Cadaveric Study on Comparison of Neck Extension Angles for Endotracheal Intubation in Rabbits Using a Rigid and Flexible Endoscope.

Endotracheal intubation in rabbits is always challenging due to the unique anatomical conformation. To improve endotracheal intubation success, this study determined the relationship between head placement angles guided by endoscope-assisted visualization techniques and the endotracheal intubation success rate. Thirty-two rabbit cadavers were used in the study. Six veterinary practitioners who had no experience with rabbit endotracheal intubation were randomly assigned to intubate rabbit cadavers using the guidance of either a rigid endoscope (RE) or flexible endoscope (FE), with the head placement angles with an ascending neck at 90, 100, 110, 120 and 130 degrees. The endotracheal intubation completed in 90 s was determined to be a success. The success rates using RE and FE were 97.2% and 95.9%, respectively. The means and standard error of means (SEM) of endotracheal intubation times guided by RE and FE were 53.7 ± 4.68 and 55.2 ± 4.24 s, respectively. Results from survival time analysis show that the five veterinarians successfully intubated the rabbit within 90 s, regardless of the different types of endoscopes. Angle was the only significant factor that affected the endotracheal intubation success. The head placement angle at 110 and 120 degrees had the highest success rate of endotracheal intubation compared to 90 degrees (p ≤ 0.05). In conclusion, for inexperienced veterinarians, the success of endotracheal intubation in rabbits, guided by endoscope-assisted visualized techniques regardless of rigid endoscope or flexible endoscope guidance, is improved when the head extension is 110 and 120 degrees.

Technical feasibility of uro-dynamic MRI study of voiding biomechanics: a pilot study.

INTRODUCTION: Dynamic volumetric MRI was used to non-invasively assess voiding biomechanics in a healthy male volunteer. METHODS: Using 3D Differential Subsampling with Cartesian Ordering (DISCO) Flex acquisition sequence, volumetric bladder images were obtained throughout the voiding effort. These were subsequently segmented using MIMICS. Segmented anatomical volumes were used to quantify total voided volume, post-void residual, volumetric displacement of urine over time, bladder neck angle, sphericity index, and prostatic urethral angle through the voiding effort. RESULTS: Bladder sphericity index correlated positively with flow rate. The greatest degree of bladder neck funneling correlated with the maximum urine flow rate. There was straightening of the prostatic urethral angle during voiding that also correlated positively with urine flow. CONCLUSION: This pilot study confirms the potential of dynamic MRI to provide non-invasive assessment of lower urinary tract anatomy and biomechanics during voiding.

Intraoperative Neck Angles in Endoscopic and Microscopic Otologic Surgeries.

OBJECTIVE: To quantitatively compare the ergonomic risk of otologic surgeries performed with endoscopes and microscopes. STUDY DESIGN: Observational cross-sectional study. SETTING: Operating room of a tertiary academic medical center. METHODS: Intraoperative neck angles of otolaryngology attendings, fellows, and residents were assessed during 17 otologic surgeries using inertial measurement unit sensors. Sensors were attached midline between the shoulder blades and on the posterior scalp of participants and were calibrated just prior to beginning each case. Quaternion data were used to calculate neck angles during periods of active surgery. RESULTS: Endoscopic and microscopic cases included similar percentages of time in high-risk neck positions, 75% and 73%, respectively, according to a validated ergonomic risk assessment tool, the Rapid Upper Limb Assessment. However, microscopic cases included a higher percentage of time spent in extension (25%) compared to endoscopic cases (12%) (p < .001). When examining the magnitude of average flexion and extension angles, endoscopic and microscopic cases were not significantly different. CONCLUSION: Utilizing intraoperative sensor data, we found that both endoscopic and microscopic approaches in otologic surgery were associated with high-risk neck angles, which can result in sustained neck strain. These results suggest that optimal ergonomics may be better achieved by the consistent application of basic ergonomic principles than by changing the technology in the operating room.

