Tibial nerve branching pattern and compatibility of branches for the deep fibular nerve.

PURPOSE: In individuals who develop drop foot due to nerve loss, several methods such as foot-leg orthosis, tendon transfer, and nerve grafting are used. Nerve transfer, on the other hand, has been explored in recent years. The purpose of this study was to look at the tibial nerve's branching pattern and the features of its branches in order to determine the suitability of the tibial nerve motor branches, particularly the plantaris muscle motor nerve, for deep fibular nerve transfer. METHODS: There were 36 fixed cadavers used. Tibial nerve motor branches were observed and measured, as were the lengths, distributions, and thicknesses of the common fibular nerve and its branches at the bifurcation region. RESULT: The motor branches of the tibial nerve that supply the soleus muscle, lateral head, and medial head of the gastrocnemius were studied, and three distinct forms of distribution were discovered. The motor branch of the gastrocnemius medial head was commonly observed as the first branch to divide, and it appeared as a single root. The nerve of the plantaris muscle was shown to be split from many origins. When the thickness and length of the motor branches measured were compared, the nerve of the soleus muscle was determined to be the most physically suited for neurotization. CONCLUSION: In today drop foot is very common. Traditional methods of treatment are insufficient. Nerve transfer is viewed as an application that can both improve patient outcomes and hasten the patient's return to society. The nerve of the soleus muscle was shown to be the best candidate for transfer in our investigation.

Patellar bone stock after extra-articular knee resection preserving extensor mechanism: A cadaveric study.

OBJECTIVE: This study aimed to evaluate the thickness of the remaining patellar bone stock following extra-articular knee resection (EKR) preserving the extensor mechanism in human cadaveric knee joints. METHODS: A total of 14 human cadaveric knee joints (8 men and 2 women) were dissected, and the patellar thickness from the joint capsule insertion to the anterior cortex of the patella was measured using an electronic caliper. The mean age of the cadavers was 37 years (range=28-50). Measurements were performed by an anatomist and an orthopedic surgeon. As the total number of the cadavers was not enough to show the patellar thickness with sampling (sex and age), we endeavored to supplement the content with magnetic resonance images (MRI). Accordingly, the patellar bone thickness was also measured on axial MRI scans of 100 adult and 25 pediatric knees of patients (71 women and 54 men; mean age=36 years; age range=7-67 years) admitted to our hospital in whom meniscal tears were suspected. The rate of specimens with remaining patellar thickness of less than 10 mm after presumed resection was evaluated. The macroscopic measurements in cadavers and MRI measurements in adult knees were compared statistically. RESULTS: The mean thickness of the residual patellar bone of the cadaver dissections following a presumed EKR preserving the extensor mechanism was 8.2 mm (range=3.4-15.8). Additionally, in 71.4% (10/14) of the cadaveric knees, the thickness of residual patellar bone was less than 10 mm. In MRI scans, the average thickness of residual patella after presumed resection was 8.6 mm (range: 3.6-16) in adult knees and 6.9 mm (range: 3.4-10) in pediatric knees, and the residual patellar thickness less than 10 mm after presumed resection was determined in 72% of all MRI scans. Macroscopic measurements in cadaveric knees were statistically similar to MRI scan measurements in adult knees (p=0.765, Mann-Whitney U test). CONCLUSION: Evidence from this study revealed that the thickness of the remaining patellar bone stock after EKR preserving the extensor mechanism may be low. A preoperative assessment with MRI can guide the surgeon to select the appropriate method for knee resection in order to prevent from the complications of resected patella.

The importance of costoclavicular space on possible compression of the subclavian artery in the thoracic outlet region: a radio-anatomical study.

OBJECTIVES: The purposes of this study were to identify possible compression points along the transit route of the subclavian artery and to provide a detailed anatomical analysis of areas that are involved in the surgical management of the thoracic outlet syndrome (TOS). The results of the current study are based on measurements from cadavers, computed tomography (CT) scans and dry adult first ribs. METHODS: The width and length of the interscalene space and the width of the costoclavicular passage were measured on 18 cervical dissections in 9 cadavers, on 50 dry first ribs and on CT angiography sections from 15 patients whose conditions were not related to TOS. RESULTS: The average width and length of the interscalene space in cadavers were 15.28 ± 1.94 mm and 15.98 ± 2.13 mm, respectively. The widths of the costoclavicular passage (12.42 ± 1.43 mm) were significantly narrower than the widths and lengths of the interscalene space in cadavers (P < 0.05). The average width and length of the interscalene space (groove for the subclavian artery) in 50 dry ribs were 15.53 ± 2.12 mm and 16.12 ± 1.95 mm, respectively. In CT images, the widths of the costoclavicular passage were also significantly narrower than those of the interscalene space (P < 0.05). The measurements from cadavers, dry first ribs and CT images were not significantly different (P > 0.05). CONCLUSIONS: Our results showed that the costoclavicular width was the narrowest space along the passage route of the subclavian artery. When considering the surgical decompression of the subclavian artery for TOS, this narrowest area should always be kept in mind. Since measurements from CT images and cadavers were significantly similar, CT measurements may be used to evaluate the thoracic outlet region in patients with TOS.

