|
| ||
|
|
||
Cadaveric Specimens (cadaveric + specimen)
Selected Abstracts3D Computerized Model for Measuring Strain and Displacement of the Brachial Plexus Following Placement of Reverse Shoulder ProsthesisTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 9 2008Tom Van Hoof Abstract The aim of the present study was to develop a method for three-dimensional (3D) reconstruction of the brachial plexus to study its morphology and to calculate strain and displacement in relation to changed nerve position. The brachial plexus was finely dissected and injected with contrast medium and leaden markers were implanted into the nerves at predefined places. A reverse shoulder prosthesis was inserted in a cadaveric specimen what induced positional change in the upper limb nerves. Computed tomography (CT) was performed before and after this surgical intervention. The computer assisted image processing package Mimics® was used to reconstruct the pre- and postoperative brachial plexus in 3D. The results show that the current interactive model is a realistic and detailed representation of the specimen used, which allows 3D study of the brachial plexus in different configurations. The model estimated strains up to 15.3% and 19.3% for the lateral and the medial root of the median nerve as a consequence of placing a reverse shoulder prosthesis. Furthermore, the model succeeded in calculating the displacement of the brachial plexus by tracking each implanted lead marker. The presented brachial plexus 3D model currently can be used in vitro for cadaver biomechanical analyses of nerve movement to improve diagnosis and treatment of peripheral neuropathies. The model can also be applied to study the exact location of the plexus in unusual upper limb positions like during axillary radiation therapy and it is a potential tool to optimize the approaches of brachial plexus anesthetic blocks. Anat Rec, 291:1173-1185, 2008. © 2008 Wiley-Liss, Inc. [source] Muscle moment arms of the gibbon hind limb: implications for hylobatid locomotionJOURNAL OF ANATOMY, Issue 4 2010Anthony J. Channon Abstract Muscles facilitate skeletal movement via the production of a torque or moment about a joint. The magnitude of the moment produced depends on both the force of muscular contraction and the size of the moment arm used to rotate the joint. Hence, larger muscle moment arms generate larger joint torques and forces at the point of application. The moment arms of a number of gibbon hind limb muscles were measured on four cadaveric specimens (one Hylobates lar, one H. moloch and two H. syndactylus). The tendon travel technique was used, utilizing an electro-goniometer and a linear voltage displacement transducer. The data were analysed using a technique based on a differentiated cubic spline and normalized to remove the effect of body size. The data demonstrated a functional differentiation between voluminous muscles with short fascicles having small muscle moment arms and muscles with longer fascicles and comparatively smaller physiological cross-sectional area having longer muscle moment arms. The functional implications of these particular configurations were simulated using a simple geometric fascicle strain model that predicts that the rectus femoris and gastrocnemius muscles are more likely to act primarily at their distal joints (knee and ankle, respectively) because they have short fascicles. The data also show that the main hip and knee extensors maintain a very small moment arm throughout the range of joint angles seen in the locomotion of gibbons, which (coupled to voluminous, short-fascicled muscles) might help facilitate rapid joint rotation during powerful movements. [source] Ultrashort TE T1rho (UTE T1rho) imaging of the Achilles tendon and meniscusMAGNETIC RESONANCE IN MEDICINE, Issue 3 2010Jiang Du Abstract In this study, we report the use of a novel ultrashort echo time T1rhoT1 sequence that combines a spin-lock preparation pulse with a two-dimensional ultrashort echo time sequence of a nominal echo time 8 ,sec. The ultrashort echo time- T1rho sequence was employed to quantify T1rho in short T2 tissues including the Achilles tendon and the meniscus. T1rho dispersion was investigated by varying the spin-lock field strength. Preliminary results on six cadaveric ankle specimens and five healthy volunteers show that the ultrashort echo time- T1rho sequence provides high signal and contrast for both the Achilles tendon and the meniscus. The mean T1rho of the Achilles tendon ranged from 3.06 ± 0.51 msec for healthy volunteers to 5.22 ± 0.58 msec for cadaveric specimens. T1rho increased to 8.99 ± 0.24 msec in one specimen with tendon degeneration. A mean T1rho of 7.98 ± 1.43 msec was observed in the meniscus of the healthy volunteers. There was significant T1rho dispersion in both the Achilles tendon and the meniscus. Mean T1rho increased from 2.06 ± 0.23 to 7.85 ± 0.74 msec in normal Achilles tendon and from 7.08 ± 0.64 to 13.42 ± 0.93 msec in normal meniscus when the spin-lock field was increased from 250 to 1,000 Hz. Magn Reson Med, 2010. © 2010 Wiley-Liss, Inc. [source] Masticatory loading and bone adaptation in the supraorbital torus of developing macaquesAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2009K. Kupczik Abstract Research on the evolution and adaptive significance of primate craniofacial morphologies has focused on adult, fully developed individuals. Here, we investigate the possible relationship between the local stress environment arising