Cadaveric Measurements Research Articles

Thickness of the eyelid structures in different age groups based on the ultrasound study

Most of the literature data on eyelid structures are based on the measurements in cadavers or histological samples. Nonetheless, such data can differ from the living tissues with interstitial fluid and filled vessels. In clinical work, specialists sometimes need to be aware of the in vivo parameters of eyelids tissue structures.Information on live thickness of eyelid structures supports diagnostic process and surgery planning. Nonetheless, the eyelids are affected by age related changes as other facial soft tissues.Purpose: To compare thickness of normal eyelid structures measured with ultrasound in various age groups.Methods. This prospective observational study was comprised of intact eyelids of 37 patients with a mean age of 46 ± 13.13 years (aged 27–79 years; 28 women). All subjects were divided into 4 groups with an interval of 10 years from 20 to 60 years and a group of aged above 60 years. Same operator took measurements skin, circular eye muscle, conjunctiva, tarsus and their composition of both eyelids with B-scan ultrasonography.Results. We established some age-related trends for all parameters, but two of them change the most significantly. The lower eyelid skin thickness in group of 31–40 years old people (1.2 [1.0;1.4] mm) significantly differed from the values in the groups of people aged 41–50 (1.65 [1.45;1.85] mm and 51–60 лет (2.05 [1.73;2.7] мм. Upper eyelid conjunctiva at the level of tarsal plate upper margin also tends to be thicker in people( older 60 years (0.97 [0.8;1.2] mm) than in younger adults, especially at the age of 21–30 (0.49 [0.44;0.55], p = 0.053) and 41-50 y.o. (0.58 [0.50;0.65] mm, p = 0.053).Conclusion. Significant differences in the skin thickness of the lower eyelid were detected in the group of 31–40 years from the values in the groups of 41–50 years (p = 0.03) and 51–60 years (p = 0.05). In persons over 60 years of age, the conjunctiva of the upper eyelid at the level of the upper edge of the TP was significantly thicker than in younger age groups. It was noted that most of the structures of the upper eyelid (skin, conjunctiva, TP, conjunctiva-TP complex, orbicularis oculi muscle and the total thickness of the eyelid at the level of TP) in all age groups are much thinner (p <0.05) than the corresponding structures of the lower eyelid. The obtained data can serve as a guide for diagnosis and planning of surgical interventions.

Evaluation of a Novel Needle Decompression Device Against Standard of Care: A Cadaveric Model

ABSTRACT Introduction Pneumothorax (PTX) incidence in patients arriving to a trauma center can be as high as 20%. The severity of PTX can range from insignificant to life-threatening. Five percent of combat casualties sustaining thoracic trauma have tension PTX (tPTX) at the time of death. Rapid diagnosis and decompression, traditionally with a needle decompression in the prehospital setting, is essential. However, high iatrogenic injury rates reveal a need for a device with the potential to decrease injury rate without compromising decompression success. The Donaldson Decompression Needle (DDN) is a 10-gauge × 3.25 inch needle with a locking mechanism designed to prevent over-insertion. During insertion, a spring-loaded blunt tip retracts, releasing the lock. After penetration of the parietal pleura, the blunt tip projects forward, which in turn locks the device in place on the chest. The device also contains an integrated 1-way valve (OWV) to prevent causing iatrogenic PTX, if placed into a healthy lung cavity. Materials and Methods We compared the DDN against a standard-of-care (SOC) needle (E-ARS 10 gauge × 3.25”) in a cadaveric randomized crossover design study. Tension pneumothorax was created by inserting a needle adjacent to the sternum and insufflating to 15 mmHg. Data collected included participant demographics/experience, cadaver measurements, and procedure data such as intrathoracic pressures and decompression time. Participants also completed a postprocedure survey. A secondary objective was evaluation of decompression rate with the OWV on vs. off. Results Twenty participants were enrolled in the study. Five participants required exclusion. While there were no differences in set-up times for the 2 procedures (DDN vs. SOC, 33 seconds vs. 28 seconds, P = .63), the decompression times were significantly different between the 2 groups (DDN vs. SOC, 2:06 vs. 1:06, P = .019). Evaluation of the secondary outcome resulted in 18 repetitions. The average decompression time for the OWV on group (n = 9) vs. OWV off group (n = 9) was 44 seconds vs. 10 seconds (P=<.05). Conclusions Despite the similar length and gauge of the DDN compared to the standard of care (SOC), the success rate of thoracic decompression was lower for the DDN when compared to the SOC (46% vs. 87%, P = .077) although statistical noninferiority was not established. Additionally, intradevice comparisons indicated decompression with the OWV on significantly prolonged decompression time when compared to when it was removed. It could be appropriate to consider removing the OWV after placement to decrease the decompression time, followed by reattachment for transport. Further research into the ability of the DDN to decrease iatrogenic injury will follow validation of decompression capabilities.

