Personalized strategies for academic success in learning anatomy: Exploring metacognitive and technological adaptation in medical students.

Personalization of learning is an educational strategy rooted in metacognition and is significant in academic training. This is especially true in medical contexts. This study explored the relationship between the metacognitive profile of students of human anatomy, the classification of questions according to their difficulty, and the anatomical domain. It also covered the integration of educational technologies to create personalized learning environments. The identification of metacognitive profiles ("Active", "Pragmatic", "Theoretical", and "Reflective") has been highlighted as a critical influence on students' responses to different pedagogical approaches. Personalized adaptation based on these profiles has shown potential for improving grades and increasing student satisfaction and engagement with learning. The results revealed variations in student performance in relation to different pedagogical approaches, learning units, and evaluation modalities. The "Experience" evaluation modality, personalized according to metacognitive profiles, level of competence, and learning objectives, resulted in higher average scores. However, there was significant variability in the results. Those findings confirm the effectiveness of metacognitive adaptation in improving academic performance. Furthermore, they provide a solid basis for formulating personalized and effective pedagogical strategies in medical education. They recognize the influence of metacognitive profiles on student performance and contribute to advancing medical pedagogy.

A Highly Unusual Source and Course of the Inferior Gluteal Nerve With Related Variations: A Case Report.

The gluteal region is rich in neurovasculature that divides in predictable ways. Though these characteristic relationships can be helpful when orienting oneself to the gluteal region, it is especially useful to be aware of anatomical variations in this region. Knowledge of such differences allows for a better appreciation of nerve entrapments and neuropathies, and such awareness is critical during surgeries. In this case report, we explore an uncharacteristic relationship among the piriformis muscle, the sciatic nerve and its components, and the inferior gluteal and posterior femoral cutaneous nerves.

Urethral Injury in Rectal Cancer Surgery: A Comprehensive Study Using Cadaveric Dissection, Imaging Analyses, and Clinical Series.

Male urethral injury during rectal cancer surgery is rare but significant. Scant information is available about the distances between the rectourethral space and neighboring structures. The aim of this study is to describe the anatomical relations of the male urethra. This three-pronged study included cadaveric dissection, retrospective MRI analysis, and clinical cases. Measurements included the R-Mu distance (shortest distance between the rectum and the membranous urethra), R-Am distance (distance from the anterior rectal wall to anal margin nearest to the membranous urethra), and the anal canal-rectum axis angle. The clinical study analyzed the incidence of urethral injury and associated factors among 244 consecutive men from January 2016 to January 2023. The overall incidence of urethral injury in our series was low (0.73%), but in men with tumors < 10 cm from the anal margin, it was 4% in abdominoperineal resection and 3.2% in TaTME. On preoperative MRI, the median R-Mu distance was 1 cm (IQR, range, 0.2-2.3), the median R-Am distance was 4.3 cm (range, 2-7.3), and the median anorectal angle was 128° (range, 87-160). In the cadaveric study (nine adult male pelvises), the mean R-Mu distance was 1.18 cm (range 0.8-2), and the mean R-Am distance was 2.64 cm (range 2.1-3). Avoiding urethral injury is crucial. The critical point for injury lies 2-7.3 cm from the anal margin, with a 0.2-2.3 cm distance between the rectum and the membranous urethra. Collaborating with anatomists and radiologists improves surgeons' anatomy knowledge.

Distal osteotomy of the first metatarsal bone for the correction of hallux valgus: comparison of the sagittal stability of two percutaneous techniques-a cadaveric study.

BACKGROUND: Distal first metatarsal osteotomy is used to correct mild or moderate hallux valgus (HV). We designed a cadaveric study to compare the resistance to axial load between two percutaneous distal first metatarsal osteotomies: Bösch osteotomy and percutaneous chevron. The first aim of this study was to develop a systematic technique for measuring the sagittal displacement on lateral foot X-rays. Our second objective was to measure the resistance to axial load for both of these osteotomies. METHODS: Ten pairs of freshly frozen cadaveric feet were randomly assigned to one of the two techniques investigated. Pre- and post-operative lateral X-rays were obtained. After surgery, the feet were placed under progressive axial loads up to 60 kg. Metaphyseo-diaphyseal angle (MDA) and the distance between bone fragments were measured, and the differences between the two techniques were statistically assessed. RESULTS: The MDA decreased in both surgical techniques. The mean plantar tilt was -6.90 degrees (SD = 10.251) for chevron osteotomy and -5.34 degrees (SD = 16.621) for Bösch osteotomy. There was no significant difference between the techniques (p = 0.41). Regarding the distance between the bone fragments, the Bösch osteotomy produced more plantar displacement than the chevron osteotomy, which was statistically significant for the 10 and 20 kg loads (p = 0.031 and 0.04, respectively). At loads ≥ 30 kg, the bone fragment distance did not differ significantly between the techniques (p = 0.114). CONCLUSIONS: Although the chevron technique confers higher stability regarding fragment displacement during axial loading, both techniques increase the plantar angulation of the metatarsal head. LEVEL OF EVIDENCE: Cadaveric study.

