OBJECTIVE: Understanding the vascular morphology is fundamental for resuscitative endovascular balloon occlusion of the aorta. This study aimed to evaluate the effect of aging on length and diameter of aorta and iliac arteries in trauma patients, and to investigate the predictiveness of anatomical landmarks for aortic zones.
METHODS: A total of 235 patients in a regional trauma center registry from September 1, 2018, to January 3, 2024, participated in the study. Reconstruction of computed tomography was applied to the torso area. The marginal diameter and length of aorta and iliac arteries were measured. Anatomical landmark distances and aortic marginal lengths were compared.
RESULTS: The length and diameter of aorta and iliac arteries increased with age, and a tortuous and enlarged morphology was observed in older patients. There was a good regression between age and diameter of the aorta. Neither the jugular notch, the xiphisternal joint, nor the umbilicus could reliably represent specific margins of aortic zones. The distance between the mid-sternum and femoral artery (427 ± 25 to 442 ± 25 mm for right, and 425 ± 28 to 440 ± 26 mm for left) was predictive for zone 1 in all groups. The distance between the lower one-third junction of the xiphisternum to the umbilicus and femoral artery (232 ± 19 to 240 ± 17 mm for right, and 229 ± 20 to 237 ± 19 mm for left) was predictive for zone 3 aorta.
CONCLUSIONS: Aging increases the length and diameter of aorta and iliac arteries, with a tortuous and enlarged morphology in geriatric populations. The mid-sternum and the lower one-third junction of the xiphisternum to the umbilicus were predictive landmarks for zone 1 and zone 3, respectively.

In biomechanics, movement is typically recorded by tracking the trajectories of anatomical landmarks previously marked using passive instrumentation, which entails several inconveniences. To overcome these disadvantages, researchers are exploring different markerless methods, such as pose estimation networks, to capture movement with equivalent accuracy to marker-based photogrammetry. However, pose estimation models usually only provide joint centers, which are incomplete data for calculating joint angles in all anatomical axes. Recently, marker augmentation models based on deep learning have emerged. These models transform pose estimation data into complete anatomical data. Building on this concept, this study presents three marker augmentation models of varying complexity that were compared to a photogrammetry system. The errors in anatomical landmark positions and the derived joint angles were calculated, and a statistical analysis of the errors was performed to identify the factors that most influence their magnitude. The proposed Transformer model improved upon the errors reported in the literature, yielding position errors of less than 1.5 cm for anatomical landmarks and 4.4 degrees for all seven movements evaluated. Anthropometric data did not influence the errors, while anatomical landmarks and movement influenced position errors, and model, rotation axis, and movement influenced joint angle errors.

OBJECTIVE: The objective of our study is to compare the success rate, duration, and incidence of complications of a right internal jugular vein (IJV) cannulation by using three different techniques.
METHODS: A randomised controlled trial was conducted at a tertiary care teaching hospital. A total of 201 patients were randomly allocated to one of the following three groups (67 in each group). Techniques were categorised as anatomical landmark technique group (Group ALT), ultrasound guided pre-location group (Group USG-Pre), and real-time ultrasound-guided technique group (Group USG-RT).
METHODS: Central venous catheter insertion via three techniques.
RESULTS: In 138 (73.01%) patients\' IJV canulated in the first attempt, USG-RT, USG-Pre, and ALT were 51 (83.6%), 44 (72.1%), and 43 (64.2%), respectively. On the other hand, 37 (19.57%) patients were required in the second attempt, while only 14 (7.40%) patients were required in the third attempt for successful IJV cannulation. The success rates, as defined in our study, were only 138 (73%) as, in 51 (27%), we cannulated in more than a single attempt or switched to another technique. We found a significant difference in preparation time in all techniques as P-value <0.05, but no significant difference was found in venous access time, cannulation time, and duration of the procedure.
CONCLUSIONS: Any technique can be used for IJV cannulation, but the most acceptable is the real-time US technique. However, no difference in the overall procedure time among all three techniques was noted, and no major incidence of complication was found.

