Straight proximal humeral nailing: Risk of iatrogenic tendon injuries with respect to different entry points in anatomical specimens

BACKGROUND

The purpose of the study was to evaluate the relationship of implant-related injuries to the adjacent anatomical structures in a newer generation straight proximal humeral nail (PHN) regarding different entry points. The proximity of the proximal lateral locking-screws of the MultiLoc proximal humeral nail (ML PHN) may cause iatrogenic tendon injuries to the lateral edge of the bicipital humeral groove (BG) as reference point for the tendon of the long head of biceps brachii (LBT) as well as the lateral insertion of the infraspinatus tendon (IST).

MATERIALS AND METHODS

The study comprised n = 40 upper extremities. Nail application was performed through a deltoid approach and supraspinatus tendon (SSP) split with a ML PHN. All tests were performed in three different entry points. First nail (N1) - standard position in line with the humeral shaft axis; second nail (N2) - a more lateral entry point; third alternative (N3) - medial position, centre of the humeral head. After nail placement, each specimen was screened for potential implant-related injuries or worded differently hit rates (HR) to the BG and the IST. The distances to the anatomical structures were measured and statistically interpreted.

RESULTS

The observed iatrogenic IST injury rate was 17.5% (n = 7/40) for N1, 5% (n = 2/40) for N2 and 62.5% (n = 25/40) for N3, which was statistically significantly higher (p < 0.001). Regarding the BG, the evaluated HR was 7.5% (n = 3/40) for both N1 and N2. Only the nail placed in the head centre (N3) showed an iatrogenic injury rate of 20% (n = 8/40) (p < 0.062). No statistically significant association between humeral head size and the HR could be observed (head diameter: IST: p = 0.323, BG: p = 0.621; head circumference: IST: p = 0.167; BG: p = 0.940). For the IST and BG, all distances in nail positions N1 and N2 as well as N2 and N3 differ statistically significant (p < 0.001).

CONCLUSIONS

An entry point for nail placement in line or slightly laterally to the humeral shaft axis - but still at the cartilage - should be advocated.

Evaluation of Monaldi's approach with regard to needle decompression of the tension pneumothorax-A cadaver study

BACKGROUND

Although needle decompression of tension pneumothorax through the second intercostal space in the midclavicular line (Monaldi's approach) is a life-saving procedure, severe complications have been reported after its implementation. We evaluated the procedure by comparing how it was performed on cadavers by study participants with different training levels.

METHODS

Six participants including one thoracic surgeon performed bilateral thoracic drainage after Monaldi on 82 torsos. After the thoraces were opened, the distances from the internal thoracic artery (A), the site of the puncture (B) and the midclavicular line (C) were measured bilaterally with reference to the median of the sternum. Further, it was determined whether the participants had correctly identified the second intercostal space. The differences between B-A and C-B were analysed.

RESULTS

The needle was placed in the second intercostal space in 136 hemithoraces (83%). The thoracic surgeon showed a hit rate of 0% laceration of adjacent vessels. All the other participants had hit rates between 10% and 15%. The interval B-A ranged from 2.88 to 5.06cm in right and from 3.00 to 5.00cm in left hemithoraces. The distance C-B lay between 1.03cm and 1.87cm (right side), and 0.84cm and 2.02cm (left side).

CONCLUSION

In our collective, the main problem was failure to assess correctly the lateral extension of the clavicle. If this fact is emphasized during training, Monaldi's approach is a safe method for needle decompression of pneumothorax.

Sensory nerve supply of the distal radio-ulnar joint with regard to wrist denervation

The objective of this study was to determine the precise departure points of the articular branches innervating the distal radio-ulnar joint from the anterior and posterior interosseous nerves. The study sample consisted of 116 upper limbs from adult human cadavers. The articular branches were prepared under the dissection microscope to take measurements using the radial styloid process as point of reference. The articular branch departed from the anterior interosseous nerve at a mean distance of 2.9 cm proximal to the styloid for a radius length of 20.5 cm, and 3.7 cm for a radius length of 26.5 cm, respectively. For the posterior interosseous nerve, the departure point was at a mean distance of 3.1 cm (radius length of 20.5 cm) and at 4.0 cm (radius length of 26.5 cm). Apart from a single branch from the posterior interosseous nerve, all articular branches were located distal to the proximal border of the pronator quadratus. Results indicate that wrist denervation from the volar approach, if performed at the proximal border of the pronator quadratus, or from the dorsal approach at a distance of 4.8 cm (for a radius length of 20.5 cm) or 6.2 cm (for a radius length of 26.5 cm) proximal to the radial styloid process, will eliminate the nerve supply to the distal radio-ulnar joint in the majority of cases.