Tendon interposition and ligament reconstruction with ECRL tendon in the late stages of Kienböck's disease: a cadaver study.

BACKGROUND: The optimal surgical treatment for Kienböck's disease with stages IIIB and IV remains controversial. A cadaver study was carried out to evaluate the use of coiled extensor carpi radialis longus tendon for tendon interposition and a strip obtained from the same tendon for ligament reconstruction in the late stages of Kienböck's disease. METHODS: Coiled extensor carpi radialis longus tendon was used to fill the cavity of the excised lunate, and a strip obtained from this tendon was sutured onto itself after passing through the scaphoid and the triquetrum acting as a ligament to preserve proximal row integrity. Biomechanical tests were carried out in order to evaluate this new ligamentous reconstruction. RESULTS: It was biomechanically confirmed that the procedure was effective against axial compression and distributed the upcoming mechanical stress to the distal row. CONCLUSION: Extensor carpi radialis longus tendon has not been used for tendon interposition and ligament reconstruction in the treatment of this disease before. In view of the biomechanical data, the procedure seems to be effective for the stabilization of scaphoid and carpal bones.

Dorsal cutaneous innervation of the hand with respect to anatomical landmarks: is there a safe zone?

OBJECTIVES: In this study, we aimed to define the borders of the triangular area between the radial and dorsal nerves on the dorsum of the hand and to determine its dimensions using measurements between anatomic landmarks. MATERIALS AND METHODS: We statistically analyzed the relation between the distance from Lister's tubercle to the blending point of the central branches of radial and ulnar nerves and the distance between styloids on 14 hands of seven adult human cadavers (5 males, 2 females). The distances of nerve branches to vertical lines drown distally from both styloid processes were also compared with interstyloid distances to help in presuming the course of these nerves. RESULTS: No statistical constant correlation was determined between the measurements. Neither the height of the triangular area nor the courses of both nerves seemed to be quantitatively related to any measurements between the anatomical landmarks. CONCLUSION: Variability in these measurements in our study indicates that there is no surgical safe zone on the dorsum of the hand.

Treatment of hyperdynamic nasal tip ptosis in open rhinoplasty: using the anatomic relationship between the depressor septi nasi muscle and the dermocartilaginous ligament.

BACKGROUND: Smiling causes a deformity in some rhinoplasty patients that includes drooping of the nasal tip, elevation and shortening of the upper lip, and increased maxillary gingival show. The depressor septi muscle leads this deformity. The dermocartilaginous ligament originates from the fascia of the upper third of the nose and extends down to the medial crus, merging into the depressor septi muscle. METHODS: In this study, 100 primary rhinoplasty patients were studied for hyperdynamic nasal tip ptosis. Of these patients, 36 had hyperdynamic nasal tip ptosis due to hyperactive depressor septi nasi muscle. The dermocartilaginous ligament was used as a guide to reach the depressor septi muscle in open rhinoplasty. Muscle excision was performed just below the footplates of the medial crura. A strong columellar strut graft was placed between the medial crura to avoid narrowing of the columellar width resulting from tissue excision and to withstand activation of depressor septi muscle remnants. RESULTS: No complications such as infection or hematoma occurred in the early postoperative period. The technique corrected the hyperdynamic nasal tip ptosis, increased upper lip length, and decreased gingival show when patients smiled. There was no narrowing of the columellar width. No depression in the columellar-labial junction due to distal resection of the depressor septi muscle was observed. CONCLUSION: The dermocartilaginous ligament can be used as a reliable guide to reach the depressor septi muscle in open rhinoplasty. Therefore, the hyperactive depressor septi muscle can be definitively identified and treated without an intraoral approach. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors at www.springer.com/00266.

Anatomic relationship between the anterior sylvian point and the pars triangularis.

