Applied anatomy for tibial intraosseous access in adults: A Radioanatomical Study.

Intraosseous access is a method for providing vascular access in resuscitation of critically ill and injured patients when traditional intravenous access is difficult or impossible. There is a lack of detailed description for the landmark for the insertion point in the literature. The aim of this study was to determine the exact location for intraosseous access. Radiographic computed tomography (CT) images of a total of 50 dry tibia bones were obtained. With 5-mm intervals, for all transverse images and by selecting transverse section, measurements were taken from the thickness of the cortex at anterior margin and mid-line medial surface, distance from anterior margin, and mid-line medial surface of the tibia to the posterior wall of medullar cavity, distance from anterior margin and mid-line medial surface of the tibia to the posterior surface of the tibia. The thinner part of the cortex of the tibia and the larger width of the medullar cavity is at 0.5 cm below the tibial tuberosity in the midline of the medial surface. The application region for proximal tibia access and landmark and most suitable insertion point for intraosseous infusion should be at level 0.5 cm below the tibial tuberosity in the midline of the medial surface. It was recommended that standard length for intraosseous canule should be 17 mm except for the thickness of skin. In conclusion, presented study provides certain localization for intraosseous access and standard length for intraosseous canule and this will be more effective in using this technique. Clin. Anat. 31:593-597, 2018. © 2017 Wiley Periodicals, Inc.

The neurovascular relationships of the oculomotor nerve.

In this study, the arterial supply of the cisternal (initial) and the subcavernous parts of the oculomotor nerve (ON) and the relation between the nerve and adjacent vascular structures like posterior cerebral artery (PCA) and superior cerebellar artery (SCA) were investigated. A total of 140 formalin fixed hemispheres from 70 human cadaveric brains were examined. The nutrient branches reaching the cisternal and subcavernous parts of the ON were investigated, along with branches of adjacent vascular structures penetrating the nerve and passing through it. In the material examined, the ON, after arising from the midbrain, mostly continues laterally between PCA and SCA or between PCA and the rostral SCA trunk. However, in three hemispheres of our specimens, the ON run between the rostral and caudal SCA trunks. We observed that the branches of PCA-P1 segment supplied the cisternal part of the ON in all specimens. In one specimen, the cisternal part of the ON was supplied by a branch arising from the rostral SCA trunk which was also originating from PCA. Differently, in four hemispheres, branches arising from PCA or SCA perforated the cisternal part of the ON and passed through it. We also observed a tortuous caudal trunk of duplicated SCA in one of our specimens and considered it as a rare variation. The anatomy of the ON and its vascular relations is significant in terms of not only understanding the compression syndromes and its vascular dysfunctions, but the exact diagnosis and treatment as well.

Histomorphological differences of spermatic cords regarding subinguinal versus inguinal levels: a cadaveric study.

AIM: Varicocele is a common disorder among male population and is the most common cause of secondary infertility. Microsurgical inguinal or subinguinal operations are the preferred approaches but the two differ in technical difficulty. Therefore, we examined the histomorphological differences of spermatic cords at both subinguinal and inguinal levels in this cadaveric study. METHODS: Spermatic cords from 9 adult male cadavers were examined at both the inguinal and subinguinal levels using a light microscope with an image analysis program in the anatomy and histology laboratories of Ankara University Medical School between July 15, 2006 and February 15, 2007. RESULTS: In terms of number and wall thickness, we did not observe any significant histomorphological differences in spermatic cord veins and arteries between the subinguinal and inguinal levels. CONCLUSION: We conclude that the subinguinal approach is not a harder technique than the inguinal approach concerning vessel dissection, but more studies must be made to compare subinguinal versus inguinal varicocelectomy.

Anatomy and clinical significance of the trigeminocerebellar artery.

The trigeminocerebellar artery (TCA) is a unique branch of the basilar artery supplying both the trigeminal nerve root and the cerebellar hemisphere. In this study, we describe and demonstrate the microanatomy of the TCA in 45 brainstems and discuss the neurological, neuroradiological and neurosurgical significance. This is the largest series of cadavers in the literature. The close relationship of the TCA to the trigeminal nerve root may have clinical implications including for the etiology of trigeminal neuralgia, thus the neurosurgeon must be aware of the vasculature of the trigeminal nerve root area and the anatomical variations.

