Safety Of Placement Research Articles

AIRWAY MANAGEMENT OF A VALLECULAR CYST EXCISION-A NIGHTMARE TO ANAESTHETISTS

Vallecular cysts are mucus retention cyst of salivary gland and might be a cause ofobstructing the laryngeal inlet posing a threat to anaesthetist for airway management(1).We present the airway management of an adult patient with difficult airway with a large vallecular cyst. A16 year old female patient with a vallecular cyst posted for robotic assisted vallecular cyst excision under general anaesthesia. After induction of general anaesthesia, laryngoscopy was attempted with C-mac blade size-3 and no laryngeal structures were seen except the epiglottis. We were unable to lift the epiglottis to visualise the vocal cords since the cyst was present in the space between base of tongue and epiglottis. An immediate plan of fibreoptic bronchoscopy guided intubation was planned. In the meantime, patient was being ventilated by bag and mask ventilation. After placing the Fibreopticbronchoscope in the trachea just above the carina, railroading of the endotracheal tube was difficult.Hence,we decided to introduce the Video laryngoscope to visualise the passage of the endotracheal tube which was being guided by fibreopticbronchoscope. The main aim is to prevent damage to the vallecular cyst and to ensure safe placement of endotracheal tube and adequate ventilation of the patient to prevent potential airway related complications.

Confirmation of Safe Nasogastric Tube Placement: The Radiology Department’s Duties Closed Cycle Audit

The NPSA issued a patient safety alert (NPSA/2011/ PSA002) and new guidelines regarding the confirmation of safe nasogastric feeding tube placement. Between September 2005 and March 2010. There were 21 deaths and 79 cases of harm attributed to the incorrect placement of nasogastric tubes in the UK. In the NPSA report chest radiograph misinterpretation was attributed to 12 of the 21 deaths and 45 of 100 incidents. • Feeding through misplaced nasogastric tube (NGT) is a ‘Never Event’. • Associated complications: pneumonia, empyema, pneumothorax, vascular injury Aim: To evaluate the radiology department’s adherence to the national Patient Safety Agency NPSA guidelines published in 2011. We aim at 100% compliance.

Who needs Daddy Warbucks: The Kinship Guardianship Assistance Program should apply to children of those who surrender their parental rights

AbstractFamilies who find themselves in the middle of child protective proceedings have three possible outcomes: (1) the family can reunify; (2) parents voluntarily surrender their parental rights; or (3) the parents have their rights terminated. While it seems we should support children in the second and third scenarios equally, having funding sources such as the Kinship Guardianship Assistance Program (KinGAP) only available to children of parents whose rights are terminated, does the opposite. This Note proposes amending the eligibility requirements of KinGAP to include children of parents who surrender their parental rights which would encourage positive safe placements for children.

Use of a modified retrograde femoral rod as a custom length tibiotalocalcaneal nail.

There has been increasing interest in the use of hindfoot tibiotalocalcaneal (TTC) nails to treat ankle and distal tibia fractures in select patient populations who are at increased risk for soft tissue complications after open reduction and internal fixation with traditional plate and screw constructs. We describe a technique which uses a retrograde femoral nail as a custom length TTC nail. By using a simple modification of the insertion jig, we are able to achieve safe screw trajectories that allow for robust distal interlocking fixation. Review of implantation in multiple cadaveric specimens demonstrates safe placement of distal screw fixation in the calcaneus without risking injury to important neurovascular structures. Because of the 2-cm incremental length options of this particular device, we are able to achieve supraisthmal fixation in the tibia which may lessen the risk for fracture that may be more likely to occur at the tip of a short TTC nail option. Furthermore, a custom length TTC nail is more costly and also requires advanced notice to acquire for the case; retrograde femoral nails are readily stocked and accessible at our level 1 trauma center. This TTC technique offers anatomic restoration while also offering convenience, instrument familiarity, cost savings, and increased patient safety.