The anterior sylvian point as a reliable landmark for the anterior temporal lobectomy in mesial temporal lobe epilepsy: technical note, case series, and cadaveric dissection.

Mesial temporal lobe epilepsy (MTLE) is one of the most prevalent forms of focal epilepsy in surgical series, particularly among adults. Over the decades, different surgical strategies have been developed to address drug-resistant epilepsy while safeguarding neurological and cognitive functions. Among these strategies, anterior temporal lobectomy (ATL), involving the removal of the temporal pole and mesial temporal structures, has emerged as a widely employed technique. Numerous modifications have been proposed to mitigate the risks associated with aphasia, cognitive issues, and visual field defects. Our approach is elucidated through intraoperative and cadaveric dissections, complemented by neuroradiological and cadaveric measurements of key anatomical landmarks. A retrospective analysis of patients with drug-resistant MTLE who were treated using our ATL technique at IRCCS Neuromed (Pozzilli) is presented. A total of 385 patients were treated with our ATL subpial technique anatomically focused on the anterior Sylvian point (ASyP). The mean FU was 9.9 ± 5.4 years (range 1-24). In total, 84%of patients were free of seizures during the last follow-up, with no permanent neurological deficits. Transient defects were as follows: aphasia in 3% of patients, visual field defects in 2% of patients, hemiparesis in 2% of patients, and cognitive/memory impairments in 0.8% of patients. In cadaveric dissections, the ASyP was found at a mean distance from the temporal pole of 3.4 ± 0.2 cm (range 3-3.8) at the right side and 3.5 ± 0.2 cm (3.2-3.9) at the left side. In neuroimaging, the ASyP resulted anterior to the temporal horn tip in all cases at a mean distance of 3.2 ± 0.3 mm (range 2.7-3.6) at the right side and 3.5 ± 0.4 mm (range 2.8-3.8) at the left side. To the best of our knowledge, this study first introduces the ASyP as a reliable and reproducible cortical landmark to perform the ATL to overcome the patients' variabilities, the risk of Meyer's loop injury, and the bias of intraoperative measurements. Our findings demonstrate that ASyP can be a safe cortical landmark that is useful in MTLE surgery because it is constantly present and is anterior to risky temporal regions such as temporal horn and language networks.

Prepectoral Breast Reconstruction Prompts Revisiting the Anatomical Boundaries of the Breast: A Radiographic and Cadaveric Study.

This study aimed to determine the location of superficial fascial system condensations in relation to classic anatomical breast boundaries. Cadaveric studies have provided some understanding, but knowledge about the precise location of these condensations remains limited. Preoperative breast magnetic resonance imaging (MRI) was conducted to assess the fascial condensations defining the breast footprint relative to landmarks such as the latissimus, clavicle, sternal border, and inframammary fold. Concurrently, cadaveric mastectomies were performed to measure the breast borders in relation to these landmarks for comparison. A total of 290 breasts underwent preoperative MRI. Eight cadaveric breast dissections were completed. Radiographically, the lateral breast fascial condensation was 3.9 cm medial to the latissimus dorsi, whereas cadaveric measurements were 4.5 cm. The medial condensation was 2.1 cm lateral to the sternal border radiographically and 4.8 cm to the midline in cadavers. The superior fascial condensation was 2.3 cm inferior to the clavicle radiographically and 5.5 cm by dissection. The inferior condensation was above the inframammary fold in 82.7% of breasts by MRI and 100% of cadaveric breasts. MRI and cadaveric investigation showed similar patterns of breast tissue fascial condensations relative to standard breast boundaries. Breast skin flap thickness was greater peripherally (MRI, 11.5 mm; cadaver, 11.1 mm) than centrally (MRI, 6.6 mm; cadaver, 5.5 mm). MRI and cadaveric analysis demonstrated a close correlation between the superficial fascial system and standard breast boundaries, although variations existed between subjects. Collaborating with breast oncologists and using preoperative imaging to identify individual fascial condensations may enhance the camouflage of prepectoral implants after mastectomy.

Development and validation of a biomechanically fidelic surgical training knee model.