The utilization of teres major muscle in facial paralysis reanimation: an anatomic study.

PURPOSE: This study explores vascular and morphologic anatomy of the teres major muscle, which can be an alternative to donor muscles used in functional muscle transfer in long-standing facial paralysis reanimation. METHODS: A total of 14 teres major muscles from 7 embalmed cadavers were dissected and examined. Diameters and lengths of major and minor arteries supplying the muscle, venous pedicle diameter, neural pedicle diameter and length, their entrances into the muscle, the extendibility of neurovascular pedicles, when necessary, and the morphology of muscle were evaluated. RESULTS: Mean results obtained for teres major muscle in the study were as follows: the longest distance between the starting point and the area where the tendon started was 17.1 +/- 0.34 cm (range, 14.5-18.8 cm), the distance between the widest points was 5.8 +/- 0.5 cm (range, 5.1-6.2 cm), the thickest area was 3.4 +/- 0.9 cm (range, 2.8-3.9 cm), and surface area was 58.2 +/- 1.02 cm2 (range, 48.1-62.7 cm2). The major pedicle of the muscle, which is type 2 according to Mahtnes-Nahai classification, has a length of 3.0 +/- 0.6 cm (range, 2.4-3.6 cm) and a diameter of 2.7 +/- 0.21 mm (range, 1.85-3.4 mm). The nerve that provides motor innervation to the muscle is 5.9 cm (range, 4.1-9.9 cm) in length and 1.7 mm (range, 1.2-2.5 mm) in diameter. CONCLUSION: As a result of this preliminary study, we think that morphologic and neurovascular structures of this muscle is suitable for use in long-standing facial paralysis reanimation.

Ultrasonographic evaluation and morphometric measurements of the suprascapular notch.

BACKGROUND: The aim of this study was to define the sonographic evaluation and morphometric measurements of the suprascapular notch. METHODS: The suprascapular notch was evaluated by ultrasound on both sides in 50 volunteers (25 males, 25 females). By means of ultrasound, the notch width, the notch depth and the distance between the skin and the notch base (skin-notch base interval) were measured and imaging of the superior transverse scapular ligament was attempted. Furthermore, imaging of the suprascapular artery and vein was performed by Doppler ultrasound. RESULTS: On the measurements performed, the notch was found to be deeper in men than in women on both the right (P = 0.022) and the left (P = 0.011) sides. Taking all volunteers into account without grouping sex, no differences were detected between the two sides with respect to the measurements of the notch width, notch depth and distance between the skin and the notch base. The superior transverse scapular ligament was demonstrated in 48 (96%) of 50 volunteers. On color Doppler ultrasound, the artery-vein complex was visualized in a total of 43 (86%) volunteers. CONCLUSIONS: Suprascapular notch measurements and the visualization of the anatomical neighborhood, which may be beneficial for the suprascapular nerve blockade procedure, can be successfully performed by the use of high-frequency ultrasound imaging.

Rotator interval dimensions in different shoulder arthroscopy positions: a cadaveric study.

The rotator interval was defined as a triangular structure, where the base of the triangle was the coracoid base, the upper border was the anterior margin of the supraspinatus, and the lower border was the superior margin of the subscapularis muscle-tendon unit. We evaluated the rotator interval dimensions in 15 shoulders from 10 lightly embalmed adult cadavers in 3 shoulder arthroscopy positions: 0 degrees of abduction and 30 degrees of flexion (beach chair [BC]), 45 degrees of abduction and 30 degrees of flexion (lateral decubitus 1), and 70 degrees of abduction and 30 degrees of flexion (lateral decubitus 2). In each shoulder position, measurements were made in neutral rotation (NR), 45 degrees of external rotation (ER), and 45 degrees of internal rotation (IR). The coracoid base lengthened with IR in all positions and shortened in ER in the lateral decubitus position but not in the BC position. Abduction significantly lengthened the coracoid base, which was shortest in the BC position with ER (24 +/- 4 mm) and longest in the lateral decubitus 2 position with IR (33 +/- 5 mm). The coracoid base, where sutures are placed during plication of the interval, was observed to lengthen and, therefore, loosen with IR and abduction. To prevent postoperative ER restriction, plication should be made in ER or neutral rotation when operating in the BC position and the degree of abduction should be decreased and the shoulder held in ER when operating in the lateral decubitus position.