The aim of this study was to show morphological sulcal variations of the pars triangularis of the inferior frontal gyrus and to provide a clearer description of the anterior sylvian point. Thirty-six hemispheres of 18 adult cadavers were studied. The hemispheres were harvested by the classical autopsy method and fixed in 10% formalin solution for three weeks. In six hemispheres, the arteries and veins were filled with colored silicone. The proximal and distal segments of the sylvian fissure, the perpendicular distance of both the anterior sylvian point and inferior rolandic point to the insular cortex and the distances between the anterior ascending ramus and the precentral, central, and postcentral sulcus were measured. The anterior horizontal and ascending rami were exposed. The sulcus located on the pars triangularis was appraised. The relationship between the anterior sylvian point and the vascular structure around the sylvian fissure was examined. The rising of the anterior horizontal and ascending ramus from the sylvian fissure defines the shape of the pars triangularis. The pars triangularis has three shapes: V, U, and Y. In V- and Y-shaped pars triangularis both rami merge but in U-shaped pars triangularis the rami do not merge. The pars triangularis was Y-shaped in 30.76% (4/13) of the right hemispheres and in 50% (7/14) of the left hemispheres; U-shaped in 20.3% (3/13) of the right hemispheres and in 35.71% (5/14) of the left hemispheres; V-shaped in 40.61% (6/13) of the right hemispheres and in 14.29% (2/14) of the left hemispheres. Minimally invasive procedures use basic anatomic landmarks intracranially to reach the targeted area; therefore, exact and detailed knowledge of the anatomy of the sylvian fissure and pars triangularis is of great importance.

Avoiding iatrogenic radial nerve injury during humeral fracture surgery: a modified approach to the distal humerus.

OBJECTIVE: Our aim was to assess the results of posterior retraction technique to prevent iatrogenic radial nerve injury during humeral fracture surgery. METHODS: Seventy-two patients who underwent surgery for a distal humerus fracture between 1996 and 2002 were reviewed. These 72 patients comprised Group 1. Following a cadaveric study on the vascularization of the radial nerve, a modified surgical approach was undertaken starting in 2002. Sixty-one patients who underwent this new surgical approach were included in Group 2. The rates of radial nerve deficit of the groups were compared using the Pearson chi-square test. RESULTS: In Group 1, 19 iatrogenic nerve deficits occurred. After defining the blood circulation of the nerve, the lateral approach was modified. The anterolateral side of the nerve was released and the nerve was left attached to the triceps muscle. In Group 2, one patient developed postoperative transient nerve deficit. CONCLUSION: The radial nerve is supplied by the branches of the deep brachial artery in close relation with the triceps muscle. Anterior dissection and posterior retraction of the radial nerve during lateral approach may preserve its blood supply and reduces the risk of iatrogenic injury.

Percutaneous ilioinguinal-iliohypogastric nerve block or step-by-step local infiltration anesthesia for inguinal hernia repair: what cadaveric dissection says?

PURPOSE: The repair of groin hernias with local anesthesia has gained popularity. Two main methods have been described for local anesthesia. This study was aimed at comparing percutaneous truncular ilioinguinal-iliohypogastric block and step-by-step infiltration technique by using cadaver dissections. METHODS: The study was performed on an adult male cadaver by using blue dye injection. A percutaneous nerve block simulation was done on right side and the dye was given in between the internal oblique and transversus muscles. On the left side, a skin incision was deepened and the dye was injected under the external oblique aponeurosis. Following the injections, stained areas were investigated superficially and within the deeper tissues with dissection. RESULTS: There was a complete superficial staining covering the iliohypogastric and ilioinguinal nerves in the inguinal floor at both sides. On the right side, intraabdominal observation showed a wide and intense peritoneal staining, while almost no staining was seen on the left side. Preperitoneal dissection displayed a massive staining including testicular vascular pedicule and vas deferens on the right side. The dye solution also infiltrated the area of the femoral nerve prominently. On the contrary, a very limited staining was seen on the left. CONCLUSION: It may not always be easy to keep the percutaneous block within optimum anatomical limits without causing adverse events. A step-by-step infiltration technique under direct surgical vision seems to be safer than percutaneous inguinal block for patients undergoing inguinal hernia repair.

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.

A neurosurgical view of anatomical evaluation of anterior C1-C2 for safer transoral odontoidectomy.