Polyurethane Scaffold vs Fascia Lata Autograft for Hip Labral Reconstruction: Comparison of Femoroacetabular Biomechanics.

Background: The integrity of the acetabular labrum is critical in providing normal function and minimizing hip degeneration and is considered key for success in today's hip preservation algorithm. Many advances have been made in labral repair and reconstruction to restore the suction seal. Purpose/Hypothesis: To compare the biomechanical effects of segmental labral reconstruction between the synthetic polyurethane scaffold (PS) and fascia lata autograft (FLA). Our hypothesis was that reconstruction with a macroporous polyurethane implant and autograft reconstruction of fascia lata would normalize hip joint kinetics and restore the suction seal. Study Design: Controlled laboratory study. Methods: Ten cadaveric hips from 5 fresh-frozen pelvises underwent biomechanical testing with a dynamic intra-articular pressure measurement system under 3 conditions: (1) intact labrum, (2) reconstruction with PS after a 3-cm segmental labrectomy, then (3) reconstruction with FLA. Contact area, contact pressure, and peak force were evaluated in 4 positions: 90º of flexion in neutral, 90º of flexion plus internal rotation, 90º of flexion plus external rotation, and 20º of extension. A labral seal test was performed for both reconstruction techniques. The relative change from the intact condition (value = 1) was determined for all conditions and positions. Results: PS restored contact area to at least 96% of intact (≥0.96; range, 0.96-0.98) in all 4 positions, and FLA restored contact area to at least 97% (≥0.97; range, 0.97-1.19). Contact pressure was restored to ≥1.08 (range, 1.08-1.11) with the PS and ≥1.08 (range, 1.08-1.10) with the FLA technique. Peak force returned to ≥1.02 (range, 1.02-1.05) with PS and ≥1.02 (range, 1.02-1.07) with FLA. No significant differences were found between the reconstruction techniques in contact area in any position (P > .06), with the exception that FLA presented greater contact area in flexion plus internal rotation as compared with PS (P = .003). Suction seal was confirmed in 80% of PSs and 70% of FLAs (P = .62). Conclusion: Segmental hip labral reconstruction using PS and FLA reapproximated femoroacetabular contact biomechanics close to the intact state. Clinical Relevance: These findings provide preclinical evidence supporting the use of a synthetic scaffold as an alternative to FLA and therefore avoiding donor site morbidity.

The lateral ulnar collateral ligament: Anatomical and structural study for clinical application in the diagnosis and treatment of elbow lateral ligament injuries.

The lateral ulnar collateral ligament (LUCL) is considered one of the main stabilizers of the elbow. However, its anatomical description is not well established. Imaging techniques do not always have agreed upon parameters for the study of this ligament. Therefore, herein, we studied the macro and microanatomy of the LUCL to establish its morphological and morphometric characteristics more precisely. Fifty-five fresh-frozen human elbows underwent dissection of the lateral collateral ligament. Morphological characteristics were studied in detail. Ultrasound (US) and magnetic resonance (MR) were done before dissection. Two specimens were selected for PGP 9.5 S immunohistochemistry. Ten additional elbows were analyzed by E12 sheet plastination. LUCL was identified in all specimens and clearly defined by E12 semi-thin sections. It fused with the common extensor tendon and the radial ligament. The total length of the LUCL was 48.50 mm at 90°, 46.76 mm at maximum flexion and 44.10 mm at complete extension. Three morphological insertion variants were identified. Both US and MR identified the LUCL in all cases. It was hypoechoic in the middle and distal third in 85%. The LUCL was hypointense on MR in 95%. Free nerve endings were present on histology. The LUCL is closely related to the anular ligament. It is stretched during flexion and supination. US and MR can reliably identify its fibers. Anatomical data are relevant to the surgeon who repairs the ligaments of the elbow. Also, to the radiologist and pain physician who interpret imaging and treat patients with pain syndromes of the elbow.