Knee arthroplasty technique is constantly evolving and the opportunity for surgeons to practice new techniques is currently highly dependent on the availability of cadaveric specimens requiring certified facilities. The high cost, limited supply, and heterogeneity of cadaveric specimens has increased the demand for synthetic training models, which are currently limited by a lack of biomechanical fidelity. Here, we aimed to design, manufacture, and experimentally validate a synthetic knee surgical training model which reproduces the flexion dependent varus-valgus (VV) and anterior-posterior (AP) mechanics of cadaveric knees, while maintaining anatomic accuracy. A probabilistic finite element modeling approach was employed to design physical models to exhibit passive cadaveric VV and AP mechanics. Seven synthetic models were manufactured and tested in a six-degree-of-freedom hexapod robot. Overall, the synthetic models exhibited cadaver-like VV and AP mechanics across a wide range of flexion angles with little variation between models. In the extended position, two models showed increased valgus rotation (<0.5°), and three models showed increased posterior tibial translation (<1.7 mm) when compared to the 95% confidence interval (CI) of cadaveric measurements. At full flexion, all models showed VV and AP mechanics within the 95% CI of cadaveric measurements. Given the repeatable mechanics exhibited, the knee models developed in this study can be used to reduce the current reliance on cadaveric specimens in surgical training.

WHAT RANGE OF MOTION (ROM) DOES A HIP ARTHROPLASTY ACTUALLY NEED? A CT-BASED METHOD TO PREDICT AN INDIVIDUAL'S HIP ROM PREOPERATIVELY

Ideally the hip arthroplasty should not be subject to bony or prosthetic impingement, in order to minimise complications and optimise outcomes. Modern 3d planning permits pre-operative simulation of the movements of the planned hip arthroplasty to check for such impingement. For this to be meaningful, however, it is necessary to know the range of movement (ROM) that should be simulated. Arbitrary “normal” values for hip ROM are of limited value in such simulations: it is well known that hip ROM is individualised for each patient. We have therefore developed a method to determine this individualised ROM using CT scans.CT scans were performed on 14 cadaveric hips, and the images were segmented to create 3d virtual models. Using Matlab software, each virtual hip was moved in all potential directions to the point of bony impingement, thus defining an individualised impingement-free 3d ROM envelope. This was then compared with the actual ROM as directly measured from each cadaver using a high-resolution motion capture system.For each hip, the ROM envelope free of bony impingement could be described from the CT and represented as a 3d shape. As expected, the directly measured ROM from the cadaver study for each hip was smaller than the CT-based prediction, owing to the presence of constraining soft tissues. However, for movements associated with hip dislocation (such as flexion with internal rotation), the cadaver measurements matched the CT prediction, to within 10°.It is possible to determine an individual's range of clinically important hip movements from a CT scan. This method could therefore be used to create truly personalised movement simulation as part of pre-operative 3d surgical planning.

Gerdy's tubercle as a novel anatomical landmark for the proximal tibial cut in total knee arthroplasty.

This study aimed to explore the use of Gerdy's tubercle (GT) as an innovative and dependable anatomical landmark for the proximal tibial cut in total knee arthroplasty (TKA) in cases with extensive knee degeneration. One hundred dry tibia bones and 10 formalin-fixed cadaveric knee specimens of both sexes were examined. A Zimmer NexGen tibial cutting guide and a Mitutoyo digital caliper were utilized to align the guide with the tibia's mechanical axis. The procedure was replicated on cadaver knees using a standardized medial parapatellar arthrotomy approach. Measurements included the distance from GT superior border to the resection line and the length of the tibia. A radiological study involving magnetic resonance imaging examinations of 48 patients, which were evaluated focusing on the upper border of GT and the least degenerated segment of the posterolateral part of the lateral tibial condyle, was conducted. Anatomical measurements of GT and proximal tibial areas in 110 specimens showed slight but consistent variations with cadaver measurements. Magnetic resonance imaging analysis of 48 patients revealed notable sex differences in the distance between the superior border of GT and the tibia's posterolateral surface. There was also a significant negative correlation between the distance from GT to the posterolateral corner and cartilage thickness. Proper alignment in TKA is crucial for success, but identifying an extra-articular landmark for horizontal tibial resection remains challenging, particularly in severely arthritic knees. This study introduces GT as a novel anatomical landmark for TKA, offering a more reliable reference for achieving desired joint levels in knees with significant degenerative changes.

