Palpable Bony Landmarks Research Articles

A direct saphenous nerve block in TKA: A surgeon friendly technique! Cadaveric study

IntroductionEffective management of postoperative pain in total knee arthroplasty (TKA) poses a significant challenge for surgeons. Achieving rapid recovery without pain and promoting early ambulation in immediate and early postoperative periods are essential for patient satisfaction. There are many pain management protocols including nerve blocks. Nerve blocks procedures were done using USG and anaesthetist dependent. This cadaveric study aimed to define the VMO (Vastus medialis obliquus) triangle to target the ‘safe zone’ of the saphenous nerve during TKA: A surgeon's friendly technique. Methods12 formalin-fixed embalmed cadaveric lower limbs were dissected to explore anatomy, trajectory, the relation of saphenous nerve and measured the distances from the nearby palpable bony landmarks. ResultsThe average distance to target the saphenous nerve i.e target point from midpoint of superior pole of the patella was 10.6cm, the average angle to target the saphenous nerve is the angle between the line joining the medial epicondyle to the midpoint of the superior pole of the patella is found to be 64.2°. The average distance from midpoint of superior pole patella to medial epicondyle is found to be 8.1cm. Therefore, triangle so formed using these three points (1. Medial epicondyle, 2. The midpoint of superior pole of the patella, 3. Target point of the saphenous nerve) is called a VMO triangle. ConclusionsThe saphenous nerve course, relations, and the distances from intraoperative bony landmarks for the VMO triangle during TKA which is a reproducible triangle so may be useful for arthroplasty surgeons to achieve successful saphenous nerve block and to avoid related complications during total knee arthroplasty (TKA).

Superior Gluteal Nerve Anatomy and Its Injuries: Aiming for a More Secure Surgical Approach of the Pelvic Region.

Because most of the recognized causes of superior gluteal nerve (SGN) injury are iatrogenic, detailed knowledge of the anatomy of the SGN is crucial to prevent its injury associated with surgical procedures. This study aims to describe the precise location of SGN or its branches at the greater sciatic foramen, measure the distances of these neural structures to palpable bony landmarks, and evaluate the possible correlation between these parameters and pelvis size. Twenty human cadaveric hemipelvises were studied. After dissection to expose the SGN or its branches at the greater sciatic foramen, the distances from these neural structures to the greater trochanter (GT), to the anterior superior iliac spine (ASIS), to the posterior superior iliac spine (PSIS), to the ischial tuberosity (IT), and to the greater sciatic notch apex were measured. We found that at the greater sciatic foramen, the SGN emerges as a common trunk in 75% of hemipelvises, and already divided in its superior and inferior branches in 25% of hemipelvises. When the SGN exits the pelvis as a common trunk, it does so, in most cases, in contact with the bone at the apex of the greater sciatic notch or superior to the level of the apex. The median distance from the SGN at the greater sciatic notch to the PSIS, ASIS, GT and IT is 7.6 cm, 10.9 cm, 7.5 cm and 10.8 cm, respectively. We found a positive correlation between some of the analyzed parameters and the size of the pelvis. The anatomical data of this study may serve as pivotal guides during orthopedic pelvic surgery, contributing to minimize SNG iatrogenic lesions with significant implications in the patient's quality of life.

Frequency Morphologic and Morphometric Properties and Osseous Relationships of Whitnall's Tubercle.

