Minimally invasive plate osteosynthesis of the humeral shaft with regard to adjacent anatomical characteristics.

The study goal was to evaluate the distances from the radial (RN), the musculocutaneous (MN) and axillary nerves (AN) and the medial neurovascular bundle of the upper arm to a minimally invasive applied plate and to define its relation to the RN during different degrees of malrotation during MIPO. The sample involved ten upper extremities. Application of a PHILOS plate was performed through a Delta-split. Intervals between the AN, MN, RN and the medial vascular bundle were defined at various positions. The humeral shaft was artificially fractured at a height of about the mean of the plate. The distal fragment was brought into 15° and 30° internal (IR) as well as external rotation (ER) and here, the plate's relation to the RN was evaluated. The medial neurovascular bundle intersected the plate at its distal part in two specimens. Regarding the distances from the RN to the plate during different rotation positions the distances became significantly longer during ER, respectively shorter during IR. The medial neurovascular bundle and the RN were identified as the main structures at risk. Care must be taken during distal screw placement and malrotation exceeding 15° must be avoided during MIPO.

Projection of the A1-Pulley of the Thumb onto Superficial Anatomical Landmarks: An Anatomical Study and a Useful Guide to Surgeons.

BACKGROUND: The aim of our study was to project the A1-pulley of the thumb onto the total thumb length to enable its complete division with and without direct sight. MATERIALS AND METHODS: The study involved 50 hands from adult human cadavers. The proximal and distal borders of the A1-pulley were measured with reference to the first metacarpophalangeal joint (MCPJ). The length of the thumb was defined as the interval between the first carpometacarpal joint (CMCJ) and the apex of the thumb. The length of the pulley is calculated proportionally with reference to the line between the first CMCJ and apex of the thumb. RESULTS: Approximated by computing 95% confidence intervals, the pulley can be expected to lie in an area between 34.0% (proximal border) and 57.8% (distal border) alongside this line. CONCLUSION: Percutaneous and minimally-invasive division of the A1-pulley needs to be performed between 34.0 and 57.8% of the length between the first CMCJ and apex of the thumb.

Definition of a Risk Zone for the Axillary Nerve Based on Superficial Landmarks.

BACKGROUND: The aim of this study was to investigate the axillary nerve's location along superficial anatomical landmarks, and to define a convenient risk zone. METHODS: A total of 123 upper extremities were evaluated. After dissection of the axillary nerve, the vertical distance between the upper border of the anterolateral edge of the acromion and the proximal border of the nerve was measured. Furthermore, the interval between the proximal border and the distal border of the axillary nerve's branches was evaluated. The interval between the distal border of the branches and the most distal part of the lateral humeral epicondyle was measured. The distance between the anterolateral edge of the acromion and the lateral humeral epicondyle was evaluated. Measurements were expressed as proportions with respect to the distance between the acromion and the lateral humeral epicondyle. RESULTS: The distance between the acromion and the proximal border of the axillary nerve's branches was at a height of 10 percent of the distance between the acromion and the lateral humeral epicondyle, starting from the acromion (90 percent when starting from the lateral humeral epicondyle). The interval between the proximal and distal margins of the axillary nerve's branches was between 10 percent and 30 to 35 percent of this interval, starting from the acromion (65 to 70 percent when starting from the lateral humeral epicondyle). CONCLUSIONS: The authors were able to locate the branches of the axillary nerve at an interval between 10 and 35 percent of the distance between the acromion and the lateral humeral epicondyle, starting from the acromion. This makes the proximal third of this distance an easily applicable risk zone during shoulder surgery.

The articular branch of the peroneal nerve to the proximal tibiofibular joint descends at a mean height of approximately 18 mm distal to the postero-lateral tip of the fibular head.