Morphometric evaluation of the linea alba in fresh corpses

PurposeDiastasis recti abdominis is an increase in the distance between the medial borders of the two rectus muscles. It is most often triggered after intra-abdominal pressure increases, such as postpartum or in obesity. Most publications are based on radiological studies or are done in certain subgroups, without unanimous reference values of the distance between the rectus abdominis or standardization. MethodsForty-one cadavers were studied. Exclusion criteria: signs of abdominal trauma, major burns, presence of scar from previous abdominal surgery, clinical signs of abdominal hernia, and identification of hernia during cadaver dissection. Linea alba (LA) length, width, and thickness were measured with a flexible tape measure and digital caliper. Anatomical landmarks were established, and subdivisions were described based on them to compare the cadavers. ResultsSex and age had little effect on LA width, thickness, or length. Obesity (compared to normal weight) was the only variable that promoted an increase in the LA width (p < 0.01). The supraumbilical length varied with the total height of the evaluated cadavers (p < 0.01), but the infraumbilical length did not (p = 0.11). ConclusionThe general statistical results of this study, regarding the evaluation of LA measurements in cadavers, showed that ethnicity, sex, and age have little effect on the width, thickness, or length of the LA. LA width differed significantly with abdominal circumference.

Clinical and Anatomical Variation During Assessment of Maximum Glottic Angle.

Quantitative measurement and analysis of glottic abduction is used to assess laryngeal function and success of interventions; however, the consistency of measurement over time has not been established. This study assesses the consistency of glottic abduction measurements across visits in healthy patients and anatomic factors impacting these measurements. Review of patients with two sequential flexible stroboscopic exams over seven months from 2019-2022. Images of maximal glottic abduction were captured and uploaded into and measured with ImageJ. Cadaver heads were used to assess the impact of visualization angles on glottic measurements with a monofilament inserted into the supraglottis of each cadaver as a point of reference. Comparisons were done with a paired T-test, T-test, or Mann-Whitney U test as appropriate. Fifty-nine patients and twenty-six cadaveric exams were included. Absolute change in maximum glottic abduction angle (MGAA) was 6.90° (95% CI [5.36°, 8.42°]; p < 0.05). There were no significant differences in change in MGAA by gender or age. Twenty percent of patients had a change of at least 25% in their MGAA between visits. Absolute differences in glottic angle between nasal side for cadaveric measurements was 4.77 ± 4.59° (p < 0.005)-2.22° less than the change in MGAA seen over time (p = 0.185). Maximal glottic abduction angles varied significantly between visits. Factors considered to be contributing to the differences include different viewing windows between examinations due to the position and angulation of the laryngoscope and changes in patient positioning, intra- and inter-rater variations in measurement, and patient effort. N/a Laryngoscope, 134:2793-2798, 2024.

Эхографические параметры век в различных возрастных группах европеоидного взрослого населения

Most of the literature data on eyelid structures are based on the measurements in cadavers or histological samples. Nonetheless, such data can differ from the living tissues with interstitial fluid and filled vessels. In clinical work, specialists sometimes need to be aware of in vivo parameters of eyelids tissue structures. Purpose. To measure thickness of normal eyelid structures with echographic method and establish normal ranges of these parameters in various age groups in Caucasians. Methods. This prospective observational study comprised 37 patients with a mean age of 46±13.13 years (aged 27–79 years; 28 women). All subjects were divided into 4 groups with an interval of 10 years from 20 to 60 years and a group aged above 60 years. Same operator took measurements of skin, circular eye muscle, conjunctiva, tarsus and their composition of both eyelids with B-scan ultrasonography. Results. We established some age-related trends for all parameters, but two of them change most significantly. The lower eyelid skin thickness in the group of 31–40 years old people (1.2 [1.0; 1.4] mm) significantly differed from the values in the groups of people aged 41–50 (1.65 [1.45; 1.85] mm, p=0.052) and 51–60 years (2.05 [1.73; 2.7] мм, p=0.05). Upper eyelid conjunctiva at the level of tarsal plate upper margin also tends to be thicker in people over 60 years (0.97 [0.8; 1.2] mm) than in younger adults, especially at the age of 21–30 (0.49 [0.44; 0.55], p=0.053) and 41–50 years (0.58 [0.50; 0.65] mm, p=0.053). In addition, it was found that the thicknesses of the upper eyelid structures differ significantly from similar structures of the lower eyelid. The ratio of orbicularis oculi muscle thickness to the thickness of the muscles lifting the upper eyelid is 1:2.1 in average, which ensures their good mobility and protective function. Conclusion. The study provides data about normal eyelid structures thickness in various age groups of Caucasians. The revealed differences between the upper and the lower eyelids are due to their different functionality. Key words: orbicularis oculi muscle; levator; blepharoplasty; aging; blinking; protective function of the eyelids; supportive function of the eyelids

Anterior Cruciate Ligament Stability in Soft-Embalmed Cadaver vs In vivo Knee: Alternative Approaches to Medical Education.

