Placement Of Instrumentation Research Articles

Transoral Endoscopic Thyroidectomy Vestibular Approach for Thyroid Lobectomy.

The manuscript describes the transoral endoscopic thyroidectomy vestibular approach (TOETVA) for thyroid lobectomy. The patient is placed in the supine position with extension and fixation of the neck. One 20 mm transverse incision and two 5 mm incisions are made through the mucosa of the oral vestibule for camera and instrument placement after disinfection of the skin and oral cavity. The workspace is established and maintained by the skin suspension device, which is made of unabsorbable string (3-0) and rubber bands, and the CO2 insufflation pressure. Lobectomy using a medial-to-lateral technique and prophylactic ipsilateral central neck dissection is performed simultaneously on patients with papillary thyroid cancer (PTC). The specimen is extracted through the 20 mm incision. The parathyroid gland is immediately searched for in the specimen and auto-transplanted to the left brachioradialis. A drainage tube is inserted through the retractor hole into the bed of the thyroid gland, and absorbable sutures are used to close the mucosal incisions in the oral vestibule and the linea alba cervicalis. Prophylactics administered intravenously are recommended for the first 24 h after surgery, and oral antibiotics are used for 7 days postoperatively.

Surgical management of lumbosacral and sacral fractures: roles of the pelvic and spinal surgeons.

In young patients, lumbosacral fractures result primarily from high-energy traumas. Life-threatening lesions (e.g. visceral organs) are frequently associated with these fractures. Management consists of medical intensive care for adequate resuscitation and specialized surgical input. Lumbosacral junction represents a frontier between the spine and pelvic ring. Any injury in this area implies a thorough examination of both spine and pelvis through clinical examinations and CT scans. Patients must be assessed specifically for neurological and bladder/bowel symptoms. Several surgical classifications may be required to describe the entire fracture pattern. In unstable fracture with large displacements, definitive surgical fixation is often recommended. Various pelvic and spine surgery techniques can be used depending on the fracture pattern, surgeon's experience, and available equipment. The use of intraoperative navigation may enhance placement of instrumentation, especially in cases of complex fractures, percutaneous fixations, and/or atypical patients' anatomy. The fracture itself can cause debilitating complications with long-term consequences such as pain, neurological deficits, and bladder/bowel impairments. Wound infection remains the most common postoperative complication and prominent posterior instrumentation is frequently a source of pain. Irrespective of the treatment, leg discrepancy can be problematic in the case of malunion. Management of lumbosacral fractures requires a thorough understanding of both lumbar spine and pelvic injuries. Surgical treatment may involve a combination of spine and pelvic surgery techniques. Therefore, this implies for the surgeon to be trained specifically for these fractures, or else a close cooperation between the pelvic surgeon and the spine surgeon in managing the patients.

357 Image-Guided Farlateral Lumbar Foraminotomy and Microdiscectomy: Operative Technique and Outcomes

INTRODUCTION: Three dimensional image-guidance is frequently used to improve the safety of complex spine surgeries. Its adoption remains mostly limited as and aid with instrumentation placement. METHODS: We performed a retrospective chart review of image-guided farlateral foraminotomies and microdiscectomies performed by a single surgeon from January 2018 to July 2021. Demographics, operative times and outcomes were collected. The stealth reference arc is fixated on the patient's skin using the Ioband. The O-arm is used to perform an intraoperative CT-scan automatically registered to the image-guided system. The location of the paraspinal incision is ascertained using the image-guided dilator to allow adequate trajectory to the neural foramen that minimizes the amount of facet joint that needs to be removed. The foraminotomy and/or discectomy is accomplished using microsurgical technique. Image guidance can be used to help guide the foraminotomy. RESULTS: 20 patients were included in our study; 14 (70%) underwent image-guided farlateral microdiscectomy and 6 (30%) foraminotomy. The most common microdiscectomy level was L5-S1 (50%). Mean age was 66 ± 10.2 (SD) years; 16(80%) were male; BMI 27.5 ± 3 kg/m2;. Total procedure time was 117.4 ± 24.6 minutes; OR time 172.5 ± 22.5 minutes; EBL 21.5 ± 16.6 ml. Average length of stay 0.85 ± 0.6 days, with 5 (25%) discharge on the same day; all patients were discharged home. We did not observe intraoperative complications; all patients reported significant improvement of their presenting symptoms. Mean follow-up was 19.4 ± 28.7 months. CONCLUSIONS: FDA-approved use of spinal image-guidance requires a reference arc to be attached to the bony spine. Our technique of attaching the reference arc to the skin is an off-label use, we do not recommend it for instrumentation placement as there is mild navigation inaccuracy (2-3 mm). This technique allows for general accuracy to ascertain the location of the incision and trajectory and can help guide the foraminotomy.