PURPOSE: The aim of the study was to evaluate the anatomical details of the articular branch of the peroneal nerve to the proximal tibiofibular joint and to project the height of its descent in relation to the fibular length. METHODS: Twenty-five lower extremities were included in the study. Following identification of the common peroneal nerve, its course was traced to its division into the deep and superficial peroneal nerve. The articular branch was identified. The postero-lateral tip of the fibular head was marked and the interval from this landmark to the diversion of the articular branch was measured. The length of the fibula, as the interval between the postero-lateral tip of the fibular head and the tip of the lateral malleolus, was evaluated. The quotient of descending point of the articular branch in relation to the individual fibular length was calculated. RESULTS: The articular branch descended either from the common peroneal nerve or the deep peroneal nerve. The descending point was located at a mean height of 18.1 mm distal to the postero-lateral tip of the fibular head. Concerning the relation to the fibular length, this was at a mean of 5.1%, starting from the same reference point. CONCLUSION: The articular branch of the common peroneal nerve was located at a mean height of 18.1 mm distal to the the postero-lateral tip of the fibular head, respectively, at a mean of 5.1% of the whole fibular length starting from the same reference point. These details represent a convenient orientation during surgical treatment of intraneural ganglia of the common peroneal nerve, which may result directly from knee trauma and indirectly from ankle sprain.

Successful reconstruction of the posterior cruciate ligament: assessment of posterior cruciate ligament footprints using an objective coordinate system.

INTRODUCTION: Anatomic cruciate ligament reconstruction is known to be correlated with better clinical results. The aim of the study was to provide a simple method to enable anatomic results in the setting of PCL reconstruction. We, therefore, assessed the tibial and femoral insertion site of the posterior cruciate ligament (PCL) by the use of an objective coordinate system in an anatomical study. We also sought to show reproducibility of these measurements using intra- and inter-observer coefficients. MATERIALS AND METHODS: We studied 64 knees, previously preserved according to Thiel's technique. After proper preparation of the articular surfaces of both the tibiae and femora, photographs were taken according to a standardized protocol. PCL footprints were measured by the use of a coordinate system twice by two examiners. We evaluated these measurements by use of the Cohen's kappa inter- and intra-observer coefficient for two observers. RESULTS: Tibial and femoral measurements of PCL footprints were generated with highly comparable inter- (k = 0.970) and intra-observer (k = 0.992) coefficients and may, therefore, be considered as highly reproducible. CONCLUSION: Our findings confirmed the reproducibility of defining PCL footprints using a coordinate system and may contribute to planning intraoperative graft-placement to ensure optimal conditions in the upcoming techniques for PCL reconstruction.

Anatomy of the Le Fort I segment: Are arterial variations a potential risk factor for avascular bone necrosis in Le Fort I osteotomies?

PURPOSE: Osteotomies of the Le Fort I segment are routine operations with low complication rates. Ischemic complications are rare, but can have severe consequences that may lead to avascular bone necrosis of the Le Fort I segment. Therefore the aim of this study was to investigate the blood supply and special arterial variants of the Le Fort I segment responsible for arterial hypoperfusion or ischemic avascular necrosis after surgery. MATERIAL AND METHODS: The arterial anatomy of the Le Fort I segment's blood supply using 30 halved human cadaver head specimens was analyzed after complete dissection until the submicroscopic level. In all specimens the arterial variants of the Le Fort I segment and also the arterial diameters measured at two points were evaluated. RESULTS: The typical known vascularization pattern was apparent in 90% of all specimens, in which the ascending palatine (D1: 1,2 mm ± 0,34 mm; D2: 0,8 mm ± 0,34 mm) and ascending pharyngeal artery (D1: 1,3 mm ± 0,58 mm; D2: <0,4 mm) were both supplying the Le Fort I segment. However in 10% of all specimens, the Le Fort I segment was dependent on the ascending pharyngeal artery alone and the missing ascending palatine artery was replaced with the anterior branch of the ascending pharyngeal artery (D1: 1,9 mm ± 0,32; D2: 1,0 mm ± 0,3 mm). CONCLUSION: This study is the first description of a special type of arterial variation of the Le Fort I segment. The type of this arterial variation, its clinical relevance and potential consequences are explained. Individuals with this special arterial anatomy may clinically be at a high risk for hypoperfusion and avascular segment necrosis after surgery. An individualized operation plan may prevent ischemic complications in at-risk patients.

