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Purpose: The paracentral lobule artery (PLA) is a typically present branch of the distal anterior cerebral artery (ACA), irrigating the homonymous lobule. The PLA origin is either a pericallosal portion of the ACA or a prominent branch of the ACA termed callosomarginal (CMA). In addition to the paracentral lobule, the PLA irrigates the cingulate gyrus in the medial hemispheric surface, and the superior portion of the precentral and postcentral gyri in the lateral hemispheric surface. The present cadaveric case series aimed at establishing previously unreported morphometric estimates of the PLA, including its length according to its site of origin, its supplying branches according to its distribution area, as well as its anastomoses., Methods: Seventeen colored latex-injected cadaveric heads were studied with a surgical microscope and microsurgical instruments., Results: The PLA was invariably present and most commonly originated from the A4 (n = 15 hemispheres, 50%) segment of the ACA. Other PLA origins were the CMA (n = 10, 30%), the A3 (n = 5, 16.7%) and the A5 (n = 1, 3.3%) segments. When the PLA originated from the A4, its mean (SD) overall length was 7.6 (17.9) mm and its mean (SD) diameter was 0.88 (0.26) mm. The PLA supplied the paracentral lobule, cingulate gyrus and post central gyrus with a mean (SD) of 28.07 (13.4), 8.53 (4.27), 5.92 (4.4) branches respectively and the precentral gyrus with a median [IQR] of 2 [0-6] branches. The most common anastomoses of the PLA in the medial and the lateral hemispheric surface involved the ipsilateral posterior internal frontal artery and the branches of the middle cerebral artery, respectively. There were no significant differences between sexes or hemispheric sides for the anatomical features of the artery analyzed., Conclusion: The present study established previously unreported morphometric estimates for the PLA by considering all possible PLA variant origins and morphological variants. Given that variable pathologies have been previously detected in the areas supplied by the PLA, a better understanding of its anatomy can aid surgical planning and approaches., Competing Interests: Declarations. Conflict of interest: The authors declare no conflict of interest. Ethical approval: The research was conducted ethically following The Code of Ethics of the World Medical Association (Declaration of Helsinki). The cadavers belonged to the Department of Neurosurgery, School of Medicine, National and Kapodistrian University of Athens., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background: Understanding the attachment patterns of the corrugator supercilii (CS) muscle is vital for treatments designed to improve facial symmetry and functionality., Objectives: The aim of this research was to elucidate the anatomical trajectory and intricate relationships of the CS within the upper face and midface, specifically focusing on its connections with the frontalis (FT) and orbicularis oculi (OOc) muscles., Methods: The CS was examined in 41 specimens of embalmed adult Korean cadavers with microdissection, histological analyses, and microcomputed tomography, performing an in-depth exploration of its anatomical positioning and the intricate interactions with adjacent muscles., Results: Some lower fibers of the CS extended to the upper orbital part of the OOc in 59.5% of cases, while the CS interdigitated or blended exclusively with the FT in 40.5% of cases. The fibers of the CS demonstrated diverse extensions toward the upper face and midface, exhibiting varied trajectories and lengths. Additionally, lower fibers of the CS extended to significant anatomical landmarks such as the OOc, malaris muscle, and the superficial musculoaponeurotic system (SMAS)., Conclusions: In this study, we demonstrate that precise understanding of the CS and its relationship with the FT and OOc is crucial for optimizing invasive or noninvasive treatment like botulinum toxin injection, SMAS lifting, and browplasty surgery. The extension of lower fibers of the CS to significant anatomical landmarks indicates complex interactions with adjacent facial structures, highlighting the necessity of detailed anatomical knowledge for clinical applications., (© The Author(s) 2024. Published by Oxford University Press on behalf of The Aesthetic Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Purpose: The stellate ganglion (SG), or cervicothoracic ganglion, is usually located anterior to the neck of the first rib. Various techniques, such as ultrasonographic imaging and fluoroscopic approaches, are used to assist in the anesthetic blockade of the SG. However, there are reported complications associated with SG block; some patients had medication-related or systemic side effects, and some had procedure-related or local side effects. So, understanding the anatomy of the SG is critical for diagnosis and treatment of nerve block accuracy and to avoid unnecessary nerve damage during surgical procedures. This study aimed to collect data for the gross shape of the SG and histologically investigate these different types., Methods: The SG from 31 formalin-fixed adult cadavers (59 sides) were studied. The prevalence and shape of the SG were recorded and photographed. Next, the SG for each type was examined histologically., Results: The SG were classified into four types based on their shape: dumbbell, spindle, star, and inverted L shapes. The frequency of each type was as follows: spindle (47.46%), dumbbell (27.12%), star (23.73%), and L-inverted shapes (1.69%). Each type had a similar number of nerve cell bodies. Interestingly, the inverted-L shaped SG was histologically, discontinuous but grossly fused., Conclusion: An improved understanding of the SG's macro and microanatomy can help better understand patient presentations and improve clinical and surgical results in procedures performed near this important neck structure., Competing Interests: Declarations. Conflict of interest: The authors declare that they have no competing interests. Ethical approval: The present study was performed in accordance with the requirements of the Declaration of Helsinki (64th WMA General Assembly, Fortaleza, Brazil, October 2013). The present study protocol did not require approval by the ethics committees of our institutions. Consent for publication: Not applicable., (© 2024. The Author(s).)

Background: The main purpose of this study was to determine the feasibility of sparing the rectoprostatic fascia (RPF) in adult male cadavers and in adult male patients who underwent total mesorectal excision (TME) for rectal cancer. A secondary objective was to evaluate urogenital function following rectal cancer surgery, pathologic, and oncologic outcomes., Methods: In accordance with PRISMA guidelines, we performed a systematic review with an a priori design to identify relevant studies via MESH terms and keywords. Research was conducted from March 1st to July 31st 2023 and was updated between September 30th to October 10th 2024 in MEDLINE, SCOPUS, the Web of Science, Google Scholar, and reference lists. Disagreements between individual judgments were resolved by referral to a third researcher., Results: In total, 3693 studies were identified, 22 of which were relevant to the main research question. Overall, 785 living individuals and 25 cadavers were included in whom RPF was identified and spared (498/785 patients or 63.44%). The quality of the surgical specimen was considered good in all cases. Urogenital integrity at 6 months after RPF-TME and the classic TME were compromised in 27.9% and 41% of patients, respectively. One study revealed that at 3 years, local/systemic recurrence was similar between the two groups., Conclusions: Despite the fact that the current practice of rectal cancer surgery requires the TME to extend anteriorly to the RPF, RPF-sparing TME is not only a feasible and safe option but also important for preserving fair male urogenital function, especially for young patients whose erectile function is a priority., Trial Registration: CRD42020171188., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests. Ethical approval: This was a systematic review study. The University Hospital of Heraklion ethics committee confirmed that no ethical approval was needed. Consent to participate’ and/or ‘Consent to publish: This is a systematic review. No human participants were involved, and no consent was needed., (© 2024. Springer Nature Switzerland AG.)

Introduction: The foramen ovale (FO) is present in the posterior part of the greater wing of sphenoid. A trauma or space-occupying lesion in this area would result in clinical manifestations due to compression of the structures passing through it. This study was undertaken because of the clinical significance of the FO in radiological and neurological procedures. The aim is to study the morphometry of the FO and its bilateral variations., Material and Methods: Fifty adult dry human skulls of unknown age and sex were studied. The shape of the FO, presence of accessory foramina or abnormal bony outgrowths, if any, were noted. Maximum length and width of FO were measured., Results: The FO was present bilaterally in all 50 skulls. Accessory foramen was present in 17 (34%) and 13 (26%) skulls on the right and left side, respectively. Bony out growths were present in 9 (18%) and 15 (30%) skulls on the right and the left side, respectively., Conclusion: Understanding the exact topography, morphometry and variations of the FO is required to enable the clinician to correctly interpret radiographs and help in planning the surgical procedures. The findings presented here should be taken into account when neurological procedures of the middle cranial fossa are performed.

