The convex-probe endobronchial ultrasound (CP-EBUS) bronchoscope is widely used in clinical practice. Despite improvements, the existing CP-EBUS remains limited in accessing areas beyond the mediastinum due to its large distal end diameter, long rigid tip segment, and oblique viewing angle. To address this limitation, Olympus Medical Systems Corporation developed the thin CP-EBUS (TCP-EBUS). This study aimed to compare the accessibility and puncturing ability of TCP-EBUS with existing CP-EBUS in cadaveric models.

Ten bronchoscopists conducted this study using 2 cadaveric models. The accessibility of TCP-EBUS was evaluated based on the number of bronchial generations that could be reached. To assess the puncturing ability of TCP-EBUS, needle punctures were performed on previously created simulated lesions in the segmental or subsegmental bronchial area, and puncture success rates were calculated.

TCP-EBUS demonstrated greater accessibility than CP-EBUS in all segmental bronchi, with statistically significant differences observed in several bronchi (P<0.05). Puncture success rates for simulated lesions using TCP-EBUS were also significantly higher than those using CP-EBUS in both the segmental (85.0% vs. 60.0%, P<0.001) and subsegmental bronchial areas (84.4% vs. 38.9%, P<0.001). In a questionnaire survey, TCP-EBUS was perceived as significantly superior in terms of usability (P<0.05).

TCP-EBUS has significantly improved both accessibility and puncture performance, providing an advantage over CP-EBUS in segmental and subsegmental bronchial areas. TCP-EBUS has the potential to expand the indications for endobronchial ultrasound-guided transbronchial needle aspiration.

The decline in trauma cases and the increase in non-surgical treatments have reduced opportunities for trauma surgery training. This study examined the effectiveness of Cadaver-Based Educational Seminar for Trauma Surgery (C-BEST) as a lifelong educational tool for novice and experienced clinicians.

From 2017 to 2023, 117 clinicians with varying levels of experience participated in the C-BEST program at Hokkaido University. Participants included novice clinicians (median years post-graduation: 5) and experienced clinicians (median years post-graduation: 19). Each participant assessed their confidence in 21 trauma techniques before, immediately after, and 6 months post-course using a self-assessment of confidence levels (SACL) scale.

The analysis showed significant improvement in SACL scores immediately after the course, with confidence levels remaining sustained 6 months later. Novice clinicians demonstrated substantial skill acquisition, whereas experienced clinicians reported the reinforcement and refinement of existing skills.

C-BEST seems valuable as a training tool for the acquisition and retention of trauma surgery skills, addressing practical needs in trauma care. C-BEST provides an effective and sustained approach to trauma surgery skill development and retention across career stages. Further research on its long-term impact and applicability in diverse clinical settings is recommended.

The ultrasound-guided proximal intercostal block (PICB) is a regional anesthesia technique used for thoracic surgeries and sympathetic blockade in refractory ventricular arrhythmias. However, the anatomical extent of injectate spread to specific targets when PICB is performed at the upper thoracic levels has not been studied comprehensively. This cadaveric study aims to evaluate the spread of moderate-volume injections at the upper thoracic level, focusing on the cervicothoracic sympathetic chain and proposing possible mechanisms of the PICB effects in patients with refractory ventricular arrhythmias.

Seven PICBs were performed in five soft-embalmed cadavers. Radiographic contrast mixed with methylene blue was injected at the proximal segment of the first intercostal space (ICS-1). Fluoroscopy and dissection were performed to examine the injectate spread.

In the six successful PICBs, both fluoroscopy and dissection revealed injectate spread within the ipsilateral ICS-1 (T1-2) with direct anteromedial fascial spread and consistent coverage of the upper thoracic and/or inferior cervical sympathetic chain in all specimens. Injectate spread to the adjacent paravertebral space was observed in 67% of specimens by fluoroscopy (2-6 segments) and 83% by dissection (1-4 segments). Limited spread to the epidural space was observed in 33% of specimens by fluoroscopy (2-5 segments) and 67% by dissection (2-6 segments).

Ultrasound-guided PICB at PICS-1 produced consistent injectate spread to the adjacent cervicothoracic sympathetic chain in all specimens. The inconsistent paravertebral and epidural spread suggests that direct interfascial spread to the sympathetic chain is likely to be the main mechanism of sympathetic block for refractory ventricular arrhythmia.

This study aimed to evaluate the effectiveness of a cadaver surgical training program at the Clinical Anatomy Laboratory Nagoya (CALNA), focusing on its impact on procedural skills, confidence, and anatomical understanding among young and mid-career thoracic surgeons.

From 2016 to 2024, 13 cadaver surgical training sessions were conducted, divided into basic, advanced, and specialized courses. The program included hands-on practice using cadavers preserved with Thiel or hypertonic saline methods. The surveys were administered post-training to assess confidence, satisfaction, and practical applicability. Statistical analysis was performed on the survey results.

A total of 100 participants attended the training sessions (mean: 12.5/session). The survey responses indicated that 92% of participants rated the training content as "good" or "excellent," and 88% found the training "applicable" or "highly applicable" to clinical practice. Reflective discussions following each session facilitated iterative program refinement. The key improvements included enhanced surgical instrument availability and optimized trainee-to-instructor ratios.

Our cadaver surgical training program was shown to significantly enhance surgical skills, boost confidence, and deepen thoracic anatomical understanding, demonstrating its value in advancing thoracic surgical education. Further development of standardized programs across institutions is needed to enable novice surgeons to acquire advanced skills efficiently.

The Thiel embalming method offers lifelike tissue preservation, yet its suitability for biomechanical studies remains debated.

Here, we investigated two human temporal bones, one Thiel-fixed and one fresh-frozen, using dynamic synchrotron-based X-ray imaging under acoustic stimulation.

Both specimens exhibited a linear response at the umbo, but the Thiel-fixed specimen displayed discontinuity after the incudo-malleolar joint, suggesting ossicular chain stiffening. Our findings align well with previous studies indicating potential tissue degradation induced by Thiel-embalming.

These observations question the use of Thiel-fixed human specimens for biomechanical measurements on the middle ear, especially using dynamic synchrotron-based X-ray imaging. They emphasize the need for further assessment of the impact of Thiel-embalming methods on tissue mechanics.