Spinal navigation with preoperative computed tomography

Safe placement of posterior cervical-sacral pedicle screws, S2-Ala-iliac screws, iliac screws, transarticular screws C1/2, translaminar screws C2 or cervical lateral mass screws under the guidance of spinal navigation. All posterior spinal instrumentations with screws: instabilities and deformities of rheumatic, traumatic, neoplastic, infectious, iatrogenic or congenital origin; multilevel cervical spinal stenosis with degenerative instability or kyphosis of the affected spinal segment. There are no absolute contraindications for spinal navigation. Cervical spine: Prone position on agel mattress, rigid head fixation, e.g., with Mayfield tongs; if appropriate, closed reduction under lateral image intensification; thoracic + lumbar spine: prone position on acushioned frame; midline posterior surgical approach at the level of the segments to be instrumented; if necessary, open reduction; insertion of the cervical/upper thoracic screws under the guidance of spinal navigation; if necessary, posterior decompression; instrumentation longitudinal rods; if fusion is to be obtained, decortication of the posterior bone elements with ahigh-speed burr and onlay of cancellous bone or bone substitutes. In stable instrumentations, no postoperative immobilization with orthosis is necessary, removal of drains (if used) 2-3days postoperatively (postop), removal of the sutures 14days postop, clinical and x‑ray controls 3and 12months postop or in case of clinical or neurological deterioration. Numerous studies showed that the use of spinal navigation significantly reduces implant malplacement rates, complications, and revision surgery. Furthermore, intraoperative radiation exposure to the operation team can be reduced by up to 90%.

Thoracolumbar Spinal Stabilization with Three Dimensional-Printed Drill Guides and Pre-Contoured Polyaxial Bone Plates.

The aim of this study was to report new preoperative and intraoperative techniques performed for canine thoracic or lumbar spine kyphosis stabilization using three-dimensional-printed patient-specific drill guides, polyaxial titanium bone plates and drill stops, and to determine the accuracy of screw placement using these techniques. Retrospective study, five client-owned dogs. Three-dimensional-printed patient-specific drill guides and drill stops allowed safe drilling and screw placement in all of the cases, with (i) 84% of the screws graded as I (ideal placement) and 16% as IIa, IIIa or IIIb according to the modified Zdichavsky classification (partial penetration of medial pedicle wall, partial penetration of lateral pedicle wall and full penetration of lateral pedicle wall respectively), (ii) mean mediolateral deviation of ± 4.06 degrees (standard deviation: 8.21 degrees) compared to planned trajectories and (iii) variation in screw depth of ± 2.29mm (standard deviation: 3.07mm) compared to planned depth. We believe that the techniques presented here for thoracic spinal stabilization in dogs show promise; they allowed safe placement of screws along planned trajectories and depth; they also removed the need to use polymethylmethacrylate, while the use of titanium offers the possibility to repeat magnetic resonance imaging in these cases with chronic spinal conditions.

The growing importance of ultrasonography in cosmetic dermatology: An update after the 23rd IMCAS Annual World Congress (2022).

Ultrasound (US) has been used for many years in the field of medicine. Many specialties have embraced US as a quick, painless, and relatively inexpensive tool to assist the clinician in determining anatomy, pathology, and aid in diagnostic or therapeutic procedures. US allows for precise mapping of cutaneous and subcutaneous structures in the face, in particular vascular structures. The use of US leads to reduced chances of complications and clinical failures, rendering more safety and high quality. US is considered the first-imaging technique for dealing with fillers and managing their potential complications. US can be deployed for vascular mapping, safe placement of fillers, and directed low-dose hyaluronidase reversal of vascular adverse events. It is a noninvasive imaging modality that provides a good definition for studying the skin, deeper layers, and blood flow in real time. In other words, we go from static to dynamic anatomy. In addition, US can guide with the application of botulinum toxin, in order to define the muscular planes. US may contribute to a more personalized procedure, better cosmetic results, and help to avoid complications. In general, physicians tend to use it for prevention. Last, for research purposes, US examination provides valuable information on the behavior, longevity, and interaction of the filler within the tissues. This new approach for US-guided treatments is a very practical and an effective method in cosmetic dermatology. As doctors, we owe it to our patients to do our best to prevent any harm. We feel that in near future, US will be an essential diagnostic tool in any dermatology or cosmetic doctor's office to both ensure safety and provide legal protection for the professional.

