Anatomical Dissection Research Articles

A Case Series of Deep Subgluteal Block: A New Block Targeting the Missed Portion of the Hip for Analgesia After Total Hip Replacement

The study aimed to evaluate the effectiveness of deep subgluteal block (DSGB) for pain relief after posterolateral-approached total hip replacement. The cadaver study and observational case series assessed the spread and outcomes of ultrasound-guided DSGB. Results showed low postoperative pain scores, minimal opioid requirements, and no complications related to DSGB. Anatomical dissection revealed effective spread of the injected substance. These findings suggest that DSGB could be a promising regional analgesic technique for postoperative pain management after posterolateral-approached total hip replacement.

Typology of Terminal Colon at the Chu of Point G in Bamako

Purpose: To describe the morphometric types of the terminal colon. Patients and Methods: This was an anatomical study by laparotomy for the terminal colon on 7 living subjects and by anatomical dissection on 8 fresh cadaveric subjects in the department of surgery B of the CHU of Point G and in the anatomy laboratory of the faculties of medicine of odonto-stomatology (FMOS) and pharmacy (FAPH) of Bamako from January 1, 2018 to December 31, 2019 or 2 years. Patients without a mass on the terminal recto-colonic junction or volvulus of the terminal colon or abdominopelvic mass on the terminal colon and fresh cadavers declared unknown without a laparotomy scar coming from Bamako University Hospitals or Reference Centers (CS Réf) were included in this study. Results: We investigated 15 cases, including 7 live cases and 8 cadavers. Males accounted for 60% (n=9) and females 40% (n=6), i.e. a sex ratio of 1.5. Mean age was 47.14 ±15.57 years. The mean length of the terminal colon was 41.79 cm±13.37. The mean length of the terminal mesocolon was 11.18 cm. The maximum height of the terminal mesocolon averaged 10.70 cm ± 3.61 cm. There were 46.72% (n=7) medium-form cases, 33.30% (n=5) short-form cases and 19.98% (n=3) long-form cases. Conclusion: The terminal colon can be short, medium or long, depending on its length and the height of its meso.

An unreported accessory muscle on the neck region

Anatomical variations or accessory muscles on the neck region are important for clinicians and surgeons. This case report aims to contribute to the literature by demonstrating the presence of a previously unrecognized muscle on the lateral neck region. During routine gross anatomy dissection of a 59-year-old male cadaver; an unreported muscle was observed next to the scalene muscles on the left lateral neck region. The distance between the center of the scalenus medius and the insertion of the muscle was 6.17 cm, and the distance between the scapular notch and the insertion of the muscle was 1.56 cm. The distance between the aponeurosis that connects the superior and the inferior bellies of the omohyoideus muscle and the first head of the muscle was 6.24 cm. This anatomical formation, which is not included in the literature, has anatomical and clinical importance in controversial clinical cases in neck pathologies.

Ultrasound-Guided Blockade of the Lateral Cutaneous Branch of the Iliohypogastric Nerve to Differentiate Neuropathy From Greater Trochanteric Pain Syndrome: Cadaver Study and Initial Case Series

ObjectiveNeuropathy of the lateral cutaneous branch of the iliohypogastric nerve (LCBIN) may represent a differential diagnosis for greater trochanteric pain syndrome (GTPS). Ultrasound-guided neural blockade of the LCBIN may lead to diagnosis of this neuropathy. The aim of this study was to evaluate the accuracy of ultrasound-guided nerve block in cadavers and to present a first clinical case series of patients with neuropathy of the LCBIN where the workup for GTPS remained unremarkable. Ultrasound-guided nerve block led to pain relief in these patients, indicating LCBIN neuropathy. MethodsFirst, ultrasound-guided injections at the LCBIN were performed bilaterally in 24 fresh, non-frozen, non-embalmed body donors. Accuracy and nerve localization were validated by anatomic dissection. Second, a clinical case series of nine patients with suspected GTPS who underwent ultrasound-guided diagnostic LCBIN blockade was retrospectively analyzed. ResultsUltrasound-guided injections at the LCBIN yielded 91.7% accuracy (95% confidence interval: 0.80–0.98). On the right side the nerve was found within a range of 3–14 cm from the anterior superior iliac spine, and within a range of 7–15 cm on the left side. This clinical case series indicates that ultrasound-guided blockade at the LCBIN provides temporary pain relief and indicates the presence of LCBIN neuropathy. ConclusionUltrasound has demonstrated high accuracy for localization and injection guidance in the examination of LCBIN. Ultrasound-guided injection of local anesthetics may help to identify LCBIN neuropathy as a differential diagnosis in patients with suspected GTPS.