Soft-embalmed cadavers have been used in medical education with a variety of success in different curriculum objectives. In the United States, the ACL is the most commonly injured ligament. Yet, there has been little focus on the stability of the knee in the sagittal plane provided by the anterior cruciate ligament within the soft-embalmed cadaver model. If the soft-embalmed cadaver ligaments contain similar elastic properties as an in-vivo knees, this will offer yet another means for further advancements in medical education to detect and assess musculoskeletal injuries. Evaluate how similarly the anterior tibial translation of soft-embalmed cadaver anterior cruciate ligaments compares to in-vivo tissue. The KT-1000 arthrometer was used to assess the laxity of the anterior cruciate ligament of thirteen soft-embalmed cadavers consisting of five females and eight males with a mean age of 79.3 years and duration of time since embalming ranging from 250 to 1156 days. Anterior displacement of the tibia in relation to the femur was registered at 67N and 89N. The soft-embalmed cadaver measurements were compared against twenty-one healthy uninjured individuals whose anterior tibial translation was measured using the same process. Data sets were analyzed using a welch two-sample t-test to determine the similarity between the means of the data sets. The t-tests proved a significant difference between live and soft-embalmed cadaver knees. The anterior tibial translation in the set of healthy live knees directly compared to the soft-embalmed cadaver group for 67N depicts an average difference of 1.76mm. The same comparison at 89N depicts an average difference of 2.12mm. While soft-embalmed cadavers may not directly replicate ATT to an exact number to that of in vivo tissue, they still allow the perception of the tibial translation against a stationary femur. The difference is less than 2.5 mm in both data sets when compared to an in-vivo knee, equivalent to one-tenth of an inch. Suggesting the viability of soft-embalmed cadavers ATT and should not exclude their use in medical education.

Three-dimensional architecture of the human subscapularis muscle in vivo

Detailed analysis of skeletal muscle architecture provides insights into skeletal muscle function. To date, measurements of the human subscapularis architecture have been limited to cadaveric measurements. In this study we demonstrate the feasibility of using anatomically constrained fibre tractography to reconstruct and quantify the 3D architecture of the human subscapularis muscle, and provide the first quantitative measurements of the architecture of the human subscapularis muscle in vivo. mDixon and diffusion tensor magnetic resonance images were obtained from the right shoulders of 20 healthy young adults. Anatomically constrained fibre tractography, in which fascicle reconstructions were forced to terminate on the internal aponeurosis of the subscapularis, was used to reconstruct muscle fibre architecture of the subscapularis muscles. Qualitatively, architectural reconstructions resembled the known subscapularis anatomy well, demonstrating face validity of the reconstructions. Muscle architectural parameters (means ± SDs) were: muscle volume 138 ± 42 cm3, fascicle length 63.6 ± 5.9 mm, physiological cross-sectional area (PCSA) 22 ± 6 cm2, and pennation angle 16 ± 2°. Architectural measurements of the subscapularis fell within the range reported in cadaver studies and were relatively insensitive to variations in fibre tractography parameters. The anatomically detailed whole-muscle reconstructions can be used to quantify the effects of joint surgery on muscle architecture and to advance computational models of the human shoulder.

A Shoulder Musculoskeletal Model with Three-Dimensional Complex Muscle Geometries.

Muscle structure is an essential component in typical computational models of the musculoskeletal system. Almost all musculoskeletal models represent muscle geometry using a set of line segments. The straight-line approach limits models' ability to accurately predict the paths of muscles with complex geometry. This approach needs knowledge of how the muscle changes shape and interacts with fundamental structures like muscles, bones, and joints that move. Moreover, the moment arms are supposed to be equivalent to all the fibers in the muscle. This study aims to create a shoulder musculoskeletal model that includes complex muscle geometries. We reconstructed the shape of fibers in the entire volume of six muscles adjacent to the shoulder using an automated technique. This method generates many fibers from the surface geometry of the skeletal muscle and its attachment areas. Highly discretized muscle representations for all muscles were created and used to simulate different shoulder movements. The moment arms of each muscle were calculated and validated against cadaveric measurements and models of the same muscles from the literature. We found that simulations using the developed musculoskeletal models generated more realistic geometries, which expands the physical representation of muscles compared to line segments. The shoulder musculoskeletal model with complex muscle geometry is created to increase the anatomical reality of models and the lines action of muscle fibers, and to be used for finite element investigations.