A comparison of muscle activity, posture and body discomfort during the use of different computer screen sizes.

This study aims to compare changes in neck angles, muscle activities, ergonomic risk and body discomfort caused by use of two different computer screen sizes. The 36 female users who participated used displays with 46.99 and 58.42-cm screen sizes and were assessed for craniocervical angle (CCA), craniovertebral angle (CVA), upper trapezius (UT) and sternocleidomastoid (SCM) muscle activity, ergonomic risk and body discomfort for a duration of 1 h. The results showed there were no significant differences when comparing usage between both computer screen sizes (p > 0.05). However, there were significant differences in the CCA, UT muscle activity and body discomfort when comparing before and after usage for both computer screen sizes (p < 0.05). The results indicate that computer users can select different screen sizes for working but should be concerned with neck angle, muscle activity and body discomfort when using for long periods of time.

Effects of Aneurysmal Neck Angle on Stent Displacement after Endovascular Repair of Abdominal Aortic Aneurysm / 医用生物力学

Objective To study the effects of aneurysmal neck angle on stent displacement after endovascular repair of abdominal aortic aneurysm (AAA). Methods The CT images of 28 patients were selected to establish preoperative AAA model, postoperative AAA model and covered stent model respectively, and the models were divided into non-severe angulation group ( n = 14) and severe angulation group ( n = 14) according to the preoperative angle of tumor neck. The geometric shape of each model was measured, and the changes of AAA geometric parameters and postoperative stent displacements before and after surgery were analyzed. The displacement force of the model during the first follow-up was calculated by hemodynamic simulation. Results Significant differences were found in tumor length, maximum diameter, displacement force, tumor neck length and tumor volume between two groups of patients (P 0. 05). For the incidence of internal leakage, there were 2 cases in non-severe angulation group and 4 cases in severe angulation group (P>0. 05).Conclusions Severe neck angulation can lead to a significant increase in support displacement force and decrease in proximal anchorage zone, and thus increase the possibility of support displacement. It is suggested that doctors should strengthen postoperative follow-up for patients with severe neck angulation and be vigilant of the occurrence of long-term internal leakage in clinic.

Evaluation of Dynamic Structural Disorders in the Upper Airways and Applied Rein Tension in Healthy Dressage Horses During Riding in Different Gaits and Head-Neck Positions.

Flexion of the horse's head and neck during dressage riding reduces the pharyngeal lumen with the risk of increased upper airway resistance and upper airway obstructions. According to the Fédération Equestre Internationale, hyperflexion is achieved through force, whereas the position low-deep-round is nonforced. The objectives of this study were to evaluate (1) applied rein tension and (2) dynamic structural disorders in the upper airways in dressage horses in different gaits and different head-neck positions (HNPs). Overground endoscopy (OGE) and rein tension were evaluated in 13 clinically healthy and high-performance Warmblood dressage horses while being ridden in a standardized program comprised of four different gaits (halt, walk, trot, and canter) and in four HNPs (unrestrained, competition frame, hyperflexion, and low-deep-round). All included horses were able to achieve the desired HNPs. The HNP low-deep-round showed significantly lower rein tension than competition frame (P < .001) and hyperflexion (P < .001). An association was found between dynamic structural disorders in the upper airway tract evaluated by OGE and head-neck flexion, but this association was not linked to the degree of flexion. The HNP hyperflexion was neither associated with greater rein tension nor severe dynamic structural disorders than the HNP competition frame. This study confirms that low-deep-round is a nonforced position, in contrast to hyperflexion. Further studies are needed to evaluate whether dynamic structural disorders are a result of flexion or if the degree of flexion has an impact.

Initial human experience with the GORE EXCLUDER Conformable AAA Endoprosthesis.