An anatomical study for evaluation of anterior C1-C2. To provide essential anatomic data for safer transoral odontoidectomy. The surface dimensions of the atlas vertebra and the transoral approach for odontoidectomy have been described in detail. Anterior arcus of C1 must be drilled out to reach odontoid process for transoral odontoidectomy. The thickness of anterior ring of C1 has not been studied before. Sixty, dried adult atlas and 60 axis vertebrae and ten cadaveric craniocervical specimens were measured for the following: (1) bony drilling depth (BDD), the distance from the anterior wall of anterior ring of C1 to anterior wall of odontoid; (2) minimum drilling diameter (MDD), distance of minimum C1 anterior ring removal for odontoid resection on horizontal plane; (3) maximum bony drilling diameter (MBDD), distance of maximum C1 anterior ring removal for odontoid resection on horizontal plane. Lateral border of this diameter is limited by medial borders of the lateral mass; (4) the widest odontoid diameters (WOD) on coronal sections were measured. On 60 atlas and axis vertebrae, the BDD was 7.0 +/- 1.2 mm on dry bones, the distance between the medial borders of the lateral mass (MBDD) was 16.1 +/- 1.5 mm, and the WOD on coronal sections (WOD) was 9.8 +/- 0.8 mm. On cadavers, the distance between the two edges of C1 anterior ring removal for odontoid resection (MDD) was 10.8 +/- 1.1 mm and the WOD on coronal sections (WOD) was 10.1 +/- 1.4 mm. An odontoid surgery through transoral approach is safe and feasible. A quantitative understanding of the anterior anatomy of C-1 and C-2 is necessary when considering transoral odontoid resection. In this study the authors define safe zones for anterior atlas and axis.

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.

A new technique for subscapularis muscle needle insertion.

OBJECTIVE: To investigate a new technique for needle insertion into the subscapularis muscle for botulinum toxin injection, nerve block with phenol, and electromyography. DESIGN: A new technique, which we have termed the inferior approach, was delineated by cadaver study. In the first step of the study, the thickest part of the subscapularis muscle and the route for the accurate course of the needle were determined by an anatomist on eight cadavers (16 sides). In the second step, using this technique, a physician attempted to inject India ink into the thickest part of the muscle on a separate 12 cadavers (24 sides). The anatomist then examined the accumulated ink by careful dissection of the involved muscle. RESULTS: The thickest part was determined to be at the lateral half of the muscle. With the exception of two muscles, all the cadavers were successfully injected using the defined route. If the route and injection sites are correct, there is no risk of injecting any muscle in that anatomic region other than the subscapularis. Furthermore, there were no neurovascular structures identified at risk in the area using the inferior approach. CONCLUSION: This new technique, termed the inferior approach, is both easy and anatomically safe: it did not involve any risk of damage to any major artery, vein, or nerve.

Medial and lateral malleolar arteries in ankle arthroscopy: a cadaver study.

Neurovascular injury may occur during ankle arthroscopy. The majority of complications are neurological injuries; however, vascular injuries do exist. Neurovascular structures are especially vulnerable during portal placement and debridement of anterior structures. Routine anteromedial and anterolateral portals are generally accepted to be safe; this is different from the anterocentral portal, which is associated with a higher risk of injury. However, injuries may occur in these relatively safe portals. The purpose of this cadaver study was to examine other relatively minor neurovascular structures such as medial and lateral malleolar arteries and to determine how these portals can be more safely placed. The distance between standard anteromedial, anterolateral portals and the medial and lateral malleolar arteries was measured in 18 ankles from 9 cadavers. These distances varied with the position of the ankle during portals placement, and measurements were obtained in both flexion and extension. The average distance in flexion and extension was 6.41 to 2.47 mm on the lateral side and 4.73 to 1.58 mm on the medial side. The distances significantly increased with ankle flexion and decreased with extension (P < .005). The current study demonstrated that there were other minor vascular structures at risk other than tibialis anterior artery and proper positioning of the ankle during portal placement, and that injury risk may be associated with ankle position. Ankle flexion may decrease the risk of damage to malleolar arteries and decrease minor vascular complications such as postoperative bleeding and hematoma.

A neurosurgical view of anatomical variations of the distal anterior cerebral artery: an anatomical study.

OBJECT: The vascularization pattern of the anatomy of the distal anterior cerebral artery (ACA) remains a subject of debate. The authors provide detailed information about the distal ACA and shed light on issues concerning it that have not previously been adequately discussed. METHODS: Fifty adult human brains (100 hemispheres) were obtained during routine autopsies. Cerebral arteries were separately cannulated and injected with latex. The vascularization patterns of the cortical branches and the variations of the arteries were investigated. The authors found that the distal ACA supplied all the inner surfaces of the frontal and parietal lobes and a median of one third of the outer surfaces. The origin of the arteries from the main trunk and their exit angles affected the vascularization patterns of the hemispheres. The authors redefine controversial terminology regarding the callosomarginal artery. CONCLUSIONS: In each hemisphere, the vascularization pattern of the distal ACA is different to a greater or lesser extent. An awareness of this fact will contribute significantly to surgical interventions.