The safe distance for the superior gluteal nerve in direct lateral approach to the hip and its relation with the femoral length: a cadaver study.

INTRODUCTION: The most inferior branch (MIB) of the superior gluteal nerve (SGN) is vulnerable during direct lateral approach to the hip. A safe distance proximal to the tip of the greater trochanter varying from 3 to 5 cm has been reported in different studies. Anatomical studies defining safe zones and clinical studies reporting the results use various reference points, and the oblique course of the MIB contributes to the confusion. Numerous efforts have been made to standardize the safe zone using patient characteristics such as body height; however, contradictory results have been reported. The purpose of this study was to measure the safe distance in line to the gluteal split and also to determine the relationship of the safe distance with femoral length, as a stable component of body height. MATERIALS AND METHODS: Fifteen lower extremities of 12 formalin-fixed cadavers (M/F: 7/5) were dissected. The most prominent lateral palpable part of the trochanter major (TM) was determined and the dissection in the gluteus medius muscle (GMM) was performed starting from this point upwards in line of the muscle fibers. The distances between the MIB in the plane of dissection in the GMM to the TM and also to the trochanteric apex (TA) were measured. Femoral lengths were measured between the TM point and the lateral epicondyle. Spearman's correlation and Mann-Whitney U tests were used for statistical analysis. RESULTS: The SGN in 13 hips had spray pattern and neural trunk pattern in two. The plane of dissection was within the anterior third of the GMM in all hips. The average femoral length was 37.5 cm. Average distance between TM and MIB was 44 mm; in three hips, the distance was <30 mm. The average distance between TA and TM was 21 mm. There was no statistically significant correlation between femoral length and TM-MIB distance. CONCLUSION: The distance from the TM to the MIB is highly variable and independent from body height or femoral length. The so called "safe zone" in which damage of significant nerve damage is excluded can have a rather small dimension in some patients. Short patients are not at increased risk and tall patients are not risk free. Modern techniques in total hip replacement which try to minimize proximal interruption of the GMM are therefore justified.

Subthalamic glutamic acid decarboxylase gene therapy: changes in motor function and cortical metabolism.

Parkinson's disease (PD) is associated with increased excitatory activity within the subthalamic nucleus (STN). We sought to inhibit STN output in hemiparkinsonian macaques by transfection with adeno-associated virus (AAV) containing the gene for glutamic acid decarboxylase (GAD). In total, 13 macaques were rendered hemiparkinsonian by right intracarotid 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine injection. Seven animals were injected with AAV-GAD into the right STN, and six received an AAV gene for green fluorescent protein (GFP). Videotaped motor ratings were performed in a masked fashion on a weekly basis over a 55-week period. At 56 weeks, the animals were scanned with (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET). Histological examination was performed at the end of the study. No adverse events were observed after STN gene therapy. We found that the clinical rating scores for the two treatment groups had different patterns of change over time (group x time interaction, P<0.001). On FDG PET, the GAD animals exhibited an increase in glucose utilization in the right motor cortex relative to GFP controls (P<0.001). Metabolism in this region correlated with clinical ratings at end point (P<0.01). Histology confirmed GAD expression in treated animals. These findings suggest that STN AAV-GAD is well tolerated and potentially effective in a primate model of PD. The changes in motor cortical glucose utilization observed after gene therapy are consistent with the modulation of metabolic brain networks associated with this disorder.

Risk of superior gluteal nerve and gluteus medius muscle injury during femoral nail insertion.

BACKGROUND: Abduction weakness and limping is a well-recognized complication of closed antegrade insertion of femoral nails. Iatrogenic injuries to the superior gluteal nerve and the gluteus medius muscle are the most likely contributing factors. The purpose of this study of cadavers was to assess the risk of nerve and muscle injury with various lower-limb positions used during nail insertion. METHODS: We studied thirteen hips of ten formalin-fixed adult cadavers. With the cadaver in the full lateral position, a 9-mm reamer was introduced in a retrograde fashion from the intercondylar notch and passed through the gluteus medius muscle. The distance between the point of entry of the reamer into the undersurface of this muscle and the inferior main branch of the superior gluteal nerve (the nerve-reamer distance) and the distance between the entry and exit points of the reamer in the gluteus medius muscle (the intramuscle distance) were measured in three different hip positions: 15 degrees of flexion and 15 degrees of adduction (Position 1), 30 degrees of flexion and 30 degrees of adduction (Position 2), and 60 degrees of flexion and 30 degrees of adduction (Position 3). RESULTS: In Position 1, the average nerve-reamer distance was 7 mm and the average intramuscle distance was 24 mm. In three hips the reamer injured the nerve directly, and in two other hips the distance was

Chronic ischemic stroke model in cynomolgus monkeys: behavioral, neuroimaging and anatomical study.