Endovascular repair has become the standard of care for treatment of abdominal aortic aneurysms. The endografts and delivery systems for endovascular aneurysm repair have undergone multiple generations of technologic advancements. However, a significant remaining challenge for a satisfactory long-term outcome is to improve the performance of these devices in nonideal proximal sealing zones. In particular, short (<15 mm) and highly angulated (>60 degrees) necks can threaten long-term exclusion of the aneurysm even with the current generation of endografts. One of the main reasons for proximal infrarenal neck failure is the inability to accurately position the endograft precisely below both renal arteries. This is a report of the first-in-human implantations of the GORE EXCLUDER Conformable AAA Endoprosthesis (W. L. Gore & Associates, Flagstaff, Ariz), an investigational device, in anatomies with standard neck lengths and angulation. This device has been designed to provide repositionability, conformability, and, for the first time, optional angulation control. This device is commercially available in Europe.

Neck posture and muscle activity in a reclined business class aircraft seat watching IFE with and without head support.

The purpose of this study is to research if a headrest benefits the comfort of the passenger and lowers muscle activity in the neck when sitting in a reclined (slouched) posture while watching in flight entertainment (IFE) in an aircraft business class seat. No significant differences in muscle activity in the musculus sternocleidomastoid and musculus trapezius pars descendant were found between the conditions with headrest and without headrest. A significant difference in expected comfort rating was found. Subjects indicated they expect to experience more comfort with a headrest when watching IFE for a duration of two movies during a long-haul flight. This study also found a significant difference in posture. In the condition without headrest the head was more upright compared to the condition with headrest. The lack of significant difference in muscle activity and the significant difference in posture may indicate that humans tend to look for a head position that is neutral, in the sense of minimal muscle effort. This study shows that the use of a headrest may benefit the comfort experience of the passenger during flight. However, further research is necessary on the design of the headrest and the long-term effects of head support on comfort, discomfort, muscle activity and fatigue for watching IFE in a slouched posture.

Measurement of the femoral neck angle in medium and large dog breeds using computed tomography.

The aim of this study was to get precise normal values of the femoral neck angle (FNA) in support of developing an optimally functioning total hip prosthesis for medium and large dog breeds. Accordingly, two- and three-dimensional computed tomographic images of the anatomical structures of the proximal femora of 58, hip-dysplasia-free, mature dogs of medium and large breeds were studied. Based on the length of their femora the dogs were allocated to Group I (from 145 to 195 mm) and Group II (from 196 to 240 mm). The FNA was measured on each femur using multi-slice spiral computed tomography (CT). The two- and three-dimensional image data were processed as multi-planar and threedimensional reconstructions using Advantage Workstation software. The CT measurements revealed that Group I had an average femoral neck angle of 147.59° (min. 144.05°, max. 153.35°), while in Group II the average FNA was 147.46° (min. 141°, max. 154.35°). There was no significant correlation between the length of the femur and the FNA in either group. The optimal FNA for a total hip prosthesis is 147.5° for medium and large dog breeds.

Differences in foetal topographical anatomy between insertion sites of the iliopsoas and gluteus medius muscles into the proximal femur: a consideration of femoral torsion.

BACKGROUND: Prenatal twisting of the femoral neck seems to result in an angle of anteversion or torsion, but the underlying process has not been elucidated. MATERIALS AND METHODS: This study analysed sagittal, frontal and horizontal sections of 34 embryo and foetal specimens of gestational age (GA) 6-16 weeks (crown-rump length 21-130 mm). At GA 6-7 weeks, the iliopsoas (IP) and gluteus medius (GME) muscles were inserted into the anterior and posterior aspects of the femur, respectively, allowing both insertions to be viewed in a single sagittal section. RESULTS: At GA 8 weeks, the greater trochanter and the femoral neck angle became evident, and the GME tendon was inserted into the upper tip of the trochanter. At GA 9 weeks, the location of IP insertion was to the medial side of the GME insertion. After 9 weeks, the IP insertion consisted of a wavy, tendino- us part of the psoas muscle and another part of the iliacus muscle, with many fibres of the latter muscle attached to the joint capsule. After GA 12 weeks, the IP was inserted into the anteromedial side of the greater trochanter, while the aponeurotic insertion of the GME wrapped around the trochanter. At GA 15-16 weeks, a deep flexion at the hip joint caused an alteration in the relative heights of the lesser and greater trochanter, with the former migrating from the inferior to the slightly superior side. CONCLUSIONS: These findings indicate that twisting of the femoral neck started at GA 8-9 weeks.