Application of PDCA to Reduce Sharp Object Injuries

<p>目的：降低牙科尖銳物扎傷，以提升安全的工作環境。方法：經專案小組重新修訂污染器械處理標準作業流程、舉辦在職教育、拍攝影片「照顧病患，更要保護 自己」宣導、調整洗牙器械擺放位置、制定標語口號「給我3分鐘，給你下一台」。結果：由改善前佔全院16.7%，改善後降低至0%，整體降低69.4%。結論：經實施對策後，能有效降低牙科尖銳物扎傷，將原有高風險環境再造改良後降低同仁傷害，日後仍需持續營造安全的工作環境。</p> <p> </p><p>Objective: To promote a safe workplace in hospital dentistry department by minimizing injuries caused by sharp objects. Methods: A task force revised the standard operating procedures for the handling of contaminated equipment and instruments, conducted on-the-job training, produced a promotional film titled “Caring for Patients, but Protecting Yourself,” rearranged the placement of dental cleaning instruments and tools in the clinic, and created the slogan “Give me three minutes, then the bench is yours.” Results: The sharp object injury incidence rate in the dentistry department dropped from 16.7% to 0%, resulting in a decrease of 69.4% in the overall hospital incidence rate. Conclusions: Following the interventions of this study, the number of sharp object injuries in the dentistry department was reduced, and the previously high-risk work environment was improved, which minimized staff exposure to hazards. Nevertheless, continuous efforts are necessary to foster a safe workplace.</p> <p> </p>

Source-detector trajectory optimization for CBCT metal artifact reduction based on PICCS reconstruction.

Precise instrument placement plays a critical role in all interventional procedures, especially percutaneous procedures such as needle biopsies, to achieve successful tumor targeting and increased diagnostic accuracy. C-arm cone beam computed tomography (CBCT) has the potential to precisely visualize the anatomy in direct vicinity of the needle and evaluate the adequacy of needle placement during the intervention, allowing for instantaneous adjustment in case of misplacement. However, even with the most advanced C-arm CBCT devices, it can be difficult to identify the exact needle position on CBCT images due to the strong metal artifacts around the needle. In this study, we proposed a framework for customized trajectory design in CBCT imaging based on Prior Image Constrained Compressed Sensing (PICCS) reconstruction with the goal of reducing metal artifacts in needle-based procedures. We proposed to optimize out-of-plane rotations in three-dimensional (3D) space and minimize projection views while reducing metal artifacts at specific volume of interests (VOIs). An anthropomorphic thorax phantom with a needle inserted inside and two tumor models as the imaging targets were used to validate the proposed approach. The performance of the proposed approach was also evaluated for CBCT imaging under kinematic constraints by simulating some collision areas on the geometry of the C-arm. We compared the result of optimized 3D trajectories using the PICCS algorithm and 20 projections with the result of a circular trajectory with sparse view using PICCS and Feldkamp, Davis, and Kress (FDK), both using 20 projections, and the circular FDK method with 313 projections. For imaging targets 1 and 2, the highest values of structural similarity index measure (SSIM) and universal quality index (UQI) between the reconstructed image from the optimized trajectories and the initial CBCT image at the VOI was calculated 0.7521, 0.7308 and 0.7308, 0.7248 respectively. These results significantly outperformed the FDK method (with 20 and 313 projections) and the PICCS method (20 projections) both using the circular trajectory. Our results showed that the proposed optimized trajectories not only significantly reduce metal artifacts but also suggest a dose reduction for needle-based CBCT interventions, considering the small number of projections used. Furthermore, our results showed that the optimized trajectories are compatible with spatially constrained situations and enable CBCT imaging under kinematic constraints when the standard circular trajectory is not feasible.