Rescue therapy for symptomatic spinal cord ischemia after thoracic endovascular aortic repair

ObjectiveSpinal cord ischemia (SCI) after thoracic endovascular aortic repair (TEVAR) can cause permanent neurologic deficits and poor long-term survival. Targeted treatment of new SCI symptoms after TEVAR (rescue therapy [RT]) might improve/resolve neurologic symptoms but few data characterize the association of specific interventions with SCI outcomes. We evaluated the effectiveness of post-TEVAR RT at our tertiary aortic center. MethodsOur institutional TEVAR database was reviewed for SCI incidence and details of RT. This included cerebrospinal fluid drainage (CSFD), medical therapy, and optimization of spinal cord oxygen delivery. SCI outcomes were categorized at discharge as paralysis/paraparesis and temporary/permanent. ResultsNine hundred forty-three TEVAR procedures were performed in 869 patients from 2011 to 2020. Post-TEVAR SCI occurred in 7.8% (n = 74) with permanent paraplegia in 1.5%. Older patient age, chronic obstructive pulmonary disease, and previous abdominal aortic surgery were predictive of SCI. Half (n = 37) of SCI episodes resulted in only temporary paralysis/paraparesis. Rescue postoperative cerebrospinal fluid drains were implanted in 3.7% (n = 35) of procedures and was predicted by higher American Society of Anesthesiologists class, lower serum hemoglobin level, elevated international normalized ratio, bilateral iliac artery occlusion, nonelective procedures, and penetrating atherosclerotic ulcer/intramural hematoma indication. The most commonly used RTs were emergent placement of or increased drainage from an existing cerebrospinal fluid drain (87.8%), induced/permissive hypertension (77.0%), corticosteroid bolus (36.5%), and naloxone infusion (33.8%). Neurologic improvement occurred in 68.9% (n = 51/74). New/increased drainage was associated with improved SCI outcome. ConclusionsPermanent paraplegia from post-TEVAR SCI is rare (1.5%). Older patients with comorbidities carry greater post-TEVAR SCI risk. SCI symptoms improved/resolved with CSFD and multimodal RT in 68.9% of patients, but no intervention was independently associated with improvement. TEVAR centers should have robust protocols for timely and safe CSFD placement to augment RT strategies for SCI.

8802 GYN 101: Introduction to Uterine Manipulators

<h3>Study Objective</h3> To understand the insertion techniques and use of various types of uterine manipulators. <h3>Design</h3> This video highlights the importance behind the use of manipulators during laparoscopy and identifies unique aspects of various types of manipulators. Additionally, we review how to properly insert and use manipulators. <h3>Setting</h3> The patient is placed in dorsal lithotomy for the video. <h3>Patients or Participants</h3> One patient is filmed to demonstrate the placement of a Fornisee manipulator for a robotic assisted total laparoscopic hysterectomy. A combination of simulation models and photographs were also utilized to review educational topics. <h3>Interventions</h3> The utility of manipulators during laparoscopy, various types of manipulators, and proper insertion techniques are reviewed. <h3>Measurements and Main Results</h3> We review how uterine manipulators assist with visualization, elevate the uterine vessels farther away from the ureters and bladder, and delineate the cervicovaginal junction assisting with colpotomy. Many manipulators have unique aspects that make them favored for specific clinical situations. This video demonstrates how extracorporeal hand movements position the uterus in an opposite fashion intra-abdominally. <h3>Conclusion</h3> It is important to know different manipulator types to tailor their use to specific clinical scenarios. Safe and accurate placement and proper movements are crucial in assisting the surgeon, especially during important dissection steps.