Effects of Physical Activity Interventions in the Elderly with Anxiety, Depression, and Low Social Support: A Clinical Multicentre Randomised Trial.

The percentage of older people is increasing worldwide. Loneliness and anxious−depressive states are emerging health conditions in this population group, and these conditions give rise to higher morbidity and mortality. Physical activity (PA) and social relationships have been linked to physical and mental health. The objective of this study was to evaluate whether a 4-month programme of moderate PA in a group would improve the emotional state, levels of social support, and quality of life in a sample of individuals >64 years of age. A multicentre randomised clinical trial was designed in primary care. Ninety (90) participants were selected. After the intervention, there were positive differences between the groups, with significant improvements in the intervention group (IG) in depression, anxiety, health status perception, and social support. Walking in a group two days per week for 4 months reduced clinical depression and anxiety by 59% and 45%, respectively. The level of satisfaction was very high, and adherence was high. In conclusion, the moderate group PA programme improved clinical anxiety, depression, social support, and perceptions of health status in the patients studied.

Hip Labral Reconstruction With a Polyurethane Scaffold: Restoration of Femoroacetabular Contact Biomechanics.

Background: Many advances have been made in hip labral repair and reconstruction and in the restoration of the suction seal. Purpose/Hypothesis: The purpose of this study was to evaluate the biomechanical effects of segmental labral reconstruction with a synthetic polyurethane scaffold (PS) in comparison with segmental labrectomy. Our hypothesis was that reconstruction with a icroporous polyurethane implant would normalize joint kinetics of the hip and restore the suction seal. Study Design: Controlled laboratory study. Methods: We used 10 hips from 5 fresh-frozen pelvises with an intact acetabular labrum without osteoarthritis. Using an intra-articular pressure measurement system, the contact area, contact pressure, and peak force were assessed for the following conditions: intact labrum, partial anterosuperior labrectomy, and PS reconstruction. For each condition, all specimens were analyzed in 4 positions (90° of flexion, 90° of flexion and internal rotation, 90° of flexion and external rotation, and 20° of extension) and underwent a labral seal test. The relative change from the intact condition was determined for all conditions and positions. Results: Compared with the intact labrum, labrectomy resulted in a significant decrease in the contact area (P < .001) and a significant increase in the peak force (P < .001) and contact pressure (P < .001) across all positions. Compared with labrectomy, PS reconstruction resulted in a significant increase in the contact area (P < .001) and a significant decrease in the contact pressure (P ≤ .02) and peak force (P < .001) across all positions. Compared with the intact labrum, PS reconstruction restored the contact area and peak force to normal values in all positions (P > .05), whereas the contact pressure was significantly decreased compared with labrectomy (P < .05) but did not return to normal values. The labral seal was lost in all specimens after labrectomy but was restored in 80% of the specimens after PS reconstruction. Conclusion: Femoroacetabular contact biomechanics significantly worsened after partial labrectomy; reconstruction using a PS restored the contact area and peak force to the intact state and improved the contact pressure increases seen after partial labrectomy. The contact area and peak force were normalized, and the labral seal was re-established in most cases. Clinical Relevance: This study provides biomechanical evidence for the use of a scaffold for labral reconstruction.

"The Accessory Ethmoidal Canal Does Not Necessarily Contain an Arterial Structure".

Introduction: The aim of our study is to describe the prevalence of the accessory ethmoidal artery in endonasal endoscopic cadaver dissections and to identify its intraorbital origin. Material and Methods: From 2018 to 2020, thirty-four nasal dissections were performed in seventeen adult cadaveric heads. We performed a complete ethmoidectomy to identify the ethmoidal canals. Then, we removed the bony canal and the lamina papiracea to verify the injected vessel and to confirm the vascular structure inside the canal. Results: We found the anterior ethmoidal canal (AEC) and the posterior ethmoidal canal (PEC) in 100% of nasal cavities (34/34). We identified 4 accessory ethmoidal canals (AcEC) in the 34 nasal fossae dissected (12%). All AEC contained an arterial vessel. The AcEC contained an arterial vascular structure in 2 cases, a neural structure in other specimen, and in the fourth case no structure could be verified. In 32 of 34 nasal cavities, the PEC contained an artery and only in 2 cases the PEC did not contain any vascular structure. In these specimens, we observed that the AcEC with an arterial vessel inside (6%) was closer to the posterior canal than the anterior canal. Conclusion: According to our findings, we can suggest that the presence of a canal does not necessarily imply the presence of an arterial vessel, and that presence of the accessory ethmoidal artery could be associated with the absence of posterior ethmoidal artery.