Whitnall tubercle (WT) of the zygomatic bone is used as an anatomical landmark in some surgical approaches to the orbit. The authors aimed to determine the localization of WT by using some palpable bony landmarks and to reveal its morphological and morphometric features. Three hundred twenty-two zygomatic bones (167 right and 155 left) belonging to adults of unknown sex, were examined. An acetate prepared by drawing a clock with a dial on it was used to determine the localization of WT according to marginal tubercle and zygomatic arch. Distances between WT and frontozygomatic suture and lateral margin of the orbital rim were measured with digital calipers. One zygomatic bone had double tubercles, thus 321 bones were taken into consideration. Whitnall tubercle was determined in 284 of 321 zygomatic bones. 181 were classified as small, 10 as medium, and 93 as large. The position of the WT according to the marginal tubercle was at the 8, 9, and 10 o'clock positions on the left, and at 2, 3, and 4 o'clock on the right. The position of the WT according to the zygomatic arch was at the 9,10 and 11 o'clock positions on the left, and at the 1 and 2 o'clock positions on the right. Distances between the WT and lateral margin of the orbital rim and the frontozygomatic suture were measured meanly as 1.94±0.31 mm and 8.17±5.82 mm, respectively. The authors believe that the data obtained regarding WT will contribute to anatomy and surgical procedures of the related region.

Anatomical landmarks for peripheral neural blocks of the forearm and the wrist: A cadaveric study

There are no data ensuring a standardized landmark-based-technique for blocking sensitive nerves of the forearm. To identify locations were with use of good palpable bony landmarks and lines between them sensitive nerve blocks on the forearm can be done with great success. Dissection of the superficial branch of the radial nerve (SBRN), the dorsal branch of the ulnar nerve (DBUN), the lateral, medial and dorsal antebrachial cutaneous nerve (LACN, MACN, and DACN) as well as the palmar branch of the median nerve (PBMN) was performed on five upper limbs of five different Caucasian cadavers. With respect to radius and ulnar styloid, Lister's tubercle, and the medial and lateral epicondyle of the humerus as well as connecting lines between these bony landmarks locations were defined, where the mentioned nerves can be found and blocked. The six nerves can be safely blocked at the following sites: the SBRN 85 mm proximal to Lister's tubercle on a line drawn between the latter and the medial humeral epicondyle; the LACN 38 mm and the dorsal one 32 mm ulnar from the lateral epicondyle; the MACN 14 mm radial to the medial epicondyle; the DBUN 27 mm proximal to the ulnar styloid in direction to the lateral epicondyle; the PBMN 45 mm proximal to the radial styloid following a line between the latter and the medial epicondyle and 21 mm ulnarwards perpendicular to this line. Using superficial good palpable landmarks at the wrist and elbow as well as connecting lines between them the SBRN, DBUN, PBMN, LACN, MACN, and DACN can easily be located.

Morphology of saphenous nerve in cadavers: a guide to saphenous block and surgical interventions.

The knowledge about detailed morphology and relation of saphenous nerve is important to obtain successful saphenous nerve regional blocks to achieve pre- and post-operative anesthesia and analgesia, nerve entrapment treatments and to avoid damage of saphenous nerve during knee and ankle surgeries. The literature describing detailed morphology of saphenous nerve is very limited. We dissected 42 formalin fixed well embalmed cadaveric lower limbs to explore detailed anatomy, relation and mode of termination of saphenous nerve and measured the distances from the nearby palpable bony landmarks. The average distance of origin of saphenous nerve from inguinal crease was 7.89±1.42 cm, the distance from upper end of medial border of patella to saphenous nerve at that level was 8.11±0.85 cm, distance from tibial tuberosity was 7.53±0.98 cm and from midpoint of anterior border of medial malleolus was 0.45±0.14 cm. Saphenous nerve provided two infrapatellar branches at the level of mid to lower limit of patellar ligament in 90% cases. It was in close contact or adhered to great saphenous vein across the lower 2/3rd of leg lying either anterior, posterior or deep to the vein. The saphenous nerve terminated by bifurcating proximal to medial malleolus in majority of cases though no obvious bifurcation was observed in 9.52% cases. The detailed morphology, relations and the distances from palpable bony landmarks may be helpful for clinicians to achieve successful saphenous nerve block and to avoid saphenous nerve damage and related complications during orthopedic procedures.

