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.

Morphology of the Posterior Interosseous Nerve with Regard to Entrapment Syndrome.

BACKGROUND: Posterior interosseous nerve (PIN) entrapment syndrome is a rare condition and is predisposed by anatomical factors such as narrow passages through fibrous arcades; whereas, the Arcade of Frohse (AF) is the most common entrapment point. The aim of this study was to evaluate the entrance and exit points of the PIN into the supinator in detail. MATERIALS AND METHODS: One hundred unpaired upper extremities underwent dissection. The PIN's entrance and exit points from the supinator were depicted. The distances between the tip of the radial head (RH) and the AF and the exit point of the PIN from the supinator were measured. Further, it was checked if the borders of the AF and the exit point were muscular, tendinous or a combination of these. RESULTS: The interval between the PIN's entry into the supinator and the tip of the RH was at a mean of 28.9 mm. Concerning the border of the AF, in 54 cases a muscular and in 46 specimens a tendinous version could be observed. The interval between the exit point of the PIN and the tip of the RH proved to be at a mean of 64.2 mm. Further, the exit's border was muscular in 65 specimens and tendinous in 35 cases. CONCLUSION: During surgical treatment of the PIN syndrome, it needs to be kept in mind that approximately one-third of all patients might also suffer from entrapment at the exit point of the PIN.

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.

Axillary nerve elongation in humeral fracture plating: A cadaveric study for comparison between straight and helical Philos plates.

Helical plating is a known concept in humeral fracture treatment. Attention should be paid to the axillary nerve when inserting a plate underneath the deltoid muscle. The purpose of this cadaveric study was to estimate axillary nerve stretching when introducing the plate. METHODS: On 42 fresh frozen human humeri, an 8-, 10- and 12-hole Philos plate in a straight and a helical shape were compared measuring the maximum plate-bone-distance. RESULTS: For all three plate lengths, the helical plates had a significantly lower plate-bone-distance. CONCLUSION: Indirectly, this suggests a lower axillary nerve elongation and hence less chance of nerve damage.

Success Rate in Puncture of the Temporomandibular Joint.

Puncture of the temporomandibular joint (TMJ) is a minimally invasive treatment for various jaw disorders. This study used a cadaveric model to evaluate the procedure from two entrance points with respect to hit ratio and possible complications, such as extraarticular extrusion of injection fluid. Ten heads, embalmed with Thiel's method, were investigated. A straight line drawn with a colored pen connected the center of the tragus and the lateral canthus. The first portal "A" was located at a distance of 1 cm anterior and 2 mm caudal from the center of the tragus. Portal "B" was located 2 cm anterior and 1 cm caudal starting from the same reference point. Punctures "A" and "B" were performed alternately on the right and left sides. Specimens were dissected and the local distribution of the injected latex was recorded. With Approach A, four punctures (40%; 4/10) reached the TMJ, whereas with Approach B, six injections (60%; 6/10) entered the TMJ. There were no statistically significant differences between the tested puncture methods (P = 0.0317) and body sides (P = 1). With each method, for example, 35% (7/20) each, the injected latex was either periarticular or retromandibular. In a further 20% (4/20), it was located subperiosteally alongside the ramus of mandible. The latex was injected into the infratemporal fossa and the external acoustic meatus in one case each (each 5%). There was no statistically significant difference between the techniques. The adjacent anatomy has to be kept in mind during TMJ puncture as the complication rate was remarkably high, suggesting that ultrasound guided intraarticular injection could improve the hit rate. Clin. Anat., 33:683-688, 2020. © 2019 Wiley Periodicals, Inc.

The Important Relationship Between the Radial Artery's Course and the Radius during Henry's Anterior Forearm Surgical Exposure.

The aim of this study was to investigate the intersection point of the radial artery (RA) with Henry's approach. Ninety forearms from adult human cadavers which had been embalmed using Thiel's method underwent dissection. Henry's approach was performed alongside the whole length of the forearm, and the RAs course was investigated. Its crossing point with the approach was identified, and the distance from this point to the radial styloid process was determined. In addition, the total radial length (RL) was measured from the radial styloid process to the proximal margin of the radial head. The former measurements were analyzed as proportions with regard to the total RLs. Concerning right radii, the intersection point was, on average, at a proportion of 56.2% of the radius, starting from the tip of the radial styloid process. In left radii, this was located at a mean proportion of 61.2%. In cases of multiply fractured radii, care must be taken at the interval between 40% and 80% to avoid RA lesions during dissection from distal to proximal. Clin. Anat., 33:983-987, 2020. © 2019 Wiley Periodicals, Inc.