Vertical Neck angle and long-term outcomes of femoral neck fractures treated with cannulated screws / 中华创伤骨科杂志

Objective To analyze the associations between long-term outcomes of fresh femoral neck fractures treated with cannulated screws and the classification based on vertical neck (VN) angle.Methods A retrospective study was conducted of the 162 fresh femoral neck fractures treated with 3 cannulated screws at Department of Orthopaedics,The Sixth People's Hospital of Shanghai from January 2012 to December 2014.The relationships were analyzed using Logistic Regression between long-term complications and VN classification,including fixation failure,fracture nonunion and osteonecrosis of femoral head (ONFH).Results All the patients were followed up for an average of 25.7 months (from 6 to 36 months).Of them,151 obtained fracture union after an average of 4.5 months (from 3 to 9 months).Internal fixation failure occurred in 23 cases,nonunion of femoral neck in 11,ONFH in 21 and femoral neck collapse in 13.Logistic Regression analysis showed no significant associations between internal fixation failure,nonunion or ONFH and gender,age or reduction method (P ＞ 0.05) but significant associations of VN classification with fixation failure (P ＜ 0.001) and nonunion (P =0.001) and insignificant association of VN classification with ONFH (P =0.109).Conclusion VN classification,a new classification method for femoral neck fractures,may be closely related with incidences of fixation failure and nonunion.

Validity of the Microsoft Kinect for measurement of neck angle: comparison with electrogoniometry.

INTRODUCTION: Considering the importance of evaluating working postures, many techniques and tools have been developed to identify and eliminate awkward postures and prevent musculoskeletal disorders (MSDs). The introduction of the Microsoft Kinect sensor, which is a low-cost, easy to set up and markerless motion capture system, offers promising possibilities for postural studies. OBJECTIVES: Considering the Kinect's special ability in head-pose and facial-expression tracking and complexity of cervical spine movements, this study aimed to assess concurrent validity of the Microsoft Kinect against an electrogoniometer for neck angle measurements. METHODS: A special software program was developed to calculate the neck angle based on Kinect skeleton tracking data. Neck angles were measured simultaneously by electrogoniometer and the developed software program in 10 volunteers. The results were recorded in degrees and the time required for each method was also measured. RESULTS: The Kinect's ability to identify body joints was reliable and precise. There was moderate to excellent agreement between the Kinect-based method and the electrogoniometer (paired-sample t test, p ≥ 0.25; intraclass correlation for test-retest reliability, ≥0.75). CONCLUSION: Kinect-based measurement was much faster and required less equipment, but accurate measurement with Microsoft Kinect was only possible if the participant was in its field of view.

Dip-in Indicators for Visual Differentiation of Fuel Mixtures Based on Wettability of Fluoroalkylchlorosilane-Coated Inverse Opal Films.

We have developed the dip-in indicator based on the inverse opal film (IOF) for visual differentiation of organic liquid mixtures, such as oil/gasoline or ethanol/gasoline fuel mixtures. The IOF consists of a three-dimensional porous structure with a highly ordered periodic arrangement of nanopores. The specularly reflected light at the interface of the nanopores and silica walls contributes to the structural color of the IOF film. This color disappears when the nanopores are infiltrated by a liquid with a similar refractive index to silica. The disappearance of the structural color provides a means to differentiate various liquid fuel mixtures based on their wettability of the nanopores in the IOF-based indicators. For differentiation of various liquid mixtures, we tune the wettability threshold of the indicator in such a way that it is wetted (color disappears) by one liquid but is not wetted by the other (color remains). Although colorimetric differentiation of liquids based on IOF wettability has been reported, differentiation of highly similar liquid mixtures require complicated readout approaches. It is known that the IOF wettability is controlled by multiple surface properties (e.g., oleophobicity) and structural properties (e.g., neck angle and film thickness) of the nanostructure. Therefore, we aim to exploit the combined tuning of these properties for differentiation of fuel mixtures with close compositions. In this study, we have demonstrated that, for the first time, the IOF-based dip-in indicator is able to detect a slight difference in the fuel mixture composition (i.e., 0.4% of oil content). Moreover, the color/no-color differentiation platform is simple, powerful, and easy-to-read. This platform makes the dip-in indicator a promising tool for authentication and determination of fuel composition at the point-of-purchase or point-of-use.

