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Background Three-dimensional (3D) printing technology has recently been well approved as an emerging technology in various fields of medical education and practice; e.g., there are numerous studies evaluating 3D printouts of solid organs. Complex surgery such as extended mesenterectomy imposes a need to analyze also the accuracy of 3D printouts of more mobile and complex structures like the diversity of vascular arborization within the central mesentery. The objective of this study was to evaluate the linear dimensional anatomy landmark differences of the superior mesenteric artery and vein between (1) 3D virtual models, (2) 3D printouts, and (3) peroperative measurements. Methods The study included 22 patients from the ongoing prospective multicenter trial “Safe Radical D3 Right Hemicolectomy for Cancer through Preoperative Biphasic MDCT Angiography,” with preoperative CT and peroperative measurements. The patients were operated in Norway between January 2016 and 2017. Their CT datasets underwent 3D volume rendering and segmentation, and the virtual 3D model produced was then exported for stereolithography 3D printing. Results Four parameters were measured: distance between the origins of the ileocolic and the middle colic artery, distance between the termination of the gastrocolic trunk and the ileocolic vein, and the calibers of the middle colic and ileocolic arteries. The inter-arterial distance has proven a strong correlation between all the three modalities implied (Pearson's coefficient 0.968, 0.956, 0.779, respectively), while inter-venous distances showed a weak correlation between peroperative measurements and both virtual and physical models. Conclusion This study showed acceptable dimensional inter-arterial correlations between 3D printed models, 3D virtual models and authentic soft tissue anatomy of the central mesenteric vessels, and weaker inter-venous correlations between all the models, reflecting the highly variable nature of veins in situ.

Worldwide, compartmentalization of the human liver into portal venous territories today follows the eight-segments scheme credited to Couinaud. However, there are increasing reports of anatomical, radiological and surgical observations that contradict this concept. This paper presents a viewpoint that enhances understanding of these inconsistencies and can serve as a basis for customized liver interventions. Clin. Anat. 30:974-977, 2017. © 2017 Wiley Periodicals, Inc.

Introduction Syndesmotic disruption may be difficult to reduce and fix, and malreduction is associated with inferior outcomes. Intraoperative computed tomography (CT) can provide accurate assessment of syndesmotic reduction. We hypothesized that three-dimensional (3-D) computer-assisted orthopaedic surgery (CAOS) with navigation of syndesmotic reduction could avoid malreduction. Our goal was to assess feasibility and accuracy of such a technic in a cadaveric study. Method Eleven through-the-knee cadaveric specimens were used. Ankle CT as control was obtained prior to intervention. The syndesmosis was destabilized by sectioning the tibiofibular ligaments, producing a malreduction temporarily fixed with a Kirschner wire (K-wire). With reference base fixed to the tibia an acquisition scan was made. A K-wire was fixed to the fibula. The K-wire holding the syndesmosis malreduced was removed. The fibula was reduced within the syndesmosis under 3-D CAOS using a navigated K-wire. Once optimal position was obtained by referencing control images, the syndesmosis was fixed with a 3.5 mm screw. A CT scan was performed to assess quality of reduction. Results Position of the fibula in control and post-reduction CT scans showed a mean anterior-posterior displacement of 0.74 (±0.62)mm. The medial-lateral position measured a mean displacement of 0.68 (±0.76)mm. Rotation of the fibula revealed a mean difference of 0.99° (± 0.73). Conclusion In this cadaveric study, CAOS with navigation allowed for very accurate syndesmosis reduction. This appears to be a promising technique to be confirmed by clinical study.

The salivary glands and pancreas have comparable anatomic and antigenic properties and can share common pathogenetic mechanisms involving toxic or autoimmune processes. The aim of this study is to assess the correlation in size between the normal submandibular glands and the pancreas. The study was based on human autopsy specimens of the pancreas, neck and oral base from 22 adults, both sexes (mean age, 57.9 years). The pancreatic and submandibular ducts were injected with a contrast medium, and the area of the salivary and pancreatic glandular ductograms was measured with the aid of software for quantification of visual information. Samples of tissue from the salivary glands and the pancreas were studied by means of light microscopy. A high correlation was found between the planimetric size of the pancreas and the submandibular glands (correlation coefficient 0.497 and 0.699 for the right and the left gland, respectively). This ratio was close to 5:1. There were no significant differences in size for the left vs. right submandibular gland (p = 0.39). The ductograms were significantly larger in size in males than in females (p lt 0.001). This study has proven a positive correlation in planimetric size between the normal submandibular glands and pancreas, a result that is expected to have possible clinical implications in the long-term follow-up of patients with chronic pancreatitis.

The anterior cruciate ligament (ACL) is a band of dense connective tissue which courses from the femur to the tibia. The ACL is a key structure in the knee joint, as it resists anterior tibial translation and rotational loads. When the knee is extended, the ACL has a mean length of 32 mm and a width of 7-12 mm. There are two components of the ACL, the anteromedial bundle (AMB) and the posterolateral bundle (PLB). They are not isometric with the main change being lengthening of the AMB and shortening of the PLB during flexion. The ACL has a microstructure of collagen bundles of multiple types (mostly type I) and a matrix made of a network of proteins, glycoproteins, elastic systems, and glycosaminoglycans with multiple functional interactions. The complex ultrastructural organization and abundant elastic system of the ACL allow it to withstand multiaxial stresses and varying tensile strains. The ACL is innervated by posterior articular branches of the tibial nerve and is vascularized by branches of the middle genicular artery.

BACKGROUND AND PURPOSE: An increasing number of surgical and radiological observations call Couinaud's concept of eight liver segments into question and such inconsistencies are commonly explained with anatomical variations. This paper was intended to demonstrate that, beyond variability, another anatomical principle may allow to understand supposedly differing concepts on liver segmentation. MATERIALS AND METHODS: The study was performed on 25 portal vein casts scanned by helical CT. The branches of the right and left portal vein and their corresponding territories were determined both anatomically and mathematically (MEVIS LiverAnalyzer, MEVISLab). RESULTS: The number of branches coming-off the right and left portal vein was never 8, but many more (mean number 20, range 9-44). Different combinations of these branches and their respective territories, carried out in this study, yielded larger entities and supposedly contradictory subdivisions (including Couinaud's eight segments), without calling upon anatomical variability. CONCLUSIONS: We suggest the human liver to be considered as corresponding to 1 portal venous territory at the level of the portal vein, to 2 territories at the level of the right and left branch of the portal vein, and to 20 at the level of the rami of the right and left branch. This "1-2-20-concept" is a rationale for reconciling apparent discrepancies with the eight-segment concept. On a pragmatic level, in cases in which imaging or surgical observations do not fit with Couinaud's scheme, we propose clinicians not to autonomically conclude to the presence of an anatomical variation, but to become aware of the presence of an average of 20 (and not 8) second-order portal venous territories within the human liver.