The aim of our study was to examine the relationship between uncus and uncal branches of anterior choroidal artery (AChA) and to observe the morphological and morphometric features of these branches. 124 hemispheres from 62 fresh cadavers were included in the study. Measurement of the length of AChA and the distances of the uncal branches to the origin of AChA were measured by ImageJ software. Morphological variations of uncal branches originating from AChA were observed. The length of AChA was found as mean 26.24 ± 4.34 mm. It was determined that the average distance of these uncal branches arising from the AChA was 13.48 ± 7.31 mm. In 4 out of 124 AChAs, no branches were observed. 594 branches originating from 120 were detected. 130/594 branches appeared to be terminal branches. AChAs of 80/120 hemispheres have been reported to have uncal branches. Thirty of 130 uncal branches were observed to originate as the first branch of AChA. It was found that uncal branches may originate from AChA with a variability between 1 and 4. When evaluated according to the origin of each branch from the AChA, it was observed that the uncal branches originated from the midpoint of the AChA on average. Also, in 64 hemispheres, morophological variations were detected regarding the origin of uncal branches. We believe that the morphological and morphometric data we obtained from the uncal branches of the AChA are of clinical importance in terms of understanding this complex region and minimizing errors in surgical procedures., Competing Interests: Declarations. Ethical approval: The Istanbul University Istanbul Faculty of Medicine’s Clinical Research Ethics Committee granted ethical permission (date: 01.12.2023, number: 2023/2145). Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: This study aims to determine the learning curve for lumbar discectomy and nerve root decompression using the unilateral biportal endoscopic (UBE) technique on fresh frozen cadavers through linear regression and cumulative sum (CUSUM) analyses., Methods: The analysis was conducted on three spine surgeons without UBE experience. They performed lumbar discectomy using the unilateral endoscopic technique on fresh frozen cadavers. Each physician performed operations on 40 lumbar spine segments, recording the time it took each physician to complete a segment of lumbar discectomy by UBE. The learning curve was assessed by linear regression and CUSUM analysis using SPSS 27.0 software and GraphPad Prism 8.0 software., Results: According to the CUSUM analysis of the learning curve, the number of segments required to complete the learning phase for the three surgeons was 20, 16, and 20, respectively. With the increased number of operated segments, the operation time for each lumbar vertebral segment gradually decreased and stabilized., Conclusions: In our study, spine surgeons without experience in UBE require 20 segments of surgery to overcome the UBE learning curve. Additionally, fresh frozen cadavers can effectively simulate real surgeries. Whenever possible, we should reasonably use fresh frozen cadavers for early UBE training of doctors, thereby better protecting the health and safety of patients., Competing Interests: Declarations. Ethical approval and consent to participate: This study was performed in line with the principles of the Declaration of Helsinki. Approval was granted by the Ethics Committee of Three Gorges University Renhe Hospital(2022KY26). The doctor was informed, and a consent form was signed before their participation in the study. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Purpose: The tibialis posterior (TP), flexor digitorum longus (FDL), and flexor hallucis longus (FHL) are muscles that contribute to the stability of foot and ankle movements, playing a crucial role in achieving optimal gait. However, a comprehensive examination of the anatomical characteristics and histological variances of each muscle has not been conclusively established., Methods: A total of 10 un-embalmed cadavers were dissected, and muscles from each cadaver were consistently harvested from the musculotendon junction. The ratio of collagen and elastic fibers was assessed through three immunohistological analyses, focusing on distinct histological characteristics in type I (slow twitch) and type II (fast twitch) fibers. Additionally, Ultrasonography was utilized to compare and analyze the thickness, fascicle angle, and muscle fiber length of each muscle., Results: Concerning the relative proportion of elastic fibers to collagen, the TP exhibited the highest collagen content (21.9 ± 0.30%, mean ± standard deviation), while the FHL had the highest elastic fiber proportion (48.4 ± 0.44%). The TP predominantly comprised slow type muscle fibers (36.88 ± 0.83%), whereas the FHL contained a higher density of fast type muscle fibers (32.46 ± 4.02%). US analysis indicated that the thickness of the TP was relatively greater (2.0 ± 0.2 mm) compared to the FDL (1.2 ± 0.1 mm) and FHL (1.1 ± 0.1 mm). Additionally, the fascicle length was notably longer in the TP (25.6 ± 4.1 mm)., Conclusion: Our anatomical and histological findings indicate that the tibialis posterior (TP) is the thickest with a significant physiological angle and a high collagen content. This characteristic enables the TP to provide stability by transmitting a constant force to the calf. On the other hand, the flexor hallucis longus (FHL) exhibits the highest elastic fiber content, confirming its ability to exert instantaneous, swift, and powerful force., Competing Interests: Declarations. Conflicts of interest: The authors declare no competing interests. Human ethics: This report was approved by the Institutional Review Board of the Catholic University of Korea, Seoul, Korea (MC23EISE0022). Consent to participate: This research involves using cadavers. Therefore, we would like to submit the human participant declaration as a document to the IRB (Institutional Review Board) and affiliated research institute (Approval of the Catholic University of Korea: MC23EISE0022)., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Purpose: Knowledge of a large communication between posterior circumflex humeral and deep brachial arteries, although infrequent, it is important to avoid damage during a Leechavengvongs procedure or used as recipient artery in free flaps for upper limb reconstruction., Methods: A dissection of a latex-injected cadaver revealed the presence of a large communication between the posterior circumflex humeral and deep brachial arteries. Furthermore, this communicating artery was observed during a Leechavengvongs procedure. A comprehensive review of the existing literature on the anatomical variations of the posterior circumflex humeral and deep brachial arteries was conducted., Results: A communicating artery between the posterior circumflex humeral and deep brachial arteries was identified during a routine dissection. This communicating artery establishes a posterior collateral pathway of substantial caliber between the axillary and the brachial arteries. Given its oblique trajectory posteriorly along the humeral shaft, this artery is susceptible to injury during a posterior approach to the humerus. Despite the existence of numerous anatomical variations involving the posterior circumflex humeral and deep brachial arteries, this communicating artery has not been previously described in the literature. Additionally, we report this anatomical variation crossing the surgical field during a Leechavengvongs procedure., Conclusion: Our findings suggest that a large communicating artery between the posterior circumflex humeral artery and the deep brachial artery has the potential to cross the surgical field and become a source of risk during a posterior approach to the arm. It can also be used as recipient artery in free flaps for upper limb reconstruction., Competing Interests: Declarations. Conflict of interest: The authors declare that they have no conflict of interest., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Introduction: The Marginal Mandibular Nerve (MMN), despite being didactically described as being a unique branch of the other branches of the Facial Nerve, has in practice an abundant anatomical variation. Both in relation to its ramifications and the positioning of these in relation to the lower edge of the mandible, as well as its anastomoses along its path, play a fundamental role in the surgical strategy during the approach of this cervicofacial site, and can generate, as underestimated its characteristics, inadvertent injuries and motor consequences to the patient., Objective: To analyze the types of anatomical variations of the MMN in relation to its position, ramification, and distance from reference points, as well as its incidence that could imply technical difficulties in surgery., Methods: A systematic review was conducted in the literature in search of anatomical studies, in vivo or in cadavers, between 1981 and 2024, which described the quantification of the MMN branches, their positioning and peculiarities in relation to anastomoses with other peripheral nerves., Results: 511 hemifaces were studied, with the identification of 290 cases of single nerve, 160 cases of double branch, 54 cases of triple branch, and 7 cases of quadruple branch. Of the 456 nerves that were possible to study, the average distance when superior to the lower limit of the mandible was 1.61 cm, while its lower analysis was 2.53 cm. The branches presented different proportions of presentation in relation to this reference point depending on how many branches it had, being more common to remain below it. Anastomoses were identified between the MMN and the buccal and cervical branch of the Facial Nerve, as well as with the Trigeminal Nerve., Conclusion: The varied presentations of the MMN, both in its anatomical positioning and in the number of branches leads us to question whether the surgical thinking when performing an exploration in this site may not be the reason whythe authors verify several motor complaints superior to described injuries., Competing Interests: Conflicts of interest The authors declare no conflicts of interest., (Copyright © 2024. Published by Elsevier España, S.L.U.)

Study Design: Human cadaver study., Objectives: To provide a qualitative and quantitative evaluation by demonstrating measurements of the proximity of vital structures involved and assessed injuries during a T12-corpectomy and cage implantation via a far lateral approach., Material and Methods: Six fresh-frozen adult cadaveric specimens were dissected according to standardized protocol. A formal left-sided far lateral T12-corpectomy was carried out by trained experienced spine fellows. Upon completion of the procedure, a cage was placed between T11 and L1. We then turned the patient supine and performed a formal celiotomy and sternotomy to allow for an open anterior central inspection of all structures concerned. Vital structures as in vessels, diaphragm, pleural membranes, neural elements, important foramina of the diaphragm (Bochdalek, Morgagni) and the thoracic duct were identified. Any injuries to these structures were recorded and proximity to key relevant structures to this exposure were measured., Results: We were able to quantify the actual diaphragm excursions and describe its origins to the spine. There was no actual diaphragm injury in any of the cadavers and there were no injuries to the neurovascular structures. We found expected parietal but no visceral pleural injuries., Conclusion: Our cadaver study identified the feasibility of performing a T12-corpectomy through a far lateral approach with no violation of the actual diaphragm and expected limited injuries to the parietal pleura only., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

The ethmoidal foramina (EF), located on the medial orbital wall along the frontoethmoidal sutures, are critical anatomical landmarks for surgeries involving the medial orbital wall. This review aimed to review the surgical anatomy of the EF, including their embryology and radiology. Although the frontoethmoidal sutures mostly have two foramina passing through them, there are reports of single foramen or multiple, up to six foramina. These foramina provide a passage for the ethmoidal arteries and nerves, branches of ophthalmic arteries and nerves. The surgical guideline "24-12-6" is based on the approximate distance between the anterior lacrimal crest, the anterior and posterior ethmoidal arteries, and the optic canal, commonly used to navigate this area. However, some studies from various populations defined different ratios. Embryologically, the EF were formed by the union of intramembranous ossified frontal bones and endochondral ossified ethmoid bones. EF and neurovascular structures can be identified in computed tomography even in the 3 mm sectional intervals. A comprehensive anatomical understanding of EF will help clinicians improve surgical guidelines and ultimately reduce the risk of complications.