Physical activity, emotional state and socialization in the elderly: study protocol for a clinical multicentre randomized trial.

OBJECTIVE: To evaluate whether a 4-month physical activity (PA) group program and visits to sociocultural organizations improve emotional state, social support levels and health-related quality of life in elderly individuals with depression and/or anxiety and/or loneliness. METHODS: This will be a multicentre, randomized, two-group clinical trial with a 1-year follow-up. Participants will be 150 primary care patients aged >64 years allocated equally to a control group and an intervention group. Inclusion criteria are Beck Depression Inventory (BDI-II) score ≥14 and/or General Anxiety Disorder (GAD-7) scale score ≥10 and/or Duke-UNC-11 scale score ≥32. The intervention group will participate in a 4-month group PA program. The program will comprise two walks per week and a monthly visit to a sociocultural facility. RESULTS: Measured outcomes are clinical remission of depression (BDI-II score <14) and anxiety (GAD-7 scale score <10), improved social support (reduction in DUKE-UNC-11 score), improved quality of life and/or response to the intervention at 4 and 12 months post-intervention. Intervention satisfaction and adherence and post-intervention links with sociocultural organizations will also be assessed. CONCLUSION: The findings could encourage the provision of activity-based community interventions for older individuals.

Spinal arachnoid sleeves and their possible causative role in cauda equina syndrome and transient radicular irritation syndrome.

INTRODUCTION: We have previously described arachnoid sleeves around cauda equina nerve roots, but at that time we did not determine whether injections could be performed within those sleeves. The purpose of this observational study was to establish whether the entire distal orifice of a spinal needle can be accommodated within an arachnoid sleeve. MATERIALS AND METHODS: We carefully dissected the entire dural sacs off four fresh cadavers, opened them by longitudinal incision, and immersed them in saline. Under direct vision, we penetrated the cauda equina roots nerves traveling almost vertically downward at 30 locations each with a 27- and a 25-G pencil-point needle (60 punctures total). We captured the images with a stereoscopic camera. RESULTS: The nerve root offered no noticeable resistance to needle entry. Although the arachnoid sleeves could not be identified with the naked eye, they were translucent but visible under microscopy. In 21 of 30 attempts with a 27-gauge needle, and in 20 of 30 attempts with a 25-gauge needle, the distal orifice of the spinal needle was completely within the arachnoid sleeve. CONCLUSION: It seems possible to accommodate the distal orifice of a 25- or a 27-gauge pencil-point spinal needle completely within the space of the arachnoid sleeve. An injection within this sleeve could potentially lead to a neurological syndrome, as we have previously proposed.

Direct emergence of the conus artery from an independent ostium. A cadaveric study on a Spanish sample

The main purpose of this study was to evaluate the frequency with which the conus artery originates from an independent ostium in the right aortic sinus. Twenty-five adult hearts (3 females, 5 males and 17 unknown sex), from the body donation program of the University of Girona, were analysed. After intravascular injection of natural coloured latex in the coronary ostia, the origin of the conus artery and its distribution pattern were analysed by microdissection. Three of the 25 hearts analysed (12.0%) displayed the direct emergence of the conus artery from a discrete ostium in the right aortic sinus: in two specimens (8%) showing a single ostium for the independent conus artery, and in one heart (4%) two ostia for two independent conus arteries. In all cases, the independent conus arteries were shorter than the coronary artery and extended up to the anterior wall of the right ventricle, coinciding with the observations of previous authors. The independent conus artery may be an important source of collateral blood flow to the infundibulum. It may be an important source of apex and interventricular septum collateral irrigation. To ascertain the origin of the conus artery and its distribution is clinically important, particularly in obstructions of the anterior interventricular artery. The independent conus artery's collateral perfusion can both obscure the detection of any ischaemic modification in the apex and septum regions, and serve as a therapeutic source. Consequently, interpretations of the coronary occlusion clinical test should take this vascular channel into account

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The Posterior Lumbar Epidural Space: Three-Dimensional Reconstruction of High-Resolution MRI: Real and Potential Epidural Spaces and Their Content In Vivo.