UNASSIGNED: The transverse-sigmoid-sinus-transition constitutes an important landmark during a retrosigmoid craniotomy. Due to anatomical variations, the location is highly variable. Landmarks for identification of the anterior border of the sigmoid sinus have been described extensively, such as the mastoid notch, digastric point, external auditory meatus and crux of the helix curvature. There is a paucity of landmarks for the identification of the posterior border, however.
UNASSIGNED: We examined the relationship between the transverse-sigmoid-sinus-transition and the most-posterior-part-of-the-auricula.
UNASSIGNED: We performed a retrospective analysis of one-hundred patients (38 males and 62 females) who underwent cerebral MRI examinations at Antwerp University Hospital (Belgium). Using Brainlab®, the transverse-sigmoid-sinus-transition and most-posterior-part-of-the-auricula coordinates were calculated and compared. Left and right sides were compared in both the anteroposterior and craniocaudal axis.
UNASSIGNED: Mean age was 56.4 ± 16.1 years. Mean MPPA-TSST-distance in the anteroposterior direction was -1.93 mm (right) and -1.96 mm (left). Mean MPPA-TSST-distance in the craniocaudal direction was -5.16 mm (right) and -5.04 mm (left).
UNASSIGNED: The transverse-sigmoid-sinus-transition seems to be located more anterior and caudal with respect to the most-posterior-part-of-the-auricula, meaning that it can be considered a save landmark. A correction of five mm needs to be applied in order to identify the inferior border of the transverse sinus. Left/right and gender had no significant influence. The most-posterior-part-of-the-auricula can be considered a fast and practical anatomical landmark for identification of the transverse-sigmoid-sinus-transition, without affecting operative fluency, especially during an emergency craniotomy.

UNASSIGNED: There is limited data on the relative effectiveness of different techniques used for administering genicular nerve block (GNB) for pain management of chronic knee osteoarthritis (OA) in the Malaysian population. This study aims to determine and compare the effectiveness of GNB administered using two pain management techniques?\"anatomical landmark-guided (ALG) and ultrasound-guided (USG)?\"for chronic knee OA in this population.
UNASSIGNED: This retrospective cohort study included 40 patients with chronic knee OA who received GNB, 20 of whom underwent treatment with the USG technique and the other 20 with the ALG technique. Pain, stiffness, and functional limitation scores were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index Questionnaire (WOMAC) and Numeric Rating Scale (NRS-11) at baseline and post-treatment day one, three weeks, and six weeks.
UNASSIGNED: Both groups reported a significant reduction in WOMAC and NRS-11 scores as per their feedback on day one, three weeks, and six weeks post-treatment. Greater reductions in WOMAC and NRS-11 scores were reported by patients who received GNB via USG than by ALG technique, the difference achieving statistical significance at six weeks after treatment (p =0.026).
UNASSIGNED: GNB administration using USG and ALG techniques are both effective in significantly reducing pain, stiffness, and functional limitation in patients suffering from chronic knee OA. Among the two techniques, USG appears to be more effective. Nevertheless, GNB guided by ALG continues to be a viable treatment modality, especially in healthcare settings with limited to no USG facilities.

UNASSIGNED: To determine the incidence and characteristics of Zuckerkandl\'s tubercle (ZT), and its relationship with recurrent laryngeal nerve (RLN) and the superior parathyroid gland (SPG) in the setting of total thyroidectomy.
UNASSIGNED: A total of 421 patients (mean (min-max) age: 45.6 (18-78) years, 76.2% were females) who had total thyroidectomy were included in this prospective single-surgeon thyroidectomy series study. Patient demographics and thyroidectomy indications (benign and malignant) were recorded in each patient. The presence, grade and laterality of ZT, and its relationship with RLN and SPG were recorded during surgery.
UNASSIGNED: Most of the thyroidectomy indications (69.1%) were related to a malignant disease. The ZT was unrecognizable in 41(9.7%) of 421 patients. In 380 patients with identifiable ZT, the grade 2 (46.3%) ZT was the most common finding. Majority of ZTs (92.9%) were unilaterally located (right-sided: 64.9%; left-sided: 35.1%). In majority of the cases (83.2%), the RLN was found to lie medial to ZT. Overall, SPG was identified in close proximity to ZT in 66.6% of patients (Class 2 [0.5-1 cm from ZT] in 46.6% and Class 3 [<0.5 cm from ZT] in 20.0%). SPG was more likely to be identified in close proximity to ZT when the grade of ZT was higher, which was found to be located 0.5-1 cm from the ZT in 56.9% and 42.7% of grade 2 and grade 3 ZTs, respectively, and <0.5 cm from the ZT in 46.1% of grade 3 ZTs.
UNASSIGNED: In conclusion, this prospective single-surgeon thyroidectomy series study indicates the likelihood of localizing the RLN medial to ZT, and the SPG in close proximity to ZT during total thyroidectomy operations. Hence, the ZT can be used as a reliable and constant landmark to localize both the RLN and the SPG during thyroid surgery, which enables minimizing the risk of iatrogenic injury to RLN, while ensuring a parathyroid-sparing thyroidectomy. The thyroid surgeon should have complete knowledge of thyroid gland anatomy and embryogenesis and should follow a careful and meticulous approach particularly for dissections around larger ZTs, given the increased likelihood of SPG and RLN to be in close proximity.