This study explores the main surface markers in the hemodialysis puncture catheterization pathway and the relative spatial position of venous vessels in the puncture results, providing data support for venous puncture. Seventy cadavers were studied; angles of vertical axis with superior vena cava, left and right brachiocephalic vein at the confluence and circumference of superior vena cava were the primary parameters. Bivariate correlation analysis was used to determine in relation to other body parameters, and a regression equation was also obtained. The angle of the vertical axis with the superior vena cava at the confluence was linearly correlated with the distances between the coracoid processes and the jugular notch to coracoid processes. The angle of the vertical axis with left brachiocephalic vein was linearly correlated with the thickness of thorax and the length from the upper pericardial margin to the confluence. The angle of the vertical axis with right brachiocephalic vein was correlated with clavicular midline length, acromial distance, intersection point of clavicle to clavicular midline, confluence to clavicular midline, superior edge of the blood vessels to superior edge of clavicle at the right intersection, and superior edge of pericardium to confluence. There is a linear relationship between the superior vena cava circumference and the distance from the superior vena cava to the aorta. A number of parameters influence angles of the vertical axis with superior vena cava, left and right brachiocephalic veins and the superior vena cava circumference which can provide guidance for intubation., Competing Interests: Declarations. Ethics approval and consent to participate: This study has been approved by the Ethics Committee of Zhengzhou University, and the informed consent of the next of kin of the research subject has been obtained, allowing the data in this paper to be used and published. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Laminectomy and posterior fixation are well-established surgical techniques to decompress nervous structures in case of lumbar spinal stenosis. While laminectomy is suspected to increase the instability of the spine, posterior fixation is associated with some complications such as adjacent segment degeneration. This study aimed to investigate how laminectomy and posterior fixation alter the biomechanics of the lumbar spine in terms of range of motion (ROM) and strains on the intervertebral discs. Twelve L2-S1 cadaveric spines were mechanically tested in flexion, extension, and lateral bending in the intact condition, after two-level laminectomy and after L4-S1 posterior fixation. The ROM of the spine segment was measured in each spine condition, and each loading configuration. The strain distribution on the surface of all the intervertebral discs was measured with Digital Image Correlation. Laminectomy significantly increased the ROM in flexion (p = 0.028) and lateral bending (p = 0.035). Posterior fixation decreased the ROM in all the loading configurations. Laminectomy did not significantly modify the strain distribution in the discs. Posterior fixation significantly increased the principal tensile and compressive strains in the disc adjacent the fixation both in flexion and in lateral bending. These findings can elucidate one of the clinical causes of the adjacent segment degeneration onset., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

Bone conduction implants enable patients to hear via vibrations transmitted to the skull. The main constraint of current bone conduction implants is their maximum output force level. Stimulating closer to the cochlea is hypothesized to increase efficiency and improve force transfer, addressing this limitation. This study evaluated stimulation at four positions in human cadaveric specimens: the cochlear promontory, the posterior wall of the outer ear canal, the lateral semi-circular canal, and the standard Bone-Anchored Hearing Aid (Baha) location. To assess potential hearing sensation, three objective measures were simultaneously recorded. For intracochlear pressure and promontory velocity, stimulating at the lateral semi-circular canal and promontory results in the highest response, with a gain of up to 20 dB. Ear canal pressure shows less conclusive results, with significant differences at only a few frequencies. These findings suggest that stimulation closer to the cochlea offers higher efficiency, which could benefit patients needing higher output force levels than currently available or those eligible for electro-vibrational stimulation, e.g. a cochlear implant combined with a bone conduction device., Competing Interests: Declarations. Competing interests: GF is employed by Cochlear Ltd. The remaining authors declare no competing interests., (© 2024. The Author(s).)

Purpose: This study aimed to clarify the origin, insertion, and subdivision of the orbicularis oculi in detail with in situ specimens, as well as with isolated muscle specimens from the superficial and deep aspects., Methods: The periorbital muscles in fifteen cadavers fixed with formalin were examined in situ and/or in isolated muscle specimens, and evaluate their actions., Results: The orbicularis oculi arose via the nasoglabellar aponeurosis, which was observable in the deep aspect of isolated specimens as a rigid sheet of connective tissue in the middle of both orbits and adhered to the dorsum nasi in situ (100%). The two subdivisions of the orbicularis oculi were demarcated at the lateral angle of the eye and exhibited different insertions. The fascicles of the upper and lower halves of the inner part met each other at the lateral canthus and formed a shallow groove between them as observed in situ, and terminated via the lateral palpebral raphe on the deep aspect of the muscle to the temporal fascia. The fascicles of the upper and lower halves of the outer part extended over the orbital margin and intermingled with each other to disperse in the temporal subcutaneous tissue., Conclusions: The nasoglabellar aponeurosis was structurally characterized as the common origin of the periorbital muscles. The present study confirmed that the inner and outer parts of the orbicularis oculi are distinguished by the difference of lateral termination and interpreted as having different function on the palpebral movement in each., Competing Interests: Declarations. Ethics approval: All cadavers examined were from persons who had donated their bodies to Juntendo University School of Medicine for medical education and research. Prior to donation, written consent was obtained from the individuals and families. The protocol for the present research project was approved by the Ethics Committee of Juntendo University School of Medicine (approval No. 2014138). Competing interests: The authors declare no competing interests. Conflict of interest: The authors declare no potential conflict of interest., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background and Objectives: The subcostal transversus abdominis plane block (scTAPB) provides analgesia to the anterior abdominal wall but analgesic spread following a single injection remains modest and variable. The oblique scTAPB, which is performed with a continuous injection during needle progression into the TAP along the oblique subcostal line, may extend the block to the whole anterior abdominal wall but needle progression by hydrodissection may be difficult, explaining why this block is not widely used. This study investigated if two sequential scTAPB injections (2scTAPI) may reach more nerves than a single scTAPB (1scTAPI)., Methods: After institutional approval and under ultrasound guidance, a single injection of 20 mL of blue dye was performed in 16 cadaveric subjects into the TAP along the costal margin and lateral to the semilunaris line (1scTAPI). On the opposite side, a 20 mL of green solution was split into two injections (2scTAPI), using one injection medial and one lateral to the semilunaris line. Dye spread was assessed via gross anatomical dissection using an indirect method to quantify the involvement of the anterior cutaneous branches of the intercostal nerves with each technique. A nerve was considered stained if the dye was observed in the TAP, reaching the costal margin aligned with the bony extremity of its corresponding rib., Results: According to the spread to the costal margin, the estimated median number of consecutive nerves reached by dye after 2scTAPI was 5 (IQR 5-6) vs 3 (IQR 3-4) for 1scTAPI (p=0.00001). Spread after 2scTAPI suggested coverage of nerves originating from T8 to T12 in 85% of the subjects, and from T7 to T12 in 5 out of 17 cases. Spread following the 1scTAPI suggested coverage of nerves from T9 to T11 in most cases., Conclusions: In a cadaveric model, a larger spread at the costal margin was obtained after 2scTAPI, suggesting a greater coverage of anterior branches of abdominal wall nerves compared with 1scTAPI. Clinical studies are needed to confirm these results., Competing Interests: Competing interests: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: This cadaveric study aimed to analyze injectate spread to target nerves during a single-injection, ultrasound-guided intertransverse process block., Methods: An ultrasound-guided intertransverse process block with three different injectate volumes was administered to 12 cadavers. Each hemithorax was subjected to computer-generated random allocation of 10, 15, or 20 mL ultrasound-guided, single-injection intertransverse process block at the T2 vertebral level. Latex dye solution was injected into each hemithorax in accordance with the allocated volume. The presence of dye at the nerve root in the sympathetic chain and intercostal nerves at various injection levels was examined via dissection., Results: Injectate spread into the dorsal rami was observed in seven of eight (87.5%), seven of eight (87.5%), and all eight (100%) of the 10, 15, and 20 mL specimens, respectively. In all 20 mL specimens, consistent staining of the dorsal rami, spinal nerve, and dorsal root ganglion was observed., Conclusions: An injectate volume of 20 mL was required for consistent staining of the dorsal rami, spinal nerve, and dorsal root ganglion in an intertransverse process block. Although an augmented injectate volume was associated with an increased likelihood of target nerve staining, consistent staining of the sympathetic ganglion, rami communicans, and ventral ramus was not observed, even at a volume of 20 mL. The current study presents initial findings suggesting that as opposed to a sympathetic ganglion block, a 20 mL intertransverse process block may act as a feasible substitute for dorsal root ganglion, spinal nerve, and medial branch blocks within a clinical context., Competing Interests: Competing interests: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

This study aimed to compare the angular, platform, and apical deviation of zygoma implants placed with the aid of a dynamic navigation (DN) device compared with the implants placed freehand. Eight cadaver heads were used for the study. Preoperative cone beam computerized tomography (CBCT) scans were made for the heads, and an implant-planning software was used to plan zygoma implants bilaterally in each scanned head. A total of 16 zygoma implants were placed using each surgical technique. Postimplant CBCT scans were merged with the preoperative plan to evaluate and compare the accuracy of the implants using each technique. Angular and linear deviations of the implants were measured and compared. The effect of implant length and position on the deviation was also investigated. The results showed a mean angular deviation of 2.44° ± 1.10° for implants placed using DN compared with 6.63° ± 4.81° for implants placed freehand. The mean apical deviation for implants placed using DN and for implants placed freehand was 2.14 ± 1.02 mm and 3.80 ± 2.49 mm, respectively. Finally, the mean platform deviation for implants placed using DN and for implants placed freehand was 1.66 ± 0.9 mm and 2.81 ± 2.1 mm, respectively. The analysis showed a significant difference between the two techniques in angular and apical deviation (p = .001 and .029, respectively). Zygoma implants placed with a DN device resulted in less apical and angular deviation than implants placed freehand.

Objective: Despite its potential advantages, robotic surgery has yet to be applied to skull base procedures. Complex anatomy and restricted access have limited the development of robotic skull base surgery. The authors' aim was to conduct a feasibility study of robotic surgery for posterior fossa skull base lesions., Methods: Six silicone-injected postmortem human heads were prepared for the robotic surgery. Because there was no drilling tool with the robot, specimens were dissected in advance using an endoscope and microscope. The following approaches were investigated: 1) supracerebellar-infratentorial; 2) retromastoid; and 3) posterior occipitocervical junction surgeries. For each approach specific anatomical landmarks were identified, and the surgical freedom (vertical distance angle between the tools) was measured., Results: In the case of the supracerebellar-infratentorial approach, the authors used 3 burrs with 1.5 cm of diameter: 1 paramedian and 2 laterally. The view of the pineal region was visualized, and sufficient surgical freedom of both tools was secured. The median vertical distance was 1.2 cm (range 1.1-1.8 cm), and the median angle between the tools was 105° (range 92°-110°). On the other hand, in the retromastoid approach, with a single burr 2.5 cm in diameter, the root exit zone of the facial nerve was barely visible, and a space for tools to access was not secured. The median vertical distance was 0.8 cm (range 0.6-1.0 cm), and the median angle between the tools was 10° (range 6°-12°). In the case of the posterior occipitocervical junction approach, the authors used the 3 tubular retractors, 1 in the middle and 2 laterally. Even though the space was narrow, the medulla and adjacent nerves could be identified, and a moderate level of surgical freedom could be obtained for tool mobilization. The median vertical distance was 1.6 cm (range 1.2-2.5 cm), and the median angle between the tools was 90° (range 88°-95°)., Conclusions: Although robotic surgery has yet to be applied to neurosurgery, it is expected to be helpful in posterior fossa skull base surgery if appropriate tools can be developed.