Background: The coracohumeral ligament (CHL) is inserted in the coracoid process, from which it extends laterally and caudally, blending with the tendinous insertions of the subscapularis muscle and the supraspinatus muscle, with a third intermediate area between the muscles inserted between the humeral tubercles, and it contributes to the fibrous tunnel that engulfs the long head of the biceps tendon. Most previous studies mention insertions from the base of the coracoid process, but not from the tip, and some authors describe anterior and posterior columns. In contrast, others stress the existence of superficial and deep fascicles. Also, the relationship between the coracohumeral and the glenohumeral ligaments is unclear. Given the position of the CHL covering most of the rotator interval, and its role in the stability of the shoulder capsule and pathologies like frozen shoulder, a clear description of its fascicles in a plane-wise manner might be helpful for a selective surgical approach. Methods: We studied sixteen soft-embalmed shoulders to avoid misclassifying fascicles due to formalin-linked tissue amalgamation. Further histological assessment was performed on the two remaining non-embalmed shoulders. Results: In our sample, the coracohumeral ligament hung from the anterior and posterior edges of the coracoid process' inferior surface, defining two columns that converged near the tip of the coracoid process. Both columns were formed by superficial and deep fascicles directed to different depths of the rotator cuff, usually via the rotator interval, fusing with the connective tissue around the muscles without direct distal attachments. We performed histological and morphometrical assessments, and we discuss clinical and biomechanical implications. Conclusions: The coracohumeral ligament contains four fascicles that fuse with the connective tissue of the shoulder joint, forming a double necklace around the subscapularis and supraspinatus. Therefore, its functions probably extend beyond simple vertical stabilization.

The object of this study was to perform an anatomical dissection of Thiel-embalmed specimens in a step-by-step procedure, to establish a 'safe zone' in which to perform a less invasive supercharged end-to-side (SETS) anterior interosseous nerve to ulnar motor nerve transfer without tension and to demonstrate its feasibility. The sample size was calculated with a 5 mm error to reach a 95% confidence interval. Dissection was performed in 15 specimens and the 'safe zone' was established between 40 and 90 mm proximal to the pisiform. Several surgical tips are recommended to help complete the procedure. A reproducible 'safe zone' was found for performing a SETS anterior interosseous to ulnar motor nerve transfer with 95% certainty, reducing soft tissue damage and enhancing the original surgical technique.

Anatomical embalming forms a mainstay in the provision of teaching materials based on human post-mortem tissues. As a consequence of regulations worldwide to minimize the use of formaldehyde due to its harmful nature, effective measures must be taken to minimize its application in the anatomy laboratory. This study aimed to identify commonalities among embalming protocols used in Austrian, German and Swiss anatomies to reduce formaldehyde usage and provide a foundation for joint accreditation.

Survey data on all procedures, technologies and chemicals related to embalming were collected from 28 participating institutions and analyzed using an automated clustering approach. Special attention was given to chemicals, explosion-proof facilities, and air ventilation technology. After conducting principal component analyses, the data was evaluated using an unsupervised K-means learning algorithm.

Six distinct clusters of common chemical usage were identified, namely (1) Thiel embalming with explosion-proof facilities, (2) potassium- and sodium salt-based embalming with downdraft ventilation, (3) ethanol/glycerin/glutaraldehyde/sodium alkyl ether sulphate-based embalming, (4) ethanol-based embalming, (5) formaldehyde-based embalming, and (6) ethanol/phenoxyethanol/alkyl (C12-16) dimethylbenzyl ammoniumchloride-based embalming. All clusters included the use of formaldehyde to varying extent. These clusters demonstrated high stability for fixation, combined fixation and conservation, as well as the incorporation of explosion-proof facilities and air ventilation technology. Moreover, a number of institutions used more than one similar protocol, so-called 'Superclusters', with Clusters (4) and (1) or Clusters (5) and (1) combined being the most common observation.

These findings provide a basis for optimizing, streamlining and sharing embalming protocols among central European anatomy institutions.

Crosado-embalming has been successfully used as embalming technique in research and teaching for over 20 years. It is applied in biomechanical testing experiments if the fresh tissues are unavailable, e.g., for cultural, ethical, logistical or health and safety reasons. However, features of human Crosado-embalmed tissues biomechanical characteristics including its load-deformation properties in comparison to fresh tissues and its controllability through hydration fluids may be insightful and therefore need to be studied further. This study compared the uniaxial load-deformation properties and the cross-sectional area (CSA) measurements of fresh-frozen and Crosado-embalmed collagen-rich tissues, namely the iliotibial band (ITB, 16 unembalmed and 35 embalmed specimens) and cranial dura mater (DM, 60 unembalmed cadavers, and 25 embalmed specimens). The water content of 120 Crosado-embalmed ITB samples (30 cadavers) were analysed considering established rehydration treatments, including polyethylene glycol (PEG). Crosado-embalmed tissues presented an increased elastic modulus (EM) (all p < 0.050; e.g., Crosado ITB PEG only 306 ± 91 MPa vs. fresh-frozen ITB PEG only 108 ± 31 MPa; mean ± standard deviation; p < 0.001) and ultimate tensile strength (UTS) (e.g., Crosado ITB PEG only 46 ± 15 MPa vs. fresh-frozen ITB PEG only 21 ± 8 MPa; p < 0.001) when rehydrated similar to the fresh tissues. The maximum force was different for the dura mater (Crosado 25 ± 13 N vs. fresh 21 ± 20 N; mean ± standard deviation; p = 0.050) but not for the ITB. The CSA following rehydration in PEG only was decreased for Crosado-embalmed samples (3.4 ± 1.2mm2, ITB; 1.1 ± 0.5 mm2, DM) compared to fresh-frozen (5.8 ± 2.1mm2, ITB; 3.1 ± 1.2mm2, DM) (all p ≤ 0.003). Furthermore, rehydration effects were observed following 24 h of PEG treatment (untreated tissues, 49 ± 9% vs. PEG only, 77 ± 4%; p < 0.001), in comparison to fresh samples (69%) tissues were hyperhydrated. In conclusion, Crosado-embalming appears to alter collagen-rich tissues' morphological and mechanical properties. While an increase in material properties of Crosado-embalmed tissues was observed (Emod and UTS), the overall load-bearing capacity and peak structural strength remained unaltered for ITB tissues. This may result from CSA-related, geometric or molecular alterations after the fixative and osmotic water protocols related to changes in the collagen backbone and water-binding capacity.

The aim of this study was to evaluate the feasibility of using patient-specific implants (PSI) for complex shaft corrective osteotomies in multiplanar deformities of long bones in the lower extremities. Additionally, it aimed to investigate the added value of these implants by quantifying surgical accuracy on postoperative CT, comparing their outcomes to two commonly used techniques: 3D virtual visualizations and 3D-printed surgical guides.

Six tibial and femoral shaft corrective osteotomies were planned and performed on three Thiel embalmed human specimen. Depending on the specimen a different respective technique was used; 1) '3D Visualization' using 3D virtual plan preoperatively and free-hand corrective osteotomy techniques with standard manually contoured plates; 2) '3D guided' utilizing 3D surgical guides and manually contouring of conventional implant; and 3)'3D PSI' utilizing a 3D surgical guide with a patient-specific implant. Accuracy of the corrections was assessed through measurements for varus/valgus angulation, ante/recurvation, rotation and osteotomy plane error as quantified on postoperative CT-scans.

Twelve corrective osteotomies were performed. For, the median difference between the surgical plan and postoperative CT assessment was 3.4°, 4.6°, and 2.2° for the '3D visualization', '3D guided', and '3D PSI' methods respectively. Regarding ante/recurvation, the differences were 3.8°, 43.8°, and 1.2°, respectively. For rotation, the differences were 11.9°, 18.7°, and 3.5°, respectively. Discrepancies between planned and executed levels of osteotomy plane were 6.2 mm, 3.2 mm, and 1.4 mm, respectively.