Hybrid of Smith-Peterson and Watson-Jones minimally invasive direct anterior approach to the hip joint

BackgroundMuscle-sparing techniques, more consistent acetabular component positioning with fluoroscopy guidance, development in implants and instrumentation, expedited rehabilitation, and patients’ expectations have led to increased utilization of various direct anterior and anterolateral approaches to the hip joint.Methods and surgical techniqueIn this technical note, we demonstrate for the first time a hybrid modification of traditional Smith-Peterson and Watson-Jones approaches to the hip joint on a standard operating room (OR) table.ConclusionsAs demonstrated in this article, a precise knowledge of anatomy and clear goals in the surgical approach can minimize complications and facilitate visualization and instrumentation placement in the “direct anterior approach” to the hip joint.

Routine postoperative computed tomography (CT) scans following acetabulum open reduction internal fixation (ORIF): A survey of orthopaedic traumatologists

ObjectiveThe purpose of this study was to assess the practices related to obtaining postoperative pelvic CT scans following acetabular ORIF and revision surgery rates. DesignA 20-question survey published on the Orthopaedic Trauma Association (OTA) website assessed each surgeon's preference and rationale for or against the routine use of postoperative CT scans for acetabular fractures. ParticipantsFellowship-trained orthopaedic traumatologists. Main outcome measurementsWe examined the percentage of surgeons ordering routine postoperative CT scans, surgeon demographics, and revision surgery rates based on these routine CT scan results. ResultsResponses were received from 57 surgeons. Practices varied regarding postoperative CT scans, with 16 surgeons (28%, Group A) routinely ordering them and 41 surgeons (72%, Group B) not ordering them on all patients. No significant difference in surgeon demographics were found between the groups. Majority of Group A report a revision surgery rate of <1% based on the results of the postoperative CT.Group A report routine postoperative scans were obtained to assess reduction, hardware placement, identify intra-articular fragments, and for educational purposes. Group B did not obtain routine postoperative CTs due to the following: unlikely to change postoperative treatment, adequate reduction and instrumentation placement assessed intraoperatively and by postoperative radiographs, and increased radiation exposure and cost to patients. Group B did report obtaining postop CT scans on select patients, with inadequate intraoperative imaging and postoperative neurological changes being the most common indications. ConclusionThe routine use of postoperative CTs following open reduction internal fixation of acetabular fractures is a controversial topic. While we recognize the role for postoperative CT scans in select patients, our study questions the clinical utility of these scans in all patients and in conclusion do not recommend this protocol.

Thermal environment of the Chang&amp;rsquo;E-5 landing site and its effect on the external temperature of the lander