OBJECTIVE: Our aim was to study the posterior lumbar epidural space with 3D reconstructions of magnetic resonance images (MRIs) and to compare and validate the findings with targeted anatomic microdissections. DESIGN: We performed 3D reconstructions of high-resolution MRIs from seven patients and normal-resolution MRIs commonly used in clinical practice from 196 other random patients. We then dissected and photographed the lumbar spine areas of four fresh cadavers. RESULTS: From the 3D reconstructions of the MRIs, we verified that the distribution of the posterior fat pad had an irregular shape that resembled a truncated pyramid. It spanned between the superior margin of the lamina of the caudad vertebra and beyond the inferior margin to almost halfway underneath the cephalad lamina of the cranial vertebra, and it was not longitudinally or circumferentially continuous. The 3D reconstructions of the high-definition MRI also consistently revealed a prelaminar fibrous body that was not seen in most of the usually used low-definition MRI reconstructions. Targeted microdissections confirmed the 3D reconstruction findings and also showed the prelaminar tissue body to be fibrous, crossing from side to side anterior to the cephalad half of each lamina, and spanning from the dural sac to the laminae. CONCLUSIONS: Three-dimensional reconstructions and targeted microdissection revealed the unique appearance of posterior fat pads and a prelaminar fibrous body. The exact consistency, presence, prevalence with age, presence in other regions, and function of this body are unknown and require further research.

The influence of bone loss on the three adult age markers of the innominate.

To evaluate the influence of bone loss on the three adult age markers of the innominate, 30 males and 30 females aged between 16 and 80 years coming from the British Coventry collection were analyzed. The pubic symphysis, auricular surface, and acetabulum age variables were evaluated following the descriptions of Schmitt, Buckberry-Chamberlain, and Rissech, respectively. The second metacarpal cortical index was used to evaluate bone loss. Possible sexual differences in metrical variables were explored by a Student t-test taking into account the entire sample. The possible relationships between the cortical index and the three age methods' stages were assessed by the Kruskall-Wallis test and Spearman's correlation coefficient. There were no sexual differences in the cortical index. In general, we observed no significant differences between the cortical index in the different stages of the pubic symphysis, auricular surface, or acetabulum variables in men and women. Most correlation coefficients are negatives, and their absolute values are between 0.001 and 0.44, indicating an extremely low influence of bone loss on the analyzed variables. Our findings suggest little influence of bone loss in the three ageing methods. However, further research on this topic is necessary. This is the first study to analyze the influence of bone loss in the ageing changes undergone by the variables of the three adult age indicators of the innominate taking into account both sexes.

BAES Scrotal flap: anatomical bases and usefulness in complex urethral reconstruction.

OBJECTIVE: To describe the anatomical characteristics and vascularization of the biaxial hair free scrotal flap (BAES-flap) and to detail its surgical application to reconstruction of the more complex urethral strictures. METHODS: We performed macro and micro anatomical dissections of the scrotum in 15 cryopreserved cadavers for the study of the arterial microvascularization of the BAES flap, and this anatomical knowledge has been implemented with the aim to improve the anterior and posterior urethra reconstructive surgical technique. For scrotal skin conditioning we performed definitive hair removal with the alexandrite laser. RESULTS: The BAES flap, thanks to its rich biaxial vascularization, its anatomical disposition over the urethral axis, and the suitable characteristics of hair free scrotal skin, has allowed us to perform successful one-step urethral reconstruction in complex cases such as panurethral disease, multioperated hypospadias, failed urethroplasties and obliterative stenosis. CONCLUSIONS: Detailed study of scrotal skin arterial vascularization is essential to design reliable and versatile genital skin flaps that result appropriate for the most complex reconstructive urethral surgery. The BAES scrotal flap complies with these requirements offering the patient a one step reconstructive option with a very satisfactory surgical experience over more than 20 years.