PSIs with 3D-printed drilling guides for complex multiplanar corrective osteotomies of femoral and tibial shaft malunions is feasible and achieves accurate corrections. This technique enables precise determination of the osteotomy plane, guides correction in all three planes, and ensures satisfactory implant fitting; thus accurately translating the virtual surgical plan into clinical practice. The 3D PSI method is beneficial for complex cases with significant multiplanar deformities in bone anatomy, particularly with rotational malalignment.

Limitations in human kinematics during cochlear implantation induce pressure transients and increased forces on intracochlear structures. Herein, we present a novel head-mounted surgical tool designed for the motorized insertion of cochlear implant electrode arrays. The tool integrates a force measurement feature to overcome the lack of haptic feedback in current robotic solutions.

Utilizing a prototype device, we compare force measurements with those exerted on intracochlear structures in a realistic temporal bone model. Furthermore, we test the tool on six temporal bone specimens in a surgical setting to assess its performance in various anatomies.

Force measurements exhibit good agreement with intracochlear forces, offering significantly improved resolution over manual, tactile sensing. Successful electrode array insertions in six cadaver specimens affirmed the feasibility of tool setup, motorized insertion and tool removal in different anatomies.

The tool allows the robot-assisted insertion of cochlear implant electrode arrays and offers valuable insights during the surgical procedure, demonstrating promise for application in clinical contexts.

This instrument has the potential to aid surgeons in achieving atraumatic placement of electrodes, consequently contributing to the improvement of hearing outcomes in cochlear implantation.

The functional role of the biceps femoris short head (BFsh) remains unclear. Clarifying the functional role of each biceps femoris head may provide useful insights into the reduction of biceps femoris long head (BFlh) injuries. This study aimed to clarify whether the passive tension in the BFlh would change with BFsh detachment using cadavers. The shear modulus of the BFlh and BFsh was measured using ultrasonic shear wave elastography as an index of passive tension in three tissue processing conditions (intact, removal of all tissues from skin to deep fascia, and BFsh detachment) in four limb positions, with hip [H0°, H90°] and knee [K0°, K90°] joint angles under each tissue processing condition. The measurement site was the distal 30 % of the line connecting the sciatic tuberosity (100 %) and fibular head (0 %). Three-way analysis of variance was conducted with muscles, tissue processing, and positions as factors, which revealed a significant interaction (P < 0.01). The post-test results indicated that the BFlh was significantly higher than the BFsh at H90° and K0° before tissue processing; however, no difference was observed between the muscles after skin and deep fascia removal. After BFsh detachment, the shear modulus of the BFsh decreased, whereas that of the BFlh significantly increased (P < 0.01), suggesting that the BFsh might be involved in the passive tension reduction of the BFlh in a lengthened position, as the shear modulus of the BFlh increased after detachment.

Over the last decade, there has been a rapid rise in the development and refinement of abdominal wall repair (AWR) techniques. Numerous cadaveric AWR training courses have been set up with the goal of helping practicing surgeons learn and incorporate them into their surgical repertoire. Some maybe excellent but their quality and consistency are unknown. The aim of this article is to present a stepwise cadaveric dissection template and checklist to standardize all training on open AWR courses and to help course organizers benchmark the quality of their program.

This article is based on both the authors experience as faculty and course leads of cadaveric AWR courses, and the published anatomical and operative literature. The authors represent the training committee of the European Hernia Society, and the AWR subcommittees of the British Hernia Society and Association of Coloproctology of Great Britain & Ireland.

A standardized stepwise approach for the cadaveric training of the most recognized procedures for open AWR, including retrorectus repair, posterior and anterior component separation techniques, is presented. Considerations on delegate selection, pre-course material and testing, course structure, and cadaveric models is also provided.

Time and financial resources for surgeons to attend courses to learn and hone the skills required for safe effective AWR is limited. Ideally all courses should deliver up to date consistent training of the highest quality. One step to achieve this is by developing a standardized approach to ensure delegate understanding of the operative steps and key anatomical features.

The posterior malleolus of the tibia is commonly accessed surgically through the posterolateral approach. This approach gives good access to the fibula and lateral aspect of the posterior tibia, however; there is little known on the vascular risks with this approach. The aim of this study was to assess and describe the anatomy of the fibular artery and its branches at the ankle region and relate it to the surgical access of the posterior malleolus. Eleven cadaveric foot and ankle specimens were dissected in layers, preserving the fibular artery, anterior tibial artery (ATA), and posterior tibial artery (PTA). Five distinct variations were found in the fibular artery: variable terminal branching with a hyperplastic fibular artery; a superficially located fibular artery; variation in the level and number of anastomoses; variation in the muscular branches; and a variable anterior perforating branch. The mean proximal distance from a horizontal line drawn through the medial protuberance of the medial malleolus of the tibia (horizontal line reference point-HLRP) to the posterior communicating branch of the fibular artery was 37.93 mm (range 19.03-85.43 mm). The mean proximal distance between HLRP and the anterior perforating branch of the fibular artery was 44.23 mm (range 35.44-62.32 mm). In 10 specimens, the fibular artery was immobile distal to its anterior perforating branch. The posterolateral approach specifically puts the fibular artery at risk and knowledge of its anatomy and variability is important when undertaking this approach. Understanding the common variations within the ankle's arterial anatomy can help surgeons protect these vessels from damage during the surgical approach.

Medial soft tissue release is occasionally performed to achieve mediolateral ligament balance in total knee arthroplasty (TKA), whose sequential effect on mediolateral and anteroposterior stability remains unclear. This study aimed to quantitatively evaluate the difference in mediolateral and anteroposterior stability according to a sequential medial soft tissue release in TKA.

Cruciate-retaining TKA was performed in six cadaveric knees. Medial and lateral joint gaps, varus-valgus angle, and tibial anterior and posterior translations relative to the femur with pulling and pushing forces, respectively, were measured. All measurements were performed at full extension and 45° and 90° flexion after release of the deep medial collateral ligament (MCL) (stage 1), the posteromedial capsule (stage 2), and the superficial MCL (stage 3). Mediolateral and anteroposterior stability were compared between stages, and correlations between mediolateral and anteroposterior stability were analyzed.

Medial joint gap significantly increased from stages 1 to 3 by 3.2 mm, 6.8 mm, and 7.2 mm at extension, 45° flexion, and 90° flexion, respectively, and from stages 2 to 3 by 3.5 mm at extension. Varus-valgus angle was varus at stage 2, which turned to valgus at stage 3 (-2.7° to 0.8°, -2.2° to 4.3°, and -5.5° to 2.5° at extension, 45° flexion, and 90° flexion, respectively). Anterior translation at 90° flexion significantly increased from stages 1 and 2 to stage 3 by 11.5 mm and 8.2 mm, respectively, which was significantly correlated with medial gap (r = 0.681) and varus-valgus angle (r = 0.495).