Evaluation of Styloid Process Length using Multidetector Computed Tomography Scan in Indian Population: A Cross-sectional Study

Introduction: The length of the Styloid Process (SP) has been a subject of research since Eagle's case report on a syndrome characterised by symptoms related to a painful elongated SP. Various modalities including orthopantomogram, digital radiography, cadaveric measurements, and Multidetector Computerised Tomography (MDCT) scanning have been used to study SP length. The present study aims to determine the normal SP length in the Indian population, specifically among armed forces personnel, using MDCT scans. Aim: To measure the SP length in the Indian population using MDCT scans and establish a cut-off length to define elongation. Materials and Methods: A single centre cross-sectional study was conducted at the Department of Radiology, Command Hospital Pune, Maharashtra, India from January 2023 to March 2023. The SP length was measured in 402 patients referred for CT scans of the head and Paranasal Sinus (PNS), utilising 3D Multiplanar Reformation (MPR), curved reformat, and volume rendering techniques. The patients were divided into six age groups: Group I (&lt;20 years), Group II (21 to 30 years), Group III (31 to 40 years), Group IV (41 to 50 years), Group V (51-60 years), and Group VI (&gt;60 years). Statistical analysis was performed using the Statistical Package for Social Sciences (SPSS) Version 28.0, and significance was set at p-value &lt;0.05. Results: Among the 402 patients, 210 were males, and 192 were females, with a mean age of 43.8±16.7 years. The mean SP length across all patients was 23.24±3.92 mm. The mean length was 23.74±4.50 mm on the right side and 22.74±3.72 mm on the left side, with no statistically significant difference between them (p-value=0.058). There was a significant gender difference, with males having a mean length of 23.67±4.12 mm and females 22.77±3.64 mm (p-value=0.011). The SP length increased significantly with age, demonstrating a notable difference between age groups. The upper limit of normal (90th percentile) ranged from 25.74 mm for patients &lt;20 years to 28.91 mm for patients &gt;60 years. Conclusion: A statistically significant difference in SP length was observed between genders, with a significant increase in length with age. In the Indian population, an SP length greater than 28 mm should be considered elongated.

The consequences of a thoracic outlet syndrome's entrapment model on the biomechanics of the ulnar nerve - Cadaveric study

Study DesignA cross sectional cadaveric measurement study. IntroductionThe etiology of entrapment neuropathies, such as carpal tunnel syndromes or thoracic outlet syndromes (TOS), is usually not only linked with the compressive lesion of the nerve but can also be associated with fibrosis and traction neuropathy. Purpose of the StudyThis work studies the biomechanics of the ulnar nerve in a cadaveric model of thoracic outlet syndrome (TOS). We explored the biomechanical impact of a restriction of mobility of the ulnar nerve. We measured if it could significantly affect the deformation undergone by the nerve on the rest of its path. MethodsWe studied 14 ulnar nerves from 7 embalmed cadavers. We opened three 6.5cm windows (at the wrist, forearm, and arm), and two optical markers 2cm apart were sutured to the ulnar nerve. We then studied the deformation of the ulnar nerve in three successive tensioning positions inspired by the ULNT3 manoeuvre (Upper Limb Neural Test 3). We then fixed the brachial plexus to the clavicle to mimic a nerve adhesion at the thoracic outlet. ResultsFixing the brachial plexus to the clavicle bone had significant effects on ulnar nerve mobility. In the position of intermediate tension, the nerve deformation increased by +0.68% / +1.43% compared to the control measure. In the position of maximum tension, it increased by +1.16% / +1.94%, pushing the nerve beyond the traumatic threshold of 8% of deformation causing reversible damage to axonal transport and vascularization. ConclusionsOur nerve adhesion at the thoracic outlet showed significant effects on the mobility of the ulnar nerve compared to the control situation, by significantly increasing the deformation undergone throughout the rest of the nerve's course, and by taking it over the 8% of physiological traumatic deformation.

Anatomic study of an anterior portal for percutaneous internal fixation of capitellum fractures.