As part of the trend towards personalised medicine, surgeons are increasingly using 3D printed replicas for preoperative planning. This raises the question of how reliable these models are. This paper examines the repeatability of manufacturing human mandibles. Five polyamide replicas were produced using selective laser sintering and digitised using structured light scanning. Quantitative comparisons were made using Mimics Software. The differences were analysed graphically, using histograms and kernel density estimates. The mean differences ranged between + 0.0274 (SD 0.0671) mm and − 0.0284 (SD 0.0629) mm. The median of absolute differences was 0.0308 mm, i.e. 50% of absolute differences were smaller than 31 $$\upmu \hbox {m}$$ . For the 22,811,168 differences measured, all were between + 1.9836 and − 2.0526 mm. The proportion of absolute differences below 0.10 mm was between 82.09 and 98.84%, and between 94.43 and 99.90% when using a threshold of 0.20 mm. 99.95% of the absolute differences were below 1.00 mm. In conclusion: 3D printed models may not be identical, even when based on the same imaging study and patient; on the other hand, identical replicas can be obtained with a constant production chain; we recommend that four distinguishing criteria should be used in future investigations: qualitative and quantitative accuracy, repeatability and reproducibility.

Background The middle colic artery (MCA) is of crucial importance in abdominal surgery, for laparoscopic or open right and transverse colectomies. Against this background, a high number of reports concerning anatomical variations of the MCA have been published intended to contribute to the improvement of operative techniques for the treatment of colon cancer. Despite this extensive literature, briefly reviewed in the present paper, a course of the MCA posterior to the superior mesenteric vein, called a retromesenteric trajectory, has been related to only once, to the best of our knowledge. Methods A total series of 507 patients included in two prospective trials concerning laparoscopic or open right colectomy for cancer between 2011 and 2017 are reported. The investigation included preoperative or postoperative multidetector-computed tomography angiography. Results We found four (0.79%) cases of retromesenteric MCA. They all underwent meticulous image analysis with mesenteric vessels' road mapping, detailedmorphometry, and surgical validation which revealed that, apart from their course, those cases did not differ significantly from the rest of the series. Conclusion This paper therefore documents the worth-knowing behavior causing considerable confusion for the operating surgeon unaware of the abnormality and shows its concrete impact on patient-tailored surgical practice, in particular for laparoscopic D3 colectomy (including the Buncinated process first^ approach).

Despite the fact that there are numerous reports on muscular variations in the sole of the foot, routine dissection in a formaldehyde-fixed cadaver revealed an accessory flexor digiti quinti muscle, which to the best of our knowledge is a very unusual variant. This was in the form of a slender, 38 mm long muscular slip, with a proximal and distal tendon extending from the common flexor digitorum longus tendinous plate out to the distal phalanx of the fifth toe. An associated finding was the absence of the musculotendinous portion of the flexor digitorum brevis to the same toe. A developmental explanation for this variation is presented. Clinical implications with regard to this anatomical condition may result in clawing of the fifth toe.

OBJECTIVE: Quantitative comparison of minimally invasive and standard cranial approaches remains a methodologic challenge. The aim of this study was to apply a new digital, navigation-based method to quantify multiple parameters of the pterional, supraorbital, lateral supraorbital and mini-pterional approaches and to describe a target-specific maneuverability score. - METHODS: Supraorbital, lateral supraorbital, minipterional, and standard pterional craniotomies were performed on 8 sides in 4 cadaver heads. The limits of superficial and deep exposure and surgical target points were registered with image-guidance (Medtronic Stealth). A custom software (Guided Therapeutics Eyes II Software [GTxEyesII]) calculated superficial and deep surface areas,working volumes, and target distances. Volumeswere reconstructed digitally and visualized with GTxEyesII. Finally, we defined for each approach a targetspecific maneuverability score based on surface exposure, target distance, target position, and anatomical obstacles. - RESULTS: Surface exposure and volumes were significantly smaller for keyhole approaches compared with standard pterional craniotomy (P < 0.01). Maneuverability index scores showed the greatest values for standard pterional craniotomies, but nearly equally high scores could be achieved by one or several of the less-invasive approaches for most of the targets. - CONCLUSIONS: The combination of a navigation-based measurement method with custom software (GTxEyesII) provides a powerful tool for visualization and quantification of surgical approaches. Compared with standard pterional craniotomy, alternative keyhole craniotomies offer comparable deep exposure with smaller working volumes and relatively high maneuverability for specific targets.

This protocol describes a procedure to assist surgeons in training for the implantation of microelectrode arrays into the neocortex of the human brain. Recent technological progress has enabled the fabrication of microelectrode arrays that allow recording the activity of multiple individual neurons in the neocortex of the human brain. These arrays have the potential to bring unique insight onto the neuronal correlates of cerebral function in health and disease. Furthermore, the identification and decoding of volitional neuronal activity opens the possibility to establish brain-computer interfaces, and thus might help restore lost neurological functions. The implantation of neocortical microelectrode arrays is an invasive procedure requiring a supra-centimetric craniotomy and the exposure of the cortical surface; thus, the procedure must be performed by an adequately trained neurosurgeon. In order to provide an opportunity for surgical training, we designed a procedure based on a human cadaver model. The use of a formaldehyde-fixed human cadaver bypasses the practical, ethical and financial difficulties of surgical practice on animals (especially non-human primates) while preserving the macroscopic structure of the head, skull, meninges and cerebral surface and allowing realistic, operating room-like positioning and instrumentation. Furthermore, the use of a human cadaver is closer to clinical daily practice than any non-human model. The major drawbacks of the cadaveric simulation are the absence of cerebral pulsation and of blood and cerebrospinal fluid circulation. We suggest that a formaldehyde-fixed human cadaver model is an adequate, practical and cost-effective approach to ensure proper surgical training before implanting microelectrode arrays in the living human neocortex.

SummaryThe vascular anatomy of the liver can be described at three different levels of complexity according to the use that the description has to serve. The first – conventional – level corresponds to the traditional 8-segments scheme of Couinaud and serves as a common language between clinicians from different specialties to describe the location of focal hepatic lesions. The second – surgical – level, to be applied to anatomical liver resections and transplantations, takes into account the real branching of the major portal pedicles and of the hepatic veins. Radiological and surgical techniques exist nowadays to make full use of this anatomy, but this requires accepting that the Couinaud scheme is a simplification, and looking at the vascular architecture with an unprejudiced eye. The third – academic – level of complexity concerns the anatomist, and the need to offer a systematization that resolves the apparent contradictions between anatomical literature, radiological imaging, and surgical practice. Based on the real number of second-order portal branches that, although variable averages 20, we submit a system called the “1-2-20 concept”, and suggest that it fits best the number of actual – as opposed to idealized – anatomical liver segments.