Location of the extraosseous and intraosseous arterial anastomosis of the maxillary sinus in edentulous specimens

OBJECTIVES

The aim of this anatomical study was to measure the distance from the intraosseous and extraosseous arterial anastomoses of the maxillary sinus to the alveolar ridge in edentulous specimens dissected from human cadavers.

MATERIALS AND METHODS

Forty edentulous maxillary specimens were dissected, anatomically prepared, and injected for a better visualization of the maxillary sinus artery.

RESULTS

This study showed that the mean distance from the alveolar ridge to the extraosseous anastomosis was 16 mm for the second maxillary molar, 12 mm for the first maxillary molar, and 13 mm for the second maxillary premolar. For the intraosseous anastomosis to the alveolar ridge, the mean distance was 17 mm for the second maxillary molar, 13 mm for the first maxillary molar, and 14 mm for the second maxillary premolar.

CONCLUSIONS

Under the conditions of this study, we found that the mean distance from the alveolar crest to the extraosseous anastomosis and intraosseous anastomosis was shortest for the first maxillary molar and second maxillary premolar and greatest for the second maxillary molar.

CLINICAL RELEVANCE

These findings provide data whose relevance for clinical dentistry is that they can be applied to minimize the risk of damage to the arterial network of the maxillary sinus during surgical procedures in this region.

HUMAN BODIES TO TEACH ANATOMY: IMPORTANCE AND PROCUREMENT: EXPERIENCE WITH CADAVER DONATION. Cuerpos humanos para la enseñanza de la Anatomía: Importancia y procuración: Experiencia con la donación de cadáveres

Este Debate fue propuesto para aportar diferentes puntos de vista y conocer la diversidad de circunstancias involucradas en la procuración y uso de cadáveres para la enseñanza de la Anatomía, a estudiantes de pre y post-grado, en el mundo. Un grupo reducido pero representativo de profesores de Anatomía de todos los continentes fueron invitados a participar. Se distribuyeron algunos lineamientos para que los escritos tuvieran similar orientación, aunque los autores podían incluir cualquier concepto que consideraran de interés para los lectores. Además de los profesores de diversos países, el Prof. Bernard Moxham (Presidente de IFAA) aportó al Debate la posición oficial de la Federación Internacional de Asociaciones de Anatomistas. Los panelistas acordaron en la importancia de utilizar material cadavérico para la enseñanza de la Anatomía, sin embargo, la provisión, las fuentes y los procedimientos utilizados para adquirirlos fueron algo diferentes de un país y/o universidad a otro. La experiencia de los países europeos, las limitaciones culturales en los asiáticos y africanos, y el retraso y los problemas estructurales en Sudamérica, son algunas de las particularidades que se señalan. Después de esta publicación se recibirán las preguntas y comentarios no solo de los participantes sino también de los lectores en general, las cuales serán respondidas y ambas, preguntas y respuestas, publicadas en el próximo número. Entonces, el Debate alcanzará su punto máximo al permitir a todas las personas involucradas en el tema, en cualquier lugar  del mundo, participar y aportar información adicional.  This Debate was proposed to provide different points of view and to know the diversity of circumstances involved in the procurement and use of cadavers to teach Anatomy, to pre and post-graduate students, all over the world. A reduced but representative group of professors of Anatomy of all continents were invited to participate. Some guidelines were distributed to give a common orientation to each paper instead authors were able to include whatever they considered to be of reader’s interest. Within the professors from different countries, Prof. Bernard Moxham (IFAA President) supported the Debate with the International Federation of Associations of Anatomists official position. The panelists agreed about the importance of using cadaveric material to teach Anatomy, but the provision, sources and procedures followed to get them are quite different from one to another country and/or university. The experience of European countries, the cultural limitations in Asiatic and African ones, the delay and structural problems in South America, are some of the pointed peculiarities. After this publication we will receive the questions and comments, not only from the Debate participants but also from general readers, which will be answered and both, questions and answers, published in the next issue. Then, the Debate may reach its top point by letting involved people from all over the world to take part and provide additional information.