Advanced visualization of aortic dissection anatomy and hemodynamics

Aortic dissection is a life-threatening cardiovascular disease constituted by the delamination of the aortic wall. Due to the weakened structure of the false lumen, the aorta often dilates over time, which can – after certain diameter thresholds are reached – increase the risk of fatal aortic rupture. The identification of patients with a high risk of late adverse events is an ongoing clinical challenge, further complicated by the complex dissection anatomy and the wide variety among patients. Moreover, patient-specific risk stratification depends not only on morphological, but also on hemodynamic factors, which can be derived from computer simulations or 4D flow magnetic resonance imaging (MRI). However, comprehensible visualizations that depict the complex anatomical and functional information in a single view are yet to be developed. These visualization tools will assist clinical research and decision-making by facilitating a comprehensive understanding of the aortic state. For that purpose, we identified several visualization tasks and requirements in close collaboration with cardiovascular imaging scientists and radiologists. We displayed true and false lumen hemodynamics using pathlines as well as surface hemodynamics on the dissection flap and the inner vessel wall. Pathlines indicate antegrade and retrograde flow, blood flow through fenestrations, and branch vessel supply. Dissection-specific hemodynamic measures, such as interluminal pressure difference and flap compliance, provide further insight of the blood flow throughout the cardiac cycle. Finally, we evaluated our visualization techniques with cardiothoracic and vascular surgeons in two separate virtual sessions.

Comparison of Dye Spread Pattern and Nerve Involvement between Suprainguinal and Infrainguinal Fascia Iliaca Blocks with Different Injectate Volumes: A Cadaveric Evaluation.

Background and Objectives: Fascia iliaca compartment block (FICB) is an effective and relatively safe technique in perioperative pain management for hip surgery. However, blockade of the obturator nerve (ON) using this technique remains controversial. This study aimed to compare dye spread patterns and nerve involvement in the suprainguinal FICB (S-FICB) and infrainguinal FICB (I-FICB) approaches using different volumes of dye. Materials and Methods: Following randomization, 6 S-FICBs and 6 I-FICBs were performed on the left or right sides of 6 unembalmed cadavers. For each block, 30 mL or 60 mL of dye solution was injected. The extent of dye spreading and the staining pattern in the lumbar plexus branches were investigated using anatomical dissection. Results: Twelve injections were successfully completed. The lateral femoral cutaneous nerve (LFCN) and femoral nerve (FN) were consistently stained in all injections. Extended dye spread toward lumbar plexus branches was observed volume-dependently in S-FICBs. However, I-FICBs with an increased volume only showed dye spreading in the caudad direction limited to within the fascia iliaca. When 30 mL of dye was used, the ON was not stained with either approach. A stained ON was only observed in S-FICBs when 60 mL of dye was used. Conclusions: In this cadaveric evaluation, the ON was not stained in either FICB approach with the volume of injectate commonly used in clinical practice. The S-FICBs but not I-FICBs using a high volume of injectate resulted in extended spreading to the lumbar plexus branches.