BACKGROUND AND PURPOSE: This study was prompted by recurrent angiographic observations of focal stenoses involving the proximal segment of the left upper thoracic intersegmental arteries, a few centimeters distal to their origin. The purpose was to investigate the nature and prevalence of this anomaly. MATERIALS AND METHODS: The existence of non-ostial thoracic intersegmental artery stenoses was evaluated in 50 angiograms; the contribution of stenosed branches to the anterior spinal artery was recorded. Angiograms performed in 3 patients with right-sided aortas were also reviewed. The topographic relationships of the upper thoracic intersegmental artery with surrounding structures were investigated in 3 cadavers. RESULTS: Thirty-seven non-ostial stenoses were found in 26 patients (52%), predominantly on the left side (92%), between T3 and T8, most frequently at T4 and T5 (54%). Severe lesions were observed in 10% of cases. Patients with stenoses had fewer detectable anterior radiculomedullary arteries between T3 and T5 (35% versus 54%). Upper intersegmental artery stenoses, documented on the left side of all 3 specimens, appeared to be caused by the recurrent path of these intersegmental arteries related to the leftward position of the thoracic aorta, and by their course around reinforced paramedian longitudinal strands of the endothoracic fascia. CONCLUSIONS: Upper thoracic intersegmental artery stenoses are frequent. They result from the leftward deviation of the descending aorta and the existence of a fixed point along the course of the intersegmental arteries related to the endothoracic fascia. Because contributors to the spinal vascularization often originate at similar levels, these stenoses may play a role in the susceptibility of the upper and midthoracic spinal cord to ischemia.

Background: Three-dimensional printing (3DP) technologies are a trendsetting topic, also in the field of surgery. Preoperative planning for maxillofacial and neurological surgery, for instance, increasingly involves skull models obtained by 3DP. However, the cranial replicas currently used in this context have been shown to not reproduce the exact anatomy of the individual patient undergoing surgery. Objective: The present study aimed at investigating the extent to which manual editing, using current computer software tools, can improve skull models derived from medical images. Methods: Skull computed tomography (CT) was obtained on three cadavers and sent to three institutions that provide preoperative 3DP services. Each institute independently performed 3D reconstructions, including routine manual editing, and subsequently produced the replicas. The models were then qualitatively compared with the respective original skull. For quantitative comparison surface scans of particular regions of interest were made and the deviations assessed using 3-matic software (Materialise, Leuven, Belgium). Results: Routine manual editing of CT images resulted in replicas that were clear improvements over automatically generated reconstructions. This was particularly the case for teeth artefacts and thin-walled entities (e.g. paranasal sinuses). Conversely, however, many anatomical structures remained incorrectly rendered (e.g. orbitae, pterygoid processes, and sella turcica). Extraosseous calcifications had regularly not been removed. After extensive manual editing, however, replicas were able to provide largely submillimeter accuracy (mean deviation 0.2496 mm; standard deviation ±0.2276 mm). Conclusions: This study confirms that manual editing with current computer science tools does improve the quality of CT-based 3D printed skull models. But, it also demonstrates that a number of structures remain largely incorrectly rendered when edited in the presently used surgical framework. Conversely, it shows that highly accurate replicas are feasible, provided that extensive manual editing is performed.

Background: Acute acromioclavicular joint dislocations indicated for surgery can be treated with several stabilization techniques. This in vitro study evaluated the acromioclavicular joint stability after 3 types of validated repair techniques compared with the native situation. Materials and methods: Nine pairs (right-left) of intact cadaveric shoulder specimens were assigned to 3 study groups with randomly distributed samples according to the coracoclavicular distance. The groups were instrumented with acromioclavicular and coracoclavicular cerclages (CE), a Twin Tail TightRope (TR), or a locking compression superior and anterior clavicle plate (CP). Native and instrumented specimens weretestedquasi-staticnondestructively(superior:70N;anteroposterior: � 35N,10mm/min)andcyclically until failure (superior, valley load: 20 N; initial peak load: 70 N; increment: 0.02 N/cycle). Results: The TR study group showed the highest (in N/mm) superoinferior (73.77 � 14.04) and anteroposterior(29.58 � 1.52)stiffness,followedbyCE(superoinferior:59.73 � 10.33;anteroposterior:24.31 � 4.14) and CP (superoinferior: 24.08 � 5.29). Instrumentation generally led to increased superoinferior and anteroposteriorstiffnessineachstudygroupbuttoasignificantsuperoinferiorstiffnessreductionforCP(P ¼.029). Significantly lower coracoclavicular displacement at valley load after 1 and 500 cycles was observed for TR (P ¼.018) and CE (P ¼.041) compared with CP. Cycles to failure were significantly higher in CE (7298 � 1244cycles,P ¼.011)andTR(4434 � 727cycles,P ¼.031)comparedwithCP(1683 � 509cycles). Conclusions: The CE and TR techniques led to similar biomechanical performances. The CE repair might mimic the native acromioclavicular joint stiffness better than the other 2 setups, leading to more physiological stabilization. Level of evidence: Basic science study, Biomechanical study. 2013 Journal of Shoulder and Elbow Surgery Board of Trustees.

Summary: In this cadaveric study, we explored the feasibility of a maximal mobilization of the superficial abdominal fascia, in a continuous flap, to achieve a tension-free covering of midline defects. The aponeurosis of the external oblique muscle was incised along the anterior axillary line and then detached up to the anterior rectus sheath. The latter was opened between the external and the internal oblique aponeurosis while keeping the continuity with the external oblique fascia. The obtained flap was solid and uninterrupted. The width gain reached 15 ± 3 cm on each sides, providing tissue advancement 60% longer than Ramirez’s technique (n = 8). The described technique allows large covering with respect to the anatomical planes. Further clinical tests should evaluate the validity of such concept in the repair of giant and asymmetrical hernias.

BACKGROUND Repair of the anterior skull base for cerebrospinal fluid leak requires either endoscopic endonasal approach or open transcranial approach. OBJECTIVE To present a less invasive surgical procedure for sealing of the entire anterior fossa floor for traumatic rhinoliquorrhea. METHODS Cadaver study in 3 head specimens. Endoscopic placement of a furled bovine pericardial patch bilaterally along the sphenoid ridge and planum in guidewire technique. Unfurling and spreading of the patch under endoscope assistance. RESULTS Patch placement was feasible in all 3 specimens without visible injuries to the frontal lobes. Dissection and preservation of the olfactory tracts was only possible for 50% of olfactory tracts. CONCLUSION Endoscopic transcranial keyhole duraplasty is a promising concept for traumatic rhinoliquorrhea.