Minimally invasive approach to the radial nerve--A new technique

PURPOSE

To describe a minimally invasive approach to find the radial nerve (RN) simply and safely by tracing the posterior antebrachial cutaneous nerve (PACN) without damaging muscles, using only the surgeon's hand to define a window for the skin incision.

BACKGROUND

Although it is absolutely necessary to locate the radial nerve during osteosynthesis of the humerus, the literature lacks guidelines on how to do so.

METHODS

We have dissected the upper extremities of 54 adult human cadavers, embalmed using Thiel's method. After the PACN was identified in a defined space, its course was traced proximally by incising the lateral intermuscular septum (LIS) of the upper arm and thereby reaching the radial nerve (RN). Subsequently, using the lateral epicondyle (LE) of the humerus as a reference point, the distances to the points where the PACN perforated the LIS, and where the RN was identified, were measured. These individual data were related to the total length of the humerus.

RESULTS

The results indicate that with this approach and without harming musculature, the RN can be reached by tracing the PACN at a height of 11.1-13.0 cm (females) and 11.9-14.0 cm (males) starting from the LE.

CONCLUSION

Our examination shows the PACN to be a convenient guide to the RN.

Arterial blood architecture of the maxillary sinus in dentate specimens

Aim

To describe vascular anatomy of the maxillary sinus in dentate specimens dissected from human cadavers.

Methods

Twenty dentate maxillary specimens were dissected, anatomically prepared, and injected with liquid latex for a better visualization of the maxillary sinus artery.

Results

We found an intraosseous anastomosis in 100% and an extraosseous anastomosis in 90% of the cases. The anterior lateral wall of the maxillary sinus was transversed by two anastomoses between the posterior superior alveolar artery (PSAA) and the infraorbital artery (IOA). The PSAA was divided into a gingival and dental branch. The gingival branch anastomosed with the terminal extraosseous branch of the extraosseous anastomosis (EOA) and the dental branch with the intraosseous branch of the intraosseous anastomosis (IOA). The mean distances from the alveolar ridge to the extraosseus anastomosis were 16 mm for the second maxillary molar, 12.3 mm for the first maxillary molar, and 13.1 mm for the second maxillary premolar. The mean distances from the intraosseous anastomosis to the alveolar ridge were 17.7 mm for the second maxillary molar, 14.5 mm for the first maxillary molar, and 14.66 mm for the second maxillary premolar.

Conclusion

These findings provide relevant data for clinical dentistry in order to avoid bleeding complications and minimize the risk of injury to the arterial network of the maxillary sinus during surgical procedures in the dentate maxilla region.

A new xenobiotic-induced mouse model of sclerosing cholangitis and biliary fibrosis

Xenobiotics and drugs may lead to cholangiopathies and biliary fibrosis, but the underlying mechanisms are largely unknown. Therefore, we aimed to characterize the cause and consequences of hepatobiliary injury and biliary fibrosis in 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-fed mice as a novel model of xenobiotic-induced cholangiopathy. Liver morphology, markers of inflammation, cell proliferation, fibrosis, bile formation, biliary porphyrin secretion, and hepatobiliary transporter expression were studied longitudinally in DDC- and control diet-fed Swiss albino mice. DDC feeding led to increased biliary porphyrin secretion and induction of vascular cell adhesion molecule, osteopontin, and tumor necrosis factor-alpha expression in bile duct epithelial cells. This was associated with a pronounced pericholangitis with a significantly increased number of CD11b-positive cells, ductular reaction, and activation of periductal myofibroblasts, leading to large duct disease and a biliary type of liver fibrosis. After 4 weeks, we constantly observed intraductal porphyrin pigment plugs. Glutathione and phospholipid excretion significantly decreased over time. Expression of Ntcp, Oatp4, and Mrp2 was significantly reduced, whereas Bsep expression remained unchanged and adaptive Mrp3 and Mrp4 expression was significantly induced. We demonstrate that DDC feeding in mice leads to i) a reactive phenotype of cholangiocytes and bile duct injury, ii) pericholangitis, periductal fibrosis, ductular reaction, and consequently portal-portal bridging, iii) down-regulation of Mrp2 and impaired glutathione excretion, and iv) segmental bile duct obstruction. This model may be valuable to investigate the mechanisms of xenobiotic-induced chronic cholangiopathies and its sequels including biliary fibrosis.