<p indent="0mm">The thermal environment of the lunar surface is extremely important to the thermal design of the lander, the placement of the detection instruments, and the interpretation of scientific exploration data. Clarifying the source and intensity of radiation on the outer surface of the lander is the key to its thermal management. In this paper, we first reported continuous temperature records over a 47.2 h period from five thermal couple sensors mounted on the auxiliary pillars of the landing gear of Chang’E-5 (CE-5). The recorded temperatures varied from a relatively small range of <sc>245.68–272.52 K</sc> at the beginning to a considerably wider range of <sc>284.86–369.76 K</sc> at the end of the recording period. To analyze the obtained CE-5 temperature records, we first developed a lunar surface thermal environment model with a layered regolith and temperature-dependent thermal physical properties. The model calculated that the ambient temperature of the CE-5 landing site over the sensor recording period increased from 341.40 to <sc>356.15 K.</sc> The calculated temperature was comparable to the estimates based on the <italic>in</italic>-<italic>situ</italic> spectral measurement, whereas it was systematically <sc>6–12 K</sc> higher than Diviner thermal infrared brightness temperature. We further developed a heat conduction model of the sensor-mounted auxiliary pillar and considered the surface temperature and the pillar geometry with respect to the Sun’s and the Earth’s orbital parameters. By introducing an impact factor<italic> F</italic> and via trial and error, we fitted the five CE-5 lunar temperature records with the RMESs of 0.72, 2.14, 0.53, 1.35, and <sc>3.36 K,</sc> respectively. Our analysis showed that the lunar surface thermal environment has a significant effect on the temperatures of both the shaded and sunny sides of the lunar lander. The environmental impact on the shaded side even exceeds that on the sunny side during the CE-5 recording period. The results of this paper are of great significance to both the theoretical research on the mechanism of the lunar thermal environment and the engineering applications in the thermal management design of a lunar lander, site selection of a lunar exploration mission, and temperature-related data interpretations, such as <italic>in</italic>-<italic>situ</italic> spectral data analysis.

Using Team Resource Management and Situational Simulation to Improve the Resuscitation Performance Completion Rate

Cardiopulmonary resuscitation is an important issue in patient safety. After investigation, we identified the causes of the low rate of resuscitation completion in our emergency department as: incomplete utilization of available first-aid equipment, lack of standards related to task allocation, unclear moving line and instrument placement, lack of teamwork, and poor resuscitation-related communications during the COVID-19 pandemic. The project aimed to improve the resuscitation performance completion rate. The project included designing equipment reminder cards and an airway car, designating specific responsibilities for each team member, establishing standard layouts and traffic flows, and providing situational simulation and team resource management training. After the intervention, the resuscitation performance completion rate had risen to 91.6% from the pre-intervention rate of 69.1%. This has since further risen to a relatively constant completion rate of 98.1%. The implementation of the team resource management and situational simulation training intervention in our ED improved both the resuscitation completion rate and the rate of return of spontaneous circulation (ROSC).

Radiophysical methods in the remote study of the dry soils layered structure

The necessity of joint use of radar instruments and microwave radiometers in the study of the structure and composition of the interior of the Moon is substantiated. Radar allows you to study a layer of soil up to 3 km thick, but the upper thin layers will be transparent to this instrument. The radiometer makes it possible to study the upper layer up to 1-2 m thick. The combination of the results of measuring with two instruments allows obtaining more detailed information about the structure and dielectric properties of the soil. The placement of instruments on board the orbital space module provides a fast and large-scale study of the space body. The paper presents the results of numerical simulation of the problem. The thickness of the thermal insulation ground layer, frequency of the radio waves; thickness and density of the regolith; the temperature on the surface of the Moon are taken into account for simulation. The proposed method can be used to study the soils of Mars and the Earth in dry desert regions.

Basis for error in stereotactic and computer-assisted surgery in neurosurgical applications: literature review.

Technological advancements in optoelectronic motion capture systems have allowed for the development of high-precision computer-assisted surgery (CAS) used in cranial and spinal surgical procedures. Errors generated sequentially throughout the chain of components of CAS may have cumulative effect on the accuracy of implant and instrumentation placement - potentially affecting patient outcomes. Navigational integrity and maintenance of fidelity of optoelectronic data is the cornerstone of CAS. Error reporting measures vary between studies. Understanding error generation, mechanisms of propagation, and how they relate to workflow can assist clinicians in error mitigation and improve accuracy during navigation in neurosurgical procedures. Diligence in planning, fiducial positioning, system registration, and intra-operative workflow have the potential to improve accuracy and decrease disparity between planned and final instrumentation and implant position. This study reviews the potential errors associated with each step in computer-assisted surgery and provides a basis for disparity in intrinsic accuracy versus achieved accuracy in the clinical operative environment.