Surgical Management of Second Trimester Cesarean Scar Ectopic Pregnancy with Laparoscopic Wedge Resection

<h3>Study Objective</h3> To review the case of a second trimester cesarean scar ectopic pregnancy managed with laparoscopic resection in a patient with a history of renal transplant. <h3>Design</h3> Video demonstration of surgical technique with narrated description. <h3>Setting</h3> Academic tertiary care site. <h3>Patients or Participants</h3> 36yo G5P0221 found to have a 14-week cesarean scar ectopic pregnancy, desiring fertility sparing intervention. <h3>Interventions</h3> In this video, we demonstrate the case of a second trimester cesarean scar ectopic pregnancy resected laparoscopically. We illustrate several key points including: - Safe port placement in the setting of prior renal transplant - Preemptive hemostasis management with temporary uterine artery ligation - Intraoperative strategies for reducing blood loss - Considerations for management of gestational sac rupture and abdominal spill of fetal contents <h3>Measurements and Main Results</h3> A 14-week cesarean scar ectopic pregnancy was successfully resected with minimal blood loss and excellent recovery. <h3>Conclusion</h3> Laparoscopic resection can be safely and effectively utilized even for cesarean scar ectopic pregnancies of more advanced gestational ages.

Acetabulum Rekonstrüksiyonunda Erişkin İnsan Kuru Os coxae’sına ait Morfometrik Ölçümlerin Önemi

Objective: The aim of this study was to obtain morphometric measurements of adult human hip bones, examine the relationship among these measurement parameters, and develop regression equations to estimate the acetabular dimensions for acetabular reconstruction &#x0D; Material and Method: Seventy-eight (39 right and 39 left) dry hip bones of unknown age and gender located in the laboratory of Çukurova University Faculty of Medicine, Department of Anatomy, were included in the study. Eleven hip bones with fractures, deterioration, deformities, and defects that would affect the measurements were excluded from the study. In our study, 14 morphometric measurements of hip bones were obtained. IBM SPSS program was used for statistical analysis.&#x0D; Results: Single and multiple regression equations were developed from the hip bone morphometric measurements for the estimation of the morphometric measurements of the acetabulum. The standard error of estimate (SEE) values ranged from ±1.818 mm to ±3.546 mm in single regression equations, and between ±1.633 mm and ±2.107 mm in multiple regression equations. A lower SEE value was obtained in multiple regression equations than in single regression equations. &#x0D; Conclusion: The regression equations developed in this study will allow us to obtain personalized measurements, which will aid clinicians in the correct and safe placement of the implant in hip replacement surgeries as well as in the prevention of complications with the use of appropriate prostheses.

Sagittal imaging study of the lumbar spine with the short rod technique.

The short rod technique (SRT) is a novel method for lumbar pedicle screw placement to reduce surgical trauma and avoid damage to the facet joint and articular surface. The core concept is to change the entry point and angle of the screw on the vertebrae at both ends in the sagittal plane to shorten the length of the longitudinal rods. The purpose of this study is to determine the sagittal screw angle (SSA) and its safe Maximum (MAX) value on each lumbar vertebra for the SRT and to observe the shortening effect on the longitudinal rods. A total of 152 healthy adults were investigated by measuring the lumbar spine lateral view images. The SSA and MAX-SSA were measured with SRT as reference to the conventional placement technique method. The distance between the entry points of the proximal and distal vertebrae was measured to compare the changes in the length of the longitudinal rods using the two screw placement techniques. + SSA increased from L1 to L4, and -SSA increased from L2 to L5, in which the -SSA of L2, L3, and L4 were significantly greater than those of + SSA (P < 0.05). + MAX-SSA at L1-L4 was 23.26 ± 3.54°, 23.68 ± 3.37°, 24.12 ± 3.29°, and 24.26 ± 3.42°, respectively. -MAX-SSA at L2-L5 was 36.25 ± 3.26°, 38.26 ± 3.73°, 38.62 ± 3.63° and 37.33 ± 3.31°, respectively. Theoretical reductions by calculation for the 2-segment lumbar pedicles were: L1-2: 9mm, L2-3: 9.29mm, L3-4: 6.23mm, and L4-5: 7.08mm; And the 3-segment lumbar pedicles were: L1-3: 16.97mm, L2-4: 16.73mm, L3-5, and 18.24mm, respectively. The application of the SRT to lumbar pedicles is a safe screw placement method that can significantly shorten the length of the used longitudinal rods.