Arteries in the posterior cervical triangle in man

Due to frequent changes in the anatomical nomenclature of the arteries in the posterior cervical triangle (lateral cervical region), anatomical and surgical papers relating to these topics are sometimes difficult to understand and are hard to compare. These changes, coupled with improper knowledge of the gross anatomy and nomenclature of the arteries in the posterior cervical triangle, have presented difficulties in musculocutaneous flap planning, especially in plastic and reconstructive surgery. As an illustration of this concern, the term, transverse cervical artery (A. transversa colli [cervicis]), and its associated branches, have been used frequently over the past several decades with different meanings. In an effort to address this nomenclature challenge and to offer a rational basis for arguing specific name changes, a total of 498 neck-halves were investigated in Graz, Innsbruck, and Munich. Lateral neck dissections were carried out to expose the subclavian artery and those branches destined for the posterior cervical triangle, specifically, the superficial cervical artery, the dorsal scapular artery, and the suprascapular artery. The course of these arteries and details of their origins and branching patterns were documented. Several arose either as direct branches or from trunks. The convention used in labeling trunks was similar to that described for other trunk formations in the body (e.g., linguo-facial trunk). Four trunks were observed and named according to the branches that arose from each. A cervico-dorsal trunk gave origin to the superficial cervical and dorsal scapular arteries, and was found in 30% of cases. A cervico-scapular trunk gave rise to the superficial cervical and suprascapular arteries in 22% of cases, and a dorso-scapular trunk provided origins for the dorsal scapular and suprascapular arteries in 4% of cases. A cervico-dorso-scapular trunk gave origin to the superficial cervical artery, the dorsal scapular artery, and the suprascapular artery, and was found in 24% of cases. Each of these trunks, in turn, arose from either the subclavian artery or from the thyrocervical trunk. This labeling convention necessitated omitting the term, transverse cervical artery, because this term has become inherently imprecise and variously used over the years. This study describes a simple, uniform, and rational basis for standardizing the nomenclature of the arteries in the posterior cervical triangle.

Herniation of the mylohyoid muscle

During ultrasound examinations in patients with dysphagia, deficiencies in the mylohyoid muscle with herniation of the sublingual gland were found, which may be mistaken as soft tissue tumors. Between the years 2001 and 2003, 205 half-heads used in dissection courses were examined to determine the location and contents of these gaps. In 25 of these cadaveric specimens, the hiatus (of variable size) appeared as small fissures between the divided fibers of the mylohyoid. In 18 cases (72%), the sublingual gland slipped through these deficiencies and occurred in the front part of the submandibular triangle. From the inferior surface of the muscle, the submental artery also coursed through the separated muscle fibers. The herniations of 7 specimens (28%) were found without any contents, neither with gland perforation nor with a submental artery. The following study points out the spatial relation of the salivary glands to the floor of the mouth and the clinical significance, and some factors referred to the development of herniations are discussed.

Ursodeoxycholic acid aggravates bile infarcts in bile duct-ligated and Mdr2 knockout mice via disruption of cholangioles

BACKGROUND & AIMS

The effects of ursodeoxycholic acid (UDCA) in biliary obstruction are unclear. We aimed to determine the effects of UDCA in bile duct-ligated and in Mdr2 knockout (Mdr2(-/-)) mice with biliary strictures.

METHODS

Mice fed UDCA (0.5% wt/wt) or a control diet were subjected to common bile duct ligation (CBDL), selective bile duct ligation (SBDL), or sham operation. UDCA was also fed to 2-month-old Mdr2(-/-) mice. Serum biochemistry, liver histology, and mortality rates were investigated. The biliary tract was studied by plastination, India ink injection, and electron microscopy. The effects of UDCA on biliary pressure were determined by cholangiomanometry.