Prevalence of the distal oblique bundle of the interosseous membrane of the forearm: an anatomical study.

A study was undertaken to examine the presence of the distal oblique bundle of the forearm in a large sample in order to describe its true prevalence. The study sample consisted of 200 cadaveric forearms. Fifteen were excluded due to defects in the distal interosseous membrane. In the remaining 185 specimens, the distal interosseous membrane was examined following removal of soft tissue, to determine whether a distal oblique bundle was present and whether there were connecting fibres to the distal radio-ulnar joint. The distal oblique bundle was observed in 53 specimens (29%). In 45 of these forearms (85%), one or more connecting fibres to the distal radio-ulnar joint were identified. The presence of a distal oblique bundle in 29% is less frequent than that reported in previous literature. The presence of the distal oblique bundle should be noted and may be of importance in the management of disorders of the distal radio-ulnar joint.

Apical capping as a new technique for retrograde treatment of an infected root apex: introduction and first results.

INTRODUCTION: The success rate of surgical retrograde treatment of an infected root apex is limited by the existence of infected side canals which are not treatable by conventional retrograde preparation and filling techniques. This experimental study introduces a new technique of retrograde apex preparation followed by covering the apex with a titanium cap. MATERIAL AND METHODS: In 10 extracted canines, retrograde circular preparation of the root apex was performed using a new ultrasonic preparation tip and a high-power ultrasound machine. The prepared stump was covered by a titanium cap fixed with glass ionomer cement. The teeth were examined clinically and radiologically for unevenness, steps or clefts in the border between the titanium cap and root surface. Furthermore, a histological work-up was performed to register the existence and number of side canals, as well as their covering by the titanium cap and the width of the cement layer. RESULTS: The clinical and radiological examinations revealed only a small degree of unevenness in one case. In all other teeth the border was without any unevenness. There were 0 - 4 side canals as noted in the histological cross sections, all of which were covered by the titanium cap. The mean width of the cement layer was 27.2microm. From a technical point of view there were no difficulties or complications. CLINICAL CASE REPORT: For demonstration of the clinical use, a case of a 32-old-patient with an apical cyst on an upper lateral incisor is reported. The patient was treated successfully by apical capping. CONCLUSIONS: Apical capping is a new technique for retrograde treatment of an infected root apex which seals all side canals effectively. The technique is easy to perform and can be carried out quickly without complications. The technique is suitable for clinical testing.

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.

Fractures and dislocations of the foot in children.

The challenge of managing pediatric foot injuries is the identification of the rare injuries that require operative treatment and the management of complications such as compartment syndrome, post-traumatic foot deformities, and avascular necrosis. With these complications in mind, the authors discuss fractures of the talus, calcaneus, lesser tarsal bones, Lisfranc's joint, metarsals, and phalanges. Dislocation of metatarsophalangeal or interphalangeal joints is also discussed.

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.

How close are the phrenic nerves to cardiac structures? Implications for cardiac interventionalists.

BACKGROUND: Phrenic nerve injury is a recognized complication following cardiac intervention or surgery. With increasing use of transcatheter procedures to treat drug-refractory arrhythmias, clarification of the spatial relationships between the phrenic nerves and important cardiac structures is essential to reduce risks. METHODS AND RESULTS: We examined by gross dissection the courses of the right and left phrenic nerves in 19 cadavers. Measurements were made of the minimal and maximal distances of the nerves to the superior caval vein, superior cavoatrial junction, right pulmonary veins, and coronary veins. Histologic studies were carried out on tissues from six cavaders. Tracing the course of the right phrenic nerve revealed its close proximity to the superior caval vein (minimum 0.3 +/- 0.5 mm) and the right superior pulmonary vein (minimum 2.1 +/- 0.4 mm). The anterior wall of the right superior pulmonary vein was <2 mm from the right phrenic nerve in 32% of specimens. The left phrenic nerve passed over the obtuse cardiac margin and the left obtuse marginal vein and artery in 79% of specimens. In the remaining specimens, its course was anterosuperior, passing over the main stem of the left coronary artery or the anterior descending artery and great cardiac vein. CONCLUSIONS: The right phrenic nerve is at risk when ablations are carried out in the superior caval vein and the right superior pulmonary vein. The left phrenic nerve is vulnerable during lead implantation into the great cardiac and left obtuse marginal veins.