Purpose Many regions worldwide report difficulties in recruiting applicants to surgery. One strategy proposed to reverse this trend consists of early exposure of medical students to the field. Against this backdrop, the present study presents an innovative approach for anatomy teaching, integrating a surgically relevant trend: 3D printing. Methods Whole-body computed tomography (CT) was made of two cadavers. Twelve students performed measurements and 3D reconstructions of selected anatomical structures (Osirix, Mimics). 3D printed (3DP) models were obtained (ZPrinter 310 Plus), and the students completed the analogous measurements on these replicas. Finally, classical anatomical dissection was performed and the same parameters were measured. The differences between the values obtained by the three modalities were submitted to standard statistical analysis (Wilcoxon two-tail paired test). Results Qualitative comparison of the digital 3D reconstructions based on the students' manual CT segmentation and the anatomical reality showed excellent correlation. Quantitatively, the values measured on the CT images and the physical models created by 3D printing differed from those measured on the cadavers by less than 2 mm. Students were highly appreciative of the approach (CT, 3DP, cadaver). Their average satisfaction score was 5.8 on a 1–6 scale. Conclusions This study shows that the approach proposed can be achieved. The results obtained also show that CT-based 3D printed models are close to the authentic anatomic reality. The program allows early and interactive exposure of medical students to a surgically relevant trend—in this case 3D printing.

Background Three-dimensional (3D) printed models of the human skull and parts of it are being increasingly used for surgical education and customized preoperative planning. Objective This study, using the calvaria as a model, provides a methodologic analysis with regard to future investigations aimed at evaluating patient-specific skull replicas. Methods Postmortem computed tomography was used for 3D reconstruction of a skull. The digital model obtained was converted to a physical replica by 3D printing. This copy was compared qualitatively and quantitatively with the original, using both a classical anthropometric and a 3D surface scanning approach. Results Qualitatively, the replica and the original displayed good qualitative concordance. The quantitative deviations, as measured by osteometric tools, lay partly in the submillimetric area, partly between 1 and 2 mm. The maximum difference was 3.7 mm. On the basis of the surface scans, a mean deviation of 0.2930 mm (±0.2677 mm) and a median difference of 0.2125 mm (0.0000–1.5509 mm) were observed for the inner surface. For the whole object, corresponding figures amounted to 0.9101 mm (±0.5390 mm) and 0.8851 mm (0.000–3.2647 mm). Conclusions Qualitatively flawless replicas of the skull region investigated are feasible, subject to extensive manual CT image editing. However, neurosurgeons should be aware that models of one and the same patient will vary according to the production chain used by the 3D printing laboratory in charge. Methodologically, both classic anthropological and light-stripe-based comparisons are justified for use in future studies. For trials aimed at assessing mean deviations and topographic distribution patterns, optical 3D scanning technologies can be recommended.

BACKGROUND AND PURPOSE: Hypoplasia of the rostral third of the SSS is a well-known variant and constitutes the most frequent variation of the SSS after preferential drainage to one of the transverse sinuses. Our aim was to describe unilateral hypoplasia of the rostral end of the SSS. MATERIALS AND METHODS: CTA performed in 100 consecutive patients studied for conditions other than dural sinus thrombosis was reviewed for the presence of a unilateral or bilateral hypoplastic rostral SSS. Associated dural venous sinus anomalies were recorded as well. The angiographic anatomy of unilateral hypoplastic rostral SSS was illustrated by 2 cases further imaged with DSA. RESULTS: Unilateral hypoplastic rostral SSS was found in 7 patients (7%). In all cases, compensatory drainage occurred through a large superior frontal vein that joined the SSS in the region of the coronal suture. Three of the 7 patients with a unilateral hypoplastic rostral SSS had at least another dural venous sinus anomaly. Complete or bilateral hypoplastic rostral SSS was noted in 3 patients (3%). CONCLUSIONS: Unilateral hypoplastic rostral SSS is more than twice as frequent as bilateral hypoplastic rostral SSS. It is the most frequently encountered variation of the SSS. Knowledge of this anatomic variation is important to avoid diagnostic pitfalls and to avoid erroneously mistaking it for a thrombosis. Four types of variations of the rostral SSS may be identified: 1) classic anatomy with a fully developed rostral SSS; 2) duplication of the rostral SSS; 3) complete or bilateral hypoplastic rostral SSS; 4) unilateral hypoplastic rostral SSS. The 4 types of rostral SSS variations can be explained by studying the embryologic development of the SSS.

Background: Ankle stiffness is a common complication after ankle fracture, reconstructive surgery or total ankle replacement, and the usual limitation is in dorsiflexion. There are few articles in the literature concerning this frequent problem, and furthermore they are not recent and tend to be controversial. The purpose of this anatomical study was to evaluate and quantify the effect of ankle collateral ligament release on dorsiflexion, specifically the amount of increase in ankle dorsiflexion following section of the two ligaments most often implicated in ankle stiffness: the deep posterior tibiotalar ligament (dPTTaL, or posterior deep deltoid) and the posterior talofibular ligament (PTaFL). Methods: We dissected 18 adult fresh cadaveric ankle joints, and with an electronic goniometer combined with an electronic dynamometer measured their mobility in dorsiflexion before and after transection of each ligament separately, and the two ligaments combined. Results: The results showed a significant difference between the two groups of ankles with section of the dPTTaL resulting in a greater increase in ankle dorsiflexion than section of the PTaFL (mean 7.458 vs. 3.58, respectively; p < 0.001). Combined section of both ligaments improved the gain in ankle dorsiflexion more than isolated section of each ligament, but was not statistically significant (p = 0.88). Conclusion: If after gastrocnemius recession or Achilles tendon lengthening persistent restriction remains in ankle dorsiflexion, the results of our study demonstrate that the next step should be release of the dPTTaL.

3-D relations between the ileocolic (ICA), right colic artery (RCA) with the superior mesenteric vein (SMV) have been described in cadavers. However, no data exists on preoperative evaluation of these relations. To define the length of crossing and 3-D position of the ICA and RCA to the SMV in patients undergoing multidetector computerized tomography (MDCT) angiography. MDCT angiographies were analyzed with the aid of Osirix v.3.0.2. image processing application. All the datasets included arterial and venous phase, undergoing multimodal visualization: 2D multiplanar reconstruction with maximum intensity projection and 3D Volume rendering. The anatomical relations were analyzed in various planes (orthogonal and oblique), depending upon their particular course. When a clear spatial reference was achieved, the distance of the colic artery from their origin on the aorta to the right border of the SMV was measured, and its position noted. 50 MDCT were analyzed (29 male). RCA occurred in 27 patients (54.0%), 25 (92.6%) passed anterior to the SMV. Length of crossing was 22.7 ± 8.1 (8.3–41.3) mm. The ICA occurred in 48 (96%) passing under the SMV in 38 (79.2%). Length of crossing 15.4 ± 5.8 (14.0–26.6) mm. RCA occurs in 54% patients, passes over the SMV in 92.6% specimens and leaves a 22.7 mm stump. ICA passes under the SMV in most cases, leaving a 15.4 mm stump. These data could be of crucial importance to the surgeon facing laparoscopic right colectomy for cancer.