Objective: This study aimed to introduce a novel artificial intelligence (AI)-based robotic system for autonomous planning of spinal posterior decompression and verify its accuracy through a cadaveric model., Methods: Seventeen vertebrae from 3 cadavers were included in the study. Three thoracic vertebrae (T9-11) and 3 lumbar vertebrae (L3-5) were selected from each cadaver. After obtaining CT data, the robotic system independently planned the laminectomy path based on AI algorithms before the surgical procedure and automatically performed the decompression during the procedure. A postoperative CT scan was performed, and the deviation of each cutting plane from the preoperative plan was quantitatively analyzed to evaluate the accuracy and safety of the cuts. The duration of laminectomy was also recorded., Results: A total of 285 cuts were made on thoracic and lumbar vertebrae. The average duration for unilateral longitudinal cutting was 16.38 ± 4.76 minutes, while for transverse cutting it was 4.44 ± 1.52 minutes. In terms of accuracy assessment, 3 levels were divided based on the distance between the actual cutting plane and the preplanned plane: 77 (84%) were grade A, 15 (16%) were grade B, and none were grade C. Regarding safety assessment, 74 (80%) were designated safe (grade A), with 18 (20%) classified as uncertain (grade B)., Conclusions: The results confirm the accuracy and preliminary safety of the robotic system for autonomous planning and cutting of spinal decompression.

Objective: This study aimed to develop a robotic system with autonomous functionality for holding and manipulating the endoscope in endoscopic endonasal surgery. A cost-effective prototype was created with the goal of using robotic assistance and achieving a more efficient learning curve for endoscopic surgery., Methods: A Stewart platform-based endoscope holder and positioner robotic system, developed by the Mechatronics Engineering Department of Kocaeli University, was used in conjunction with 3D Slicer and Plus Toolkit open-source health technology software. Following initial configuration on a 3D skull model, the system was applied to a fresh-frozen cadaver., Results: The robotic system and its registration process proved feasible, allowing the robot to autonomously reach predetermined anatomical points during the nasal step of the surgery. Compared with a previous study by the same authors, the surgery duration was successfully shortened. The experiment yielded positive outcomes in both the artificial skull model and the cadaver. The robotic system effectively performed the nasal stage of the surgery. The integration of a robotic surgical arm in the endoscopic endonasal approach holds the potential to enhance the learning curve through shared experiences. The robot offers assistance to surgeons during the learning phase of the endoscopic endonasal approach, aiding in the identification of anatomical landmarks through preoperative planning., Conclusions: This system may present advantages such as improved visualization, enhanced maneuverability, and reduced user fatigue compared with conventional methods. These findings show the potential of robotic assistance in endoscopic surgical techniques.

Post-traumatic osteoarthritis (PTOA) often develops following tibial pilon fractures. Evidence suggesting PTOA development is driven by elevated articular contact stress from residual malreduction has led surgeons to strive for precise articular reduction, typically at the cost of extended operative time. Post-operative bracing using carbon fiber custom dynamic orthoses (CDOs) offers another means to decrease tibiotalar joint reaction force (JRF) and contact stress. The purpose of this cadaveric study was to measure how CDO stiffness influences ankle JRF and contact stress over the stance phase of gait. A servohydraulic load frame was used to test five cadaver ankles, with axial loading (240-330 N) and pneumatic actuation of the Achilles tendon (50-436 N) serving to quasi-statically model multiple points in the stance phase of gait. Three CDO rotational stiffness conditions were tested: (1) No CDO-0 Nm/deg, (2) low stiffness CDO-1.8 Nm/deg, and (3) moderate stiffness CDO-2.3 Nm/deg. JRF and contact stresses were measured using a piezoresistive pressure sensor inserted into the tibiotalar joint. An insole plantar pressure sensor placed between the cadaveric foot and CDO footplate measured limb/device interactions via the plantar center of pressure (COP). As limb loading progressed through stance, the plantar COP progressed from hindfoot to forefoot, as it would in normal gait. Both CDOs demonstrated decreases in JRF, reaching as high as 32% for the low CDO and 26% for the moderate CDO, with associated decreases in contact stress. This suggests that post-operative bracing could lessen PTOA risk after pilon fractures., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Background: We present a method to determine and visualise the functional centre of rotation (FCOR) of the hip during total hip arthroplasty using an augmented reality head mounted display (AR-HMD)., Methods: We developed software allowing a HoloLens to provide inside-out infrared tracking of markers affixed to cadaver femurs and 3D printed acetabuli. Two observers rotated 20 cadaver femurs twice in a matching cup, producing 80 measurements. The FCOR of the acetabulum and femoral head was determined based on the point cloud generated from the displacement of the femoral trackers to the acetabular tracker., Results: Compared to the ground truth, the FCOR resulted in an absolute error of 2.9 ± 1.4 mm for the acetabulum and 2.9 ± 1.2 mm for the femur, with 95th percentiles below 5.6 and 4.7 mm., Conclusion: The proposed AR-HMD system offers an accurate and reproducible way to determine the femoral and acetabular FCOR in an experimental setting., (© 2024 The Author(s). The International Journal of Medical Robotics and Computer Assisted Surgery published by John Wiley & Sons Ltd.)

Background: The microvasculature of the human meniscus has been previously described by Arnoczky and Warren. However, to date, the qualitative and quantitative extra-articular vascular anatomy of the medial meniscus has not been characterized., Purposes: To perform a qualitative and quantitative anatomic study of the extra-articular medial meniscal vasculature and to introduce the novel "medial meniscal artery" (MMA), potentially providing future guidelines for the treatment of meniscal abnormalities., Study Design: Descriptive laboratory study., Methods: A total of 33 unpaired, frozen human cadaveric knees were dissected. The femoral artery was identified and cannulated using an angiocatheter. The arteries were perfused with a red acrylic paint solution, allowing for improved visualization. Artery dimensions and distances were measured using a digital caliper. Perfused specimens were imaged using computed tomography and segmented using 3D reconstruction software to identify vessels and repeat artery measurements digitally., Results: The MMA was consistently identified in all specimens. In 27 (82%) of 33 specimens, the MMA branched directly from the popliteal artery; in 5 (15%), the MMA shared a common trunk with the inferior medial genicular artery; and in 1 specimen (3%), the MMA shared a common branch with the inferior lateral genicular artery. The MMA was easily distinguishable from the superior, inferior, and middle genicular arteries, given its direct course to the medial joint line with terminal branches to the posterior horn of the medial meniscus and deep to the semimembranosus tendon. The MMA exhibited a consistently smaller vessel diameter relative to the genicular arteries., Conclusion: This is the first study to identify and quantitatively describe the MMA in the human knee. The MMA can be identified consistently on gross anatomic dissection in cadaveric donors of varying demographics. Further research is needed to identify and characterize the artery in vivo and to determine the MMA's role in meniscus preservation surgery., Clinical Relevance: The findings of this study will provide future avenues of research toward understanding medial meniscus vascularization and the genesis of potential degenerative changes when vascularization is poor. This will help to further refine diagnostic and treatment options for meniscus revascularization and compartment preservation. Additionally, this study may help define safe zones in the knee during posterior approaches and expand the base of knowledge for emerging vascular procedures such as genicular artery embolization., Competing Interests: Presented at the annual meeting of the AOSSM, Denver, Colorado, July 2024.One or more of the authors has declared the following potential conflict of interest or source of funding: R.S. has received consulting fees from Arthrex and Medacta. M.H. has received consulting fees from Vericel; support for education from Smith & Nephew, Arthrex, Foundation Medical, and Medwest Associates; honoraria from Encore Medical; and hospitality payments from Stryker and Medical Device Business Services. B.Z. has ownership in HeartFlow. J.C. has received consulting fees from Arthrex, CONMED Linvatec, Ossur, Smith & Nephew, DePuy Synthes, and Vericel; support for education from Medwest Associates; and hospitality payments from Medical Device Business Services and Stryker. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