Previous nonhuman primate stroke models have employed temporary occlusion of arteries, had limited behavioral testing and imaging, and focused on the short-term outcome. Our goals were 1. to develop a stable model of chronic stroke in the nonhuman primate, 2. to study in vivo the long-term biochemical changes in the area adjacent to the infarct, using proton magnetic resonance spectroscopy (H MRS), and 3. evaluate these changes in relation to the histopathological effects of stroke. Four adult cynomologous monkeys had an occlusion of the M1 segment of the right MCA. Behavioral tests included a clinical rating scale, motor planning task, fine motor task, and activity monitoring. Eight months afterwards, MRI and 1H MRS were performed. Following the imaging studies the monkeys were perfused transcardially, their brains extracted and processed. Nissl staining and immunohistochemistry for neuronal markers (NeuN) were performed and used to measure the lesion volume and neuronal optical density (OD). All animals developed a left hemiparesis and were unable to perform a fine motor task with the left hand. There was a significant (31%) decline in the motor planning ability with the nonparetic extremity. Monkeys displayed a stooped posture, episodes of rotation to the side of the lesion, partial left hemianopsia, and transient changes in activity. The clinical signs improved over the first 6-8 weeks but the deficits remained stable for the remaining six months of follow up. MRI demonstrated a subcortical and cortical infarction in the right MCA distribution. 1H MRS data detected a significant decrease in the N-acetyl-aspartate (NAA)/creatine (Cr) ratio in the area adjacent to the infarction (VOl-St) compared to a mirror area in the contralateral hemisphere (VOl-Co). Histopathological measurements revealed a significant decline in neuronal cross-sectional area and neuronal optical density in the region of the VOl-St. We established a stable and reproducible model of chronic stroke in the MCA distribution, in the macaque monkey. Our data indicate that NAA detected by 1H MRS can be used to measure neuronal loss in vivo and help target this area for intervention. Our model may be particularly suitable for studies testing the effects of therapeutic strategies involving neural or stem cell transplantation, trophic factors or gene therapy.

Drainage patterns of middle lobe vein of right lung: an anatomical study.

OBJECTIVE: The purpose of the present study was to determine the variations in the drainage patterns of middle lobe vein of the right lung. METHODS: Right lungs of 30 formalin fixed cadavers, were dissected carefully to expose the variations in the venous drainage of their middle lobes. After identifying the pulmonary veins for each lobe, middle lobe vein (MLV) drainage patterns were followed to their openings. The diameters of the MLV and its lateral and medial parts were measured with a caliper. The length of the MLV trunk was also evaluated. RESULTS: Five different types of venous drainage patterns were observed. Type-I: Union of medial and lateral parts to form MLV as a trunk and opening of this vein to the right superior pulmonary vein (RSPV) (53.3%). Type-II: Opening of medial and lateral parts to the RSPV separately (16.6%). Type-III: Union of medial and lateral parts to form the MLV trunk and opening of this vein into the left atrium (16.6%). Type-IV: Opening of medial and lateral parts into the left atrium separately (10%). Type-V: Union of medial and lateral parts to form MLV trunk and opening of this vein to the right inferior pulmonary vein (3.3%). CONCLUSION: The venous drainage patterns of right middle lobe reveals great number of variations. Knowing the frequency of different types of drainage patterns classified in this study is extremely important for the surgeons performing pulmonary surgery, atrial fibrillation and imaging techniques.

The significance of the neurovascular structures passing through the spinoglenoid notch.