from masticatory loadings and the emergence of the supraorbital torus in the developing face of the crab-eating macaque Macaca fascicularis. By using finite element analysis (FEA), we are able to evaluate the hypothesis that strain energy density (SED) magnitudes are high in subadult individuals with resulting bone growth in the supraorbital torus. We developed three micro-CT-based FEA models of M. fascicularis skulls ranging in dental age from deciduous to permanent dentitions and validated them against published experimental data. Applied masticatory muscle forces were estimated from physiological cross-sectional areas of macaque cadaveric specimens. The models were sequentially constrained at each working side tooth to simulate the variation of the bite point applied during masticatory function. Custom FEA software was used to solve the voxel-based models and SED and principal strains were computed. A physiological superposition SED map throughout the face was created by allocating to each element the maximum SED value from each of the load cases. SED values were found to be low in the supraorbital torus region throughout ontogeny, while they were consistently high in the zygomatic arch and infraorbital region. Thus, if the supraorbital torus arises to resist masticatory loads, it is either already adapted in each of our subadult models so that we do not observe high SED or a lower site-specific bone deposition threshold must apply. Am J Phys Anthropol, 2009. © 2008 Wiley-Liss, Inc. [source] Evaluating anatomical research in surgery: a prospective comparison of cadaveric and living anatomical studies of the abdominal wallANZ JOURNAL OF SURGERY, Issue 12 2009Warren M. Rozen Abstract Background:, Cadaveric research has widely influenced our understanding of clinical anatomy. However, while many soft-tissue structures remain quiescent after death, other tissues, such as viscera, undergo structural and functional changes that may influence their use in predicting living anatomy. In particular, our understanding of vascular anatomy has been based upon cadaveric studies, in which vascular tone and flow do not match the living situation. Methods:, An angiographic analysis of the abdominal wall vasculature was performed using plain film and computed tomography angiography in 60 cadaveric hemi-abdominal walls (from 31 cadavers) and 140 living hemi-abdominal walls (in 70 patients). The deep inferior epigastric artery (DIEA) and all of its perforating branches larger than 0.5 mm were analysed for number, calibre and location. Results:, Both large, named vessels and small calibre vessels show marked differences between living anatomy and cadaveric specimens. The DIEA was of larger diameter (4.2 mm versus 3.1 mm, P < 0.01) and had more detectable branches in the cadaveric specimens. Perforators were of greater calibre (diameter 1.5 mm versus 0.8 mm, P < 0.01) and were more plentiful (16 versus 6, P < 0.01) in cadaveric specimens. However, the location of individual vessels was similar. Conclusions:, Cadaveric anatomy displays marked differences to in vivo anatomy, with the absence of living vascular dynamics affecting vessel diameters in cadaveric specimens. Blood vessels are of greater measurable calibre in cadaveric specimens than in the living. Consequently, cadaveric anatomy should be interpreted with consideration of post-mortem changes, while living anatomical studies, particularly with the use of imaging technologies, should be embraced in anatomical research. [source] Three-dimensional study of the musculotendinous architecture of supraspinatus and its functional correlationsCLINICAL ANATOMY, Issue 6 2007Soo Y. Kim Abstract The supraspinatus is most frequently involved in shoulder pathology. However, the musculotendinous architecture of the supraspinatus has not been well documented. Therefore, the purpose of this study is to investigate the detailed three-dimensional architecture of the supraspinatus throughout its volume. Ten male formalin embalmed cadaveric specimens (mean age 61.9 ± 16 years) without any evidence of rotator cuff pathology were used. Three-dimensional coordinates (x, y, and z) of the tendon and muscle fiber bundles were collected in situ, using serial dissection and digitization. The data was reconstructed into a three-dimensional model using MayaÔ. Fiber bundle lengths, pennation angles (PA), muscle volumes, and tendon dimensions for each architecturally distinct area were computed and then analyzed using paired t -tests and ANOVA (P < 0.05). The supraspinatus was found to consist of anterior and posterior regions, which were each further subdivided into superficial, middle, and deep parts. Mean PA were found to be significantly different between the distinct parts of the anterior region of the muscle. Medial PA was also found be significantly different between the superficial and middle, and superficial and deep parts of the posterior region. These results provide insight into the normal function of the muscle and its possible contribution to the initiation and progression of supraspinatus tendon tears. Clin. Anat. 20:648,655, 2007. © 2007 Wiley-Liss, Inc. [source] Three-dimensional reconstruction of the ankle by means of ultrathin slice plastinationCLINICAL ANATOMY, Issue 2 2007Mircea-Constantin Sora Abstract Computerized reconstruction of anatomical structures is becoming very useful for developing anatomical teaching modules and animations. Although databases exist consisting of serial sections derived from frozen