An atypical case of abdominal vasculature, found in a 58-year-old woman is presented. The multidetector computed tomography angiogram revealed a large tortuous anastomotic vessel between the stem of the celiac trunk and the left colic artery, supplying branches for the left colon and pancreatic body and tail. We propose a simple embryological explanation for the development of this aberrant artery--the longitudinal ventral anastomosis, which connects the precursors of principal visceral arteries in a loop-like manner, loses its direct communication with the superior mesenteric artery but maintains its continuity above and below this level. This variation could pose a problem for radiological interpretation and affect surgical approaches to the aorta, left colon, and the pancreas.

Despite improvements in minimally invasive techniques over recent decades, kidney implantation into the iliac fossa has remained a domain of open surgery. However, it was hypothesized that it would be feasible to perform robotic transplant kidney implantation as a means of reducing surgical trauma. Two robotic kidney transplantations into the iliac fossa were attempted in human cadavers. In the first cadaver, a 5 cm incision was placed in the right lower abdomen, the peritoneum was mobilized in a cranial direction, the iliac vessels were identified, and the kidney placed in the pre-peritoneal space. The incision was sealed with a gel port through which the Vinci(©) Surgical System was installed. In the second cadaver, a robotic kidney implantation with robotically sutured vascular and ureteric anastomoses was performed trans-abdominally. Open incision, identification, placement of gel port, and robotic docking were feasible. Robotic performance of vascular anastomosis was not possible in the first cadaver because of advanced decay and excess fat in the surgical field. Robotic kidney positioning was feasible and anastomoses were performed successfully in the second cadaver within 35, 25, and 20 min (arterial, venous, and ureteric, respectively). Robotic kidney transplantation seems feasible in human cadavers if tissue condition is suitable, but is very technically challenging. Because of the delicacy of anatomical structures, the cadaveric model with the risk of advanced decay and the absence of circulation sets limits on the exploration of this complex procedure. Hence, further research and animal work in this area is critical to improve understanding of the benefits and limitations of robotic kidney implantation.

International audience; Introduction and hypothesisOur aim is to characterize prolapsed and non-prolapsed vaginal tissue, and thus offer a better understanding of the genital prolapse physiopathology and an improvement of surgical treatments.MethodsVaginal tissue was collected in 30 patients with prolapse (POP) and ten fresh cadavers without prolapse (nPOP) with a favorable advice of Ethics Committee. Uniaxial tension tests were performed. Statistical comparisons of rigidity under moderate deformation and under large deformation have been performedResultsPOP is significantly stiffer than nPOP tissue, both on anterior and posterior walls. A significant difference between POP and nPOP tissues was highlighted when anterior or posterior vaginal walls were respectively compared.ConclusionsThese results might explain the higher rate of relapse when repair is autologous, using already defective and more rigid vaginal tissue. This study suggests that it might be interesting to adapt the characteristics of prosthetic implants to the vaginal face concerned by the prolapsus.

BACKGROUND: Robotic technology offers technical advantages that might offer new solutions for hip arthroscopy. METHODS: Two hip arthroscopies were performed in human cadavers using the da Vinci surgical system. During both surgeries, a robotic camera and 5 or 8 mm da Vinci trocars with instruments were inserted into the hip joint for manipulation. RESULTS: Introduction of cameras and working instruments, docking of the robotic system and instrument manipulation was successful in both cases. The long articulating area of 5 mm instruments limited movements inside the joint; an 8 mm instrument with a shorter area of articulation offered an improved range of motion. CONCLUSIONS: Hip arthroscopy using the da Vinci standard system appears a feasible alternative to standard arthroscopy. Instruments and method of application must be modified and improved before routine clinical application but further research in this area seems justified, considering the clinical value of such an approach.

L’amelioration des dispositifs et des techniques endovasculaires est indispensable, particulierement au niveau de la crosse aortique et de l’aorte thoraco-abdominale. Nous presentons une nouvelle technique de reparation totalement endovasculaire de la crosse aortique et un modele experimental de circulation dans un cadavre humain afin d’evaluer la faisabilite de cette technique.

Background and Purpose— Aging affects elastin, a key component of the arterial wall integrity and functionality. Elastin degradation in cerebral vessels is associated with cerebrovascular disease. The goal of this study is to assess the biomechanical properties of human cerebral arteries, their composition, and their geometry, with particular focus on the functional alteration of elastin attributable to aging. Methods— Twelve posterior cranial arteries obtained from human cadavers of 2 different age groups were compared morphologically and tested biomechanically before and after enzymatic degradation of elastin. Light, confocal, and scanning electron microscopy were used to analyze and determine structural differences, potentially attributed to aging. Results— Aging affects structural morphology and the mechanical properties of intracranial arteries. In contrast to main systemic arteries, intima and media thicken while outer diameter remains relatively constant with age, leading to concentric hypertrophy. The structural morphology of elastin changed from a fiber network oriented primarily in the circumferential direction to a more heterogeneously oriented fiber mesh, especially at the intima. Biomechanically, cerebral arteries stiffen with age and lose compliance in the elastin dominated regime. Enzymatic degradation of elastin led to loss in compliance and stiffening in the young group but did not affect the structural and material properties in the older group, suggesting that elastin, though present in equal quantities in the old group, becomes dysfunctional with aging. Conclusions— Elastin loses its functionality in cerebral arteries with aging, leading to stiffer less compliant arteries. The area fraction of elastin remained, however, fairly constant. The loss of functionality may thus be attributed to fragmentation and structural reorganization of elastin occurring with age.

BACKGROUND AND STUDY AIMS: The advantages of a hybrid natural orifice transluminal endoscopic surgery approach to Roux-en-Y gastric bypass (hNOTES-RYGBP) might include: easier access to the peritoneal cavity, reduced number of ports and related complications, improved cosmesis, and others. However, currently available conventional endoscopic and laparoscopic instruments might be unsuitable for complex surgical procedures using transluminal access. The aim of this study was to investigate the feasibility and limitations of a NOTES RYGBP. METHODS: hNOTES-RYGBP was performed in human cadavers. Pouch creation was achieved by needle-knife dissection using a transvaginal, flexible scope. Articulating linear staplers were placed transumbilically to transect the stomach. Measurements of the small bowel were accomplished intraluminally or with flexible and rigid graspers. New methods were tested to create the gastro-jejunal anastomosis. A linear laparoscopic stapler was used to form the jejuno-jejunal anastomosis. RESULTS: Stapler manipulation and anvil docking, bowel manipulation and measurement, and tissue dissection presented the main obstacles for hNOTES-RYGBP. Conventional instruments were too short for some transvaginal manipulations. The time to complete the procedure was 6 - 9 hours. It was feasible to perform a complete hNOTES-RYGBP in four out of seven cadavers. Two cadavers were unsuitable due to anatomical abnormalities or advanced decay. One procedure was terminated before completion because of time constraints. Combinations of flexible and rigid visualization and manipulation were helpful, especially for dissection and gastric pouch creation. CONCLUSIONS: Several factors made hNOTES-RYGBP very challenging and time-consuming. A lack of proper instrumentation resulting in insufficient tissue traction, countertraction, and instrument manipulation complicated several steps during the procedure. A combination of flexible with rigid endoscopic techniques offers specific advantages for components of this type of surgery. Changes in instrument design are required to improve more complex endosurgical procedures.