Medial soft tissue release also increased tibial anterior translation as well as medial joint gap, and medial joint gap and tibial anterior translation were significantly correlated. Surgeons should be careful not to create too large medial joint gap and tibial anterior translation in flexion by excessive medial release up to the superficial MCL for achieving an equal mediolateral joint gap in extension.

This study aimed to evaluate the accuracy of detecting vertical root fractures in Biodentine™-filled teeth using the Promax 3Dmax cone-beam computed tomography (CBCT) unit compared to periapical radiographs. It tested hypotheses regarding CBCT's diagnostic superiority in non-root-filled and Biodentine™-root-filled maxillary central incisors and assessed the impact of smaller field of view and lower intensity settings on detection accuracy.

Extracted maxillary incisors were divided into groups based on fracture status and root filling material, then placed in a Thiel-embalmed skull to simulate clinical conditions. The teeth were imaged using periapical radiographs and the CBCT unit under different settings. Fracture thickness was measured with microcomputed tomography for accuracy benchmarking. Multiple observers assessed the images, and statistical analyses were conducted to evaluate diagnostic performance.

Intra-rater reliabilities of consensus scores ranged from good to very good. Specificities were generally higher than sensitivities across all imaging modalities, but sensitivities remained constantly low. None of the Area Under the Curve scores exceeded 0.6, indicating poor overall accuracy for all imaging modalities. Paired comparisons of the area differences under Receiver Operator Characteristic curves revealed no significant differences between the CBCT and periapical radiograph techniques for detecting vertical root fractures in either Biodentine™-filled or non-root-filled teeth.

There was no significant accuracy improvement of the current CBCT device (Promax 3Dmax, Planmeca, Finland) over periapical radiographs in detecting small vertical root fractures in both non-root-filled and Biodentine™-root-filled maxillary central incisors. A smaller field of view with lower intensity did not enhance detection accuracy. These results highlight the challenges in accurately detecting small VRFs, emphasizing the need for further research and technological advancements in this domain.

Our aim was to develop practical training for laparoscopic surgery using Thielembalmed cadavers. Furthermore, in order to verbalize experts' motion characteristics and provide objective feedback to trainees, we initiated motion capture analyses of multiple surgical instruments simultaneously during the cadaveric trainings. In the present study, we report our preliminary results.

Participants voluntarily joined the present cadaveric simulation trainings, and performed laparoscopic radical nephrectomy. After the trainings, scores for tissue similarity (face validity) and impression of educational merit (content validity) were collected from participants based on a 5-point Likert scale (tissue similarity: 5: very similar, 3: average, 1: very different; educational merit: 5: very high, 3: average, 1: very low). In addition, after the additional IRB approval, we started motion capture (Mocap) analyses of 6 surgical instruments (scissors, vessel sealing system, grasping forceps, clip applier, right-angled forceps, and suction), using an infrared trinocular camera (120-Hz location record). Mocap-metrics were compared according to the previous surgical experiences (experts: ≧50 laparoscopic surgeries, intermediates: 10-49, novices: 0-9), using the Kruskal-Wallis test.

A total of 9 experts, 19 intermediates, and 15 novices participated in the present study. In terms of face validity, the mean scores were higher than 3, other than for the Vena cava(mean score of 2.89). Participants agreed with the training value (usefulness for future skill improvement: mean score of 4.57). In terms of Mocap analysis, faster speed-related metrics (e.g., velocity, the distribution of tip velocity, acceleration, and jerk) in the scissors and vessel sealing system, a shorter path length of grasping forceps, and fewer dimensionless squared jerks, which indicated more purposeful motion of 4 surgical instruments (vessel sealing system, grasping forceps, clip applier and suction), were observed in the more experienced group.

The Thiel-embalmed cadaver provides an excellent training opportunity for complex laparoscopic procedures with participants' high level of satisfaction, and may become a promising tool for a better objective understanding of surgical dexterity. In order to enrich formative feedback to trainees, we are now proceeding with Mocap analysis.

To assess and compare two ultrasound-guided, minimally invasive procedures to release the A1-pulley (needle release and thread release) regarding efficacy and safety in an anatomical specimen model.

Twenty-one ultrasound-guided needle releases and 20 ultrasound-guided thread releases were performed on digits of Thiel-embalmed anatomical specimens. A scoring system was developed to assess ultrasound visibility, intervention outcome (incomplete, almost complete, or full transection of the A1 pulley), and injury to adjacent structures (neurovascular structures, tendons, A2 pulley). Statistical analysis was performed to compare the score of the two groups (group 1: needle release,group 2: thread release). A P-value of ≤ 0.05 was considered significant.

Needle release was completely successful in 15 cases (71.5%), almost complete release was achieved in four cases (19%), and incomplete transection occurred in two cases (9.5%). Thread release was completely successful in 17 cases (85%), and almost complete transection was observed in the remaining three cases (15%). In both procedures no neurovascular structures were harmed. Slight injury of flexor tendons occurred in two cases (9.5%) in needle release and in five cases (25%) in thread release. There were no significant statistical differences between the groups regarding ultrasound visibility, intervention safety and outcome, (P > 0.05).

Ultrasound-guided needle release and ultrasound-guided thread release have similar success of release, both being effective and safe techniques for the release of the A1 pulley.

Intramuscular heterogeneity exists in the shear modulus of the rectus femoris (RF) muscle. However, the underlying heterogeneity mechanisms are not entirely understood. Previous research has reported that detachment of superficial tissues reduces the shear modulus by 50%. The aim of this study was to examine the effects of the skin, deep fascia, and intermuscular connections on the shear modulus of the RF at multiple sites.

Eleven donors were fixed using the Thiel method. Measurements were performed at 0°, 60°, and 120° knee flexion in a neutral hip position. Tissue processing was performed under four conditions: superficial tissue (CONT), skin off (SKIN), deep fascia detachment (FASC), and intermuscular connections detachment (ALL). The shear modulus at the proximal, central, and distal regions were measured using ultrasound shear wave elastography. The study was approved by the Sapporo Medical University Ethical Committee.

Three-way ANOVA revealed no significant interaction between treatment, site, and angle (P = 0.156), treatment and angle (P = 0.067), or site and angle (P = 0.441). There was a significant effect of treatment (P < 0.001), site (P = 0.010), and angle (P < 0.001) and interaction between treatment and site (P < 0.001). The proximal shear modulus was greater than the central for CONT. There were no significant differences between the measurement sites for SKIN. The distal shear modulus was greater than the proximal for FASC. The distal shear modulus was also greater than the proximal and central for ALL.

Intramuscular regional differences that influence superficial tissue and intermuscular connections of RF elasticity heterogeneity were observed.