Magnetic Catheter Placement in Neonates: A Handheld Solution to Radiation Exposure and Operational Delays

AbstractThe use of subcutaneous devices has greatly advanced the field of medicine and surgery. However, localizing these devices internally requires imaging techniques such as X‐ray or ultrasound. A novel magnetic tracking system for subcutaneous medical devices is presented, providing the capability for precise device localization in an extremely compact and portable pocket‐size format. It is entirely benign, avoids X‐rays, and can be used to immediately confirm the proper instrument placement. It is implemented on umbilical catheters and endotracheal tubes and is characterized by bench‐test, cadaveric, and in vivo studies. The systems consist of a magnetic tip fixed to the distal end of the subcutaneous device, as well as a Magnetic Sensing‐Array Device that utilizes a matrix of magnetic field sensors to localize the magnetic tip. The bench‐tests show a high localization accuracy for a distance up to 4 cm. The accuracy is slightly reduced during cadaveric and in vivo tests, due to factors impacting the application, such as the dermal surface topography. Regardless, the magnetic subcutaneous medical device tracking system is shown to be robust in performance and functionality in real‐world clinical applications, and with its intuitive approach and portability, it has the potential to make real‐time subcutaneous device tracking widely accessible.

Risk Factors for the Drift Phenomenon in O-arm Navigation-Assisted Pedicle Screw Placement during Spinal Deformity Surgery.

Intraoperative O-arm navigation systems improve the accuracy of spinal instrumentation placement. However, deviation of the pedicle screw from the guide line might occur. The aim of the present study was to explore the causes of and countermeasures for the drift phenomenon during pedicle screw implantation with the aid of an O-arm three-dimensional navigation system in spinal deformity surgery. This was a retrospective analysis of 341 patients with spinal deformity who underwent O-arm navigation system-assisted pedicle screw placement from July 2015 to June 2019. The patient's general condition, Cobb angle, apical vertebra position, softness index, spinal release status, fixed reference frame position, and distance between the navigation vertebral body and the reference frame were collected and compared by independent-samples t test or Pearson's chi-square analysis. The potential risk factors for the drift phenomenon were identified using binary logistic regression analysis. The drift phenomenon occurred in 57 patients during the first navigation-assisted pedicle screw placement, for an incidence of 16.7% (57/341). There were significant differences in factors such as the apical vertebra position, softness index, spinal release status, and distance between the vertebral body and the reference frame when the drift phenomenon occurred (P < 0.05). Binary logistic regression analysis showed that the softness index, spinal release status, and distance between the vertebral body and the reference frame when drifting occurred were independent risk factors for the drift phenomenon during O-arm navigation-assisted pedicle screw placement. During the use of an O-arm navigation system to assist with pedicle screw placement, pedicle screws should not be placed away from the reference frame, and spinal osteotomy and release should be performed after pedicle screw placement. In addition, the accuracy of O-arm navigation-assisted pedicle screw placement will be affected more in those with larger softness indices.

Development of the Student Nurse Subjective Evaluation of Completed Clinical Practice Placement Instrument.

Instruments that measure clinical learning environments have lacked rigorous methodological approaches in their development and validity. Development research using a survey design approach was conducted for an instrument to evaluate the quality of nursing students' clinical practice placement. The development and validity of the Student Nurse Subjective Evaluation of Completed Clinical Practice Placement (SNEP) resulted in a 40-item instrument to evaluate nursing students' experience of their completed clinical practice placement. Adequate level of model fit was indicated (χ2[719] = 1909.47, p < .001) for the confirmatory factor analysis (χ2/df = 2.66, comparative fit index = 0.92, Tucker-Lewis Index = 0.92, and root-mean-square error of approximation = 0.07). Standardized factor loadings were high, ranging from 0.68 to 0.95. The SNEP was designed and validated incorporating the perspective of various nurse stakeholders and can be used in both research and clinical learning environments. [J Nurs Educ. 2022;61(10):559-569.].