This paper reports on a case of an omental diaphragmatic hernia revealed during routine anatomical dissection of an obese 85-year-old male with plethoric appearance of the upper body. The hernial mass, with a size of 12 cm x 9 cm, was detected in the anterior mediastinum. It had a long peduncle originating from the transverse colon and passing through the right sternocostal diaphragmatic opening of Morgagni-Larrey. The whole greater omentum was tightly packed and tumid within the serous hernial sac, but without signs of torquation. To our knowledge, this is the first systematic analysis of the omental hernial anatomy by a step-by-step iconography.

Summary Background Profound anatomical knowledge and surgical experience are essential for safe otological surgery. The surgeon's learning curve is evaluated in performing Gacek's singular neurectomy on cadaveric specimens. Materials and method One otological surgeon performed Gacek's approach on 96 halves of human heads embalmed according to Thiel's method, divided into four groups (24 halves per group) and evaluated them concurrent to the evaluation of an anatomist after a first surgical attempt. Successful operations were subdivided into “direct hits” of the osseous canal of the posterior ampullary nerve also known as the singular nerve and “indirect hits” with access to the posterior ampullary recess. Unsuccessful operations showed “no hit” of the nerve without lesion of the membranous labyrinth. “Indirect” or “no hits” were reinvestigated in a second attempt to evaluate possible reclassifications due to a learning process of the surgeon. The order of dissection, the rate of success and the changes of results in correlation with the numbers of dissected specimens were documented. Results The success rate significantly increased from 54.2% direct hits after the first group to 87.36% in the fourth group after the first attempt. Successful operations were performed in 86.5% after completion of the first attempt and 97.9% after the second attempt. The number of new allocations decreased from 11 cases in the first group of dissected specimens to zero in the fourth group. Conclusions This paper strengthens the value of cadaveric training for surgeons and the crucial role of dissection of a large number of specimens in improvement of the surgeon's experience and success rate.

When performing distal interlocking of an intramedullary humeral nail, there is risk of iatrogenic injuring to the neurovascular structures. Our cadaveric study with frozen sections through the distal humerus presents the anatomic relationship of the different neurovascular bundles and the trajectories used for the implantation of the three distal interlocking screws of the AO-UHN. The middle lateromedial pin was in direct contact with the radial nerve in 3 out of 10 cases, with the ulnar nerve in 3 out of 10 cases and with the brachial artery in 1 out of 10 cases. We recommend using only the two anteroposterior screws for distal interlocking, avoiding the lateromedial locking option. If this lateromedial locking screw is needed to gain adequate stability, it should be introduced under visual control.

The serratus anterior flap is commonly used without its cutaneous component and is covered with a skin graft. We have successfully used the free serratus anterior flap along with its skin paddle and have found it to be valuable for reconstruction of the face. We have done fresh cadaveric dissections and arteriography to identify perforator vessels to the skin overlying the muscle. Clinically, free transfer of the musculocutaneous flap to the face was carried out in 27 patients, mostly for severe noma (infection) sequellae. Anatomical dissection and arteriography revealed no cutaneous perforator vessels directly communicating with the vascular pedicle of the muscle. However, large perforators from the intercostal vessels were found passing through the muscle to reach the skin. In the clinical cases, flap survival was 100% in 24 patients. The serratus anterior musculocutaneous flap is reliable and particularly well-suited for reconstruction of the face with many advantages. We speculate that the skin paddle may be vascularised by perforators from the intercostal vessels communicating with the thoracodorsal pedicle through intramuscular choke vessels.

Methods Skin incisions for eight of the most frequent approaches used in foot and ankle surgery were performed on 10 cadaveric feet. The cutaneous nerves of the foot and ankle were dissected and localized with reference to the incisions. Results None of the eight incisions were safe. Cutaneous sensory nerves were at greatest risk following the anteromedial approach to the ankle. The total number of transected nerves on the 10 feet ranged from 37 for the anteromedial approach to the ankle to 4 for the medial approach to the first metatarsophalangeal joint. Due to the wide anatomical variability of the nerves involved, universally safe regions for skin incisions cannot be expected. Conclusions/clinical relevance This study reveals that standard orthopaedic approaches to the foot and ankle are associated with a consistent risk of cutaneous nerve injury. We recommend that the individual nerve pattern of each patient be respected by meticulous operative technique.

Cerebrospinal fluid (CSF) absorption has long been held to predominantly entail drainage into the venous outflow system via the intracranial arachnoid granulations. Newer data suggest pathways involving spinal arachnoid granulations and lymphatic channels may also make substantial contributions to CSF outflow.The putative major CSF outflow pathways and their proportionate contribution to CSF absorption were reviewed in this article.CSF is absorbed and drained in bulk not just through cerebral arachnoid granulations (CAG) but also through spinal arachnoid granulations (SAG) and a lymphatic pathway involving egress through cranial and spinal nerve sheaths. The proportions of CSF that efflux through each of these major pathways have yet to be determined with any certainty in humans, though existing evidence (the majority of which is derived from animal studies) suggests that lymphatic pathways may account for up to 50% of CSF outflow-presumably leaving the CAG and SAG to process the balance.Knowledge of the CSF pathways holds implications for our ability to understand, prognose, and even treat diseases related to CSF circulation and so is a matter of considerable relevance to neuroradiology and neurology.