This study aims to explore the concept of liminality in the lives of chronic kidney disease (CKD) patients in Turkiye who are undergoing dialysis while awaiting kidney transplants. The research focuses on how patients experience this transitional state, being between life stages, and how they cope with the uncertainty of their condition while aspiring for a transplant. The research involved in-depth, semi-structured interviews and participant observations of 34 dialysis patients who had been registered on the national organ waiting list for over five years. The research was conducted between August 16, 2022, and November 11, 2022. The principal findings reveal that these patients experience profound uncertainty and hope, viewing potential transplants as a "second birthday" and symbolic rebirth. The study also highlights significant cultural and familial dynamics influencing the organ donation process, with many patients facing disappointment when relatives are unwilling or unable to donate. Additionally, patients report various physical and psychological challenges, including social isolation, strict dietary restrictions, and the emotional toll of dependence on hemodialysis. The significant conclusions indicate that the anticipation of receiving a cadaveric organ donation provides both hope and anxiety, motivating patients to adhere strictly to medical advice while coping with the emotional burden of uncertainty. The research underscores the complex interplay between cultural beliefs, medical practices, and the lived experiences of CKD patients. This paper contributes to knowledge by comprehensively understanding the cultural and emotional dimensions of the dialysis experience in Turkey. It offers valuable insights for healthcare providers and policymakers to improve patient care and support systems., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: Arterial fenestration involves an artery emerging from the same embryological origin, with its lumen divided into two channels that subsequently rejoin. This kind of vascular variant has consequences, such as focal defects in the histologic layers of the arteries, hemodynamic stress, and challenges for endovascular procedures in the management of vascular pathologies. The main objective of this work is to present a rare vascular variant, a double fenestration of the same P1 segment of a cadaveric specimen, and a literature review of these kind of vascular variants., Methods: A cadaveric study was performed in which 20 central nervous system specimens, from patients without neurological pathology obtained as a donation from the National Institute of Legal Medicine and Forensic Sciences, were dissected for educational and research purposes., Results: In one specimen it was found a double fenestration of the right P1 segment, associated with a single fenestration of the right superior cerebellar artery. Few cases of posterior circulation fenestration, beyond the vertebrobasilar trunk are reported in the literature, with limited understanding of the potential hemodynamic consequences thereof. In all the literature available, only eight cadaveric cases of P1 segment fenestration are documented, often linked with other central nervous system vascular abnormalities such as aneurysms or duplications., Conclusions: There is a single report of unilateral double P1 segment fenestration in a living patient. To our knowledge, this is the second case reported in the literature on this specific anatomical anomaly, and the first such report in a cadaver., Competing Interests: Declarations. Ethical approval: All specimens were authorized and legally given by the National Institute of Legal Medicine and Forensic Sciences of Bogota, Colombia, for academic purposes. It was submitted and approved by the “Comité de Investigaciones y Ética Institucional” of the Pontificia Universidad Javeriana. Patient consent: Specimens were a donation from by the National Institute of Legal Medicine and Forensic Sciences of Bogota, Colombia, for academic purposes, it was not needed a consent. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Purpose: The use of "mesh" in implant-based reconstruction is widespread, with both acellular dermal matrices (ADMs) and extracellular matrices (ECMs) being used, especially in prepectoral device placement. This study compared Ovitex (ovine ECM) versus human cadaveric ADMs to determine safety profiles and cost-effectiveness., Methods: A single surgeon's longitudinal experience with 2-stage, immediate tissue expander breast reconstruction from 2018 to 2023 was analyzed. Patients with AlloDerm and Cortiva (human ADM) were compared with those receiving Ovitex, and 90-day complications were analyzed by chi-squared and analysis of variance. Costs of each mesh were tabulated based on available market data., Results: Patient demographics were comparable. Of 127 patients, 85 received ovine ECM (163 breasts) and 42 received cadaveric ADM (81 breasts). No significant difference between the groups for complications requiring return to the operating room (12.7% ovine vs 14.8% human (P = 0.31) or minor complications (9.8% ovine vs 7.4% human, P = 0.34). There was no difference between reconstructive success and failure between the 2 groups (P = 0.066). The cost of Ovitex was 24%-38% cheaper than Cortiva and AlloDerm, respectively., Conclusions: In this longitudinal, single-surgeon study of 2 different types of meshes in 2-stage expander implant breast reconstruction, we found ovine multilaminated reinforced extracellular matrix (Ovitex) was comparable in outcomes with human acellular dermal matrices (AlloDerm and Cortiva). Ovine mesh was considerably cheaper. Multiple factors determine which mesh should be chosen for implant breast reconstruction. This study supports the use of Ovitex as a cost-effective substitute for human acellular dermal matrices in implant breast reconstruction., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Adhesive-augmented sternal fixation (AASF) has been investigated as an alternative to the clinical standard of cerclage wires; however, previous studies have focused on a full adhesive layer across the sternal midline, which acts as a barrier to bone healing. This study used a human cadaveric model to investigate if partial coverage AASF used in combination with wired fixation could provide adequate stability. Median sternotomies were performed on fifteen human cadaveric sterna. Three groups (n = 5) with varying adhesive coverage (50 %, 62.5 %, 75 %) of the sternal midline and traditional wiring were investigated. Cyclic lateral distraction loading of 10 N to 100 N was applied at 50 N/s. Every 30 cycles, the maximum load was increased by 100 N to a maximum of 500 N. Displacement was measured using transducers spanning the transection line at the manubrium, body, and xiphoid. Mean maximum total displacement (MMTD) for all groups was significantly below 2 mm (p < 0.001) with 1.49 mm ± 0.82 mm, 0.97 mm ± 0. 55 mm, and 0.67 mm ± 0.65 mm in the 50 %, 62.5 %, and 75 % groups respectively. MMTD in the 50 % group was significantly greater than MMTD in the 62.5 % and 75 % groups. AASF improved stability as coverage of the sternal surface with adhesive increased. Partial coverage of the sternal midline with adhesive may provide similar rigidity to a full layer while enabling earlier sternal ossification at the transection line compared to wiring alone., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: The study investigated the relationship between computed bony range of motion (BROM) and actual functional range of motion (FROM) as directly measured in cadaveric hips. The hypothesis was that some hip movements are not substantially restricted by soft tissues, and therefore, computed BROM for these movements may effectively represent FROM, providing a reliable parameter for computational pre-operative planning., Methods: Maximum passive FROM was measured in nine cadaveric hips using optical tracking. Each hip was measured in at least ninety FROM positions, covering flexion, extension, abduction, flexion-internal rotation (IR), flexion-external rotation (ER), extension-IR, and extension-ER movements. The measured FROM was virtually recreated using 3D models of the femur and pelvis derived from CT scans, and the corresponding BROM was computed. The relationship between FROM and BROM was classified into three groups: close (mean difference<5°), moderate (mean difference 5-15°), and weak (mean difference>15°)., Results: The relationship between FROM and BROM was close for pure flexion (difference = 3.1° ± 3.9°) and IR in deep (>70°) flexion (difference = 4.3° ± 4.6°). The relationship was moderate for ER in minimal flexion (difference = 10.3° ± 5.8°) and ER in minimal extension (difference = 11.7° ± 7.2°). Bony impingement was observed in some cases during these movements. Other movements showed a weak relationship: large differences were observed in extension (51.9° ± 14.4°), abduction (18.6° ± 11.3°), flexion-IR at flexion<70° (37.1° ± 9.4°), extension-IR (79.6° ± 4.8°), flexion-ER at flexion>30° (45.9° ± 11.3°), and extension-ER at extension>20° (15.8° ± 4.8°)., Conclusion: BROM simulations of hip flexion, IR in deep flexion, and ER in low flexion/extension may be useful in dynamic pre-operative planning of total hip arthroplasty., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. However, the study received funding from Corin Group, UK (AP) and HVM Catapult, UK (AP and EK). VS receives PhD studentship from University of Warwick. MAW is a Professor at University of Warwick. JP and CP are employee of Corin. RK receive royalties and consultancy fees from Brainlab, and payments from Corin for consultancy and education., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Purpose: Traditional dissection methods are primarily limited by challenges in identifying minute structures, which can lead to irreversible tissue damage. Anatomical observation of the larynx is particularly challenging in educational and clinical settings owing to its microscopic structures and complex three-dimensional (3D) nature, making it difficult to dissect. Therefore, this study aimed to demonstrate that micro-computed tomography (micro-CT) imaging of the larynx can serve as an effective alternative for educational and clinical purposes, overcoming these limitations., Methods: Three laryngeal specimens were obtained from cadavers, stained with a phosphotungstic acid-based contrast agent, and imaged using enhanced micro-CT. The resulting images were reconstructed in three dimensions, allowing for a detailed 3D observation of the specimens., Results: Phosphotungstic contrast-enhanced micro-CT provided comprehensive anatomical information on laryngeal structures, including muscles, nerves, arteries, and vocal folds., Conclusion: This study demonstrates the high effectiveness of micro-CT in producing detailed structural images of the larynx, enabling 3D observation of even the smallest anatomical structures. These images can be applied in both educational and clinical settings to analyze the human larynx, effectively overcoming the limitations of traditional dissection methods. This approach facilitates the analysis of laryngeal structures that are otherwise difficult to observe with the naked eye., Competing Interests: Declarations. Institutional review board statements: This study was conducted in accordance with the Declaration of Helsinki and was approved by the Institutional Review Board of the Catholic University of Korea (MC22SISI0098). Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Introduction: Hamstring autografts are frequently used for ligament reconstruction surgery. Between 12% and 84% of patients report hypoesthesia or dysaesthesia secondary to injury of the saphenous nerve or one of its branches after hamstring harvesting. Type of incision (orientation and length) is subject of much regarding limiting the risk of nerve damage. A cadaveric study was performed to determine which type of incision limits the risk of injury to the saphenous nerve or one of its branches, based on an anatomic model for mapping nerve pathways at the harvest site., Methods: An anatomical study was performed on 20 knees from 12 embalmed bodies. Distance between saphenous nerve branches and 4 points of interest along the tibial crest was measured. Based on these measurements, a digital model of the saphenous nerve and its branches was created. A model of three common types of incision (vertical, horizontal and oblique) was overlaid. Each incision was modeled for three lengths (2, 3, and 4 ​cm). Percentage of collision between nerve course model and incision model was then calculated to determine the risk of nerve damage for each type of incision. Based on the nerve course model, a 'low-collision-risk' safe zone was identified., Results: Nerve damage risk after an oblique incision was significantly lower than for a horizontal or vertical incision, for incision lengths of 3 and 4 ​cm (p ​< ​0.05). For a specific incision orientation, the length of the incision did not affect the risk of nerve damage. A trapezoidal space close to the tibial crest and distal to the anterior tibial tuberosity appears to reduce risk of nerve damage., Conclusion: This cadaveric study suggests that during hamstring harvesting, incisions shorter than 2 ​cm reduce the risk of saphenous nerve's branches injuries. For incisions longer than 2 ​cm, using an oblique incision may reduce the risk compared to vertical or horizontal incisions., Level of Evidence: Level of evidence not applicable: Laboratory experiments., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the precise origin of sensory nerves through gross anatomical study of the TFCC, synthesized alongside imaging and histological techniques., Method: Six cadaveric forearm specimens were obtained to map the course and branches of the ulnar nerve through macrodissection. Immunohistochemical staining targeting PGP 9.5 and type IV collagen was performed on frozen TFCC sections to visualize nerve fibers microscopically. Computed tomography, magnetic resonance imaging, and arthrography findings were also reviewed., Results: At the macroscopic level, the articular branches supplying the TFCC originated predominantly from the dorsal branch of the ulnar nerve. Microscopic analysis revealed positive PGP 9.5 expression and discernible neural marker expression, signifying fine nerve fiber ingrowth within the TFCC. Imaging modalities aided the diagnosis of TFCC lesions. The dorsal cutaneous branch of the ulnar nerve, medial cutaneous nerve of the forearm, and volar sensory branch of the ulnar nerve emerged as the principal nerves innervating the TFCC., Conclusions: This study provides anatomical evidence that the TFCC receives innervation from branches of the ulnar nerve and contains sensory nerve fibers. These findings enhance understanding of potential neuropathic pain mechanisms in TFCC injuries and offer insights to guide surgical interventions. Further investigations are warranted to elucidate the clinical implications., Competing Interests: Declarations. Ethical approval: This study was approved by the Ethical Committee of Wuxi 9th People’s Hospital Affiliated to Soochow University (registration number: IEC 1/2022). These cadavers have been voluntarily donated by individuals. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background: Reconstruction of the axillary fossa represents a surgical challenge given the functional implications for mobility of the upper limb. The posterior brachial flap is a solution of choice for this indication, providing fine and functional local reconstruction, but little is known about its perforasome. This study aimed to identify the location of the perforator, analyze perfusion flow, and link vessel distribution, and propose an aesthetic refinement to the surgical technique by medializing the skin paddle to conceal aesthetic scarring at the donor site., Methods: Fifteen fresh cadavers were harvested and dissected. Twenty-six arms were injected with methylene blue. Two arms were injected with radiopaque dye. A dynamic (4-dimensional) computed tomographic angiography was performed to complete the analysis., Results: The perforasome was centered on the posterior axis of the arm with a perfusion area ranging from 82.2 to 142.9 cm², with a median of 112.7 (96.7-125.6) cm². The median length of the pedicle was 83 mm on an average (65-91 mm). Its caliber at the emergence of the source vessel had a mean diameter of 1.43 mm (1.27-1.61 mm). The distal limit of the paddle was located on an average 10.7 cm from the olecranon (7.8-12.2 cm). The scans showed direct linking vessels toward the perforasomes on the medial side of the arm, suggesting that it is possible to medialize the cutaneous paddle., Conclusion: The posterior brachial flap presents with a constant perforasome. It can be harvested more medially than previously described to improve the aesthetic results, while maintaining reproducibility and satisfactory vascular reliability., (Copyright © 2024 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)