The sigmoidea ima artery: A player in colonic ischemia?

INTRODUCTION: The sigmoidea ima artery is defined as the lowest sigmoid artery, which forms the distal end of the marginal artery by linking with the superior rectal artery. It supplies the rectosigmoid junction, which is a critical area for ischemia. The aim of the present study was to delineate the area supplied by the inferior mesenteric artery with special consideration of the sigmoidea ima artery. MATERIALS AND METHODS: The inferior mesenteric artery was dissected from its origin to the bifurcation of the superior rectal artery in 30 cadavers (15 male, 15 female). Vessel length and distance to the promontory were measured for each branch. RESULTS: There were two manifestations of the sigmoidea ima artery, irrespective of the branching pattern of the inferior mesenteric artery. It originated below the promontory in 25 cases (83.3%) and above it in three (10%). It did not derive from the superior rectal artery in two cases (6.7%). In these 16.7%, the marginal artery was absent near the rectosigmoid junction. CONCLUSIONS: We suggest the terms "arteria sigmoidea ima pelvina" and "arteria sigmoidea ima abdominalis" for the two variants. The terms "arteria marginalis pelvina" and "arteria marginalis abdominalis" could be applied in clinical practice. An abdominal marginal artery could be considered a risk factor for colonic ischemia in colorectal resections and abdominal aortic aneurysm repair. Both variants should be considered when pre- and intra-operative perfusion measurements are interpreted.

Correlation Analysis of the Anterolateral Ligament Length with the Anterior Cruciate Ligament Length and Patient's Height: An Anatomical Study.

The aim of this study was to evaluate the anatomical characteristics of the anterolateral ligament of the knee (ALL) with the focus on potential gender differences. The ALL length and the length of the lateral collateral ligament (LCL) were taken in extension. The length of the anterior cruciate ligament (ACL) was measured at 120° flexion. We correlated the length of the ALL with the LCL and ACL with respect to potential gender differences. The ALL was significantly (p = 0.044) shorter in females (mean length: 32.8 mm) compared to males (mean length: 35.7 mm). The length of the ALL correlated significantly positively with the lengths of the ACL (p < 0.001) and the LCL (p < 0.001). There was no significant correlation with the total leg length (TLL) (p = 0.888) and body size (p = 0.046). Furthermore, TLL and donor size correlated significantly positively (p < 0.001). The ALL length correlated significantly positively with the ACL and the LCL length. The ALL length did neither correlate with the TLL nor the donor size. This fact may contribute to planning of graft harvesting in the upcoming techniques for ALL 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.

Safe zone for the posterior interosseous nerve with regard to the lateral and posterior approaches to the proximal radius.

PURPOSE: The posterior interosseous nerve (PIN) is at risk during the posterior and lateral approaches to the proximal radius. We aimed to define a safe zone for these approaches to avoid injury of the PIN and to evaluate their close and changing relationship to the nerve during forearm rotation. METHODS: The study collective consisted of 50 upper limbs. After performance of the lateral approach, the distance between the tip of the radial head and the PIN's exit point from the supinator (= distance 1) and the shortest interval between the nerve's exit to the radial margin of the ulna (= distance 2) were measured in maximum pronation and supination. Then, the dorsal approach was conducted and again distance 1 and the interval between the distal margin of the anconeus and the nerve's exit point (distance 2) were evaluated (pronation and supination). RESULTS: There were significantly shorter distances during supination in comparison to pronation. Regarding the lateral approach, distance 1 changed from a mean of 60.3 mm (supination) to 62.7 mm in pronation (p < 0.001). For the dorsal approach, distance 1 decreased significantly (p < 0.001) from 62.9 mm (pronation) to 60.2 mm (supination). CONCLUSION: Supination during the lateral and dorsal approaches to the proximal radius needs to be avoided to protect the PIN. Furthermore, the nerve appeared at an interval between 45 and 84.1 mm (lateral approach) and 47.5-93.8 mm (dorsal approach), respectively. Therefore, care must be taken at this height during extension of the approaches in a distal direction.

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.

Avoiding radial nerve palsy in proximal radius shaft plating - a cadaver study.