Fractures of the capitellum are uncommon and difficult to treat surgically. Capitellar open reduction-internal fixation uses a lateral open approach with posterior-to-anterior or anterior-to-posterior screw fixation. We investigated the use of an anterior portal for placement of anterior-to-posterior screw fixation through cadaveric measurement of the anatomic relationships from an anteriorly to posteriorly placed Kirschner wire (K-wire) to anterior elbow structures and calculated the percentage of articular surface accessed from the anterior portal. Eight fresh-frozen cadaveric elbows without radiographic or cutaneous evidence of prior trauma or surgery were used for this study. An arthroscopic proximal anteromedial portal was cannulized, and the radiocapitellar joint was evaluated. A single 1-cm portal was placed 1 cm distal to the elbow flexion crease and based lateral to the biceps tendon. The location of the portal was confirmed with a spinal needle, and blunt dissection with a hemostat was performed down to capsular tissue and for arthrotomy. A spinal needle sheath was threaded over a blunt switching stick and served as a cannula for placement of a 0.062 K-wire. Articular mapping was performed with cartilage scraping by the K-wire; the K-wire was then placed at the perceived center along the proximal-to-distal and radial-to-ulnar axis of the capitellum. Fluoroscopic confirmation of the wire's location was performed. Under loupe magnification, anatomic dissection was performed and the shortest distance measurements were recorded with digital calipers from the K-wire to the dissected structures. Capitellar articular measurements were recorded, in addition to the articular area defined by the K-wire. Data analysis was performed, and the average distance and standard deviation (in millimeters) were calculated. For structures that were pierced by or touching the K-wire, the distance was recorded as 0.1 mm. The average distance from the K-wire to the radial, lateral antebrachial cutaneous, and median nerves was 1.8 mm, 11.5 mm, and 28.0 mm, respectively. The average distance from the median cubital vein and biceps tendon was 3.7 mm and 13.4 mm, respectively. The pin track pierced the brachioradialis and supinator muscles in all but 1 specimen. The average capitellar articular surface marked was 39.1% of the calculated articular footprint of the capitellum. The anterior portal to the capitellum is directly adjacent to the radial nerve and lateral antebrachial cutaneous nerve, where each is susceptible to injury. We recommend blunt dissection and insertion of a cannula to allow drilling and placement of internal fixation in a relatively safe manner with respect to neurovascular structures.

Lumbar plexus safe working zones with lateral lumbar interbody fusion: a systematic review and meta-analysis.

Significant risk of injury to the lumbar plexus and its departing motor and sensory nerves exists with lateral lumbar interbody fusion (LLIF). Several cadaveric and imaging studies have investigated the lumbar plexus position with respect to the vertebral body anteroposterior plane. To date, no systematic review and meta-analysis of the lumbar plexus safe working zones for LLIF has been performed. This systematic review was conducted according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. Relevant studies reporting on the position of the lumbar plexus with relation to the vertebral body in the anteroposterior plane were identified from a PubMed database query. Quantitative analysis was performed using Welch's t test. Eighteen studies were included, encompassing 1005 subjects and 2472 intervertebral levels. Eleven studies used supine magnetic resonance imaging (MRI) with in vivo subjects. Seven studies used cadavers, five of which performed dissection in the left lateral decubitus position. A significant correlation (p < 0.001) existed between anterior lumbar plexus displacement and evaluation with in vivo MRI at all levels between L1-L5 compared with cadaveric measurement. Supine position was also associated with significant (p < 0.001) anterior shift of the lumbar plexus at all levels between L1-L5. This is the first comprehensive systematic review and meta-analysis of the lumbar neural components and safe working zones for LLIF. Our analysis suggests that the lumbar plexus is significantly displaced ventrally with the supine compared to lateral decubitus position, and that MRI may overestimate ventral encroachment of lumbar plexus.

Longus Colli and Vertebral Artery Guide Safety of Cervical Spine Surgery

Objective: To improve the safety of the anterior cervical vertebral surgical approach, MRI and CT have been used and the distances between the medial borders of the longus colli (LC) to expose the uncinated process (UP) have been reported. The anatomic parameters of the LC and vertebral artery (VA) were considered here in relation to the UP to minimize complications.Materials and Methods: Data were obtained from 60 Thai adult skeletons and 20 embalmed cadavers. Direct measurements of the dry cervical vertebrae were performed using digital Vernier calipers, while computer imaging analysis was used for the cadaveric measurements after capturing the images.Results: No significant difference was noted in the inter-UP distance between the dry and cadaveric cervical measurements. The average UP width was 6.7 ± 0.2 mm. The average distance from the tip of the UP to the VA was 2.6 ± 0.1 mm. The calculated distance from the LC to the UP which derived from the inter-UP distance and the distance between the LC increased from C2 to C7 with an average distance of 11.9 ± 0.3 mm.Conclusion: Within a distance of 11.9 ± 0.3 mm from the medial border of the LC, UP can be identified. Dissecting at a distance less than 10 mm posterior, 5–6 mm lateral and superior to the base of the UP can avoid VA injury and optimize the safety of the anterior cervical vertebral surgical approach.