Scapular neck length and implications for reverse total shoulder arthroplasty: An anatomic study of 442 cadaveric specimens.

PURPOSE: Reverse total shoulder arthroplasty (RTSA) may be used to treat a variety of pathologic shoulder conditions, but complications such as scapular notching continue raise concerns. Variable anatomy surrounding the glenoid may have implications for future RTSA design, but at present the anatomy of the scapular neck in the human population has not been clearly defined. MATERIALS AND METHODS: 442 human scapulae from the Hamann-Todd Osteological Collection were measured for scapular neck length (SNL) and scapular neck angle (SNA). SNL was defined as the distance from the most lateral portion of the infraglenoid tubercle to the most inferolateral portion of the glenoid fossa. The SNA was measured according to Gerber et al. previously. The mean, standard deviation and ranges for SNL and SNA were calculated and compared based on sex and race, and interobserver variability was calculated. RESULTS: The mean SNL was 1.06 cm ± 0.33 cm (0.37-2.43 cm). Males demonstrated a larger SNL (1.08 cm ± 0.33 cm) than females (1.01 cm ± 0.32 cm) (P < 0.12), and Caucasians (1.09 cm ± 0.33 cm) demonstrated a significantly larger SNL than African-Americans (1.00 cm ± 0.32) (P < 0.01). The mean SNA was 106.7° ± 11.0° (76.9-139.4°). No significant correlation was found between SNL and SNA (Pearson Correlation Coefficient = 0.018) (P < 0.702). CONCLUSION: Scapular neck length and SNA vary widely within the population but there appears to be a tendency towards increased SNL in males and Caucasians. CLINICAL RELEVANCE: The anatomy of the scapular neck may have significant implications for RTSA design, surgical planning, and reduction of associated complications.

The influence of humeral head inclination in reverse total shoulder arthroplasty: a systematic review.

BACKGROUND: Humeral component inclination may play an important role in implant stability and the incidence of scapular notching in reverse total shoulder arthroplasty (RTSA). This study was conducted to determine if a difference exists between RTSA prostheses with a 135° vs 155° humeral component inclination angle with respect to dislocation rates and scapular notching rates. We hypothesized that the rate of dislocation would be significantly higher with the 135° inclination design and that the rate of scapular notching would be significantly higher with the 155° inclination design. METHODS: A systematic review was registered with PROSPERO and performed with Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines using 3 publicly available free databases. Therapeutic clinical outcome investigations reporting the number of dislocations, number of patients with scapular notching, and postoperative range of motion after RTSA with levels of evidence I to IV were eligible for inclusion. All study and subject demographics were analyzed. Statistics were calculated using 2-proportion z tests. RESULTS: Thirty-eight studies including 2222 shoulders (average age, 70.3 ± 3.91 years; 67% female) undergoing RTSA were included. Of these, 1762 (79.3%) used the 155° inclination prosthesis and 460 (20.7%) used the 135° inclination prosthesis with a lateralized glenosphere. The rate of scapular notching was 2.83% in the 135° group and 16.80% in the 155° group (P < .0001, z = -7.7107). The rate of dislocation was 1.74% in the 135° group and 2.33% in the 155° group (P = .4432, z = -0.7669). CONCLUSIONS: Our systematic review of 38 studies and 2222 shoulders found that the rate of scapular nothing was significantly higher with the 155° prosthesis than with the 135° prosthesis with a lateralized glenosphere, with no difference in dislocation rates between prostheses.