The posterior interosseous artery in the distal part of the forearm. Is the term "recurrent branch of the anterior interosseous artery" justified?

In 1993 Angrigiani raised the question as to whether the distal part of the posterior interosseous artery (AIP) is a recurrent branch of the anterior interosseous artery (AIA) and forms a "choke"--anastomosis with the AIP in the middle of the forearm. A dissection study was conducted on 66 upper extremities to evaluate the diameters of the dorsal branch of the anterior interosseous artery, the anastomotic branch, the diameter of the posterior interosseous artery at the point of origin of the septocutaneous perforators in the middle of the forearm and the diameter of the posterior interosseous artery at the point of emergence in the dorsal compartment. We further tried to identify different forms and types of the "distal" anastomosis and the connections to the dorsal carpal arch and the ulnar artery. A distal anastomosis between the AIA and AIP was found in 65 of the 66 upper extremities. Three different types of anastomosis could be identified. The smallest diameter was found at the middle of the forearm (mean diameter AIA 1.28 mm; anastomotic branch 0.6 mm; AIP at the middle of the forearm 0.39 mm; AIP prox. 1.35 mm). A branch through the fifth extensor compartment was present in all of our specimens (mean diameter 0.54 mm). A branch through the forth extensor compartment could be found in 16 specimens. Based on our findings and the embryological development, we conclude that the AIP is only present in the proximal half of the forearm. In the distal part, the dorsal branch of the anterior interosseous artery forms a vascular arcade, which gives off branches to the dorsal carpal arch, the ulnar head and the ulnar artery. This arcade anastomoses with the posterior interosseous artery in the middle of the forearm by means of a choke anastomosis. We also conclude that the term "recurrent branch of the anterior interosseous artery" for the distal part of posterior interosseous artery is correct.

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.

The lower trapezius musculocutaneous flap from pedicled to free flap: anatomical basis and clinical applications based on the dorsal scapular artery.

The pedicled lower trapezius musculocutaneous flap is a standard flap in head and neck reconstruction. A review of the literature showed that there is no uniform nomenclature for the branches of the subclavian artery and the vessels supplying the trapezius muscle and that the different opinions on the vessels supplying this flap lead to confusion and technical problems when this flap is harvested. This article attempts to clarify the anatomical nomenclature, to describe exactly how the flap is planned and harvested, and to discuss the clinical relevance of this flap as an island or free flap. The authors dissected both sides of the neck in 124 cadavers to examine the variations of the subclavian artery and its branches, the vessel diameter at different levels, the course of the pedicle, the arc of rotation, and the variation of the segmental intercostal branches to the lower part of the trapezius muscle. Clinically, the flap was used in five cases as an island skin and island muscle flap and once as a free flap. The anatomical findings and clinical applications proved that there is a constant and dependable blood supply through the dorsal scapular artery (synonym for the deep branch of the transverse cervical artery in the case of a common trunk with the superficial cervical artery) as the main vessel. Harvesting an island flap or a free flap is technically demanding but possible. Planning the skin island far distally permitted a very long pedicle and wide arc of rotation. The lower part of the trapezius muscle alone could be classified as a type V muscle according to Mathes and Nahai because of its potential use as a turnover flap supplied by segmental intercostal perforators. The lower trapezius flap is a thin and pliable musculocutaneous flap with a very long constant pedicle and minor donor-site morbidity, permitting safe flap elevation and the possibility of free-tissue transfer.

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.