3D quantitative analysis of normal clitoral anatomy in nulliparous women by MRI.

We present a 3D computational approach for automated clitoral measurements. We hypothesized that computationally derived measurements would be comparable and less variable than reported manual measures. In this retrospective study, MRIs of 22 nulliparous women age 20-49 years with normal vaginal and clitoral anatomy were collected. Manual segmentations were performed to reconstruct 3D models of the whole clitoris (glans, body, crura, and bulbs) and vagina. The length, width, and volume of the clitoral structures and the distance between the vagina and clitoral structures were calculated. Computed clitoral morphometrics (length, width) were compared to median [range] values from a previously published cadaver study (N = 22) using the median test and Moses extreme reaction test. Calculated distances were compared to mean (± SD) reported by a 2D MRI study (N = 20) using independent t-test and Levene's test. Overall, computed clitoral morphometrics were similar to manual cadaver measurements, where the majority of length and width measures had ~1-2 mm difference and had less variability (smaller range). All calculated distances were significantly smaller and had smaller SDs than manual 2D MRI values, with two-fold differences in the means and SDs. Large variation was observed in clitoral volumetric measures in our cohort. The proposed 3D computational method improves the standardization and consistency of clitoral measurements compared to traditional manual approaches. The use of this approach in radiographic studies will give better insight into how clitoral anatomy relates to sexual function and how both are impacted by gynecologic surgery, where outcomes can assist treatment planning.

Comparison of the Coracoid, Distal Clavicle, and Scapular Spine for Autograft Augmentation of Glenoid Bone Loss: A Radiologic and Cadaveric Assessment

Background: Glenohumeral instability caused by bone loss requires adequate bony restoration for successful surgical stabilization. Coracoid transfer has been the gold standard bone graft; however, it has high complication rates. Alternative autologous free bone grafts, which include the distal clavicle and scapular spine, have been suggested. Study Design: Controlled laboratory study. Purpose: The purpose of this study was to determine the percentage of glenoid bone loss (GBL) restored via coracoid, distal clavicle, and scapular spine bone grafts using a patient cohort and a cadaveric evaluation. Methods: Autologous bone graft dimensions from a traditional Latarjet, congruent arc Latarjet, distal clavicle, and scapular spine were measured in a 2-part study using 52 computed tomography (CT) scans and 10 unmatched cadaveric specimens. The amount of GBL restored using each graft was calculated by comparing the graft thickness with the glenoid diameter. Results: Using CT measurements, we found the mean percentage of glenoid restoration for each graft was 49.5% ± 6.7% (traditional Latarjet), 45.1% ± 4.9% (congruent arc Latarjet), 42.2% ± 7.7% (distal clavicle), and 26.2% ± 8.1% (scapular spine). Using cadaveric measurements, we found the mean percentage of glenoid restoration for each graft was 40.2% ± 5.0% (traditional Latarjet), 53.4% ± 4.7% (congruent arc Latarjet), 45.6% ± 8.4% (distal clavicle), and 28.2% ± 7.7% (scapular spine). With 10% GBL, 100% of the coracoid and distal clavicle grafts, as well as 88% of scapular spine grafts, could restore the defect (P < .001). With 20% GBL, 100% of the coracoid and distal clavicle grafts but only 66% of scapular spine grafts could restore the defect (P < .001). With 30% GBL, 100% of coracoid grafts, 98% of distal clavicle grafts, and 28% of scapular spine grafts could restore the defect (P < .001). With 40% GBL, a significant difference was identified (P = .001), as most coracoid grafts still provided adequate restoration (congruent arc Latarjet, 82.7%; traditional Latarjet, 76.9%), but distal clavicle grafts were markedly reduced, with only 51.9% of grafts maintaining sufficient dimensions. Conclusions: The coracoid and distal clavicle grafts reliably restored up to 30% GBL in nearly all patients. The coracoid was the only graft that could reliably restore up to 40% GBL. Clinical Relevance: With “subcritical” GBL (>13.5%), all autologous bone grafts can be used to adequately restore the bony defect. However, with “critical” GBL (≥20%), only the coracoid and distal clavicle can reliably restore the bony defect.