Augmented reality in minimally invasive spine surgery: early efficiency and complications of percutaneous pedicle screw instrumentation

Augmented reality (AR) employs an optical projection directly onto the user's retina, allowing complex image overlay on the natural visual field. In general, pedicle screw accuracy rates have improved with increasingly use of technology, with navigation-based instrumentation described as accurate in 89%-100% of cases. Emerging AR technology in spine surgery builds upon current spinal navigation to provide 3-dimensional imaging of the spine and powerfully reduce the impact of inherent ergonomic and efficiency difficulties. This publication describes the first known series of in vivo pedicle screws placed percutaneously using AR technology for MIS applications. After IRB approval, 3 senior surgeons at 2 institutions contributed cases from June, 2020 - March, 2022. 164 total MIS cases in which AR used for placement of percutaneous pedicle screw instrumentation with spinal navigation were identified prospectively. 155 (94.5%) were performed for degenerative pathology, 6 (3.6%) for tumor and 3 (1.8%) for spinal deformity. These cases amounted to a total of 606 pedicle screws; 590 (97.3%) were placed in the lumbar spine, with 16 (2.7%) thoracic screws placed. Patient demographics and surgical metrics including total posterior construct time (defined as time elapsed from preincision instrument registration to final screw placement), clinical complications and instrumentation revision rates were recorded in a secure and de-identified database. The AR system used features a wireless headset with transparent near-eye display which projects intra-operative 3D imaging directly onto the surgeon's retina. After patient positioning, 1 percuntaneous and 1 superficial reference marker are placed. Intra-operative CT data is processed to the headset and integrates into the surgeon's visual field creating a "see-through" 3D effect in addition to 2D standard navigation images. MIS pedicle screw placement is then carried out percutaneously through single line of sight using navigated instruments. Time elapsed from registration and percutaneous approach to final screw placement averaged 3 minutes and 54 seconds per screw. Analysis of the learning curve revealed similar surgical times in the early cases compared to the cases performed with more experience with the system. No instrumentation was revised for clinical or radiographic complication at final available follow-up ranging from 6-24 months. A total of 3 screws (0.49%) were replaced intra-operatively. No clinical effects via radiculopathy or neurologic deficit postoperatively were noted. This is the first report of the use of AR for placement of spinal pedicle screws using minimally invasive techniques. This series of 164 cases confirmed efficiency and safety of screw placement with the inherent advantages of AR technologies over legacy enabling technologies.

Applying 3-Dimensional Printing and Modeling for Preoperative Reconstruction and Instrumentation Placement Planning in Complex Deformity Surgery.

Advances in three-dimensional (3D) printing technology have enabled the development of customized instrumentation and surgical training platforms. However, no existing studies have assessed how patient-specific 3D-printed spine models can facilitate patient education and operative planning in complex spinal deformity correction. To present a cost-effective technique for constructing personalized 3D-printed spine models for patients with severe spinal deformities and to outline how these models can promote informed consent, trainee education, and planning for instrumentation placement and alignment correction. We present 2 patients who underwent surgical correction of progressive thoracolumbar deformities. Full-scale 3D-printed models of each patient's spine were produced preoperatively and used during clinic evaluations, surgical planning, and as intraoperative references. Each model took 9 days to build and required less than 60 US dollars of material costs. Both patients were treated with a posterior approach and contiguous multilevel osteotomies. Postoperatively, their alignment parameters and neurological deficits improved. Personalized 3D-printed spine models can aid in patient education, surgical training, visualization, and correction of complex spinal deformities.