OBJECTIVE: To define the detailed anatomy of the neurovascular bundle at the spinoglenoid notch and to report the dimensions of these structures in cadavers. METHODS: In the present study, the external diameters of suprascapular artery, vein and nerve were measured at the spinoglenoid notch region in 18 formalin fixed cadavers (36 shoulders) by using a caliper. The study was carried out in the dissection laboratory of Anatomy Departments of Hacettepe University, Ankara University, Ankara and Mersin University, Mersin, Turkey, between 2002 and 2003. RESULTS: The average external diameter for the suprascapular vein was 2.6 mm, artery was 2.2 mm and nerve was 2.2 mm. The spinoglenoid notch was roofed by the spinoglenoid ligament and appeared as a fibroosseous foramen in all cadavers. We found that the vascular structures (suprascapular artery and vein) occupied 68.5% and the suprascapular nerve occupied 31.5% of this foramen. CONCLUSION: Although the diameters of the vascular structures at the spinoglenoid notch measured by magnetic resonance imaging have been reported, to our knowledge, external diameters of these structures at the spinoglenoid notch have not been described in cadavers. We believe that detailed anatomy of suprascapular neurovascular bundle at the spinoglenoid notch should be appreciated for better understanding of risk factors possibly causing the suprascapular nerve entrapment syndrome, specially for those who are involved in violent overhead sports activities such as volleyball and baseball.

The significance of the neurovascular structures passing through the spinoglenoid notch.

OBJECTIVE: To define the detailed anatomy of the neurovascular bundle at the spinoglenoid notch and to report the dimensions of these structures in cadavers. METHODS: In the present study, the external diameters of suprascapular artery, vein and nerve were measured at the spinoglenoid notch region in 18 formalin fixed cadavers (36 shoulders) by using a caliper. The study was carried out in the dissection laboratory of Anatomy Departments of Hacettepe University, Ankara University, Ankara and Mersin University, Mersin, Turkey, between 2002 and 2003. RESULTS: The average external diameter for the suprascapular vein was 2.6 mm, artery was 2.2 mm and nerve was 2.2 mm. The spinoglenoid notch was roofed by the spinoglenoid ligament and appeared as a fibroosseous foramen in all cadavers. We found that the vascular structures (suprascapular artery and vein) occupied 68.5% and the suprascapular nerve occupied 31.5% of this foramen. CONCLUSION: Although the diameters of the vascular structures at the spinoglenoid notch measured by magnetic resonance imaging have been reported, to our knowledge, external diameters of these structures at the spinoglenoid notch have not been described in cadavers. We believe that detailed anatomy of suprascapular neurovascular bundle at the spinoglenoid notch should be appreciated for better understanding of risk factors possibly causing the suprascapular nerve entrapment syndrome, specially for those who are involved in violent overhead sports activities such as volleyball and baseball.

Vascular anatomy of the metatarsal bones and the interosseous muscles of the foot.

Utilization of the metatarsal bones and interosseous muscles in foot reconstruction should be based on the vascular anatomy of the metatarsal bones and interosseous muscles. We studied the vascular anatomy of the metatarsal bones and the interosseous muscles to design a split metacarpal musculoosseous flap and dorsal interosseous muscle flap. Twenty-two feet from eleven cadavers that had been embalmed in formalin were studied. Dissection was done using a dissection microscope (x3.5), delineating meticulously the arcuate artery, dorsal metatarsal arteries and the small branches arising from the metatarsal arteries. The dorsal metatarsal arteries do not course at the midline of the interosseous muscles. The first dorsal metatarsal artery proceeds close to the first metatarsal bone in the first metatarsal space. While proceeding to the distal, it shoots out a branch that individually feeds the lateral head of the first dorsal metatarsal muscle and medial face of the second metatarsus, thereby feeding muscle and bone. Except for this branch, the first dorsal metatarsal gives off segmental and periosteal branches that individually feed the medial heads of the first dorsal metatarsal muscle and first metatarsal bone. The second, third and fourth metatarsal arteries proceed close to the third, fourth and fifth metatarsal bones in the metatarsal spaces. In these courses, the arteries give out segmental branches to both faces of the interosseous muscles and periosteal branches to the medial face of metatarsal bones. For defects or disease of the ankle bones, the metatarsal bones can be split at the medial border distally, and a split metatarsal musculoosseous flap, based proximally on the dorsal metatarsal artery, can be done. Distal intermetatarsal anastomoses between the dorsal and plantar vascular networks enables a split metatarsal musculoosseous flap based distally, including the dorsal metatarsal artery for bony defects of the proximal phalanx.