The feasibility of ultrasound-guided latex labeling of the anterolateral ligament in anatomical dissection – A cadaveric study

BackgroundThe present study aims to investigate the feasibility of labeling ligaments using ultrasound-guided injections. On formalin-fixed cadavers, the anterolateral ligament was selected and targeted for demonstration. The development of portable ultrasound machines and the ability to connect them to tablets via Bluetooth or WLAN makes it an accessible tool to implement into the anatomical dissection courses in order to associate medical imaging (MRI and ultrasound), anatomical structures and their subsequent dissection. Methods8 formalin fixed human cadavers were used for the ultrasound-guided injections of 1 mL of blue latex into the anterolateral ligament. 8 cadavers were not injected with latex for comparative purposes. The injections were performed by an experienced ultra-sonographer. After approximately 10 months, five dissections were carried out by students during the dissection course and three specimens were dissected by anatomists. ResultsThe anterolateral ligament was successfully marked and demonstrated in 7 out of 8 cases. In 4 out of 5 cases, the dissection was primarily conducted by students, while in 3 out of 3 cases, it was performed by anatomists. The accuracy was 80 % and 100 %, respectively. ConclusionThe present study demonstrated that labeling obscure ligaments, such as the anterolateral ligament, using ultrasound guidance is feasible on formalin-fixed cadavers. It also showed that students can successfully perform the dissections as the structure is highlighted and that the time between injection and dissection (approximately 10 months) has little impact on the outcome. The use of ultrasound in dissection courses should be further encouraged.

Knowledge Retention of Undergraduate Medical Students in Regional Anatomy Following a One-Month Gross Anatomy Course Setting

Background: In the achievement of optimal learning outcomes, knowledge retention presents a major concern for medical students and educators. Practical dissection courses facilitate the consolidation of knowledge of anatomy. Previously, it was shown that a regional anatomy dissection course is more beneficial over a 3-month than a 1-month duration for gathering pre examination knowledge. This study aimed to assess if follow-up anatomy interventions help consolidate regional anatomy knowledge and facilitate knowledge retention of undergraduate medical students. It was hypothesized that knowledge retention could be enhanced using post-dissection teaching interventions. Methods: Upon completion of the dissection course, Objective Structured Practical Examinations (OSPEs) were performed for the neck, thorax, and abdomen immediately before the start of the oral examinations, with follow-ups at 6 and 12 months. Between each of the examinations, virtual and in-person lectures and seminars on (radiologic) anatomy and pathology were held, including Cinematic Rendering, but without additional teaching on human tissues. Results: Significant improvements were observed for knowledge of the neck and abdomen regions in the 6- and 12-month follow-up OSPEs. The effects of knowledge gain were less marked in ethanol-glycerin- than in Thiel-embalmed tissues. Student perceptions regarding tissue quality correlated positively with their assessment of tissue suitability for examination preparation. In conclusion, even anatomy teaching interventions not utilizing human tissues may help consolidate and improve regional anatomy knowledge over a one-year term. Conclusion: Knowledge retention can be enhanced by accompanying virtual with physical teaching interventions.

Ultrasound-guided trigeminal nerve approach at the level of the pterygopalatine fossa in cat cadavers

ObjectiveTo describe an ultrasound-guided suprazygomatic approach to the trigeminal nerve block in cat cadavers. Study designProspective descriptive study. AnimalsTen feline cadaver heads. MethodsA 25:75 methylene blue–iopamidol mixture (0.1 mL cm–1 cranium length) was injected into 10 cadaver heads using an ultrasound-guided suprazygomatic approach. A computed tomography (CT) scan was performed to identify contrast presence at the orbital fissure, foramen rotundum and ovale, followed by anatomical dissection to identify staining of the pterygopalatine fossa (PPF), extraconal retrobulbar area, mandibular and maxillary nerves. Descriptive statistics were used to summarize results. ResultsA total of 20 injections were performed. Of these, 1/20 misinjection occurred and excluded from further reporting. The volume of injectate was 0.9 (0.9–1.1) mL [median (range)]. Staining of the PPF, extraconal space, maxillary and mandibular nerves over more than 6 mm was achieved in 19/19 (100%), 18/19 (95%), 17/19 (89%) and 19/19 (100%) of injections, respectively. CT showed presence of contrast within 5 mm of the orbital fissure, foramen rotundum and ovale in 18/19 (95%), 19/19 (100%) and 19/19 (100%) of the injections, respectively. No intracranial migration was observed. Conclusions and clinical relevanceThis cadaver study illustrates that the suprazygomatic ultrasound-guided trigeminal nerve injection technique can successfully stain the PPF, retrobulbar cone extraconally, mandibular and maxillary nerves. Consequently, this technique has the potential to be used in vivo in cats to desensitize areas innervated by the trigeminal nerve.