Supplemental Digital Content is available in the text, Impingement after reverse shoulder arthroplasty (RSA) is believed to occur from repetitive contact in adduction between the humeral component and the inferior scapular pillar. The primary purpose of this biomechanical study was to confirm the presence of different types of impingement and to examine which daily-life movements are responsible for them. A secondary aim was to provide recommendations on the type of components that would best minimize notching and loss of range of motion (ROM). The study included 12 fresh frozen shoulder specimens; each had a computed tomography (CT) image of the entire scapula and humerus in order to acquire topological information of the bones before RSA implantation. Cyclic tests were run postimplantation with 3 shoulders in each modalities. To quantify bone loss due to impingement, 3-dimensional anatomical models of the scapula were reconstructed from the CT scans and compared to their intact states. We found 8 bony impingements in 7 specimens: 2 at the lateral acromion, 1 at the inferior acromion, 4 scapular notching, and 1 with the glenoid resulting to wear at the 3:00 to 6:00 clock-face position. Impingements occurred in all kinds of tested motions, except for the internal/external rotation at 90° of abduction. The 3 specimens tested in abduction/adduction presented bone loss on the acromion side only. Scapular notching was noted in flexion/extension and in internal/external rotation at 0° of abduction. The humeral polyethylene liner was worn in 2 specimens—1 at the 6:00 to 8:00 clock-face position during internal/external rotation at 0° of abduction and 1 at the 4:00 clock-face position during flexion/extension. The present study revealed that 2 types of impingement interactions coexist and correspond to a frank abutment or lead to a scapular notching (friction-type impingement). Scapular notching seems to be caused by more movements or combination of movements than previously considered, and in particular by movements of flexion/extension and internal/external rotation with the arm at the side. Polyethylene cups with a notch between 3 and 9 o’clock and lower neck-shaft angle (145° or 135°) may play an important role in postoperative ROM limiting scapular notching.

Introduction The “tension-free” procedures are widely used by surgeons for the treatment of urinary incontinence and prolapse. The clinical results are largely in favour of these procedures. The aim of our study is to determine objectively the mechanical tissue resistance when using these techniques, before healing begins. Material and methods We measured the mechanical resistance using four different routes: the retro-pubic space, the transobturator, the translevator ani muscle and the trans-sacrospinous ligament. We compared five different meshes, TVT ® , IVS ® , Lift ® , Prolene ® and Prolene Soft ® . In order to study the effect of increasing dimensions, we tested Prolene ® tapes measuring 1, 1.5 and 2 cm in width. We performed traction tests on meshes implanted in cadavers. Measurements were made with a dynamometer and the results expressed in Newtons. Results This study shows that TVT ® offers a better resistance to traction via the retro-pubic space route. There was no significant difference among the four routes when the same type of mesh measuring 1 cm was used. However, an increase in the dimensions of Prolene ® tapes improves their resistance in the tissues, thereby facilitating fixation before healing begins. Also, these increasing dimensions (in width) show that there is better resistance with the trans-sacrospinous ligament compared with the transmuscular one. Discussion The increasing size of prosthetic meshes does not show the superiority of certain routes with commercial meshes of 1 cm in width. The higher resistance obtained with wider tapes is probably due to an increased surface area between the tissues and meshes. This increase in resistance does not seem to be important for the treatment of urinary incontinence. However, it should be of interest for the treatment of prolapse where traction and surface are more important. Conclusion Two different recommendations can be deduced from our study. On one hand, the arms of prosthetic meshes for pelvic floor repair should measure more than 1 cm in width in order to improve their maintenance in the tissues in the immediate post-operative period. On the other hand to improve fixation, the posterior arms of the transperineal mesh should be passed through the sacrospinous ligament rather than via the transmuscular route. The resistance of tissues is also influenced by the armature of the prosthetic mesh. They must therefore be developed commercially specifically for “tension-free” fixation. Our results need to be confirmed by further studies including more cadavers and younger patients.

A popliteal cyst, originally called Baker's cyst, is a synovial fluid-filled mass located in the popliteal fossa. The most common synovial popliteal cyst is considered to be a distension of the bursa located beneath the medial head of the gastrocnemius muscle. Usually, in an adult patient, an underlying intra-articular disorder is present. In children, the cyst can be isolated and the knee joint normal. The anatomy, etiopathogenesis, clinical presentation, differential diagnosis, imaging and treatment modalities of the popliteal cyst are presented. The authors try to answer some questions dealing with this condition. Is the cyst isolated, can it be treated as such, is its origin always well-defined and does surgical excision provide a permanent cure?

The aim of this study was to compare the intra-articular volumes of the wrist's joint measured by CT-arthrography and by dissection on ten cadavers. A good correlation was found between CT-arthrography and dissection in the assessment of the intra-articular volume of both wrist joints. A volume of 1.34 (+/-0.46) milliliter and 0.97 (+/-0.32) milliliter were found by Ct-arthrography for the radiocarpal and midcarpal joints, respectively. Dissection of the same wrists gives a volume of 1.24 (+/-0.33) and 0.90 (+/-0.21) for the radiocarpal and midcarpal joints, respectively. The knowledge of normal wrist-joint volume is a major prerequisite to evaluate carpal instability without ligaments' tears. We believe that CT-arthrography could be helpful in evaluating patients with suspected carpal instability.

The lateral surface of the frontal lobe shows functional activation in a large number of language related tasks. Group analyses, however, demonstrate remarkable intersubject variability of activation. There are different sources for functional variability, anatomical variability being considered as one of them. The aim of the present study therefore was to qualitatively and quantitatively investigate the anatomical variability of the lateral frontal lobe surface and to search for reliable and stable landmarks connected to language functions. MRIs of 23 healthy right-handed subjects were investigated using the publicly available software “Anatomist/BrainVISA”. After standardization of the brains (SPM) and sulci identification, the most frequent pattern was determined and the variance of selected landmarks calculated. The variability of the lateral frontal lobe surface is remarkable, particularly in the prefrontal region. Relatively stable landmarks were selected as follows: (1) connection between the superior frontal sulcus (SFS) and the superior precentral sulcus (SPCS); (2) connection between the inferior frontal sulcus (IFS) and the inferior precentral sulcus (IPCS); (3) inferior end of the precentral sulcus (PCS); and (4) origin of the ascending ramus (AscR) of the Sylvian fissure (SYF). The variability (standard deviation) of the spatial coordinates along the 3 axis of these landmarks after normalization ranged from 2.5 to 5.7 mm. The present study demonstrates that intersubject variability of selected landmarks of the frontal lobe surface remains notable even after spatial normalization of the brains. These results support the concept that anatomical variability is a relevant source of functional variability. We therefore suggest to express functional activation in relation to landmarks obtained from individual anatomy. This approach may contribute to a better analysis of the differences between individuals.

We report a case of bilateral collateral tentorial venous sinus drainage of the basal vein (of Rosenthal) (BV). The observation was made on a corrosion cast of the cerebral venous system obtained from a fresh cadaver. Radiographic correlation was obtained by performing standard X-ray imaging of the corrosion cast. Embryologic and clinical considerations are discussed. Clin. Anat. 16:264–268, 2003. © 2003 Wiley-Liss, Inc.