Adjunctive techniques for percutaneous enteral access in children: a pictorial review.

Primary percutaneous gastrostomy and gastrojejunostomy tube placements are fundamental procedures performed in pediatric interventional radiology, with both antegrade and retrograde techniques described. In pediatric patients, however, challenges may arise due to smaller patient size and anatomical variations. Several adjunctive techniques may facilitate safe percutaneous access in the setting of a limited percutaneous gastric access window. These include the intra-procedural use of cone beam computed tomography (CT), percutaneous needle decompression in the setting of distended air-filled bowel interposed between the stomach and abdominal wall, post-pyloric balloon occlusion to facilitate gastric distension, ultrasound-guided gastric puncture, and intra-gastric contrast-enhanced ultrasound (ceUS) to define the relationship of the gastric wall and the anterior abdominal wall. Adjunctive techniques may increase successful primary percutaneous gastroenteric tube placement and may improve operator confidence in safe placement.

Fluoroscopy-guided vs. navigated iliosacral screw placement with intraoperative 3D scan or postoperative CT control: Impact of the clinical workflow on patients’ radiation exposure: Radiation exposure of different workflows for iliosacral screw placement

IntroductionTo guide iliosacral screws (ISS) and verify safe placement different techniques, e.g. Fluoroscopy-guided (FSG) or 3D navigation are known. However, higher radiation exposure for the conventional technique is a concern. It was the aim of this experimental study to evaluate radiation exposure for three clinical workflows. MethodsAn anthropomorphic, cross sectional dosimetry phantom was equipped with metal oxide semiconductor field effect transistors to measure organ specific radiation exposure. The effective dose was calculated. Radiation exposure was measured for FSG placement of 2 transverse ISS based on clinical experience regarding fluoroscopy time (240s). Additional measurements were conducted to calculate the effective dose for an intraoperative 3D scan as used for navigated ISS (high-quality 3D), for intraoperative verification of proper guide wire placement (standard-quality 3D) and for postoperative CT, using three different protocols. The following workflows were compared: FSG including postoperative CT (FSG-CT, including 3 different protocols) vs. FSG with intraoperative 3D scan in standard quality (FSG-3D) vs. navigation including two intraoperative 3D scan for navigated ISS (NAV-3D). ResultsThe effective dose for FSG-CT ranged from 4.41 mSv to 5.27 mSv. FSG-3D resulted in a total of 4.93 mSv. For NAV-3D, the effective dose was the lowest (3.00 mSv). The effective dose of a high-quality 3D scan required for navigation was 1.94 mSv, compared to 1.06 mSv for a standard-quality 3D scan as used for control. ConclusionsIntraoperative 3D scanning may be recommended, either combined with prior FSG ISS placement or following 3D navigation without increasing radiation exposure compared with alternative workflows with postoperative CT control.

Compared learning curves of the direct anterior and anterolateral approach for minimally invasive hip replacement

Minimally invasive hip arthroplasty becomes increasingly popular. It is technically challenging and the approaches used are associated with a considerable learning curve. This nurtures concerns regarding patient safety, surgical training, and cost effectiveness. Consequently, we initiated a study comparing the learning curves of a supervised trainee surgeon utilizing both the anterolateral and direct anterior approach (DAA) when introduced to minimally invasive hip replacement surgery. Outcome measurements included the Harris hip score (HHS), cup inclination and anteversion, offset and leg length, stem placement, surgical time and complications. Time from incision to suture decreased significantly over time but did not differ between both groups. The functional outcomes (HHS) after six weeks and three months were comparable (p=0.069 and 0.557) and within the expected range equalling 90.3 (anterior) and 89.2 (anterolateral) points. With both approaches safe component placement was readily achieved. Both offset and leg length, however, were reconstructed more reliably with the DAA (p=0.02 and 0.001). A higher rate of dislocations was seen with the anterior, more perioperative infections with the anterolateral approach. We suggest that supervision by an experienced surgeon favourably influences the learning curves for both the minimally invasive DAA and anterolateral approach and conclude that the greatest improvement is seen within the first 60 cases.