Empirical data on decomposition ecology have long established blowflies (Calliphoridae) and flesh flies (Sarcophagidae) (Diptera) as the most frequent colonizers of carrion, especially at early stages of decomposition. However, the scarcity of studies based on human cadavers has hindered inferences about colonization of homicide victims in real case scenarios. We describe here a survey of insects associated with cadavers retrieved from the site of death in Northeastern Brazil, with emphasis on the association between species diversity and the surrounding environment. We examined 81 cadavers, most of which were of men and resulting from violent death. Twelve cadavers (14.8 %) contained insect larvae, which were reared in the laboratory until adult emergence and identification. Ten species of Diptera effectively colonized the cadavers; seven of Family Calliphoridae - Chrysomya albiceps (Wiedemann, 1819), Chrysomya megacephala (Fabricius, 1794), Chrysomya putoria (Wiedemann, 1830), Cochliomyia macellaria (Fabricius, 1775), Hemilucilia segmentaria (Fabricius, 1805), Lucilia cuprina (Wiedemann, 1830), Lucilia eximia (Wiedemann, 1819) and three of Family Sarcophagidae, Blaesoxipha (Gigantotheca) stallengi (Lahille, 1907), Microcerella halli (Engel, 1931) and Peckia (Sarcodexia) lambens (Wiedemann, 1830). The species C. albiceps and C. macellaria were the most frequent colonizers, while Sarcophagidae was reported in only four cases. Insects were present on cadavers found in urban (n = 8) and rural (n = 4) sites, outdoors (n = 6) and inside (n = 6) residences. Presence of larvae was more frequent in the natural orifices in the head (n = 11). Clothing did not prevent from ovi/larviposition for most species. We present the first register of B. stallengi colonizing human corpses and expand the knowledge on the geographical distribution of necrophagous insects. Our protocol may contribute to forensic entomology in areas exposed to fast decomposition, such as the Neotropical Region., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Cranial dural arteriovenous fistulas (DAVFs) that display cortical venous drainage are at risk of hemorrhage, unlike spinal DAVFs, which seldom bleed. The underlying mechanism for this difference is poorly understood. We hypothesized that cerebral veins are more fragile than spinal veins due to differences in histologic compositions. Thus, spinal and cerebral veins from five formalin-fixed human cadavers were examined through macroscopic and histological analysis, using hematoxylin, eosin and safran (HES), and orcein stains to compare them. Twenty-four cerebral veins and thirteen spinal veins were analyzed. The mean diameter of the cerebral veins was 1.02 ± 0.59 mm, while that of spinal veins was 0.52 ± 0.26 mm (p = 0.003). The mean thickness of cerebral veins was similar to their spinal counterparts (0.09 ± 0.07 mm vs 0.06 ± 0.02 mm; p = 0.12). The mean diameter-to-thickness ratio was 13.76 ± 6.05 mm for cerebral veins and 10.06 ± 7.23 mm for spinal veins (p = 0.023). In most of the analyzed vessels, the venous wall was composed of endothelial cells resting on layers of smooth muscle, separated by elastica lamina. Cerebral and spinal veins exhibit distinct calibers while maintaining comparable wall thicknesses, resulting in a greater diameter-to-thickness ratio for cerebral veins compared to spinal veins. This difference may after their resistance to pressure. Furthermore, variations in the transparietal pressure gradient between cranial and spinal subarachnoid space, along with differences in arterial blood flow through the fistulous veins, might contribute to the observed differences in clinical presentation., Competing Interests: Declaration of Competing Interest All authors declare: no support from any organization for this study; no financial relationships with any organizations that might have an interest in the submitted work., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Understanding the mechanism underlying the evolution of knuckle-walking in African great apes but not in humans may provide important implications about the origin and evolution of human bipedal locomotion. In this study, aiming to reveal possible structural adaptations of the chimpanzee's forearm and hand musculature related to knuckle-walking, we measure the passive elastic moment of the chimpanzee's and orangutan's wrist as it was rotated into extension, immobilizing the metacarpophalangeal joint at three different positions: extended (as in knuckle-walking), flexed (as in fist-walking), and an intermediate position. Our findings demonstrate that when the metacarpophalangeal joints are extended, the rigidity of the wrist joint in the extended direction increases. This increased rigidity is attributed to the passive elongation and force generation of digital flexor muscles, which are relatively short in chimpanzees. Consequently, this enhanced wrist-joint rigidity contributes to the stability and energetically efficient transmission of propulsive force to the ground during the stance phase. Overall, our study supports the hypothesis that knuckle-walking is an adaptation to terrestrial locomotion for an ancestor characterized by the restricted capacity for wrist extension owing to the relatively shorter tendons of digital flexor muscles., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: While traditional metallic cerclage remains the primary method in clinical application, non-metallic cerclage systems have recently gained popularity due to low risks of soft tissue irritation and bone intrusion. The objective of this study was to assess the performance of a novel non-metallic suture-based cerclage in comparison to traditional metallic cerclage cables for fixation of periprosthetic femoral fractures., Methods: An extended trochanteric osteotomy was performed on eight pairs of cadaveric femora, followed by reduction using either metallic cerclages (Group I) or the suture-based cerclage (Group II). A modular tapered fluted stem was then implanted in each specimen. The fragment translation during canal preparation and stem implantation was quantified using laser-scanning. Subsequently, each specimen underwent 500 cycles of multiaxial loading, with fragment translation and stem subsidence measured using a motion capture system., Findings: Following stem implantation, specimens in Group II exhibited a significantly greater lateral fragment translation (466 μm vs 754 μm, p = 0.017). However, there were no significant differences in anterior and distal translation between groups (p > 0.05). During multiaxial loading, the average stem subsidence in Group I was 0.36 mm (range, 0.04-1.42 mm), compared to 0.41 mm (range, 0.03-1.29) in Group II (p > 0.05). No significant difference was found in fragment translations between the two groups (p > 0.05)., Interpretation: The suture-based cerclage system exhibited comparable biomechanical performance in fixation stability to conventional metallic cerclage cables. Yet, it was associated with a larger residual lateral gap between the fragments following stem implantation. Ultimately, the choice of fixation method should account for multiple factors, including patient characteristics, surgeon preference, and bone quality., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: David Rodriguez-Quintana reports a relationship with Zimmer Biomet Holdings Inc. that includes: paid speaker, paid consultant, and research support. The metallic cerclage cables used in this study were donated by Zimmer Biomet. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: The essential component of managing femoroacetabular impingement involves restoration of the original labral function. Circumferential labral reconstruction (CLR) has shown positive results. However, biomechanical studies of CLR are limited and have not established the efficacy of the modern knotless all-suture anchor (ASA) pull-through technique., Hypotheses: (1) CLR with knotless ASA fixation will restore native labral suction seal biomechanics; (2) tensioning the ASA to a high-tension state will increase the peak distractive force., Study Design: Controlled laboratory study., Methods: Eight fresh-frozen human cadaveric hips were dissected free of all soft tissue except the native labrum and transverse acetabular ligament. On an electromechanical testing system, the hips were compressively loaded to 250 N to initiate a suction seal and distracted at a rate of 10 mm/s until rupture of the suction seal. Hips were tested in 4 states: intact labrum, full labral removal, knotless CLR with moderate anchor tension, and CLR with high anchor tension. Peak distractive force (in newtons) was compared using repeated measures analysis of variance ( P < .05). Acetabular bevel angles (θ) were measured at labral clockface positions outside the transverse acetabular ligament using a 3-dimensional digitizer stylus after rim preparation. Linear regression plots compared θ and peak distractive force in the CLR state., Results: Peak force values were 138.5 ± 13.6 N (mean ± SE) for the intact labrum, 18.4 ± 2.79 N for labral excision, 95.4 ± 23.3 N for moderate-tension CLR, and 126.2 ± 27.3 N for high-tension CLR. Significant differences were observed only when full labral removal was compared with the other conditions: intact ( P < .001), moderate-tension CLR ( P = .016), and high-tension CLR ( P = .002). Steeper acetabular bevel angles (smaller θ) were correlated with greater suction seal restoration ( P < .05)., Conclusion: CLR restored distractive stability on average to 82.0% of the intact value after labral deficiency. Retensioning did not significantly increase peak distractive forces., Clinical Relevance: These findings provide biomechanical validation supporting CLR using knotless ASAs in an effort to minimize volumetric bone loss and provide other surgical advantages. The prepared rim's bevel angle may be an important variable to optimize for improved suction seal restoration., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: This work was funded by Arthrex, Inc (grant AIRR-20106). A.C.L. has received consulting fees from Arthrex and Graymont Medical; research support from Arthrex and Stryker; and other financial or material support from Iroko, Medwest Associates, Smith & Nephew, Stryker, Vericel, and Zimmer Biomet. B.L.S. A.N.K., and C.A.W. are employees of Arthrex. B.G.D. is a board or committee member for the AANA Learning Center and American Hip Institution Research Foundation and has received consulting fees from Arthrex; royalties from Arthrex, DJO Global, Medacta, and Orthomerica; and research support from Arthrex, Medacta, Ossur, and Stryker. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.