Quantitative and qualitative assessment of airborne microorganisms during gross anatomical class and the bacterial and fungal load on formalin-embalmed corpses

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

Uniportal Thoracoscopic Complex Combined Seg-Sub-subsegmentectomy of RS9+10bii: Dual-Display Method and Combined Approaches (Trans-fissure and Trans-ligament).

Uniportal thoracoscopic lateral basal segmentectomy is the most technically challenging anatomic segmentectomy,1-3 especially when it involves combined subsegmentectomy or sub-subsegmentectomy. Therefore, there are very few reports detailing its technical aspect. In this multimedia article, we describe a very complex uniportal thoracoscopic combined seg-sub-subsegmentectomy of RS9+10bii through the oblique fissure approach and the inferior pulmonary ligament approach, following a single-direction strategy4,5 to advance the procedure, utilizing the stem-branch method3,6 for segmental/subsegmental/sub-subsegmental structure tracking, and employing dual-display method, which comprises the intravenous ICG injection method and the inflation/deflation method, to identify intersegmental and inter-seg-sub-subsegmental planes. The operation lasted 169min, with approximately 20mL of blood loss. The patient experienced an active hemothorax and two spontaneous pneumothoraxes on postoperative days 1, 4, and 19, respectively, all of which resolved promptly after treatment. Histopathological examination of the specimen documented invasive non-mucinous adenocarcinoma with negative surgical margins and lymph nodes. The staging was determined as pT1bN0M0, stage IA2. During the 14-month follow-up period, there were no signs of tumor recurrence or metastasis observed. The FVC, FEV1, and FEV1%pred decreased by 11.9%, 12.5%, and 12.8%, respectively, at postoperative month 6. Complex basal segmentectomies, which necessitate combined subsegmental or sub-subsegmental resections, such as RS9+10bii, are feasible using the dual-display and combined approaches method. This method simplifies the steps of the very complex combined subsegmentectomy, averting the need for extensive lung resection. In addition, when performing these combined segmentectomies, precise anatomical dissection is crucial to prevent complications such as minor bronchopleural fistulas.

Fostering young talents for surgery : Laparoscopy in preclinical education-Too early or exactly right?

Due to the declining interest among medical students in pursuing asurgical career, the impact of demographic changes and the technical challenges, there is an increasing need to attract medical students to the surgical profession. Against this backdrop, ateaching project was developed to familiarize medical students with minimally invasive surgical techniques early in the preclinical education, thereby increasing the interest in surgery. Within the framework of the regular anatomical dissection course the following modules on laparoscopic surgery were integrated: (1)clinical lecture on the technique and application of laparoscopy, (2)exploratory live laparoscopy on abody donor and (3)practical exercises on laparoscopic trainers. The impact of this teaching project on the interest in asurgical career and on the clinical anatomical understanding was evaluated among 295 participating medical students. The evaluation revealed apronounced gender-independent interest in learning surgical skills early in the preclinical study phase. The teaching project led to asignificantly increased interest in pursuing asurgical career. Moreover, the incorporation of laparoscopic teaching modules into the preclinical anatomy course enhanced the learning motivation and understanding of clinically relevant topographic anatomy. The integration of practical surgical content into preclinical anatomical education can increase the attractiveness of surgical disciplines and simultaneously optimize teaching of anatomy. Longitudinal studies are required to examine the sustainability of these clinical teaching modules in career decisions of medical students.

