males, 10 females; ranged from 18 years to 78 years old, average of 40.4 years; 9 domestic falls, 15 traffic accidents, 6 fall from height, and 2 sports injury; AO12 A1: 9 cases; A2: 14 cases; A3: 4 cases; B2: 5 cases) were retrospectively analyzed. All were treated with Humeral Antegrade Locking Nail. For inserting the two distal locking screws, the SURESHOT Distal Targeting System was used. Results Accurate placement of the distal screws was accomplished in all 32 cases, which meant one drilling and one screw locking. The mean duration of the two distal screw locking was 197±30 s (range, 156-253 s) in the preparation phase and 393±39 s (range, 336-481 s) in the operation phase. The mean follow-up period was 18 months, ranging from 11 to 25 months. All the fractures were healed in an average time of 15.9 weeks, ranging from 12 to 20 weeks. The range of motion was: 80° to 180° in abduction (155° in average), 80° to 180° in anteflexion (160° in average), 60° to 100° in external rotation (80° in average), and 17 cases internal rotation to L3 level, 10 to T12 level and 5 to T7 level. The mean score of Constant-Murley was 89, ranging from 74 to 96. All the patients obtained good results. 27 patients restored self-care ability within 3 months after surgery. Shoulder discomfort occurred in 2 patients because of nail tail outside the articular surface. The symptom recovered after removal of the nail as well as joint release in arthroscopy. Conclusion The distal aiming device can be used in humeral intramedullary nailing, by which the distal screw can be inserted by one time. Meanwhile, it has the advantages of short time-consuming, secure operation, and no X-ray radiation. Key words: Humeral fractures; Fracture fixation, intramedullary; Bone screws; Surgery, computer-assisted

Fluoroscopic freehand and electromagnetic-guided targeting system for distal locking screws of humeral intramedullary nail.

The current techniques used to lock distal screws for the nailing of long bone fractures expose the surgeons, radiologists and patients to a hearty dose of ionizing radiation. The Sureshot™ Distal Targeting System is a new technique that, with the same results, allows for shorter surgery times and, consequently, less exposure to radiation. The study was performed on 59 patients (34 males and 25 females) with a simple humerus fracture diagnosis, type 1.2.A according to the AO classification, who were divided into two groups. Group 1 was treated with ante-grade intramedullary nailing with distal locking screws inserted with a freehand technique. Group 2 was treated with the intramedullary nail using the Sureshot™ Distal Targeting System. Two intra-operative time parameters were evaluated in both groups: the time needed for the positioning of the distal locking screws and the time of exposure to ionizing radiations during this procedure. Group 2 showed a lower average distal locking time compared to group 1 (645.48″ vs. 1023.57″) and also a lower average time of exposure to ionizing radiation than in group 1 (4.35″ vs. 28.96″). The Sureshot™ Distal Targeting System has proven to be equally effective when compared to the traditional techniques, with the added benefits of a significant reduction in both surgical time and risk factors related to the exposure to ionizing radiation for all the operating room staff and the patient.

A distal-lock electromagnetic targeting device for intramedullary nailing: Suggestions and clinical experience

PurposeTo describe our clinical experience with a system named SureShot™ Distal Targeting (Smith & Nephew, Memphis, USA) based on magnetic field presence and discuss our suggestions on this technique. MethodsWe analysed prospectively 47 patients affected by humeral, tibial or femoral fractures, treated in our institution during a 3-year period of time (August 2010 to September 2013). We considered the following parameters: the time to set up, the time to position a single screw, the effectiveness of the system (drilling ad screwing), the irradiation exposure time during distal locking procedure and surgical complications. ResultsA total number of 96 screws were inserted. The mean preparation time of the device was 5.1 min ± 2 min (range 3–10 min). The mean time for single screw targeting was 5.8 min ± 2.3 min (range 4–18 min). No major complications occurred. Only a few locking procedures were needed to be practiced in order to obtain the required expertise with this targeting device. ConclusionAccording to our results, this device is reliable and valid whenever the correct technique is followed. It is also user friendly, exposes to lower radiation and needs less surgical time compared to relative data from the literature. However, the surgeon should always be aware of how to use the free hand technique in case of malfunctioning of the system.

A New Mechanism of Receptor Targeting by Interaction between Two Classes of Ligand-Gated Ion Channels.