Topographic anatomy of the neurovascular bundle at the tarsal tunnel and its applied significance

BACKGROUND: There are different surgical procedures and treatment modalities dealing with medial ankle region such as placement of percutaneous pins in the calcaneus, decompression in tarsal tunnel syndrome, and nerve block. This requires detailed anatomical knowledge about the neurovascular bundle to avoid iatrogenic injury. AIM OF THE WORK: To study the topography of nerves and vessels at the tarsal tunnel in relation to surface anatomical landmarks. MATERIALS AND METHODS: The medial calcaneal region of 20 lower limbs of formalin preserved specimens was dissected. The neurovascular structures were identified within a quadrangle named ABCD, formed by four palpable bony landmarks, respectively: inferior tip of medial malleolus, posterior superior tip of calcaneal tuberosity, posteroinferior aspect of medial calcaneus, and tuberosity of navicular bone. A regression analysis was done to correlate the lengths of the four imaginary lines connecting the four bony landmarks with the location of the neurovascular structures. RESULTS: The posterior tibial artery was located medial to the tibial nerve in 50% of cases. The bifurcation of the artery was found to be proximal to that of the nerve in only one case. The number of the medial calcaneal nerves (MCNs) varied from 1 to 3 branches; the most common was one branch (50%). In two cases, there was high origin of the MCN at a distance of 15.4 and 23.5 cm proximal to the ankle region. CONCLUSION: The location of the neurovascular bundle at the tarsal tunnel could be predicted by measuring the distances between the anatomical bony landmarks.

Monoaxial external fixation of the calcaneus: An anatomical study assessing the safety of monoaxial pin insertion

The use of external fixation for intra-articular calcaneal fractures is increasing in popularity. Studies have shown fine wire and monoaxial external fixation to be a viable surgical alternative to more invasive methods of open reduction and internal fixation of the calcaneus. However, there is an absence of literature that quantifies the risk of pin insertion for monoaxial fixation.This study aimed to determine the safety of inserting monoaxial pins within the calcaneus to house the Orthofix Calcaneal Mini-Fixator. Five formalin embalmed cadaveric ankle and lower leg specimens were inserted with six monoaxial pins. Careful dissection then revealed the presence of the tendons of peroneus longus and brevis, the sural nerve and the small saphenous vein in relation to these pins. Measurements from each pin to each of these structures were made as the structures transected lines drawn from each pin to two palpable bony landmarks: the inferior tip of the lateral malleolus and the posterosuperior calcaneus. In doing this, the risk posed by each pin could be evaluated. We found that two particular pins, those used to hold the articular surface of the subtalar joint in a reduced position, posed a larger risk of injury to surrounding structures than the remaining pins. These findings therefore suggest that monoaxial fixation of the calcaneus using a six pin approach is a relatively safe method of rectifying calcaneal fractures and thus may serve as a welcome alternative to other methods of calcaneal fixation.

Perforating arteries of the thigh: An anatomical and radiological study.

We aimed to advance the understanding of the anatomy of the perforating branches of the profunda femoris artery to facilitate the avoidance of iatrogenic injury in surgery around the thigh and ensure safe percutaneous embolisation. Dissection was carried out on seven cadavers, examining the relationship of the point of origin of the perforating branches of profunda femoris, relative to lines connecting palpable bony landmarks (lines A and B). These were compared with 16 computed tomography angiograms (CTA). Left to right variation within subjects and variation between the dissection and imaged group was examined. The anatomy of the two groups was then compared with that described in anatomical textbooks. The side to side variation in number of perforators was not significant in the dissection (P = 0.20) nor the CT group (P = 0.70). Similarly, the point of origin of the perforating vessels along lines A and B did not demonstrate any significant difference except for the fourth perforator along line B (P = 0.03). There was no significant difference in points of origin along line B between the dissection and CT groups for the first four perforators on the left (P = 0.51, P = 0.80, P = 0.66, P = 0.09 respectively) and right (P = 0.79, P = 0.45, P = 0.56, P = 0.11 respectively). The number and distribution of perforators were then compared with commonly used anatomical texts. As in other parts of the body, textbook descriptions of anatomical structures may not be reflected consistently in vivo. However, the perforating branches of the profunda femoris demonstrate a predictable topographical relationship to palpable bony landmarks.

Sphenopalatine foramen: endoscopic approach with bony landmarks.