Unfortunately, the long-awaited revision of the official anatomical nomenclature, the Terminologia Anatomica 2 (TA2), which was issued in 2019 and after a referendum among the Member Societies officially approved by the General Assembly of the International Federation of Associations of Anatomists in 2020, is built on a new version of the Regular Anatomical Terminology (RAT) rules. This breaks with many traditional views of terminology. These changes in the Terminologia Anatomica of 1998 (TA98) met great resistance within many European Anatomical Societies and their members are not willing to use terms following the RAT rules. European anatomy teachers and scientists using traditional Latin in their teaching, textbooks and atlases will keep using the TA98. The German Anatomical Society (Anatomische Gesellschaft) recently announced the usage of the TA2023AG in curricular anatomical media such as textbooks and atlases, based on the TA98 and the Terminologia Neuroanatomica (TNA). We are preparing a more extensive improvement of the TA98, called Terminologia Anatomica Humana (TAH). This project is fully based on the noncontroversial terms of TA98, incorporating the recent digital version (2022) of the TNA from 2017. Further, it is completed with many new terms, including those in TA2, along with their definitions and relevant references, clinical terms, and correcting inconsistencies in the TA98. The TAH is still in process, but many chapters are already freely available at the IFAA Website in Fribourg ( https://ifaa.unifr.ch ) as is the digital version of the TNA.

Mold growth on body donations remains an underreported yet serious issue in anatomical teaching. Bacterial and fungal growth pose health risks to lecturers and students, alongside with ethical and aesthetic concerns. However, limited information exists on the presence of bacteria and fungi on body donations and their underlying causes. To investigate the potential impact of airborne germs on body donation contamination, we conducted indoor air measurements before, during, and after our anatomical dissection course, with outdoor measurements serving as a control. Tissue samples from the dissected body donations were collected to assess the germ load, with qualitative and quantitative microbiological analyses. Air samples from the dissection hall contained no fungi, but various fungal species were identified in the adjacent stairways and outdoors which implies that fungal occurrence in the dissection hall air was independent of lecturers' and students' presence. Moreover, our results indicate that adequate ventilation filters can effectively reduce indoor fungal germs during courses, while the bacterial load in room air appears to increase, likely due to the presence of lecturers and students. Additionally, the tissue samples revealed no bacterial or fungal germs which implies that our ethanol-formalin-based embalming solution demonstrates an effective long-term antimicrobial preservation of corpses.

The suprascapular nerve is an ideal target for nerve blockade to alleviate shoulder pain given its widespread innervation to the shoulder girdle. To widen availability of this treatment, we investigate whether an anatomical landmark technique can be adopted by novice injectors to provide efficacious blockade.

Five injectors were recruited with varying experience. 10 shoulders of Thiel embalmed cadavers were injected with blue dye. Written instructions and an illustration of the Dangoisse landmark technique were provided prior to injection. Cadavers were dissected and the presence or absence of dye staining reported by three observers and a consensus agreement reached.

Dissection demonstrated diffuse staining in the suprascapular fossa. 90% of shoulders had adequate staining of the suprascapular nerve directly, or distal branches, which would provide adequate anaesthesia. Inter-observer agreement was good (k = 0.73) for staining at the supraspinous fossa and excellent (k = 0.87) for staining distally. The technique was performed by novice injectors with a good success rate.

This technique is reproducible by a range of clinicians to effectively provide anaesthesia of the SScN. Within a resource strained healthcare environment greater uptake of this technique is likely to be of benefit to a wider group of patients.

The posterolateral region of the knee has a complex and diverse anatomy. Hydrarthrosis of the knee can potentially communicate with other parts of the joint space. The joint fluid distribution reflects anatomical communications between synovial spaces. To observe the continuity between the knee joint cavity and the surrounding bursa, we devised a dissection method with a new injection agent, an eosin-containing congealed liquid that spreads uniformly over the entire space. The purpose of this study was to perform a detailed examination of the subpopliteal recess (SPR) where a bursa connects to the knee joint capsule. We also reported the advantages of this new injection agent compared with conventional materials (latex and epoxy resin). Twenty-two formalin-fixed cadavers (34 knees), two N-vinyl-pyrrolidone (NVP)-fixed cadavers (4 knees), and two cadavers (3 knees) fixed by Thiel's method were used. After filling the knee joint space and SPR with eosin congealed liquid, the specimens were dissected to investigate the morphology of the SPR. In addition, three different types of injection agents were assessed. The SPR extended distally along the popliteus tendon. The SPR length was 22.64 ± 11.38 mm from the upper end of the lateral tibial condyle to the lower end of the depression. The existence of a fabellofibular ligament made the SPR significantly longer, but abrasion of the femoral articular cartilage did not affect the SPR. Furthermore, the relationship between the popliteus muscle and the SPR was classified into three types (types 1-3). Types 2 and 3 in which the SPR extended to the proximal tibiofibular joint may cause instability of the knee joint. The eosin congealed liquid was highly useful in many aspects, such as fluidity and injection workability. The new dissection method with eosin congealed liquid provides insights into the anatomy of the posterior lateral knee, which are useful for radiological diagnoses and clinical treatments.

(1) Background: This study aimed to integrate an augmented reality (AR) image-guided surgery (IGS) system, based on preoperative cone beam computed tomography (CBCT) scans, into clinical practice. (2) Methods: In preclinical and clinical surgical setups, an AR-guided visualization system based on Microsoft's HoloLens 2 was assessed for complex lower third molar (LTM) extractions. In this study, the system's potential intraoperative feasibility and usability is described first. Preparation and operating times for each procedure were measured, as well as the system's usability, using the System Usability Scale (SUS). (3) Results: A total of six LTMs (n = 6) were analyzed, two extracted from human cadaver head specimens (n = 2) and four from clinical patients (n = 4). The average preparation time was 166 ± 44 s, while the operation time averaged 21 ± 5.9 min. The overall mean SUS score was 79.1 ± 9.3. When analyzed separately, the usability score categorized the AR-guidance system as "good" in clinical patients and "best imaginable" in human cadaver head procedures. (4) Conclusions: This translational study analyzed the first successful and functionally stable application of the HoloLens technology for complex LTM extraction in clinical patients. Further research is needed to refine the technology's integration into clinical practice to improve patient outcomes.

Learning suturing skills is an important area of the undergraduate curriculum and ideally requires realistic and anatomically accurate surgical training models to prepare students for treating patients. Little is currently understood regarding which model might be perceived by students to be the best or which might most effectively facilitate their learning. The aim of this study was to compare four teaching models: a tabletop silicon dental model, a restricted access tabletop model, a traditional phantom head mounted model, and a Thiel cadaver. Student preferences were explored for each of the models. Following lecture and video-based teaching 67 fourth-year students attended a practical suturing teaching session followed by the second session more focused on the experience of cutting and suturing mucoperiosteal flaps. Forty-six students (67%) gave online anonymous feedback on the first session. The majority (95%) felt prepared to place a simple interrupted suture on a patient, and 88% felt confident to do so. Twenty-eight students (40%) provided feedback on the second session with 82% agreeing that they were prepared to cut a mucoperiosteal flap and 48% felt confident to do this for a patient. The cadaver model was rated as the best of the four models for both suturing and mucoperiosteal flap skills. These results support its use for teaching students to suturing and surgical skills. However, despite this teaching student-rated confidence to cut and suture flaps for a patient remains poor.