Evaluation of preoperative rectus sheath block with bupivacaine for analgesia in cats undergoing ovariohysterectomy: a cadaveric and randomized clinical study

ObjectivePhase 1: to determine the feasibility of desensitizing ventral branches of spinal nerves within the rectus sheath using an ultrasound-guided rectus sheath block (USRSB). Phase 2: to determine the effect of preoperative USRSB on intraoperative responses to surgical stimulation and postoperative pain. Study designCadaveric study and prospective, randomized, blinded, parallel-arm clinical trial. AnimalsA group of five cat cadavers and 37 shelter-owned cats undergoing ovariohysterectomy. MethodsPhase 1: anatomical dissection was performed on one uninjected cadaver. Abdominal walls were dissected in four cadavers (eight hemiabdomens) following bilateral USRSB using 1:1 new methylene blue and 0.5% bupivacaine (0.8 mL kg–1 total). Phase 2: preoperative bilateral USRSB was performed with 0.8 mL kg–1 of 0.25% bupivacaine (RSB) or equivalent volume of 0.9% saline (CONTROL). Intraoperative systolic arterial blood pressure (SAP), heart rate (HR), respiratory rate (fR) and vaporizer setting (vap%) were recorded before skin incision, during celiotomy and abdominal wall closure. In recovery, cats were administered robenacoxib (2 mg kg–1; CONTROL) or 0.9% saline (0.1 mL kg–1; RSB) subcutaneously. Postoperative pain was evaluated for 6 hours using the Glasgow Composite Measure Pain Scale. ResultsPhase 1: spinal nerves T9–L3 were identified within the rectus sheath, and stained in 0%, 40%, 63%, 75%, 100%, 88%, 50% and 13% of hemiabdomens, respectively. Phase 2: 37 cats were included (RSB, n = 17; CONTROL, n = 20). Intraoperatively, SAP, HR and fR were not significantly different between groups. Vap% was significantly lower in RSB during celiotomy (p = 0.036) and closure (p = 0.044). Postoperatively, RSB cats were 5.3 times (95% CI 1.8–8.3) more likely to require rescue analgesia than CONTROL cats. Conclusions and clinical relevanceDuring surgery, USRSB with bupivacaine offered minor benefits and provided markedly less postoperative analgesia than robenacoxib, indicating that relying on USRSB provides insufficient postoperative analgesia for ovariohysterectomy in cats.

Dissection layer selection based on an understanding of pelvic fascial anatomy in transanal total mesorectal excision.

This study aimed to review the historical transition of rectal cancer surgery and recent evidence regarding transanal total mesorectal excision (TaTME). Additionally, it outlined the anatomical landmarks and technical considerations essential for successful TaTME. Anatomical studies and surgical techniques were analyzed to identify key landmarks and procedural steps crucial for TaTME. TaTME offers improved visibility and maneuverability even in the deep and narrow pelvis and is expected to contribute to tumor radical cure rates. By securing the circumferential resection margin and distal margin while preserving pelvic autonomic nerve function, TaTME holds promise for maintaining postoperative urinary and sexual functions. Key anatomical landmarks include the endopelvic fascia posteriorly, the S4-pelvic splanchnic nerve laterally, and the prostate or posterior vaginal wall anteriorly. Selecting the appropriate dissection layer based on tumor depth and ensuring precise incision of the tendinous arch of the pelvic fascia contributes to successful TaTME outcomes. TaTME represents a significant advancement in rectal cancer surgery, offering improved outcomes through meticulous attention to anatomical detail and precise dissection techniques. Understanding the historical context of rectal cancer surgery alongside recent evidence on TaTME is essential for optimizing patient outcomes and expanding the safe implementation of this innovative approach.

Frontal trans opercular approaches to the insula: building the mental picture from procedure-guided anatomical dissection.