Imaging, post-processing and navigation: Surgical applications in pelvic fracture treatment

Technical advancements of the past decade have led to massive improvements regarding imaging and visualization in trauma care. Digital imaging technology has fundamentally changed most processes in fracture management. However, the digital revolution in trauma surgery has just begun.Optical tracking navigation is currently the gold standard for positioning of implants for advanced applications in trauma surgery. Digital technology may enable the surgeon to achieve the same level of safety even in non-navigated placement of screws: We developed a new planning tool to transcript a preoperative into a semi-transparent “fluoroscopic like” image that can be identified intraoperatively and used as a map for the safe placement of sacro-iliac screws based on the “vestibule concept”. In the future, development of artificial intelligence algorithms may provide features like automated segmentation of bone-fragments and other applications for a systematic fracture analysis to improve the standard of care in trauma surgery.Digital transformation has massive impact on diagnostics and surgical management of pelvic fractures. Improved visualization technology provides a better understanding of the surgical anatomy of the pelvis and may enable the surgeon to achieve greatest safety in percutaneous placement of screws even without using optical tracking navigation tools. The “para-axial fusion technique” is a useful tool to plan fluoroscopic views based on a 3D dataset prior to the surgery.

Design and Functionality of a Multilumen Thoracic Access Port for Pericardial Access Under Direct Visualization.

Small vasculature, venous obstruction, or congenital anomalies can preclude transvenous access to the heart, often resulting in open chest surgery to implant cardiac therapy leads for pacing, defibrillation, or cardiac resynchronization. A minimally invasive approach under direct visualization could reduce tissue damage, minimize pain, shorten recovery time, and obviate the need for fluoroscopy. Therefore, PeriPath was designed as a single-use, low-cost pericardial access tool based on clinical requirements. Its mechanical design aids in safe placement of conductive leads to the pericardium using a modified Seldinger technique. The crossed working channels provide an optimal view of the surgical field under direct visualization. Finite element analysis (FEA) confirms that the device is likely not to fail under clinical working conditions. Mechanical testing demonstrates that the tensile strength of its components is sufficient for use, with minimal risk of fracture. The PeriPath procedure is also compatible with common lead implantation tools and can be readily adopted by interventional cardiologists and electrophysiologists, allowing for widespread implementation. Prior animal work and a physician preliminary validation study suggest that PeriPath functions effectively for minimally invasive lead implantation procedures.

CT imaging measurement of sacral related anatomical parameters

To investigate the CT measurement of sacral anatomical parameters and understand the safe nail placement channel of DenisⅠ area with a new sacral butterfly plate. The CT data of 101 normal adult sacrum from January 2020 to June 2020 were retrospectively analyzed, including 49 females and 52 males, aged(49.11±15.02) years old. Firstly, the three-dimensional model of sacrum was reconstruct, the three-dimensional model according to the plane was re segment to be measured, and data measurement and statistical analysis were carried out. The vertical distance from the lower edge of superior sacral articular process to the lower edge of S2 posterior sacral foramen was (42.55±4.73) mm;The horizontal distance from the lateral sacral crest of S1, S2 and S3 hole plane to the sacroiliac joint surface was (19.09±3.07) mm, (15.34±2.69) mm and (8.29±2.48) mm respectively;The plane of S1 hole moves forward from the lateral sacral ridge, the inner and outer angles are (7.49±7.49)° and (24.07±4.89)° respectively;The inside and outside angles of S2 hole plane are (-3.10±8.95)° and (24.95±5.74)° respectively. There were significant differences between different genders except S1 horizontal distance and S1 medial angle, and there was no correlation between age and all data. The new sacral butterfly plate has enough safe nail placement range in DenisⅠ area;There are differences in sacral morphology among adults. The differences are mainly related to gender but not age.