To examine the lateral rectus muscle pulley and its bony insertion concerning the orbital rim and periorbita.

Prospective. An observational anatomic study.

Study population: Twenty postmortem orbits (10 right, 10 left) of 10 Caucasian cadavers (8 females, 2 males; age range at death, 57-100 years; median age, 79.5 years) fixed by the Thiel method.Intervention: The floor of the temporal fossa was exposed, and a bone window on the lateral wall of the orbit, posterior to the sphenozygomatic suture, was created, keeping the periorbita intact. The lateral canthus and lateral palpebral ligament were isolated and opened, and the eyelids were folded back. The frontozygomatic suture was identified, and the orbital septum opened adjacent to the orbital rim. The conjunctiva was opened at the limbus, and the lateral rectus insertion was isolated. The bone pillar containing the frontozygomatic suture and the insertion of the periorbita and the pulley was isolated and removed en bloc. The lateral rectus muscle was isolated and excised.Main outcome measures: Position of the pulley ring on the lateral rectus muscle belly and its bony attachment area in the lateral wall of the orbit.

The pulley bony attachment was roughly quadrilateral with an approximate area of 90 mm2, 3 mm (mean, range 1-5 mm) posteroinferior to the frontozygomatic suture and 1 mm posterior to the orbital rim. The anterior margin of the pulley sleeve was found at 21.0 mm (median, p25-75 20.0-22.8) from the scleral insertion.

The lateral rectus pulley is stereotyped in its position in the muscle belly and its bony insertion, coinciding with the point of greatest adhesion of the periorbita to the anterior part of the lateral wall of the orbit.

Guyon's canal syndrome is caused by compression of the ulnar nerve at the wrist, occasionally requiring decompression surgery. In recent times, minimally invasive approaches have gained popularity. The aim of this study was to assess the efficacy and safety of ultrasound-guided thread release for transecting the palmar ligament in Guyon's canal without harming surrounding structures, in a cadaveric specimen model.

After ethical approval, thirteen ultrasound-guided thread releases of Guyon's canal were performed on the wrists of softly embalmed anatomic specimens. Cadavers showing injuries or prior operations at the hand were excluded. Subsequently, the specimens were dissected, and the outcome of the interventions and potential damage to adjacent anatomical structures as well as ultrasound visibility were evaluated with a score from one to three.

Out of 13 interventions, a complete transection was achieved in ten cases (76.9%), and a partial transection was documented in three cases (23.1%). Irrelevant lesions on the flexor tendons were observed in two cases (15.4%), and an arterial branch was damaged in one (7.7%). Ultrasound visibility varied among specimens, but essential structures were delineated in all cases.

Ultrasound-guided thread release of Guyon's canal has shown promising first results in anatomic specimens. However, further studies are required to ensure the safety of the procedure.

Our study showed that minimally invasive ultrasound-guided thread release of Guyon's canal is a feasible approach in the anatomical model. The results may provide a basis for further research and refinement of this technique.

• In Guyon's canal syndrome, the ulnar nerve is compressed at the wrist, often requiring surgical release. • We adapted and tested a minimally invasive ultrasound-guided thread release technique in anatomic specimens. • The technique was effective; however, in one specimen, a small anatomic branch was damaged.

The incidence of hamstring muscle strain varies among muscles, suggesting that the mechanical stresses associated with elongation may differ among muscles. However, the passive mechanical properties of whole human muscles have rarely been directly measured and clarified. This study aimed to clarify the stress-strain relationship of the hamstring muscles using a soft-embalmed Thiel cadaver. The long heads of the biceps femoris (BFlh), semimembranosus (SM), and semitendinosus (ST) muscles were dissected from eight cadavers. The proximal and distal hamstring tendons were affixed to the mechanical testing machine. Slack length was defined as the muscle length at the initial loading point detected upon the application of a tensile load. Muscle length was measured using a tape measure, and the anatomical cross-sectional area (ACSA) of the muscle was measured at the proximal and distal sites using B-mode ultrasonography. In the loading protocol, the muscle was elongated from its slack length to a maximum of 8% strain at an average rate of 0.83 L0/s, and the amount of displacement and tensile load were measured for each muscle. Further, the strain (%, displacement/slack muscle length) and stress (kPa, tensile load/ACSA) were calculated to evaluate the mechanical properties. Two-way repeated-measures analysis of variance (ANOVA) was used to compare stress changes with increasing muscle strain. A significant interaction between the muscle and strain factors was observed with respect to stress. Post-hoc tests revealed higher stresses in the BFlh and SM than in ST after 3% strain (P < 0.01). However, no significant differences were observed between the BFlh and SM groups. At 8% strain, the BFlh, SM, and ST exhibited stresses of 63.7 ± 12.1, 53.7 ± 23.2, and 21.0 ± 11.9 kPa, respectively. The results indicate that the stress changes associated with muscle strain differed among muscles. In particular, the stress applied to the three muscles at the same strain was found to be higher in the BFlh and SM. Thus, these findings suggest that increased mechanical stress during elongation may contribute to the frequent occurrence of muscle strain in BFlh and SM.

This study aimed to quantify the change in pressure on the cage during compression manipulation in lumbar interbody fusion. While the procedure involves applying compression between pedicle screws to press the cage against the endplate, the exact compression force remains elusive. We hypothesize that an intact facet joint might serve as a fulcrum, potentially reducing cage pressure.

Pressure on the intervertebral disc cage was measured during compression manipulation in 4 donor cadavers undergoing lumbar interbody fusion. Unilateral facetectomy models with both normal and parallel compression and bilateral facetectomy models were included. A transforaminal lumbar interbody fusion cage with a built-in load cell measured the compression force.

Pressure data from 14 discs indicated a consistent precompression pressure average of 68.16 N. Following compression, pressures increased to 125.99 N and 140.84 N for normal and parallel compression postunilateral facetectomy, respectively, and to 154.58 N and 150.46 N for bilateral models. A strong linear correlation (correlation coefficient: 0.967, P < 0.0001) between precompression and postcompression pressures emphasized the necessity of sufficient precompression pressure for achieving desired postcompression outcomes. None of the data showed a decrease in compression force to the cage with the compression maneuver.

Both normal and parallel compression maneuvers effectively increased the pressure on the cage, irrespective of the facet joint resection status. Compression manipulation consistently enhanced compressive force on the cage. However, when baseline pressure is low, the manipulation might not yield significant increases in compression force. This underlines the essential role of meticulous precompression preparation in enhancing surgical outcomes.

Lumbar radicular pain is a common symptom of lumbar disc herniation and spinal canal stenosis, and L4 nerve root impingement is difficult to diagnose. This study aimed to elucidate the extension rate of L4 nerve roots in Thiel-embalmed specimens using both classic and new femoral nerve stretch test (FNST), as well as straight leg raising test (SLRT). Additionally, the extension rate of the L2 and L3 nerve roots and L5 and S1 roots were determined using FNST (both classic and new) and SLRT, respectively.