Colgajo escrotal "BAES": Bases anatómicas y utilidad en reconstrucción uretral compleja / BAES Scrotal flap: Anatomical bases and usefulness in complex urethral reconstruction

OBJETIVO: Describir las características anatómicas y la vascularización del colgajo escrotal biaxial depilado ("BAES-flap"), y detallar su aplicación quirúrgica en la reconstrucción de las estenosis uretrales más complejas. MÉTODOS: Se han realizado macro y microdisecciones anatómicas de la bolsa escrotal en 15 cadáveres criopreservados para estudiar la microvascularización arterial que posee el colgajo "BAES", y este conocimiento anatómico ha sido implementado con la intención de mejorar la técnica quirúrgica reconstructiva de la uretra anterior y posterior. Para el acondicionamiento cutáneo escrotal se ha empleado la técnica de depilación definitiva con láser de Alejandrita. RESULTADOS: El colgajo "BAES" gracias a su abundante vascularización bi-axial, a su disposición anatómica sobre el eje uretral y a las características idóneas de la piel escrotal depilada, nos ha permitido desde el año 1989 reconstruir con éxito la uretra en un tiempo quirúrgico en casos complejos como son la enfermedad panuretral, los hipospadias multioperados, las uretroplastias fracasadas y las estenosis obliterantes. CONCLUSIONES: El estudio detallado de la vascularización cutánea arterial es fundamental para diseñar colgajos de piel genital fiables y versátiles que resulten aptos para la cirugía reconstructiva uretral más compleja. El colgajo escrotal "BAES" cumple con estos requisitos ofreciendo al paciente una opción reconstructiva en un solo tiempo con una experiencia quirúrgica muy satisfactoria de más de 20 años

OBJECTIVE: To describe the anatomical characteristics and vascularization of the biaxial hair free scrotal flap (BAES-flap) and to detail its surgical application to reconstruction of the more complex urethral strictures. METHODS: We performed macro and micro anatomical dissections of the scrotum in 15 cryopreserved cadavers for the study of the arterial microvascularization of the BAES flap, and this anatomical knowledge has been implemented with the aim to improve the anterior and posterior urethra reconstructive surgical technique. For scrotal skin conditioning we performed definitive hair removal with the alexandrite laser. RESULTS: The BAES flap, thanks to its rich biaxial vascularization, its anatomical disposition over the urethral axis, and the suitable characteristics of hair free scrotal skin, has allowed us to perform successful one-step urethral reconstruction in complex cases such as panurethral disease, multioperated hypospadias, failed urethroplasties and obliterative stenosis. CONCLUSIONS: Detailed study of scrotal skin arterial vascularization is essential to design reliable and versatile genital skin flaps that result appropriate for the most complex reconstructive urethral surgery. The BAES scrotal flap complies with these requirements offering the patient a one step reconstructive option with a very satisfactory surgical experience over more than 20 years

Ultrasound-guided popliteal sciatic block with a single injection at the sciatic division results in faster block onset than the classical nerve stimulator technique.

BACKGROUND: For successful, fast-onset sciatic popliteal block (SPB), either a single injection above the division of the sciatic nerve, or 2 injections to block the tibial nerve (TN) and common peroneal nerve (CPN) separately have been recommended. In this study, we compared the traditional nerve stimulator (NS)-guided SPB above the division of the sciatic nerve with the ultrasound (US)-guided block with single injection of local anesthetic (LA) between the TN and CPN at the level of their division. We hypothesized that US-SPB with a single injection between TN and CPN would result in faster block onset than a single-injection NS-SPB. METHODS: Fifty-two patients were randomized to receive either an NS-SPB or a US-SPB. For both blocks, a single injection of 20 mL mepivacaine 1.5% was given using an automated injection pump while controlling for injection force. For NS-SPB, a TN response below 0.5 mA was sought 7 cm above the popliteal fossa crease (and proximal to the divergence of the TN and peroneal nerves). For US-SPB, the injection was made after a US-guided needle was inserted between the TN and CPN at the level of their separation. Motor response was not actively sought but registered if present. The location and spread of LA were evaluated by US in both groups. Onset of motor and sensory blocks was serially assessed in 5-minute intervals in the TN and CPN divisions and compared between the groups. RESULTS: All patients in both groups had successful block at 30 minutes after the injection, defined as sensory block to allow surgery without supplementation. A higher proportion of patients in the US-SPB group had a complete sensory (80% vs 4%, P < 0.001) and motor block (60% vs 8%, P < 0.001), defined as anesthesia and paralysis in all nerve territories, at 15 minutes after injection. US signs of intraepineural injection were present in 19 patients (73%) in the NS-SPB group and 25 patients (100%) in the US-SPB group (P < 0.001). CONCLUSIONS: A single injection of LA in US-SPB with needle insertion at the separation of the TN and CPN results in a similar success rate at 30 minutes; however, more patients in the US-SPB group than in the NS-SPB group had complete block at 15 minutes.