Purpose: This study sought to evaluate the biomechanical properties of the interface between the rotator cuff and the semicircular humeral ligament or rotator cable (RCa) using histological and biomechanical techniques., Methods: Out of 13 eligible cadaver specimens, 5 cadaver shoulders with an intact rotator cuff were included, 8 were excluded due to an injured rotator cuff. The histological study enables us to describe the capsule-tendon interface between the infraspinatus tendon (IST) or supraspinatus tendon (SST) and RCa, and to detect loose connective tissue layers to determine their precise location and measure their length along the interface. The biomechanical study sought to characterize and compare the mechanical strength of the IST-RCa versus SST-RCa interfaces., Results: The average thickness of the RCa was 1.44 ± 0.20 mm. The histological study revealed a loose connective tissue layer at the IST-RCa interface, a finding not observed at the SST-RCa interface. The biomechanical study showed that the rigidity of the SST-RCa interface (72.10 -2  N/mm) was 4.5 times higher than for the IST-RCa interface (16.10 -2 N/mm) and the average maximum forces reached were 19.0 N and 10.6 N for the SST-RCa and IST- RCa interfaces, respectively., Conclusion: The IST-RCa interface consists of a loose connective tissue layer contrary to the SST-RCa interface. In parallel, two different groups in terms of the mechanical response were identified: the IST-RCa interface group had less rigidity and ruptured more quickly than the SST-RCa interface, therefore emerging as the most vulnerable interface and explaining a potential extension of rotator cuff tears., Competing Interests: Declarations. Conflict of interest: The authors declare no competing interests. Ethical approval: The research protocol was approved by our institutional review board Rennes School of Surgery (Rennes University anatomy laboratory). The university scientific committee ensured that written consent for body donation had been obtained and filed prior to death for all anatomical subjects. Our work complied with French regulations. The study was also exempt from French law pertaining to biomedical research (Huriet–Serusclat law of December 20, 1998) as no additional interventions were required. IRB information: This study was approved by our institutional review board., (© 2024. The Author(s).)