Effects of anode position on pedicle screw testing during lumbosacral spinal fusion surgery

SUMMARY OF BACKGROUND DATAPedicle screws are commonly placed with lumbar/lumbosacral fusions. Triggered electromyography (tEMG), which employs the application of electrical current between the screw and a complementary anode to determine thresholds of conduction, may be utilized to confirm the safe placement of such implants. While previous research has established clinical thresholds associated with safe screw placement, there is variability in clinical practice of anode placement which could lead to unreliable measurements. PURPOSETo determine the variance in pedicle screw stimulation thresholds when using four unique anode locations (ipsilateral/contralateral and paraspinal/gluteal relative to tested pedicle screws). STUDY DESIGNProspective cohort study. Tertiary medical center. PATIENT SAMPLETwenty patients undergoing lumbar/lumbosacral fusion with pedicle screws using tEMG OUTCOME MEASUREStEMG stimulation return values are used to assess varied anode locations and reproducibility based on anode placement. METHODSMeasurements were assessed across node placement in ipsilateral/contralateral and paraspinal/gluteal locations relative to the screw being assessed. R2 coefficients of correlation were determined, and variances were compared with F-tests. RESULTSA total of 94 lumbosacral pedicle screws from 20 patients were assessed. Repeatability was verified using two stimulations at each location for a subset of the screws with an R2 of 0.96. Comparisons between the four anode locations demonstrated R2 values ranging from 0.76 to 0.87. F-tests comparing thresholds between each anode site demonstrated all groups not to be statistically different. CONCLUSIONThe current study, a first-of-its-kind formal evaluation of anode location for pedicle screw tEMG testing, demonstrated very strong repeatability and strong correlation with different locations of anode placement. These results suggest that there is no need to change the side of the anode for testing of left versus right screws, further supporting that placing an anode electrode into gluteal muscle is sufficient and will avoid a sharp ground needle in the surgical field.

Posterior Atlantoaxial Screw Placement in a Portuguese Population: A Morphometric Analysis Based on Computed Tomography Scan Measurements.

Objective The present study aims to evaluate the screw length and trajectory angles for posterior atlantoaxial fixation in a Portuguese population, through the study of cervical computed tomography (CT) scans. Methods Cervical CT scans of 50 adults were measured according to predefined screw trajectories of C1-C2 transarticular (C1C2TA), C1 lateral mass (C1LM), C2 pedicle (C2P), C2 pars and C2 laminar (C2L) screws. For each of these trajectories, screw length and angles were measured and compared between males and females. Results For the C1C2TA screw trajectory, the mean length, medial, and cranial angles were 34.12 ± 3.19 mm, 6.24° ± 3.06, and 59.25° ± 5.68, respectively, and for the C1LM screw trajectory, they were 27.12 ± 2.15 mm, 15.82° ± 5.07, and 13.53° ± 4.80, respectively. The mean length, medial, and cranial angles for the C2P screw trajectory were 23.44 ± 2.49 mm, 27.40° ± 4.88, and 30.41° ± 7.27, respectively; and for the C2 pars screw trajectory, they were 16.84 ± 2.08 mm, 20.09° ± 6.83, and 47.53° ± 6,97. The mean length, lateral, and cranial angles for the C2L screw trajectory were 29.10 ± 2.48 mm, 49.80° ± 4.71, and 21.56° ± 7.76, respectively. There were no gender differences except for the lengths of the C1C2TA ( p = 0,020) and C2L ( p = 0,001) screws, which were greater in males than in females. Conclusion The present study provides anatomical references for the posterior atlantoaxial fixation in a Portuguese population. These detailed data are essential to aid spine surgeons to achieve safe and effective screw placement.