Four Thiel-embalmed specimens were used. The extension rate data of the nerve root were obtained using a displacement sensor under the following conditions: knee joint flexed to 0°/45°/90°/135° with either the hip extension/flexion of 0° (classic FNST) or extension of 15° (new FNST); and hip joint flexed to 0°/30°/60°/90° with the knee flexion of 0° (SLRT).

Case A had almost no L4 nerve root lengthening at 45° and 90° knee joint flexion; however, at 135° of knee flexion, the nerve root was lengthened. In Case B, the L4 nerve root was hardly extended by the classic FNST, but it was extended at 135° of knee flexion and 15° of hip extension. In Case C, the L4 nerve root showed little change by classic FNST and it was shortened by new FNST, whereas, it was extended by SLRT. Case D showed a shortened L4 nerve root at 135° of knee flexion in classic FNST and at 0°/45°/90°/135° of knee flexion and 15° of hip extension. Further, no root shortening was observed for L2 and L3 nerve roots according to both classic and new FNST. In contrast, the extension of L2 and L3 nerve root with the new FNST was high. In all cases, nerve roots were lengthened by the SLRT. Further, as the hip flexion angle increased, the rate of nerve elongation also increased.

It was shown that in patients in whom L4 nerve root was extended by FNST, it was shortened by SLRT. The opposite pattern was also observed. Further, it is believed that FNST and SLRT are reliable tests for L2 and L3 radiculopathy and L5 and S1 radiculopathy, respectively, and that more tension on the femoral and sciatic nerves is better. Furthermore, we recommend that FNST should be performed with 15° hip extension and 135° knee flexion to improve the diagnostic accuracy.

We assessed types of cadaveric head and brain tissue specimen preparations that are used in a high throughput neurosurgical research laboratory to determine optimal preparation methods for neurosurgical anatomical research, education, and training.

Cadaveric specimens (N = 112) prepared using different preservation and vascular injection methods were imaged, dissected, and graded by 11 neurosurgeons using a 21-point scale. We assessed the quality of tissue and preservation in both the anterior and posterior circulations. Tissue quality was evaluated using a 9-point magnetic resonance imaging (MRI) scale.

Formalin-fixed specimens yielded the highest scores for assessment (mean ± SD [17.0 ± 2.8]) vs. formalin-flushed (17.0 ± 3.6) and MRI (6.9 ± 2.0). Cadaver assessment and MRI scores were positively correlated (P < 0.001, R2 0.60). Analysis showed significant associations between cadaver assessment scores and specific variables: nonformalin fixation (β = -3.3), preservation within ≤72 h of death (β = 1.8), and MRI quality score (β = 0.7). Formalin-fixed specimens exhibited greater hardness than formalin-flushed and nonformalin-fixed specimens (P ≤ 0.006). Neurosurgeons preferred formalin-flushed specimens injected with colored latex.

For better-quality specimens for neurosurgical education and training, formalin preservation within ≤72 h of death was preferable, as was injection with colored latex. Formalin-flushed specimens more closely resembled live brain parenchyma. Assessment scores were lower for preparation techniques performed > 72 h postmortem and for nonformalin preservation solutions. The positive correlation between cadaver assessment scores and our novel MRI score indicates that donation organizations and institutional buyers should incorporate MRI as a screening tool for the selection of high-quality specimens.

The mechanical characterization of the oesophagus is essential for applications such as medical device design, surgical simulations and tissue engineering, as well as for investigating the organ's pathophysiology. However, the material response of the oesophagus has not been established ex vivo in regard to the more complex aspects of its mechanical behaviour using fresh, human tissue: as of yet, in the literature, only the hyperelastic response of the intact wall has been studied. Therefore, in this study, the layer-dependent, anisotropic, visco-hyperelastic behaviour of the human oesophagus was investigated through various mechanical tests. For this, cyclic tests, with increasing stretch levels, were conducted on the layers of the human oesophagus in the longitudinal and circumferential directions and at two different strain rates. Additionally, stress-relaxation tests on the oesophageal layers were carried out in both directions. Overall, the results show discrete properties in each layer and direction, highlighting the importance of treating the oesophagus as a multi-layered composite material with direction-dependent behaviour. Previously, the authors conducted layer-dependent cyclic experimentation on formalin-embalmed human oesophagi. A comparison between the fresh and embalmed tissue response was carried out and revealed surprising similarities in terms of anisotropy, strain-rate dependency, stress-softening and hysteresis, with the main difference between the two preservation states being the magnitude of these properties. As formalin fixation is known to notably affect the formation of cross-links between the collagen of biological materials, the differences may reveal the influence of cross-links on the mechanical behaviour of soft tissues.

Distal radioulnar joint (DRUJ) instabilities are challenging and their optimal treatment is controversial. In special cases or when reconstruction of the stabilizing triangular fibrocartilage complex (TFCC) fails, K-wire transfixation can be performed. However, no consensus has been reached regarding the rotational position of the forearm in which this should be done. Therefore, it was investigated whether anatomical reduction would best be achieved by transfixation in neutral position or supination of the forearm.

Twelve cadaveric upper limbs were examined before dissection of the DRUJ stabilizing ligaments and after closed transfixation in both positions by C-arm cone-beam CT. Whether this was first done in neutral position or in supination was randomized. The change in the radioulnar ratio (RR) in percentage points (%points) was analyzed using Student's t-test. RR was used since it is a common and sensitive method to evaluate DRUJ reduction, expressing the ulnar head's position in the sigmoid notch as a length ratio.

The analysis showed an increased change in RR in neutral position with 5.4 ± 9.7%points compared to fixation in supination with 0.2 ± 16.1%points, yet this was not statistically significant (p = 0.404).

Neither position leads to a superior reduction in general. However, the result was slightly closer to the anatomical position in supination. Thus, transfixation of the DRUJ should be performed in the position in which reduction could best be achieved and based on these data, that tends to be in supination. Further studies are necessary to validate these findings and to identify influential factors.

In terms of the optics used for Knee arthroscopy, a large number of different endoscopes are currently available. However, the use of the 30° optics in knee arthroscopy has been established as the standard procedure for many years. As early as the 1990s, needle arthroscopy was occasionally used as a diagnostic tool. In addition to the development of conventional optics technology in terms of camera and resolution, needle arthroscopes are now available with chip-on-tip image sensor technology. To date, no study has compared the performance of this kind of needle arthroscopy versus standard arthroscopy in the clinical setting in terms of the visibility of anatomical landmarks. In this monocentric prospective feasibility study, our aim was to evaluate predefined anatomical landmarks of the knee joint using needle arthroscopy (0° optics) and conventional knee arthroscopy (30° optics) and compare their performance during knee surgery.

Examinations were performed on eight cadavers and seven patients who required elective knee arthroscopy. Two surgeons independently performed the examinations on these 15 knee joints, so that we were able to compare a total of 30 examinations. The focus was on the anatomical landmarks that could be visualized during a conventional diagnostic knee arthroscopy procedure. The quality of visibility was evaluated using a questionnaire.