Background: The anatomical study of the modified medial approach for addressing fractures of the distal third of the humeral shaft aimed to elucidate the benefits of this method in providing optimal exposure for surgical intervention., Methods: Sixteen upper limb specimens from eight cadavers, obtained from the Anatomy Teaching Department of Fujian Medical University, were dissected. Three-dimensional anatomical structures were mapped onto a two-dimensional coordinate system. Key anatomical structures relevant to the modified medial approach, including the medial cutaneous nerve, musculocutaneous nerve, ulnar nerve, basilic vein, brachial artery, superior ulnar collateral artery, and inferior ulnar collateral artery, were documented in detail., Results: The average humeral shaft length measured (29.22 ± 2.78) cm, with its medial surface being flat and well-suited for plate fixation. The basilic vein, located superficially in the upper arm's first quadrant, measured (1.35 ± 0.35) cm from the most prominent point of the medial epicondyle of the humerus, with the deep fascia being penetrated at (12.41 ± 1.71) cm. The basilic vein serves as a key landmark for the modified medial approach. The nervi cutanei antebrachii medialis, running along the medial biceps humerus, closely accompanies the basilic vein, perforating the deep fascia above the medial epicondyle and extending anterior external and posterior medial branches. These branches are positioned (0.80 ± 0.17) cm and (0.45 ± 0.29) cm, respectively, from the basilic vein. Additionally, all nervi cutanei antebrachii medialis pass anteriorly to the basilic vein before continuing distally to the forearm. The ulnar nerve initially accompanies the basilic vein in the upper arm but diverges posteriorly without branching at (14.75 ± 1.74) cm, with the maximum separation from the basilic vein measuring (2.28 ± 0.59) cm. The brachial artery bifurcates into the superior and inferior ulnar collateral arteries along the humeral shaft. The superior collateral ulnar artery primarily supplies the ulnar nerve, positioned (14.14 ± 1.27) cm from the medial epicondyle, which ensures a sufficient blood supply for operative procedures. The musculocutaneous nerve and radial nerve branch are located in the lateral region of the brachial muscle, with minimal postoperative impact on muscle strength when splitting the brachial muscle by one-third., Conclusions: The modified medial approach, as revealed by anatomical studies, focuses on the fracture site with a straight skin incision aligned between the most prominent point of the medial epicondyle and the midpoint of the axilla, positioned one transverse finger from the radial side. Using the basilic vein as a reference, major vessels and nerves remain undisturbed, ensuring a safe operative zone. This technique allows for significant exposure of both the anterior and external humeral shaft fracture site and the ulnar side butterfly fragment while minimizing tissue damage and facilitating rapid recovery. The approach offers notable clinical value due to its reduced invasiveness and accelerated postoperative rehabilitation., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: The placement of clavicle tunnels in coracoclavicular ligament reconstruction is well established, but the optimal position of the coracoid tunnel remains unclear. This study aimed to investigate how the coracoid tunnel's position affects horizontal stability during coracoclavicular ligament reconstruction using a double-button technique., Methods: Fifteen fresh frozen shoulder cadaver specimens were tested under various conditions: intact coracoclavicular ligaments, disrupted ligaments, and reconstructions with a single coracoid and clavicle tunnel or double clavicle tunnels. The coracoid tunnel was positioned at the coracoid base 1/9, and 1/5 anterior to the base. Specimens underwent displacement-controlled loading, with 2D motion analysis conducted on captured digital images using TEMA motion analysis., Findings: Mean displacement for intact coracoclavicular ligaments was 1.61 ± 0.92 mm, and 3.69 ± 1.09 mm for disrupted ligaments. For reconstructed conditions, displacements were as follows: Single-Tunnel Base (1.87 ± 0.64 mm), Single-Tunnel 1/9 (2.54 ± 1.13 mm), Single-Tunnel 1/5 (2.62 ± 1.17 mm), Double-Tunnel Base (1.25 ± 0.73 mm), Double-Tunnel 1/9 (2.03 ± 1.22 mm), and Double-Tunnel 1/5 (1.88 ± 1.20 mm). Differences among intact, reconstructed, and disrupted states were statistically significant (p = 0.01-0.0001), with all reconstruction techniques restoring horizontal displacement near the intact state., Interpretation: At point zero both single coracoid tunnel and single- and double-clavicle tunnel restored horizontal displacement to its intact state. Coracoid tunnel placement anterior to the base of the coracoid did not influence horizontal displacement but single coracoid at the coracoid base and single clavicle tunnel resulted in the most anatomic reconstruction. Single coracoid tunnel at the base and double-clavicle resulted in the most stable reconstruction., Competing Interests: Declaration of competing interest The authors declare no conflict of interest with the presented body of research., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Pupose: This study aims to reveal the relationship of the phrenic nerve (PhN) with its neighboring structures in the lower neck region more comprehensively than previous studies and to minimize nerve damage by enabling invasive procedures in this region to be performed with high accuracy., Methods: Forty-one heminecks were evaluated. The relationship between the PhN and the anterior scalene muscle (ASM), internal thoracic artery (ITA), branches of subclavian artery (SA) and subclavian vein (SV) was examined., Results: It was observed that the PhN was located medial to the ASM in all cases. The distances were higher in male cadavers. The PhN was found to enter the thorax lateral to the ITA in 15/41 and medial to it in 25/41 sides. In 17/41 cases, the closest SA branch to the PhN was the thyrocervical trunk (TT) and in 24 cases the ITA. The PhN was located behind the SV in 38 cases and in front of it in 2 cases.The accessory PhN was found in 4/41 sides. There was no significant difference in morphometric findings between genders (p > 0.05). However, significant differences were observed between the parameters (p < 0.05)., Conclusion: The anatomy and variations of the PhN are of great importance in surgical interventions and invasive procedures in the neck region. The study provides important information to reduce the risk of damage to the PhN in surgical procedures. In addition, knowledge of the anatomical variations of the nerve may contribute to more successful results in nerve grafting and other surgical applications., Competing Interests: Declarations. Ethical approval: Ethics committee approval of our study was received by the Istanbul Medical Faculty Clinical Research Ethics Committee (date: 01/06/2022; decision number: 907986). Prior conference presentations: Preliminary study dated was presented by Nilay Yıldız at the 23rd National Anatomy Congress 2023 (11–15 October, Haccetepe University, Faculty of Medicine, Ankara, Turkiye). Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Anomalous muscles are rarely seen in the popliteal region of the lower limb. Some of them are harmless and go unnoticed and some create problems such as neuropathies. We report a novel case of an unusual additional muscle in this region. The additional muscle was closely associated with the short head of the biceps femoris muscle. It took its origin from the lower part of the lateral supracondylar line and the adjoining popliteal surface of the femur. The muscle was 10 cm in length, 1 cm in breadth and was fleshy throughout. It was oriented parallel to the medial side of the tendon of biceps femoris. It was inserted to the posterior aspect of the head of the fibula, medial to the insertion of the biceps femoris. The additional muscle derived its nerve supply from the sciatic nerve. The common peroneal nerve was closely related to the medial border of the additional muscle., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background: Accurate diagnostic imaging is crucial for managing facial fractures, which are a common global occurrence. This study aimed to compare the image quality of Photon Counting Detector CT (PCD-CT) with state-of-the-art Energy Integrating Detector CT (EID-CT) and intraoperative C-arm CBCT (CBCT) in visualizing maxillofacial anatomy using a cadaveric sheep head model., Methods: Three fresh sheep heads were used, with surgical interventions simulating metal implants in two of them. The specimens were imaged using PCD-CT, EID-CT, and CBCT, following which quantitative assessments of signal-to-noise ratio, sharpness, and artifacts were conducted. A visual grading study was performed by six observers, using criteria focusing on the mandible, orbit, and soft tissues. Statistical analyses included Friedman tests for comparing modalities and Kendall's W and Gwet's AC1 for assessing inter- and intrarater agreement., Results: PCD-CT demonstrated a significantly higher signal-to-noise ratio (p = 0.03) and bone sharpness (p < 0.001) compared to CBCT. In visual grading, PCD-CT outperformed CBCT, but not EID-CT, particularly in delineating mandibular and orbital structures. EID-CT and PCD-CT showed slightly more severe hypodense artifacts (p = 0.01) but were comparable in streak artifact presentation. The interrater and intrarater agreements indicated consistent evaluations across and within observers., Conclusion: PCD-CT exhibits superior image quality over CBCT in key parameters essential for maxillofacial imaging, while no apparent improvement was shown compared to state-of-the-art EID-CT. PCD-CT offers enhanced visualization of critical anatomical structures, suggesting its potential as a preferred modality in managing maxillofacial trauma. The findings in this study align with limited existing research on PCD-CT, underscoring its promise for advanced diagnostic imaging in maxillofacial applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Synthetic bone models have increasing utility in orthopaedic research due to their low cost and low variability and have been shown to be biomechanically equivalent to human bones in a variety of ways. The rise in additive manufacturing (AM) for orthopaedic applications presents an opportunity to construct synthetic whole-bone models for biomechanical testing applications, but there is a lack of research comparing these AM models to cadaveric or commercially available bone surrogates. This study compares the mechanical properties of 3D printed clavicle models to commercially available (4th generation Sawbones) and human cadaveric clavicles via nondestructive cyclic 4-point bending, axial compression, and torsion, and a final axial compression test to failure. Commercially available synthetic clavicles had 57.8-203% higher superior-inferior bending rigidity (p < 0.0001), 80.9-198% higher axial stiffness (p < 0.001), and 314-557% higher torsional rigidity (p < 0.05) on average than AM and cadaveric clavicles. Cadaveric and AM clavicles printed from a BoneMatrix/VeroWhite composite material had similar failure mechanisms under axial compression while AM VeroWhite clavicles experienced catastrophic failure, but these groups did not have significantly different ultimate failure loads. Together, these results demonstrate that current commercially available synthetic clavicles may be too rigid to emulate the mechanical properties of elderly cadaveric clavicles, and that AM bone models can closely mimic these cadaveric bones in a variety of biomechanical loading schemes. These results show promising applications for future work using 3D printed bone surrogates for biomechanical analysis of orthopaedic implants and other surgical repair techniques., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: This study aims to map the point of emergence of the lateral cutaneous branch of the fourth intercostal nerve in both sexes, addressing gaps in the current literature. The findings are intended to support surgeons in restoring breast function by providing precise anatomical data, regardless of the specific surgical technique employed., Methods: An anatomical study was conducted using 50 sides from 25 formalin-preserved full-body donors, with equal representation of male and female subjects. Measurements were taken to determine the fascial point of emergence of the lateral cutaneous branch of the fourth intercostal nerve relative to the anterior axillary line and the transverse line. Multiple linear regression models were applied to evaluate the influence of variables such as sex, height, and side., Results: Our findings indicate that the fascial point of emergence of the lateral cutaneous branch of the fourth intercostal nerve is consistently located within 20 to 24 mm relative to the transverse line in 37 (74%) cases, and within 4 to 10 mm relative to the anterior axillary line in 39 (78%) cases, regardless of sex, height, or side. The multiple linear regression analysis showed no significant correlation between these variables and the position of the point of emergence (p > 0.05)., Conclusion: These results provide surgeons with a practical tool for nerve coaptation during breast reconstruction, showing that sex and height do not affect the anatomical localization of the point of emergence. Precise knowledge of this point can improve surgical accuracy and enhance sensory recovery, leading to better patient outcomes., Competing Interests: Declarations. Ethics approval: This study was performed in line with the principles of the Declaration of Helsinki. Written informed consent was obtained by the Institute of Clinical and Functional Anatomy (Medical University of Innsbruck) before death from all body donors included in the study. Ethics approval was waived by the local Ethics Review Board of the Medical University of Innsbruck in view of the exclusive use of specimens from body donors. Consent to publication: Written informed consent was obtained by the Institute of Clinical and Functional Anatomy (Medical University of Innsbruck) before death from all body donors included in the study. Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Purpose: A comprehensive understanding of neural distribution within the vastus medialis is crucial for the effective administration of botulinum neurotoxin injections to manage spasticity. The aim of this study was to develop an anatomically informed approach to guide the administration of botulinum neurotoxin injections into the vastus medialis muscle., Methods: Using a modified Sihler's method, we examined the vastus medialis muscles (20 specimens) to delineate the distribution of nerves relative to a transverse line extending from the anterior superior iliac spine to the base of patella. The vastus medialis muscle was divided into 10 areas from top to bottom. Then, using two fresh cadavers, ultrasonography-guided injections were performed based on the distribution of nerves within the vastus medialis. Each specimen was subsequently dissected to verify if the dye was accurately directed to the most densely innervated regions of the vastus medialis and to assess the precision of the injections., Results: The intramuscular nerve distribution within the vastus medialis muscle showed distinct patterns, particularly in areas between 6 and 9. Four injections were successfully administered on each side, targeting the regions between 6 and 9 of the vastus medialis. Upon dissection of the cadavers, the dye was found to be distributed along the muscle fiber., Conclusion: We recommend targeting botulinum neurotoxin injections toward regions displaying a prominent nerve distribution, specifically focusing on areas between 6 and 9. By adhering to these guidelines, clinicians can minimize doses and mitigate potential adverse effects, such as gait disturbances, antibody development, and bruising, resulting from multiple injections. Furthermore, these findings can be incorporated into electromyography practices., Competing Interests: Declarations. Ethics approval: Appropriate consent was obtained for the cadavers donated to the Catholic University of Korea, and approval was granted by the institutional review board of the College of Medicine (Approval IRB No. MC23EISE0022). Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer-Verlag France SAS, part of Springer Nature.)

Background: Insertional Achilles tendinopathy (IAT) is a common source of heel pain in active adults and athletes. The Zadek osteotomy (ZO) is a calcaneal dorsal closing wedge osteotomy that has demonstrated clinical success as a treatment for IAT, purported to favorably improve tendon mechanics, decrease impingement, and decrease pressure within the retrocalcaneal bursa. The present study aims to evaluate the biomechanical effects of ZO on Achilles strain, position of the Haglund prominence relative to the Achilles insertion, and retrocalcaneal pressure., Methods: The ZO was performed on 10 fresh-frozen foot and ankle mid tibia-fibula cadaveric specimens. An osteotomy was performed using a 1-cm dorsal closing wedge procedure secured with a 7.0 mm cannulated screw. Point pressure sensor catheters and differential variable reluctance transducers were used to measure the retrocalcaneal pressure and Achilles strain, respectively, pre- and postosteotomy. Paired t-tests were utilized to detect statistical differences ( P  < .05)., Results: After the ZO, the Haglund prominence was translated 9.9 mm anteriorly with respect to the insertion of the Achilles ( P  < .05) and the Achilles tendon insertion was translated 3.4 mm proximally ( P  < .05). The ratio of calcaneal length to greater tuberosity length, the X/Y ratio, increased from 2.56 to 3.52 with the osteotomy ( P  < .05). At maximum dorsiflexion, retrocalcaneal pressure decreased from 117 to 66 mm Hg (44%, P  = .018). The Achilles strain changed from 0.00362 to 0.00436 in the anterior fibers ( P  = .484) and changed from 0.00467 to 0.00283 in the posterior fibers ( P  = .088)., Conclusion: Biomechanical testing in a cadaveric model demonstrates that the ZO decreased retrocalcaneal pressure, shifted the Achilles tendon insertion proximally, increased the X/Y ratio of the calcaneus, and did not significantly change the strain of the Achilles tendon., Clinical Relevance: Despite the clinical success demonstrated in recent literature, there are no biomechanical studies describing the effect of the ZO on the biomechanics of the hindfoot, and the mechanism of symptom relief of the ZO for IAT is not well understood. The present study measures two potential ZO effects relative to Haglund prominence by measuring retrocalcaneal pressure and displacement of the Achilles tendon with respect to the Haglund prominence, and measures one ZO effect relative to calcification of the tendon by measuring the Achilles tendon strain., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. Disclosure forms for all authors are available online.