Intra- and inter-observer repeatability of radiographic measurements for previously slipped capital femoral epiphysis at skeletal maturity.

BACKGROUND: Recent studies suggest that even a mild slip of the femoral capital epiphysis may lead to later degenerative changes when undiagnosed. However, little is written on the accuracy of radiographic measurements used to diagnose a slip at skeletal maturity. PURPOSE: To assess the accuracy of radiographic measurements commonly used for assessment of previously slipped capital femoral epiphysis (SCFE) at skeletal maturity. MATERIAL AND METHODS: All children born at our hospital during 1989 (n = 4006) were invited to participate in a follow-up hip trial at age 18-19 years. Erect pelvic anteroposterior and supine frog leg radiographs were obtained in a standardized fashion. For the purpose of this study, we selected a subset of 100 radiographs. To balance the data-set, we added another 28 radiographs from skeletal mature patients diagnosed and operated for a SCFE. Two observers independently measured Southwick's head-shaft angle, Murray's tilt-index, and the femoral head-neck angle. Intra- and inter-observer variation was assessed using the mean difference, with its 95% limits of agreement. RESULTS: A high percentage of the images (40%), particularly for the measurement of the Southwick's head-shaft angle, were judged immeasurable by at least one observer. Mean head-shaft angle was 11.0° (SD = 17.0), head-neck angle was 8.0° (SD = 12.0), and Murray's tilt-index was 1.18 (SD = 0.4). For head-shaft angle, the mean difference between measurements (Observer 2) was 0.8° (SD = 2.7°, 95% limits of agreement -4.5° to 6.1°), while the corresponding figure for the Murray's tilt-index was 0.02 (SD = 0.08, 95% limits of agreement -0.18 to 0.14), and for the head-neck angle 0.9° (SD = 4.0, 95% limits of agreement of -6.9° to 8.7°). Slightly higher variance was seen for Observer 1 and between the two observers. CONCLUSION: Common radiographic measurements for the assessment of a previously slipped capital femoral epiphysis are relatively inaccurate in skeletal mature adolescents, in particular between observers (inter-observer), but also for the same observer (intra-observer). Our results underscore the importance of thorough standardization for both image and measurement technique when used in a clinical setting.

Effect of Pregnancy and Delivery on the Pelvic Floor Function / 实用妇产科杂志

Objective:To investigate the change of petvic floor function in the third trimester of pregnancy and early postpartum.Methods :46 pregnant women in the third trimester in our hosprtal from July to October 2007 were randomly selected.In late pregnancy, 6 ～8 weeks and 12 ～14 weeks after delivery, the incidenca of stress urinary incontinence (SUI) and bladder neck mobility in different stage of puerperium was carried out.They were respectively given score, protectrve pad experiment, ultrasonic testing residual urine and peri-neum ultrasound examination.An anarysis on their.Results :The incidence of SUI that diagnosis by POP-Q or POP-Q combined with pat test was 47.83% ,39.13% respectively in late pregnancy group;21.74% ,15.22% in 6 ～8 weeks after delivery;17.24%.13.7g% in 12 ～14 weeks after delivery.The difference between late pregnancy group and 6～8 waeks after delivery group was statistical significance (P<0.05).There was no significantly difference between 6 ～8 weeks and 12 ～14 weeks after delivery groups(P>0.05).There was significant difference between 6 ～ 8 weeks and 12～14 weeks after delivery group while compared the bladder neck angle[(88.11± 13.36)° vs(82.17 ±10.28)°]with the bladder neck rotation angle[(21.67 ±10.64) ° vs (16.79±8.57) °].Conclusions :Pregnancy and delivery can damage the function of pelvic floor, which has certain rehabilitation after delivery.