So far, receptor targeting mechanisms were found to involve intracellular partner proteins or supramolecular complexes that couple receptors to cytoskeletal elements and recruit them into cargo vesicles. In this paper, we describe a new trafficking mechanism for the neuronal serotonin 5-HT3A ionotropic channel receptor, in which the role of routing partner is endowed by a functionally interacting purinergic receptor: the P2X2 receptor. This work not only unveils the mechanism by which 5-HT3 receptors can reach their axonal localization required for the control of neurotransmitter release, but also suggests that, in addition to their modulatory role, the family of P2X receptors could have a previously undescribed functional role of trafficking partner proteins dynamically involved in the targeting of other receptors.

SURESHOT Distal Targeting System used for insertion of distal locking screws of tibial intramedullary nails

Objective To compare SURESHOT Distal Targeting System with free-hand technique in the distal locking process of femoral intramedullary nails. Methods From May 2013 to May 2014, we treated 42 patients with femoral shaft fracture with the SURESHOT Distal Targeting System (study group) and 44 similar patients with free-hand technique (control group) in the distal locking process of intramedullary nails. The study group had 30 males and 12 females, with a mean age of 37.5±2.8 years. By AO classification, they were 18 cases of type 32-A, 14 ones of type 32-B and 10 ones of type 32-C. The control group had 32 males and 12 females, with a mean age of 38.2±3.1 years. They were 20 cases of type 32-A, 13 ones of type 32-B and 11 ones of type 32-C. The 2 groups were compared in terms of time for distal locking, once locking rate, fluoroscopy frequency, fracture healing time, and The Hospital for Special Surgery (HSS) score. Results The time for distal locking in the study group (7.3±1.5 minutes) was significantly shorter than in the control group (10.8±2.6 minutes), the once locking rate in the study group (100% ) was significantly higher than in the control group (83% ), and the fluoroscopy frequency in the study group (1.0±0.5 times) was significantly lower than in the control group (5.0±2.3 times) (P 0.05). Conclusion Compared with free-hand technique, the SURESHOT Distal Targeting System used in the distal locking of intramedullary nails can significantly improve once locking rate, reduce distal locking time, and more importantly, decrease the radiation exposure. Key words: Femoral fractures; Fracture fixation, internal; Bone nails; Targeting system

Insertion of distal locking screws of intramedullary nails: a comparison of the free-hand technique, the distal targeting device and the SURESHOTTM Distal Targeting System

Insertion of distal locking screws of intramedullary nails: a comparison of the free-hand technique, the distal targeting device and the SURESHOT^TM Distal Targeting System

Nonlinear dendritic integration in CA1 pyramidal neurons during locomotion.

Event Abstract Back to Event Nonlinear dendritic integration in CA1 pyramidal neurons during locomotion. Jeff Magee1* and Katie Bittner1 1 Howard Hugues Medical Institute, Janelia Farm, United States Most neuronal circuits receive at least two functionally distinct input types (intrinsic vs. extrinsic; sensory vs. motor; etc). In many pyramidal neuron based microcircuits integration of these two input signals can proceed nonlinearly through the production of active dendritic voltage signals. For example, appropriately timed, perisomatically located, hippocampal (SC) and distal dendrite targeting entorhinal (EC3) input produces a distal dendritic Ca2+ plateau potential that drives burst firing output from CA1 pyramidal neurons in vitro. Related signals have been observed in neocortical pyramidal neurons. Until recently it was unknown whether these events occurred in vivo and, if so, during what behavioral states. Here we used simultaneous whole-cell patch and field potential recordings in head-fixed mice running on a linear track treadmill to study this dendritic plateau driven burst firing (plateaus) in CA1 neurons. We find that during locomotion dendritic plateau potentials occur within the neuron’s place field with initiation probability peaking near the peak of the firing field. Plateaus produce a large (32±4mV; n=12), slow (duration; 51±7ms) somatic depolarization that appears similar to that measured in vitro. Interestingly, plateaus exhibit a dramatic level of theta-phase modulation (~97%) that peaks late in the theta cycle (~330°). This late phase peak in plateau potential initiation is near the theta-phase preference of EC3 inputs, suggesting a theta-phase dependent interaction of SC and EC3 inputs. We tested this idea by manipulating the phase of SC inputs by injecting phase adjusted theta frequency currents into CA1 somas. Biasing AP firing earlier in the theta phase decreased plateau probability to ~48% of control whereas biasing AP firing later in phase increased plateau probability 276%. We next directly examined the role of EC3 inputs by inactivating the EC3 axons in CA1 via local light activation of axons expressing archaerhodopsin. This manipulation reduced the probability of plateau initiation by ~40% and decreased the duration of the plateaus ~60%. These data indicate that CA1 pyramidal cells compare theta-phase relations of SC and EC3 inputs with backpropagating action potentials acting as a link between the two isolated subcellular input integration compartments. Keywords: Ca spikes, Hippocampus, in vivo, Entorhinal Cortex, supervised learning Conference: 4th NAMASEN Training Workshop - Dendrites 2014, Heraklion, Greece, 1 Jul - 4 Jul, 2014. Presentation Type: Poster presentation Topic: dendritic integration and compartmentalization Citation: Magee J and Bittner K (2014). Nonlinear dendritic integration in CA1 pyramidal neurons during locomotion.. Front. Syst. Neurosci. Conference Abstract: 4th NAMASEN Training Workshop - Dendrites 2014. doi: 10.3389/conf.fnsys.2014.05.00020 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 11 Apr 2014; Published Online: 12 Jun 2014. * Correspondence: Dr. Jeff Magee, Howard Hugues Medical Institute, Janelia Farm, Ashburn, VA, United States, mageej@janelia.hhmi.org Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Jeff Magee Katie Bittner Google Jeff Magee Katie Bittner Google Scholar Jeff Magee Katie Bittner PubMed Jeff Magee Katie Bittner Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Distal targeting device for long Gamma nail®. Monocentric observational study