Minimally invasive plating of the distal tibia: do we really sacrifice saphenous vein and nerve? A cadaver study.

OBJECTIVE: To investigate the risk of saphenous nerve (SN) and great saphenous vein (GSV) injury during percutaneous screw placement of the 3.5/4.5 LCP Distal Tibial Metaphyseal Plate and the 3.5-mm LCP Medial Distal Tibia Plate with tab in distal tibias of cadaver extremities. METHODS: Thirty-one unpaired (1 fresh and 30 formalin fixed) adult cadaveric lower extremity specimens were dissected. Using the principles of minimally invasive plating, a 3.5/4.5 LCP Distal Tibial Metaphyseal Plate was implanted in 16 extremities and a 3.5-mm LCP Medial Distal Tibia Plate with tab in the remaining 15 extremities. Injuries to or any evidences of direct contact with the SN or GSV were recorded. Additionally, the shortest distances of each hole to the main branches of these anatomic structures were measured. RESULTS: The risk of injury to the SN and GSV was higher in holes 4, 5, and 6 when using the 3.5/4.5 LCP Distal Tibial Metaphyseal Plate and in holes 3, 5, and 8 when using the 3.5-mm LCP Medial Distal Tibia Plate. CONCLUSIONS: The SN and GSV are at high risk for injury during percutaneous screw placement of the 3.5/4.5 LCP Distal Tibial Metaphyseal Plate and the 3.5-mm LCP Medial Distal Tibia Plate at the distal tibia. Careful dissection in the stab incisions down the plate, atraumatic placement of the drill sleeves, and protection of the soft tissues during screw insertion might decrease the risk of injury to the SN and GSV.

Morphologic assessment of the tendon graft donor sites: palmaris longus, plantaris, tensor fascia lata.

The purpose of this study is to compare and measure the tendon graft donor sites and to predict the sizes of these tendons preoperatively. Seventeen cadavers were included in the study. The morphologic evaluation of the palmaris longus (n = 29), plantaris (n = 32), and tensor fascia lata (n = 34) tendons were done. The length of the forearm, leg, and thigh and the width of the wrist, ankle, and knee joints were noted. The length, width, and the thickness of the tendons were measured. Degree of association between measurements was calculated by Pearson's correlation coefficient. We found statistically significant correlation between the length of the extremities and the length of the muscle tendons, and we formulated these correlations. The correlation between the length or width of the extremity and the tendon to be harvested could be designated as the ratios presented, and this could ease the preoperative planning at the craniofacial and other areas of surgery.

Innervation of three weight-bearing areas of the foot: an anatomic study and clinical implications.

The aim of this cadaver study is to improve our knowledge on the anatomy of the sensory fibres of the three weight-bearing areas of the plantar region. Previous studies mainly focused on the innervation of the heel but the innervation of the other two weight-bearing areas over the most medial and lateral metatarses have been neglected and are not well known. The study was carried out on 10 feet of five male cadavers. The tibial nerve was dissected down to the fat pads over the heel and the first and fifth metatarsal heads under the microscope. The distances of the branching point of the tibial nerve and origins of the medial and inferior calcaneal nerves to a line drawn from the centre of the medial malleolus to the centre of the calcaneous were all measured. The tibial nerve was divided into two branches called the lateral and medial plantar nerves 23.45 mm proximal to the predefined axis. The medial plantar nerve passed underneath the abductor hallucis muscle and gave two sensory branches to the fat pad over the first metatarsal head. The lateral plantar nerve coursed beneath the abductor hallucis and flexor digitorum brevis muscles and supplied innervation of the fat pad over the fifth metatarsal head. The sensory innervation of the heel was provided by medial calcaneal and inferior calcaneal nerves. The medial calcaneal nerve originated from the tibial nerve 41.89 mm proximal to the axis. It divided into two or three branches innervating the fat pad over the heel. The inferior calcaneal nerve originated from the lateral plantar nerve (70%) or the medial calcaneal nerve (30%) 10.66 mm proximal to the axis. This study describes the sensory fibres to the heel and the previously neglected weight-bearing areas over the first and fifth metatarses. Reconstruction of defects in these areas is very difficult so every attempt should be made to protect the sensory fibres during any surgical procedure.