Performing transopercular frontal approaches to the insula, widely used in glioma surgeries, necessitates a meticulous understanding of both cortical and subcortical neuroanatomy. This precision is vital for preserving essential structures and accurately interpreting the results of direct electrical stimulation. Nevertheless, acquiring a compelling mental image of the anatomy of this region can be challenging due to several factors, among which stand out its complexity and the fact that white matter fasciculi are imperceptible to the naked eye in the living brain. In an effort to optimize the study of the anatomy relevant to this topic, we performed a procedure-guided laboratory study using subpial dissection, fiber dissection, vascular coloration, and stereoscopic photography in a "real-life" surgical perspective. Nine cerebral specimens obtained from body donation were extracted and fixed in formalin. Colored silicone injection and a variant of Klinglers's technique were used to demonstrate vascular and white matter structures, respectively. We dissected and photographed the specimens in a supero-antero-lateral view to reproduce the surgeon's viewpoint. The anatomy related to the development of the surgical corridor and resection cavity was documented using both standard photography and the red-cyan anaglyph technique. The anatomy of frontal transopercular approaches to the insula involved elements of different natures-leptomeningeal, cortical, vascular, and fascicular-combining in the surgical field in a complex disposition. The disposition of these structures was successfully demonstrated through the aforementioned anatomical techniques. Among the main structures in or around the surgical corridor, the orbital, triangular, and opercular portions of the inferior frontal gyrus are critical landmarks in the cortical stage, as well as the leptomeninges of the Sylvian fissure and the M2-M4 branches of the middle cerebral artery in the subpial dissection stage, and the inferior fronto-occipital, uncinate and arcuate fasciculi, and the corona radiata in establishing the deep limits of resection. Procedure-guided study of cerebral hemispheres associating subpial, vascular, and fiber dissection from a surgical standpoint is a powerful tool for the realistic study of the surgical anatomy relevant to frontal transopercular approaches to the insula.

Ultrasound-guided perineural injection of the saphenous nerve in goat cadavers

BackgroundSurgery of the goat stifle joint requires good perioperative analgesia, ideally without affecting motor function in the postoperative period. The objective of this study was to describe an ultrasound-guided technique for saphenous nerve block in goats. Eleven fresh female goat cadavers from two different age groups were used: seven of them were four years old with a mean ± SD body weight of 65.9 ± 7.3 kg. Four animals were six months old and their mean ± SD body weight was 20.1 ± 3.1 kg. The cadavers were positioned in lateral recumbency with the limb to be blocked lowermost. A high-frequency linear transducer (6–12 MHz) was used to localise the interfascial plane between the sartorius and the vastus medialis muscles and to identify the saphenous nerve on the medial aspect of the thigh, caudal to the femur, at the level of the femoral triangle. In 22 pelvic limbs 0.1 mL/kg of methylene blue was injected around the saphenous nerve under ultrasound guidance, followed by gross anatomical dissection. The length of circumferentially stained nerve was measured, and the success rate of achieving at least 1 cm of staining is presented with a 95% confidence interval (CI).ResultsAlthough not all saphenous nerves were sonographically identified, their boundaries were defined as cranial to the femoral artery, lateral to the sartorius muscle, and medial to the vastus medialis and rectus femoris muscles, within the perivascular fat. During anatomical dissection, the overall dye solution distribution was graded as complete in 17/22 limbs indicating a 77.3% success rate [95% CI (0.598, 0.948)], partial in 3/22 limbs and failed in 2/22 limbs.ConclusionsThe success rate of this study indicates the feasibility of employing the ultrasound-guided technique to perform saphenous nerve block in goats. However, further in-vivo studies are recommended to assess the block's clinical efficacy before implementation on clinical patients.

New anatomical findings in the mandibular body region: Two parts that make up bucco-mandibular space.

Soft tissue spaces not only enable gliding by contraction of the facial muscles, but they also cause drooping of the superficial fat due to gravity in the upright position. This study was performed to clarify the structures around the bucco-mandibular space (BMS) and to apply this anatomical knowledge to clinical practice. Four sides of the face were dissected using a conventional gross anatomical dissection technique, and 10 sides (5 horizontal and 5 frontal sections) of the removed semi-facial soft tissue were dissected using the stretched tissue dissection (STD) method. Histological examination of the mandible was performed on two sides to confirm the findings of conventional gross anatomical dissection and STD. In all cases, both gross dissection and STD revealed that the BMS was composed of two parts. The superficial part was filled with adipose tissue containing nerves and vessels, including the marginal mandibular branch of the facial nerve, facial artery, facial vein, and mental nerve. We named this part the adipo-neuromandibular part. By contrast, the deep part was separated from the adipo-neurovascular part by facial deep fascia and composed of loose connective tissue. We named this deep part the loose connective tissue part. The STD method enabled us to obtain detailed anatomical findings of the mandibular region and elucidate two parts of the BMS in which the neurovasculature is distributed. We believe that these findings provide new insights into facial anatomy by resolving existing anatomical uncertainties and will contribute to safer surgical treatment in the facial region.