BACKGROUND: Opinions vary concerning the position of forearm rotation during detachment of the supinator in radial nerve palsy Henry's and Thompson's approaches. PURPOSE: To define the optimal forearm position for a safe detachment of the supinator during these approaches and to clarify their close relationship to the posterior interosseous nerve (PIN). METHODS: The study sample comprised 90 upper extremities of 45 human adult cadavers, embalmed using Thiel's method. After detection of the radial nerve in the interval between the brachialis and brachioradialis, its pathway was traced to the Arcade of Frohse (AF). Measurements involved the distance between the AFand the radial border of the distal biceps tendon (DBT) in pronation and supination, the interval between the AF and the radiocapitellar joint space (RCJS) in supination and the radial length (RL). RESULTS: Distances between the DBT and the AF were significantly shorter during pronation (right side: 14.1 ± 3.4mm; left side: 13.5 ± 3.2mm) compared with supination (right side: 20.5 ± 3.6mm; left side: 19.8 ± 3.5mm) for both right and left extremities. The mean interval between the AF and the centre of the RCJS was 25.2 ± 5.9mm for the right side and 24.7 ± 5.6mm for the left side, which correlated positively with the RL. CONCLUSION: These results indicate a safe detachment of the supinator from the radius with the forearm placed in supination during both Henry's and Thompson's approaches.

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 cadaver study evaluating a new measurement technique for graft volumes after sinus floor elevation.

PURPOSE: Volumetric data can be used as complementary information to characterize grafting materials. The aim of this cadaveric study was to analyze a noncommercial measurement technique based on the novel concept of an "interactive rigid registration algorithm" (IRRA). Parameters analyzed included the reproducibility of IRRA measurements and their reliability in comparison with the established measurement technique of "region growing segmentation thresholding" (RGST). MATERIALS AND METHODS: Three human skulls were used to simulate a total of 18 sinus grafts, using three incremental grafting procedures in each sinus (three skulls ×t wo sinuses × three grafting increments). Radiopaque impression material was used for the simulated grafts, whose volumes were recorded by computed tomography from three different tilt angles. The reproducibility of IRRA measurements and the reliability of volumetric results obtained with both the IRRA and RGST techniques were evaluated by appropriate intraclass correlation coefficient (ICC) and Bland-Altman analysis. RESULTS: ICC greater than 0.9 indicated close to perfect agreement of the results obtained with both methods and good reproducibility of the IRRA measurements. Bland-Altman analysis demonstrated good inter-method and intramethod agreement. CONCLUSIONS: The IRRA measurement technique can be recommended as a noninvasive tool to evaluate graft volumes in human maxillary sinuses.

Position of the mental foramen in Kosovarian population.

The aim of this study was to determine the position, shape, number and radiographic appearance of the mental foramen in a selected Kosovarian population. Five hundred panoramic radiographs of dental Kosovarian patients were selected and analyzed according to the mental foramen position, shape, radiographic appearance, number and symmetry. The mean distance in the horizontal plane of the mental foramen to the posterior border of the mandibular ramus was 67.5 mm and for distance from the mental foramen to symphysis menti 24.84 mm. In the vertical plane the mean distance of the mental foramen to alveolar crest was 20.38 mm and 14.68 mm for distance of the mental foramen to the lower border of mandible. The majority of mental foramen was oval in shape and the most frequent radiographic appearance was the separated type. Accessory mental foramina were detected in < 1% of the cases and the mental foramen was not bilaterally symmetrical but no statistical differences were found. This study showed that the most common position of the mental foramen investigated using panoramic radiographs from a selected group in Kosovarian population was between the first and second mandibular premolars with distinct tendency to be positioned near to the second mandibular premolar.

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.

Distribution of RoekoSeal sealer applied by three obturation techniques.

The aim of the study was to evaluate the distribution of Roekoseal Automix sealer using three different obturation techniques. Forty-five single-rooted extracted human teeth were prepared in a crown-down manner using ProFile instruments. After instrumentation the specimens were filled using Roekoseal Automix with the cold lateral condensation, Thermafil and Obtura II techniques. Each root was sectioned horizontally. Color images were obtained using a reflected-light microscope. The cross-sections were assessed by microscopy for distribution of the sealer. Root canals filled with cold lateral condensation technique had statistically significant (p = 0.0001) more sealer in the apical portion in comparison to the apical portion of the specimens obturated with Thermafil and Obtura II techniques.