Optimisation of satellite geometries in Very Low Earth Orbits for drag minimisation and lifetime extension

The utilisation of the Very Low Earth Orbit (VLEO) region offers significant application specific, technological, operational, and cost benefits. However, attaining sustained and economically viable VLEO flight is challenging, primarily due to the significant, barely predictable and dynamically changing drag caused by the residual atmosphere, which leads to a rapid deterioration of any spacecraft’s orbit unless mitigated by a combination of active and passive techniques. This article addresses one passive method by optimising satellite shapes in order to achieve a minimisation of the atmospheric drag force and thus extension of operational lifetime. Contrary to previous investigations in the field, a constant internal volume is maintained to account for the placement of satellite instruments and payload inside the structure. Moreover, the satellite geometry is not varied heuristically but optimised, via a numerical 2D profile optimisation specifically developed for this purpose. From the resulting optimal satellite profiles, 3D satellite bodies are derived, which are then verified via the Direct Simulation Monte Carlo method within the open-source particle code PICLas. In addition, rather unconventional designs, i.e. ring geometries, which are based on the assumption of fully specular particle reflections, are proposed and assessed. The optimised satellite geometries offer pure passive lifetime extensions of up to 46% compared to a slender reference body, while the above-mentioned ring geometries achieve passive lifetime extensions of more than 3000%. Finally, the article presents design recommendations for VLEO satellites in dependence of different surface properties.

Marker-Based Method for Analyzing the Three-Dimensional Upper Body Kinematics of Violinists: Reproducibility.

Recently, Wolf et al. proposed a novel, marker-based method to analyze the three-dimensional upper-body kinematics of high string players for clinical application. The method provides an objective evaluation of high string players' motor strategies, especially in the shoulder complex, by distinguishing between the scapulothoracic (ST) and glenohumeral (GH) joints, while minimizing skin movement artifacts, marker occlusions, and limitations due to instrument placement. Nevertheless, reproducibility of kinematic measurements is crucial for clinical applications. The aim of this study was to assess the method's reproducibility in terms of reliability and repeatability. One healthy professional violinist underwent a total of nine bowing trials in three different laboratory sessions. Each trial was conducted by one of two different examiners. A biomechanical model was applied to motion capture data of the pelvis, thorax, spine, and head, as well as both upper limbs (consisting of the scapula, upper arm, forearm and hand). Reproducibility was assessed by calculating inter- and intra-tester, inter-session, and intra-subject measurement errors for each rotational degree of freedom in the upper-body segments and joints. Small measurement errors were accepted to be good indicators for reproducibility. Intra- and inter-tester errors were found to be small (< 3° for the most part). Both inter-session and intra-subject repeatability were found to be larger (< 5° for the most part). This study generally showed the novel, marker-based method to have good reproducibility for a healthy violinist. This indicates that the proposed method is a reliable tool for quantifying upper-body movements during violin playing across subjects, examiners, laboratories, and motion capture systems.

Preclinical evaluation of a prototype freehand drill video guidance system for orthopedic surgery.

Purpose: Internal fixation of pelvic fractures is a challenging task requiring the placement of instrumentation within complex three-dimensional bone corridors, typically guided by fluoroscopy. We report a system for two- and three-dimensional guidance using a drill-mounted video camera and fiducial markers with evaluation in first preclinical studies. Approach: The system uses a camera affixed to a surgical drill and multimodality (optical and radio-opaque) markers for real-time trajectory visualization in fluoroscopy and/or CT. Improvements to a previously reported prototype include hardware components (mount, camera, and fiducials) and software (including a system for detecting marker perturbation) to address practical requirements necessary for translation to clinical studies. Phantom and cadaver experiments were performed to quantify the accuracy of video-fluoroscopy and video-CT registration, the ability to detect marker perturbation, and the conformance in placing guidewires along realistic pelvic trajectories. The performance was evaluated in terms of geometric accuracy and conformance within bone corridors. Results: The studies demonstrated successful guidewire delivery in a cadaver, with a median entry point error of 1.00mm (1.56mm IQR) and median angular error of 1.94deg (1.23deg IQR). Such accuracy was sufficient to guide K-wire placement through five of the six trajectories investigated with a strong level of conformance within bone corridors. The sixth case demonstrated a cortical breach due to extrema in the registration error. The system was able to detect marker perturbations and alert the user to potential registration issues. Feasible workflows were identified for orthopedic-trauma scenarios involving emergent cases (with no preoperative imaging) or cases with preoperative CT. Conclusions: A prototype system for guidewire placement was developed providing guidance that is potentially compatible with orthopedic-trauma workflow. First preclinical (cadaver) studies demonstrated accurate guidance of K-wire placement in pelvic bone corridors and the ability to automatically detect perturbations that degrade registration accuracy. The preclinical prototype demonstrated performance and utility supporting translation to clinical studies.