Science in Community: Anatomy, Academy, and Argument in the Eighteenth-Century Holy Roman Empire.

Understanding physicians as actors who implemented the early modern ideal of collective empiricism into their practices within the local contexts of everyday life, the paper explores two cases from imperial cities in southern Germany in the 1720s and 1780s in which anatomical studies were contested. By analyzing the strategies and arguments that the two physicians used to justify and continue their anatomical dissections, it focuses on their references to different kinds of (local) community and relates these references to another type of collective: membership in a scientific academy. To examine references to community, it is proposed, offers an opportunity to better understand the spread and practice of the ideal of the study of nature as a collective project and how it was intertwined with concepts and structures of order and society in the Holy Roman Empire.

Ultrasound-guided retromammillary injections in dogs: a feasibility, descriptive and anatomical study

ObjectiveTo evaluate the feasibility of an ultrasound-guided technique targeting the medial branches of the dorsal ramus of the spinal nerves (DRSN) by injecting a dye solution at the caudal aspect of the base of lumbar mammillary processes [i.e. the retromammillary (RM) space]. Study designFeasibility, descriptive, anatomical study. AnimalsEleven canine cadavers. MethodsUsing anatomical dissections, the relationship between the mammillary processes and the branches of the DRSN of the thoracolumbar and lumbar spine was studied in two cadavers. Subsequently, ultrasound-guided RM injections were administered in nine cadavers, randomly assigned to low volume (LV; 0.01 mL kg–1) of a dye solution at multiple points from L3 to L6 on one side, and high volume (HV; 0.4 mL kg–1) at a single L4 point on the contralateral side. Gross anatomical dissections were immediately performed after the injections. The RM injections were feasible if ultrasonographic landmarks were identifiable in at least 80% of cases, and 80% of LV injections showed medial branch staining. A one-sample binomial test was used for testing feasibility. ResultsThe medial branches emerged shortly after the DRSN exited the intervertebral foramen and traveled towards the caudal aspect of the base of the mammillary process, which served as the target injection point. With LV, 36 out of 36 (100%) injected medial branches were stained, meeting the criteria of feasibility (p < 0.001). The median (range) number of stained medial branches per cadaver were 4 (4–4) and 2 (1–3), with LV and HV, respectively. Although no lateral branches were stained with LV, 1 (0–2) was stained with HV. Neither ventral branch staining nor epidural spread was noted in any cadaver. Conclusions and clinical relevanceUltrasound-guided RM injections are feasible and allow for selective staining of the medial branch of the DRSN in canine cadavers at the lumbar spine.

Comparison of Terminal Elbow Extension between Humans and Baboons (Papio anubis).

It is assumed that hyperextension of the elbow joint beyond 0° in humans is due to local ligament and other soft tissue laxity. The common extant old-world olive baboon (Papio anubis), with a quadrupedal gait, commonly has a mild elbow joint flexion contracture. This study compares anatomic and functional roles of the olecranon-coronoid notch angle of the proximal ulna and the anterior direction of its opening on terminal elbow extension in humans and baboons. Active terminal elbow extension was measured in 211 elbows of skeletally mature humans using the neutral zero method. Passive elbow extension and radiographs were performed on 60 extremities of 30 anesthetized baboons. The mean olecranon-coronoid notch angle for humans and baboons was 22.2 ± 6.0° and 11.3 ± 3.2°, respectively (P < 0.001). Mixed effect regression analysis showed that the magnitude of the angle was a significant predictor of terminal elbow extension (P < 0.001) when accounting for species. Also, the causal mediation analysis showed that 18% of the difference in terminal elbow extension between species could be attributed to the olecranon-coronoid notch angle (P < 0.001). Anatomic dissection of 16 baboon arms showed that sectioning of all the anterior soft tissue structures increased mean terminal elbow extension from -18.2 ± 5.9° to -7.1 ± 6.0° and that further elbow extension was blocked primarily by the intact humeroulnar joint. The size of the notch angle and the positioning of its anterior proximal opening played a significant role in deciding terminal elbow extension in both species.