The scaling properties of the portal vein and the hepatic vein are examined, based on three-dimensional computed tomography images of casts of human livers. In particular, a quantitative analysis of the branching ratio based on the Strahler ordering scheme as well as the diameter and length ratios are performed. To quantify the segment anatomy of the liver, the volume of supplied liver parenchyma is measured and related to the corresponding vessel radius. The implications of these findings for segment-oriented liver surgery are discussed. We also investigate the 3D interdependence of the intertwined portal and hepatic veins based on a concept of tree distance that will be introduced.

The physicians of the Alexandrine school seem to have been able to follow the way of the optic nerves from the retina to the brain. It was very probable that they should discover the thalamus. Sadly, anatomic knowledge, deriving from the first scientific human dissection performed in history, was destroyed in the fire of the Alexandrine Library. When, in the second century A.D., Galen introduced the term thalamus opticus, he was describing the central part of the lateral ventricles of the brain. After Galen, an anatomy with philosophical inferences substituted an anatomy based on direct observation. At that time the purpose was to find the site of the soul. During the thirteen centuries following Galen, including the Byzantine epoch and the High Middle Ages, the knowledge of the anatomy of the central nervous system did not make any substantial progress. The deep location of the thalamus contributed, for a very long time, to make it invisible to the eyes of the anatomists. It was Mondino da Luzzi, during the thirteenth century A.D., who gave the first incontestable description of the thalamus. He named the thalamus anchae (buttocks). Nevertheless, we should also consider the hypothesis that Galen, from whom Mondino always got his inspiration, could already have used the Latin term nates to name the pulvinar of the thalamus. Three centuries later, Andreas Vesalius, the true father of modern anatomy, first illustrated the thalamus in his artwork De humani corporis fabrica (1543). The thalamus was perfectly represented by Vesalio. He provided figures of the thalamus with accurate legends in many brain sections with different perspectives but, strangely, he did not mention it in the text. In the seventeenth century, Jean Riolan and Thomas Willis inaugurated the use of the term "thalamus" in its actual meaning, probably as a consequence of an inaccurate interpretation or the transcription of Galen's writings. The thalamus has superbly been represented by Willis and Vieussens in their De CerebriAnatome (1664) and Neuronographia Universalis (1684). These works were the first monographs of the human history to be integrally devoted to the central nervous system. During the eighteenth century the anatomic illustration began to conform itself more to a scientific than an artistic approach. Nevertheless, despite the presence of the thalamus in most atlases, only little scientific progress was made in its understanding. During that century,Alexander Monro (Monro Primus, 1697-1767) described the hypothalamic sulcus and the interventricular foramens clarifying their topography with the thalamic walls. Giovanni Domenico Santorini (1681-1737) accurately reported the link between the optic tracts and the structure he first named as the lateral geniculate body of the thalamus. Francois Pourfour du Petit (1664-1741), Santorini and then Felix Vicq d'Azyr (1748-1794) described the mammillothalamic tract. The modern approach to thalamic morphology began with the improving of the microscopy and histology techniques. In this context, K. F. Burdach proposed to separate the thalamus into distinct nuclei (1823) and later Jean Luys established the link between this anatomic subdivision and the idea of a functional specialisation (1865). Since then, a great amount of, often imprecise or contradictory, anatomic-functional data has accumulated rapidly.

Mitral valve dysfunction is not always amenable to repair, and may necessitate valve replacement. An alternative to standard mechanical and biological prostheses, is the use of homografts. The following manuscript and videos describe our surgical approach to mitral valve replacement with a complete mitral homograft in a cadaveric heart model.

Background and purpose: Accurate placement of an external ventricular drain (EVD) for the treatment of hydrocephalus is of paramount importance for its functionality and in order to minimize morbidity and complications. The aim of this study was to compare two different drain insertion assistance tools with the traditional free-hand anatomical landmark method, and to measure efficacy, safety and precision. Methods: Ten cadaver heads were prepared by opening large bone windows centered on Kocher's points on both sides. Nineteen physicians, divided in two groups (trainees and board certified neurosurgeons) performed EVD insertions. The target for the ventricular drain tip was the ipsilateral foramen of Monro. Each participant inserted the external ventricular catheter in three different ways: 1) free-hand by anatomical landmarks, 2) neuronavigation-assisted (NN), and 3) XperCT-guided (XCT). The number of ventricular hits and dangerous trajectories; time to proceed; radiation exposure of patients and physicians; distance of the catheter tip to target and size of deviations projected in the orthogonal plans were measured and compared. Results: Insertion using XCT increased the probability of ventricular puncture from 69.2 to 90.2% (p = 0.02). Non-assisted placements were significantly less precise (catheter tip to target distance 14.3 ± 7.4mm versus 9.6 ± 7.2mm, p = 0.0003). The insertion time to proceed increased from 3.04 ± 2.06min. to 7.3 ± 3.6min. (p

Background Subclinical neurological lesions after reverse shoulder arthroplasty are frequent, mainly those involving the axillary nerve. One of the major reported risk factors is postoperative lengthening of the arm. The purpose of this study was to evaluate the anatomical relationship between the axillary nerve and prosthetic components after reverse shoulder arthroplasty. The study hypothesis was that inferior overhang of the glenosphere relative to glenoid could put this nerve at risk. Material and methods Eleven fresh frozen shoulder specimens were dissected after having undergone reverse shoulder arthroplasty using a classic deltopectoral approach. Results The mean distance from the inferior border of the glenoid to the inferior edge of the glenosphere was 6.0 ± 4.3 mm (range, 1.0 to 16.2 mm). The axillary nerve was never closer than 15 mm to the glenosphere. The main anterior branch of the axillary nerve was in close contact with the posterior metaphysis or humeral prosthetic implant. The mean distance between the nerve and the humeral implants was 5.2 ± 2.1 mm (range, 2.0 to 8.1 mm). Conclusions The proximity of the axillary nerve to the posterior metaphysis or humeral implants may be a risk factor for axillary nerve injury after reverse shoulder arthroplasty. Clinical relevance This study quantifies the proximity of the axillary nerve to the implant after reverse shoulder arthroplasty. Level of evidence Basic science study, cadaver study.

The anterior approaches that have been described for open reduction internal fixation of multifragmentary pilon fractures are designed to reconstruct the comminuted and impacted anterior articular surface onto a stable posterior column. Thus, reduction of the posterior column, particularly proper length, is critical. There are differing opinions of how best to surgically approach the posterior pilon fracture. There is also no clear indication as to the timing of both anterior and posterior reconstructions. Our objectives were (1) to develop a more midline posterior approach that might provide better visualization of the posterior aspect of the posterior column and juxtametaphyseal/diaphyseal parts of the tibia, first on the cadaver and then with patients, and (2) to use this as part of a combined posterior and anterior approach during the same anesthesia for complex tibial pilon fractures (AO/OTA 43-C) in a preliminary study of 6 patients.