cadaver material, plastination represents an alternate method for developing anatomical data useful for computerized reconstruction. Plastination is used as an excellent tool for studying different anatomical and clinical questions. The sheet plastination technique is unique because it offers the possibility to produce transparent slices series, which can easily be processed morphometrically. The purpose of this study was to describe a method for developing a computerized model of the human ankle using plastinated slices. This method could be applied to reconstruct any desired region of the human body. A human ankle was obtained, plastinated, sectioned, and subjected to 3D computerized reconstruction using WinSURF modeling system (SURFdriver Software). Qualitative observations revealed that the morphological features of the model were consistent with those displayed by typical cadaveric specimens. Morphometric analysis indicated that the model did not significantly differ from a sample of cadaveric specimens. These data support the use of plastinates for generating tissues sections useful for 3D computerized modeling. Clin. Anat. 20:196,200, 2007. © 2006 Wiley-Liss, Inc. [source] Nerve supply of the brachioradialis muscle: Surgically relevant variations of the extramuscular branches of the radial nerveCLINICAL ANATOMY, Issue 7 2005Maria D. Latev Abstract The brachioradialis muscle is utilized in tendon-transfer operations, carried out for a variety of purposes. The extramuscular branches of the radial nerve to the brachioradialis were dissected and studied in 43 embalmed cadaveric specimens. The number of primary and secondary branches and the spatial locations of their origins and muscle-entry points was determined for each specimen. All distances were measured relative to the lateral epicondyle. A wide anatomic variation was observed in both the nerve branching pattern as well as the number and locations of muscle-entry points. A single primary nerve branch was found in 20 specimens, or 46.5% of the cases. On an average, single primary nerve branches arose from the radial nerve 30 mm proximal to the lateral epicondyle. In 16 of these cases, the primary branch splits into two to four secondary branches, and in four cases there was only one branch entering the muscle. Seventeen specimens had two primary branches whose origin points were separated by 5 to 40 mm with an average of 15 mm. In seven of these seventeen cases one or both of the primary branches split into secondary branches. Six specimens had three primary branches; the origin points of the most proximal and the most distal branch were separated by up to 30 mm with an average of 13 mm. Excluding the four cases with extensive fanning into multiple thin branches, the number of muscle-entry points ranged from 1 to 4 (mean 2.7). The locations of the muscle-entry points for all specimens were widespread ranging from 50 mm proximal and 40 mm distal to the lateral epicondyle with an average at 6 mm proximal to the lateral epicondyle. The greatest distance between muscle-entry points was 50 mm in a single specimen. In surgical procedures involving dissection of the brachioradialis muscle more proximal than 50 mm distal to the elbow, the extramuscular branch(es) of the radial nerve branches to the brachioradialis may be at risk. Clin. Anat. 18:488,492, 2005. © 2005 Wiley-Liss, Inc. [source] Fenestration of the superior medullary velum as treatment for a trapped fourth ventricle: A feasibility studyCLINICAL ANATOMY, Issue 2 2004R. Shane Tubbs Abstract We developed a novel approach for fenestration of the trapped fourth ventricle utilizing the superior medullary velum (valve of Vieussens). Trapped fourth ventricles, which are seen often in the pediatric hydrocephalic population, are troublesome entities surgically. A right burr hole was carried out in 10 adult cadavers with no gross intracranial pathology and the superior medullary velum was fenestrated to the quadrigeminal cistern with the aid of an endoscope. This technique was carried out easily in all cadaveric specimens. With endoscopy, no vascular insult was appreciated either before or after fenestration of the superior medullary velum. These preliminary findings demonstrate that fenestration of the superior medullary velum may provide a good alternative to the present therapy of shunting trapped fourth ventricles, a therapy wrought with complications. Clin. Anat. 17:82,87, 2004. © 2004 Wiley-Liss, Inc. [source] Anatomical variations and clinical implications of the artery to the lingual nerveCLINICAL ANATOMY, Issue 4 2003Stanton D. Harn Abstract The pterygomandibular space is a critical anatomic area for the delivery of local anesthesia in the practice of dentistry. The neurovascular contents of this area are subject to trauma and its resultant local and systemic complications. This study of 202 cadaveric specimens reaffirms the literature as to the percent distributions of the superficial and deep routes of the maxillary artery and details for the first time the anatomic variations of the artery to the lingual nerve. This artery courses through the pterygomandibular space placing it at risk for injection trauma along with the other neurovascular contents. It has been uncommonly identified and referred to in the literature, yet it may be the first artery encountered when entering the space with a needle or during surgical intervention in the area. Clin. Anat. 16:294,299, 2003. © 2003 Wiley-Liss, Inc. [source] | |||||||||||||