RESULTS

UDCA feeding in CBDL mice increased biliary pressure, with subsequent rupture of cholangioles and aggravation of hepatocyte necroses, resulting in significantly increased mortality. UDCA feeding in SBDL mice aggravated liver injury exclusively in the ligated lobe. Mdr2(-/-) mice developed liver lesions resembling sclerosing cholangitis characterized by biliary strictures and dilatations. UDCA induced bile infarcts in these animals.

CONCLUSIONS

UDCA aggravates bile infarcts and hepatocyte necroses in mice with biliary obstruction via disruption of cholangioles as a result of increased biliary pressure caused by its choleretic action.

Anatomical and safety considerations in establishing portals used for wrist arthroscopy

Eight portals are used for wrist arthroscopy, five for the radiocarpal joint and three for the midcarpal space. These portals pass between important vessels and cutaneous nerves and the extensor tendons underlying the extensor retinaculum and permit access to the common pathologies of the wrist joints. The portals can be safely established making precise use of the external landmarks and are associated with little soft tissue damage and few complications when performed gently and through the dorsal side of the wrist.

The Graz learning and training model for arthroscopic surgery

Up to 30% of all operative procedures in orthopaedic surgery are performed arthroscopically. Because of the steadily increasing number of residents, it seems to be difficult both to maintain high standards and to guarantee an adequate training in arthroscopic surgery. However, in contrast to many other surgical techniques it is possible to learn and practice arthroscopy using artificial models and cadaver joints, provided that experienced surgeons and anatomists act as supervisors and instructors. The aim of this paper is to assess practice models and training programs which should guarantee sufficient practical experience during the training period.

[Colliculus atlantis--a rarely observed anatomic structure--in a transoral roentgen image of the thoracic spine]

PURPOSE

To study the time and mode of the development of the colliculus atlantis, the rate of its occurrence, the causes for its absence, and the radiological-clinical importance in the analysis of open-mouth-view radiographs.

MATERIAL AND METHODS

Retrospective analysis of standardized radiographs of the cervical spine in more than 20,000 adults and 100 children. Study of 234 human skeletons of different ages and of 38 isolated adult atlases. Cadaveric dissection of 42 adults (age 48-87). Axial radiographs of isolated atlases and analysis of the bony structures of the colliculus atlantis.

RESULTS

The colliculus atlantis develops between age 10 and 13 years. It is always present after age 13 years. For the development of the colliculus atlantis a normal function of the craniocervical joints is necessary. In congenital dysmorphias of the craniocervical region with dysfunction of the craniocervical joints and in fractures of the dens axis before age 10 years with instable healing the colliculus atlantis is absent.

CONCLUSIONS

The colliculus atlantis is developed at age 13 years apart from some rare exceptions as mentioned. Changes of the site and the structure of the colliculus atlantis allow an early diagnosis of certain traumatically and inflammatory diseases of this region. Furthermore, it serves as an additional parameter in functional analysis of the craniocervical joints.

Plastination in the neurosciences. Keynote lecture

Plastination is a unique technique of tissue preservation developed by Dr. Gunther von Hagens in Heidelberg, Germany, in 1978. In this process, water and lipids in biological tissues are replaced by curable polymers which are subsequently hardened, resulting in dry, odorless and durable specimens. In neuroanatomy silicone and polyester resins are used. Silicone rubber is used for whole brains and brain dissections resulting in natural looking specimens. Polyester resin is used for brain slices resulting in an excellent distinction between gray and white matter. The silicone S 10 standard technique and the polyester P 35 technique are described in detail. The advantages of plastinated specimens in neuroanatomy teaching and research are discussed.

Anatomic basis of the lower trapezius musculocutaneous flap

Differences in the description of the blood supply of the lower trapezius m. and the fact that all former findings are based on very few cases caused us to reinvestigate the arterial supply of the lower trapezius m. Based on the anatomic investigation of 70 human cadavers, the trapezial branch of the dorsal scapular a. was found to be the constant vessel to the lower trapezius m. The origin of the dorsal scapular a., however, was found to be very variable. In 45% it was a direct branch of either the subclavian a. or the costocervical trunk. In the remaining 55% the dorsal scapular a. formed different trunks with the superficial cervical a. and/or suprascapular a. branching off either the subclavian a., the thyrocervical trunk, or the internal thoracic a. Additional segmental musculocutaneous perforators also supply the lower part of the trapezius m. and the overlying skin. Consequently, the lower or ascending part of the trapezius m. has a vascular pattern type V. Thus, the lower trapezius musculocutaneous flap merits consideration in head and neck reconstruction.