The histology of blood vessels shows they are structured in three layers or tunics: tunica intima, which includes the internal limiting lamina with high elastin content; tunica media of smooth muscles fibers of circular disposition, which includes the external limiting lamina; and tunica adventitia of connective tissue. The vascular system is essential in regulating body temperature, especially in the scrotum and testis. This study aimed to analyze the histology of the scrotal arteries and their possible relationship to testicular temperature homeostasis. This study used scrotal samples from human adults, anonymized and obtained from the University of Chile\'s teaching bank. The control group corresponds to an arteriole of muscle tissue. The results show that the middle layer of the scrotal artery is made up of smooth muscle fibers distributed in two layers: a longitudinal inner sublayer and a circular outer sublayer, different from the findings in muscle tissue arteries, with a single, circularly arranged muscle layer. This arrangement could be related to testicular temperature homeostasis by reducing the temperature of the testis and seminiferous tubules. The results described in this work suggest that these anatomical adaptations may be very significant in the face of the constant increase in global temperature. Further and better research is required to understand the mechanisms of thermoregulation in human reproduction and the histological particularities of the tissues that form the scrotum. RESEARCH HIGHLIGHTS: The human scrotal artery has a histological composition adapted for regulation of testicular temperature. The muscular double middle layer of the scrotal artery retains intravascular temperature.

OBJECTIVE: The purpose of this study was to evaluate the reproducibility and the accuracy of distal tibiofibular syndesmosis (DTFS) as landmark to perform controlled varus tibial resections during total knee arthroplasty (TKA). The hypothesis was that DTFS can be used to perform an accurate 3° varus tibial cut.
METHODS: A retrospective analysis on a consecutive series of standard weightbearing full-length anteroposterior views of the lower limbs radiographic images was conducted. For each radiograph, the hip-knee-ankle (HKA) angle, the angle between the tibial mechanical axis and the line connecting the centre of the tibial spines and the DTFS (tibiofibular angle, TFA) and the medial proximal tibial angle (MPTA) were calculated. Each measurement was carried out twice by three independent observers, and intra- and inter-observer measurement reliability were assessed using the intraclass correlation coefficient (ICC) analysis.
RESULTS: A total of 1296 lower limbs were analysed from a series of 648 weightbearing full-length anteroposterior radiographs. The ICC were > 90% for all measurements. The mean TFA value was 2.94 ± 0.68 (range 2.38-3.51). No differences were detected comparing the mean TFA value on the right and left limb (p = 0.795) as well as comparing the values in male and female patients (p = 0.691). Linear regression analysis did not find statistically significant correlation between TFA and MPTA, or TFA and HKA angles, respectively.
CONCLUSIONS: The distal tibiofibular syndesmosis is a reliable and easy reproducible radiographic landmark that can be used when planning a 3° varus tibial cut. Future studies are needed to confirm the validity of this method also in clinical settings.
METHODS: IV, retrospective case series.

The objective of this study was to investigate whether the base of the third metacarpal can predict the location of the thenar branch (TB) of the median nerve and the accuracy of palpating the base of the third metacarpal.
In 15 patients with ulnar nerve lesions around the elbow, we transferred the opponens motor branch to repair the deep terminal division of the ulnar nerve (DTDUN). Before surgery, we located the TB by palpating the base of the third metacarpal volarly. During surgery, we placed three needles at the following places: one at the entrance of the TB into the abductor pollicis brevis, another at the point where the TB contacted the thenar muscles, and third at the DTDUN\'s trajectory over the third metacarpal. We obtained fluoroscopic images and measured distances between the needles and structures with image software. We also examined the relationship between the TB, DTDUN, and the volar tubercle of the base of the third metacarpal in cadaver hands. Finally, we invited 22 surgeons to palpate the base of the third metacarpal on volunteer hands and verified their accuracy using fluoroscopy.
During surgery, after dissection and palpation of the TB, under fluoroscopy, we confirmed that the palpable bone prominence was the base of the third metacarpal. In cadaver dissections, we observed the TB crossing the volar tubercle of the base of the third metacarpal superficially from proximal to distal and from ulnar to radial. The DTDUN was, on average, 14 mm distal to the base of the third metacarpal distal limit. In total, 19 of the 22 surgeons correctly identified the base of the third metacarpal and consequently the trajectory of the TB.
The palpable base of the third metacarpal can be used to determine the trajectory of both the TB and DTDUN.
Diagnostic II.

Anatomical liver resection and liver resection close to major blood vessels are quite challenging and require a high level of expertise. In addition, anatomical hepatectomy requires extensive knowledge of the positions of blood vessels and techniques for hemostasis because the resection surface is extensive and operations around blood vessels are required. A hepatic vein-guided cranial and hilar approach using a modified \"two-surgeon technique\" is effective in resolving these problems. Herein, we present a middle hepatic vein (MHV)-guided cranial and hilar approach using a modified two-surgeon technique in laparoscopic extended left medial sectionectomy to resolve these problems. This procedure is feasible and effective.