To establish whether nasal bony landmarks on computed tomography could be utilised reliably in endoscopic approaches to the sphenopalatine foramen. A prospective analysis of 102 consecutive helical computed tomography scans of the paranasal sinuses was carried out by 2 senior ENT surgeons. Distances from the sphenopalatine foramen to endoscopically palpable bony landmarks were measured. There were a total of 102 patients (45 females and 57 males), with a mean age of 62 years. The mean distance from the posterior fontanelle to the sphenopalatine foramen was 14.1 mm (standard deviation = 2.13). The average vertical distance of the sphenopalatine foramen opening from the bony attachment of the inferior turbinate was 14.13 mm. There were no statistically significant differences between any of these measurements (foramen width p-value = 0.714, distance from fontanelle p-value = 0.43 and distance from inferior turbinate p-value = 0.48). Determination of reliable bony landmarks is clinically useful in endoscopic surgery and can aid identification of the sphenopalatine foramen. The inferior turbinate concha and posterior fontanelle may be used as reliable computed tomography landmarks for endoscopic approaches to the sphenopalatine foramen.

Transformation methods for estimation of subject-specific scapular muscle attachment sites

The parameters that describe the soft tissue structures are among the most important anatomical parameters for subject-specific biomechanical modelling. In this paper, we study one of the soft tissue parameters, namely muscle attachment sites. Two new methods are proposed for transformation of the muscle attachment sites of any reference scapula to any destination scapula based on four palpable bony landmarks. The proposed methods as well as one previously proposed method have been applied for transformation of muscle attachment sites of one reference scapula to seven other scapulae. The transformation errors are compared among the three methods. Both proposed methods yield significantly less (p < 0.05) prediction error as compared to the currently available method. Furthermore, we investigate whether there exists a reference scapula that performs significantly better than other scapulae when used for transformation of muscle attachment sites. Seven different scapulae were used as reference scapula and their resulting transformation errors were compared with each other. In the considered statistical population, no such a thing as an ideal scapula was found. There was, however, one outlier scapula that performed significantly worse than the other scapulae when used as a reference. The effect of perturbations in both muscle attachment sites and other muscle properties is studied by comparing muscle force predictions of a musculoskeletal model between perturbed and non-perturbed versions of the model. It is found that 10 mm variations in muscle attachments have more significant effect on muscle force predictions than 10% variations in any of the other four analysed muscle properties.

Predicting the lumbosacral joint centre location from palpable anatomical landmarks

The kinematics of the lumbar spine have previously been described by considering the bearing of the pelvis and lower back. However earlier studies have not described an intersegmental angle measured about a single point; which is necessary for investigation into movement, posture and balance, and lower back pain and injury. This study used computed tomography (CT) scans of 16 pelves to determine the location of palpable bony landmarks, and the junction of the fifth lumbar and first sacral vertebrae within a pelvis axis system. Data were used to derive equations which express the three-dimensional location of the lumbosacral joint centre as an offset from palpable surface landmarks. The magnitude of X, Y, Z offsets was controlled using individual pelvic geometry, and robustness and repeatability of the method was assessed. Regression equations provided the location of the lumbosacral junction to within 8.2mm (+/- 3.4mm) of its true coordinate. Leave-one-out analyses calculated equation coefficients using 15 of the original pelves, with the 16th acting as a control; average errors increased by 6.7 per cent (+/- 0.1 percent). To the authors' knowledge the current method is the most accurate non-invasive means of locating the lumbosacral junction and may be useful for constructing biomechanical models.