A rare variant of thyroid gland vascularization

Usually the thyroid gland obtains its blood via two paired arteries. One pair, the right and left superior thyroid aa., most commonly arises from the external carotid aa. and the second pair, the right and left inferior thyroid aa. commonly arises from the thyrocervical trunk of the subclavian a. In this particular case the right inferior thyroid a. was replaced by an artery branching off the right internal thoracic a.; the left inferior thyroid a. was replaced by an artery branching off the vertebral a. between the transverse process of the second and third cervical vertebrae. This finding might be explained by the suggestion that in the fetus there exists an anastomotic arterial chain ventral to the spinal column consisting of the thyrocervical trunk and the ascending cervical a. which itself is connected to the vertebral a.

Postnatal development of the facial canal. An investigation based on cadaver dissections and computed tomography

The anatomy of the facial nerve canal in the adult and the prenatal development of this canal are well described in the literature. It is divided into three segments (the labyrinthine segment, the tympanic segment and the mastoid segment). However, little is known of the facial canal anatomy in the newborn and almost nothing in the child. Postnatal changes in the development of the facial canal are directly connected with the postnatal development of the temporal bone. Particularly the development of the mastoid process and the bony external ear canal contribute to the development of the third (mastoidal) portion of the facial canal. Therefore, most of the postnatal changes in the facial canal are observed in this segment. However, the second (tympanic) portion also shows some postnatal changes in its direction caused by the changes of the squamous bone. The most significant changes take place during the first four years after birth. Provided with the anatomical description of the entire facial canal in the child, it is also easy to identify the canal on computed tomography scans. In summary, the first and the second part of the facial canal in the child are almost similar to the adult in length and in width; the only change from the newborn to the adult is in the direction of the second part which is more horizontal in the adult than during early childhood. The most significant changes are the changes in the length of the mastoidal part, the change in the position of the stylomastoid foramen and the change of the divergence of the chorda tympani.

Variations and topography of the arteries in the lesser omentum in humans

Modern surgical techniques depend in part on knowledge of both the "normal" and the anomalous arterial blood supply. For instance, in liver transplantation, during surgery of the gallbladder, gastrectomy, and gastric lymphadenectomy, or when selective arterial chemotherapy is used for treatment of liver cancer, aberrant hepatic arteries can be a significant problem. A series of 138 cadavers with arterial latex injection were dissected and 10 corrosion casts were made to obtain an exact knowledge of the topography of the normal and anomalous arteries of the lesser omentum in humans. The so-called normal anatomy was found in only 9% (15 of 148 individuals), the remaining five-sixths presenting some variations from this, many of direct surgical importance. In these cases one or two aberrant hepatic arteries (37%), an artery in the free border of the hepatoduodenal ligament (19%), a right hepatic artery crossing the portal vein posteriorly (4%), the right hepatic artery entering the triangle of Calot anteriorly (29%) or not (7%), or an accessory left gastric artery branching off the left hepatic artery (2%) were found.

Imaging of the facial canal by means of multiplanar angulated 2-D-high-resolution CT-reconstruction

The facial canal containing the intratemporal portion of the facial nerve is very important for the otologist and radiologist concerning fractures and other lesions of the temporal bone. Axial and/or coronal standards are sufficient for imaging of the labyrinthine and the mastoidal segment of the facial canal. The sensitivity of visualization (sensitivity = number of identified structures per number of examinations) of the tympanic segment, however, is low and particularly the pyramidal segment (elbow, posterior knee) is not visualized in these standards. Based on anatomical considerations a new plain for imaging both the tympanic and mastoidal segment in continuity was obtained. The pyramido-longitudinal plain is achieved by a twice angulated 2-D-reconstruction based on axial high-resolution CT-scans.