216. The arrival of augmented reality in MIS: initial results of use for percutaneous pedicle screw instrumentation

<h3>BACKGROUND CONTEXT</h3> Augmented reality (AR) employs computer-generated sensory inputs to enhance the user's perception of his or her environment. Pedicle screw instrumentation has become a mainstay of spinal stabilization. In general, pedicle screw accuracy rates have improved with increasing use of technology; navigation-based instrumentation have been described as accurate in 89-100% of cases. Some inherent difficulties persist with regards to ergonomics and efficiency of spinal navigation. Traditional navigation requires removing focus from the surgical field to interpret and coordinate input of external visual data. Line-of-sight disturbance and attention-shift has known impact on cognitive load and optimization of workflow in surgery. Emerging AR technology in spine surgery aims to reduce the impact of these pitfalls. <h3>PURPOSE</h3> To describe the first known series of in vivo pedicle screws placed percutaneously using AR technology for minimally invasive surgery (MIS) applications. <h3>STUDY DESIGN/SETTING</h3> After IRB approval, three senior surgeons at two institutions collected cases from June, 2020 - October, 2021, in which AR was used for placement of percutaneous pedicle screw instrumentation. <h3>PATIENT SAMPLE</h3> A total of 148 total MIS cases were studied; the average patient age was 59.7 ±13.84 and average BMI was 30.8 ±7.2. <h3>OUTCOME MEASURES</h3> Patient demographics and surgical metrics including total posterior construct time (defined as time elapsed from pre-incision instrument registration, percutaneous posterior fusion and final screw placement) were recorded. Screw revision intraoperatively after fluoroscopic evaluation and revision rates postoperatively were recorded. <h3>METHODS</h3> The xvision^TM (Augmedics Inc., Arlington Heights, IL, USA) system features a wireless headset with transparent near-eye display which projects intraoperative 3D imaging directly onto the surgeon's retina. After patient positioning, one percuntaneous and one superficial reference marker are placed. Intra-operative CT data is processed to the headset and integrates into the surgeon's visual field creating a "see-through" 3D effect in addition to 2D standard navigation images. MIS pedicle screw placement is then carried out percutaneously through single line of sight using navigated instruments. <h3>RESULTS</h3> Of the 148 cases, 139 (93.9%) were performed for degenerative pathology, 6 (4.1%) for tumor and 3 (2.0%) for spinal deformity. A total of 535 pedicle screws were placed; 519 (97.0%) lumbar and 16 (3.0%) thoracic. Eighty-four (58.8%) cases were 1-level, 42 (28.4%) were 2-level, 16 (10.8%) were 3-level and 6 (4.1%) were 4-level, equating to an average of 3.51 screws per case. A total of one screw (0.20%) was replaced intraoperatively after examining position with fluoroscopy. No instrumentation was revised postoperatively at final available follow-up ranging from 3-18 months. The mean total posterior construct time was 5 minutes and 56 seconds per screw overall; cases later in the learning curve achieved total posterior construct mean time of 2 minutes and 51 seconds per screw. <h3>CONCLUSIONS</h3> This study represents the first report of the use of AR to place MIS pedicle screws. These data support an exceedingly low rate of complications with screw placement and confirms a rapid learning curve with a high level of surgical efficiency demonstrated. These advances are achieved with an image- and implant-agnostic system which requires no physical footprint in the operating room. <h3>FDA DEVICE/DRUG STATUS</h3> xvision^TM (Augmedics Inc., Arlington Heights, IL, USA) (Approved for this indication)