The Anatomy of the Supraclavicular Nerve During Surgical Approach to the Clavicular Shaft

BackgroundSurgery for clavicular shaft fractures is becoming more common but incisional and chest wall numbness reportedly occurs in 10% to 29% of patients. This may be the result of iatrogenic injury to the supraclavicular nerve branches.Questions/purposesWe determined if there was a predictable branching pattern of the supraclavicular nerve at the anterior clavicular border and determined the distances to these nerves from clavicular landmarks.MethodsWe performed an anatomic dissection along the anterior border of the long axis of the clavicle in 37 cadavers. The branches of the supraclavicular nerve were identified at the anterosuperior clavicular border and the distances from these nerves to palpable bony landmarks were measured.ResultsNinety-seven percent of specimens had a medial and a lateral branch of the supraclavicular nerve. Nearly half (49%) possessed an additional intermediate branch. No branch was found within 2.7 cm of the sternoclavicular joint or within 1.9 cm of the acromioclavicular joint. Between these two positions, there was wide variability in nerve branch location.ConclusionsThere were two or three branches of the supraclavicular nerve crossing the clavicle 97% of the time and a wide variability of the location of these branches outside the safe zones.Clinical RelevanceThere are safe zones within 2.7 cm of the sternoclavicular joint and 1.9 cm of the acromioclavicular joint. Between these safe zones, the location of the nerve branches is variable and the surgeon must use meticulous dissection if he or she wishes to prevent transection.

Abstract No. 370 EE: An Approach to Routine Bone Marrow Aspiration and Biopsy (BMAB) by the Interventional Radiologist

Bone Marrow aspiration and biopsy is a painful procedure traditionally performed at bedside by hematologist-oncologists. Needle placement is accomplished solely using palpable bony landmarks, and is thus dependent on patient body habitus. Marrow aspiration will typically cause intense pain. Herein we report a step-by-step image guided approach using IR techniques to both reliably obtain adequate specimens and minimize patient pain. For these reasons we have been asked to perform fluoroscopic guided BMAB, with sedation, in over one hundred patients.

Computed Tomographic Diagnosis of Nongastrointestinal Foreign Bodies in Dogs

Clinical data and computed tomography (CT) studies were reviewed for 13 dogs with confirmed nongastrointestinal foreign bodies. Locations of foreign bodies were the nasal cavity, thoracic wall, retropharyngeal region, and cerebellum. Types of foreign bodies included small plant components, blades of grass, wooden sticks, cloth fibers, and a needle. Foreign bodies in five dogs were not identified on CT, and secondary reactions resembled neoplastic or fungal disease. In eight dogs, foreign bodies were recognized by their shape and/or internal architecture. In two dogs, three-dimensional reformatting helped demonstrate foreign bodies in relation to palpable bony landmarks.

Sonoanatomy Of The Ulnar Nerve In The Distal Forearm

Sonoanatomy Of The Ulnar Nerve In The Distal Forearm

Die Bestimmbarkeit des Hüftrotationszentrums anhand palpabler Landmarken des Beckens

The object of this study was to develop a new method to predict the location of the centre of rotation of the hip joint reasonably accurately. We collected the coordinates of palpable bony landmarks in 50 patients, 25 males and 25 females, using CT scans to predict the physiological location of the centre of the hip joint centre. The centre of the hip was located, on average, at 12% (+/- 2.9) of the inter-ASIS (anterior superior iliac spine) distance medial, 33% (+/- 3.9) distal and 19% (+/- 2.7) posterior to the anterior superior iliac spine (ASIS). Knowledge of the physiological centre of rotation of the hip may be useful in navigation of the cup in total hip arthroplasty.

Hip joint center location from palpable bony landmarks—A cadaver study

An anatomical anthropometric study of adult human cadaveric pelves was performed to investigate the relationship between hip joint center (HJC) and selected aspects of pelvic geometry. Sixty-five pelves (35 female and 30 male) were examined. Measurements of pelvic geometry and HJC (center of bony acetabular rim) were taken from bony landmarks of de-fleshed pelves. Correlation analysis revealed that HJC cannot be accurately located as a function of pelvic width alone, but requires estimation as a function of pelvic height and depth as well. HJC was optimally located relative to the respective ASIS: 14% of pelvic width medial (mean error 0.58 cm), 34% of pelvic depth posterior (mean error 0.30 cm), and 79% of pelvic height inferior (mean error 0.35 cm). No significant differences were found between males and females in HJC estimation.