Intramedullary nail distal locking screws make it possible to control length and rotation but include an increased risk of radiation exposure. A distal targeting device was recently developed for long Gamma(®) nails (Stryker(®)). The aim of this practical observational study was to evaluate the reliability of this system. Our hypothesis was that the targeting device would be systematically used without conversion or complications. All of the long Gamma(®) nails implanted between November 2011 and October 2012 were recorded: 91 nails (59W/32M, mean age 73.5years old) for 68 traumatic fractures, 14 preventive nailings and nine pathological fractures. A junior surgeon performed the procedure in 45 cases and a senior in 46 cases. The number of times the device was used, the difficulties and complications encountered, the duration of fluoroscopy and the dose of radiation were noted. Risk factors were looked for. The targeting device was used 79 times (the surgeon chose not to use it 11 times, and it was not available in one case). There was a measurement error in one case, therefore 78 nails could be evaluated. Three wrong positions of the distal locking screw occurred. No statistically significant risk factors were identified. Distal locking screw corresponded to 18% of the entire procedure at a radiation dose of 7.44% (this was higher with titanium nails and pathological fractures). Total fluoroscopy time was longer with junior than with senior surgeons but the dose and duration for distal locking were not different. The hypothesis was not confirmed. The device was not systematically used and the risk of complications was not null. No risk factors were identified. The distal locking screw is a difficult step but the use of the targeting device can limit the dose of radiation. This device is effective and allows young surgeons to perform distal locking without increasing the dose of radiation compared to senior surgeons. Level IV, cohort study, observational prospective follow-up.

Insertion of distal locking screws of tibial intramedullary nails: A comparison between the free-hand technique and the SURESHOT™ Distal Targeting System

IntroductionPositioning of the distal locking screws of an intramedullary nail is often challenging and time consuming because of difficult localisation of the distal locking holes, potential screw malalignment and nail deformation during insertion. The standard free-hand technique under fluoroscopic control involves considerable radiation exposure of both the patient and the surgical team. In this study, we aimed to compare the free-hand technique with a new system that utilises electromagnetic (EM) tracking data (SURESHOT™ Distal Targeting System) to localise distal locking holes. Material and methodsPatients admitted from March 2010 to January 2013 for tibial fracture that required intramedullary nailing were analysed retrospectively. We compared intraoperative radiation exposure time and distal locking time in patients treated with the standard free-hand technique and distal locking using the EM field-generating device. Intraoperative radiation exposure time and distal locking time were used for comparison. ResultsData from a total of 50 patients were analysed. The standard free-hand technique and the EM field-generating device were used in 25 (group 1) and 25 (group 2) patients, respectively. Mean distal locking time was 1258.6 (450–2289) s in group 1 and 603.5 (360–1140)s in group 2. Mean radiation exposure time was 19.4 (6–33) s in group 1 and 4.6 (1–10) s in group 2. ConclusionThe EM field-generating device significantly reduces distal locking time and, more importantly, significantly decreases duration of exposure to ionising radiation.

Distal Targeting of Screws Through Nails without X-Rays

Distal Targeting of Screws Through Nails without X-Rays