In summary, the average visibility for all the anatomic landmarks was rated 4.98/ 5 for the arthroscopy using 30° optics. For needle arthroscopy, an average score of 4.89/ 5 was obtained. Comparatively, the needle arthroscope showed slightly limited visibility of the retropatellar gliding surface in eight (4.5/ 5 vs. 5/ 5), medial rim of the patella in four (4.85/ 5 vs. 5/ 5), and suprapatellar recess in four (4.83/ 5 vs. 5/ 5) cases. Needle arthroscopy was slightly better at visualizing the posterior horn of the medial meniscus in four knee joints (4.9/ 5 vs. 4.85/ 5).

Needle arthroscopy is a promising technology with advantages in terms of minimally invasive access and good visibility of anatomical landmarks. However, it also highlights some limitations, particularly in cases with challenging anatomy or the need for a wide field of view.

Anatomy is an essential component of clinical anesthesiology. The use of simulated patients and alternative materials, including embalmed human bodies, have become increasingly common during resident physician training due to the deemphasis on anatomical education during undergraduate medical training. In this report, the need for a more extensive review of relevant anatomy for the practice of anesthesiology was addressed by the design, evaluation, and dissemination of a human dissection course for procedural training of anesthesiology residents. The course utilized "freedom art" embalmed human bodies that allowed trainees to perform ultrasound-based regional and neuraxial techniques followed by detailed dissections of critical anatomy. One hundred and four residents participated in workshops and small group discussions and were evaluated using pre- and post-course assessments. A variety of clinical techniques were performed on the bodies, including regional blocks and neuraxial catheter placement. Insertion of peripheral/neuraxial catheters was successful, with dissections demonstrating the expected placement. Assessment scores improved following the course (pre-course mean 52.7%, standard deviation (σ) 13.1%; post-course mean 72.2%, σ 11.6%; t-test p < 0.0001) and feedback highlighted the usefulness and clinical relevance of course content. The ability to correlate ultrasound imaging with subsequent dissections of the "blocked" area and visualization of dye staining was extremely relevant for spatial understanding of the anatomy relevant for the clinical practice of these techniques. This manuscript demonstrates successful implementation of a comprehensive course for anesthesiology resident physicians to address gaps in undergraduate anatomical education and suggests that broader adoption of dissection courses may be beneficial for training anesthesiologists.

There is a debate whether corrective osteotomies of the distal radius should be performed using a 3D work-up with pre-contoured conventional implants (i.e., of-the-shelf) or patient-specific implants (i.e., custom-made). This study aims to assess the postoperative accuracy of 3D-assisted correction osteotomy of the distal radius using either implant.

Twenty corrective osteotomies of the distal radius were planned using 3D technologies and performed on Thiel embalmed human cadavers. Our workflow consisted of virtual surgical planning and 3D printed guides for osteotomy and repositioning. Subsequently, left radii were fixated with patient-specific implants, and right radii were fixated with pre-contoured conventional implants. The accuracy of the corrections was assessed through measurement of rotation, dorsal and radial angulation and translations with postoperative CT scans in comparison to their preoperative virtual plan.

Twenty corrective osteotomies were executed according to their plan. The median differences between the preoperative plan and postoperative results were 2.6° (IQR: 1.6-3.9°) for rotation, 1.4° (IQR: 0.6-2.9°) for dorsal angulation, 4.7° (IQR: 2.9-5.7°) for radial angulation, and 2.4 mm (IQR: 1.3-2.9 mm) for translation of the distal radius, thus sufficient for application in clinical practice. There was no significant difference in accuracy of correction when comparing pre-contoured conventional implants with patient-specific implants.

3D-assisted corrective osteotomy of the distal radius with either pre-contoured conventional implants or patient-specific implants results in accurate corrections. The choice of implant type should not solely depend on accuracy of the correction, but also be based on other considerations like the availability of resources and the preoperative assessment of implant fitting.

A substantial proportion of conventional tibial plateau plates have a poor fit, which may result in suboptimal fracture reduction due to applied -uncontrolled- compression on the bone. This study aimed to assess whether patient-specific osteosyntheses could facilitate proper fracture reduction in medial tibial plateau fractures.

In three Thiel embalmed human cadavers, a total of six tibial plateau fractures (three Schatzker 4, and three Schatzker 6) were created and CT scans were made. A 3D surgical plan was created and a patient-specific implant was designed and fabricated for each fracture. Drilling guides that fitted on top of the customized plates were designed and 3D printed in order to assist the surgeon in positioning the plate and steering the screws in the preplanned direction. After surgery, a postoperative CT scan was obtained and outcome was compared with the preoperative planning in terms of articular reduction, plate positioning, and screw direction.

A total of six patient-specific implants including 41 screws were used to operate six tibial plateau fractures. Three fractures were treated with single plating, and three fractures with dual plating. The median intra-articular gap was reduced from 6.0 (IQR 4.5-9.5) to 0.9 mm (IQR 0.2-1.4), whereas the median step-off was reduced from 4.8 (IQR 4.1-5.3) to 1.3 mm (IQR 0.9-1.5). The median Euclidean distance between the centre of gravity of the planned and actual implant was 3.0 mm (IQR: 2.8-3.7). The lengths of the screws were according to the predetermined plan. None of the screws led to screw penetration. The median difference between the planned and actual screw direction was 3.3° (IQR: 2.5-5.1).

This feasibility study described the development and implementation of a patient-specific workflow for medial tibial plateau fracture surgery that facilitates proper fracture reduction, tibial alignment and accurately placed screws by using custom-made osteosynthesis plates with drilling guides.

The purpose of this study was to investigate the positional effect of guide pins used in the transtibial pullout repair of medial meniscus posterior root tears on the popliteal artery.

We used eight cadaveric knees. Two 2.4-mm guide pins were inserted into the posterior root of the medial meniscus at 50° to the articular surface from the medial edge of the tibial tuberosity (anteromedial group) and the anterior edge of the medial collateral ligament (posteromedial group) using an aiming guide placed at the posterior root attachment of the medial meniscus from the anteromedial portal. The posterior capsule was dissected, and the popliteal artery was identified. The positional effect of the guide pins on the popliteal artery was photographed arthroscopically at 0°, 30°, 60°, and 90° knee flexion angles. The popliteal artery diameter and the minimum distance between the popliteal artery center and the guide pin tip were measured.

At 90° knee flexion, most of the guide pins in the anteromedial (6 knees; 75 %) and posteromedial groups (7 knees; 87.5 %) collided with the femoral intercondylar wall. The rate of collision was significantly higher at the 90° knee flexion position than that at other angles (p = 0.02). The average shortest distance between the popliteal artery center and the guide pin tip at 0° knee flexion in the posteromedial group (5.4 mm ± 3.4 mm) was significantly greater than that at other knee flexion angles, although the mean distance in the posteromedial group was so negligible that the guide pin could penetrate the popliteal artery.

Knee flexion at 90° causes less damage to the popliteal artery during the transtibial pullout repair of medial meniscus posterior root tears.