Ultrasound-anatomic correlation of the peripheral nerves of the upper limb.

BACKGROUND: Sonography allows good visualization of the peripheral nerves and the vascular and muscular structures that surround them. Our goals are to provide an easy-to-use atlas that gives accurate information about the locations and relations among the nerves in the different parts of the arm and to correlate it with the probe position and the ultrasound images. MATERIALS AND METHODS: A cadaver right arm was used for the present study. The arterial and venous vessels were injected with red and blue-colored latex to obtain a better correlation with ultrasound slices from two healthy volunteers. The specimen was frozen and then cut into slices with an average thickness of 2 cm, starting from the lower part of the axilla. RESULTS: Close correlation was present between the ultrasound and anatomic slices identifying the main muscular, vascular and nervous structures. In the arm, median, ulnar and radial nerves were easily seen because of the proximity to vascular landmark and their size. In the forearm, the ulnar nerve was also easy to identify because of the factors previously mentioned; the median nerve was easy to locate between the flexor digitorum superficialis and profundus muscles. The superficial branch of the radial arm was seen in most cases, although some skill was required. CONCLUSION: Ultrasound is a useful tool to identify the main nerves of the upper arm. This atlas indicates the locations and relations among the nerves, correlating with the ultrasound appearance.

Arteries of the scrotum: a microvascular study and its application to urethral reconstruction with scrotal flaps.

OBJECTIVE: To study scrotal microvascularization and apply the findings to the design of reliable skin flaps for reconstructive surgery of complex urethral or panurethral stenoses. MATERIALS AND METHODS: In 15 cryopreserved male cadavers, scrotal skin vascularization was explored using macro- and microdissections, and the scrotal sac made transparent using the Spalteholtz method. A meticulous descriptive analysis of the arterial network was conducted out in all cases to evaluate the number, distribution and anastomosis of the cutaneous arteries of the scrotum. RESULTS: Scrotal skin is irrigated by two main vascular systems, through the inferior external pudendal arteries and the perineal arteries, which branch into multiple scrotal arteries. These arteries are distributed in three cutaneous territories, two lateral and one central, which are widely inter-anastomosed. Each lateral territory receives an inferior external pudendal artery which accesses at the midpoint of the scrotal root and fans out to cover the entire corresponding hemiscrotum. The central cutaneous territory is vascularized through the branches of two main scrotal arteries which are a continuation of the perineal arteries and which access via the posterior face, running deeply on both sides of the septum. CONCLUSIONS: The special anatomical distribution of scrotal branches stemming from perineal arteries enables the construction of adequate reliable longitudinal median island scrotal flaps for the reconstructive surgery of panurethral stenosis, as profuse axial vascularization is ensured.

Cutaneous perforators of the fourth dorsal interosseous space: anatomic study.

PURPOSE: Many investigators have studied the vascular anatomy of the dorsal metacarpal arteries but little attention has been paid to the exact distribution of the cutaneous perforators of the dorsum of the hand. We present an anatomic study of the cutaneous perforators within the fourth dorsal interosseous space, which was supposed to have the most inconsistent vascular anatomy. METHODS: Twenty hands were dissected after black latex injection. A skin paddle was outlined along the fourth dorsal metacarpal space. Suprafascial dissection was performed, preserving any vessel piercing the fascia and reaching the skin. Each perforator was traced back to its origin. The location and origin of each perforator was recorded by digital pictures and measured from a reference point. RESULTS: In 17 of the cases (85%) at least 1 perforator was identified within the fourth space piercing the dorsal interosseous muscle fascia and reaching the skin. In 10 hands, a perforator branching off the proximal communicating branch was identified, located a mean distance of 11 mm from the carpometacarpal joint line. CONCLUSIONS: A dissectable perforator was found consistently (17 of 20; 85%) in the proximal third of the fourth dorsal interosseous space branching off the proximal communicating branch. Few perforators branch off the middle third of the dorsal metacarpal artery. The perforator described herein shows the connection between the superficial and deep vascular systems of the ring and small metacarpal spaces, and establishes the anatomic basis for reconstructive flaps.