Evaluation of lumbar lordosis in symptomatic individuals and comparative analysis of six different techniques: a retrospective radiologic study.

PURPOSE: The aim of this study; evaluate lumbar lordosis (LL) in symptomatic individuals with six different techniques and to examine the techniques comparatively. Thus, to provide an overview of lumbal lordosis and techniques. METHODS: Cobb L1-L5, Cobb L1-S1, Posterior Tangent, tangential radiologic assessment of lumbar lordosis (TRALL), vertebral centroid measurement of lumbar lordosis (CLL) and Risser Ferguson measurement techniques were used to assess LL from radiographs of 175 symptomatic adults. Correlations between techniques and relationship between the measurements obtained, gender and age were analyzed. Also interclass correlation (ICC) analyzed. Bland-Altman plots were performed to compare the techniques with Cobb. RESULTS: ICC for all methods were greater than 0.96. For each method, no difference in LL was observed with respect to gender or age (p > 0.05). High positive correlation was observed between the Risser Ferguson, Posterior Tangent, Cobb L1-L5, Cobb L1-S1 and CLL techniques (p < 0.001), and moderate positive correlation between TRALL and all other techniques (p < 0.001). CONCLUSION: In this study, it was found that the mean lumbar lordosis values of symptomatic participants were lower than most of the other asymptomatic studies in the literature and there was no significant difference in lumbar lordosis values in terms of gender and age in symptomatic individuals. Based on statistical findings, Risser Ferguson can be used to assess LL. These results and the data obtained as a result of the comparative examination of techniques according to age groups and gender will benefit clinicians and those working in the field by providing a better understanding LL.

Morphometric analysis of the infratemporal fossa using three-dimensional (3D) digital models.

PURPOSE: The infratemporal fossa contains important neurovascular components and is directly related to other anatomical regions and structures. The morphometric distances between the bones forming its borders have not been thoroughly investigated. The aim of this study was to determine the morphometry of the infratemporal fossa. METHODS: 3D models of the skull of 83 individuals were reconstructed from DICOM datasets, from which length, depth and width measurements were determined and compared between genders and the right and left sides. RESULTS: All measurements obtained were significantly different between males and females. There were also significant differences between the left and right sides for depth and width measurements. CONCLUSION: This is the first study to determine and investigate measurements of the infratemporal fossa; as such it provides a comprehensive view of the morphology of the fossa. It provides valuable information for surgical interventions and differential diagnoses of pathologies in this region, as well as enhancing its understanding in medical education.

The association between coracoacromial ligament morphology and rotator cuff tears: A cadaveric study.

To determine the association between coracoacromial ligament (CAL) morphology and rotator cuff tears. The present study is a prospective cohort study based on the dissection of 172 shoulders from 86 (46 female, 40 male) formalin embalmed European Caucasian cadavers, with a median age of 82 years. The anatomy of CAL was examined, including its morphology and parametric measurements, while the rotator cuff tendons were inspected for the presence of tears. Gross examination of the CAL in 155 shoulders revealed a variable number of bands as follows: 28 (18%) had one band, 56 (36%) two bands and 71 (46%) three or more bands. Inspection of the rotator cuff tendons showed the presence of tears in 77 (50%) shoulders, of which 37 (24%) were partial and 40 (26%) were full-thickness tears. Statistical analysis showed a significant association (P < 0.05) between CAL band number and the prevalence of a rotator cuff tear. A high proportion of rotator cuff tears were observed in shoulders with two (52%) and three or more CAL bands (56%) compared to single band ligaments (29%). Parametric assessment of the CAL in shoulders with rotator cuff tears showed significantly greater (P < 0.05) attachment widths and ratios, thicker ligament bands, and larger cross-sectional areas compared to the control group. Coracoacromial ligaments with more than a single band have a strong association with rotator cuff tears.

The glenoid and humeral head in shoulder osteoarthritis: A comprehensive review.

The key management of glenohumeral osteoarthritis is shoulder arthroplasty which aims to reduce pain and restore full shoulder function: it has increased in recent years. A detailed understanding of the anatomy of the glenoid and humeral head, as well as morphological changes of the glenoid in osteoarthritis, are important factors to consider when deciding on replacement components. This review begins with a brief introduction of the glenohumeral joint itself, and then considers the detailed anatomy of the glenoid fossa and humeral head, both of which are reported to have variable morphology. Several studies have been undertaken to assess various parameters, especially of the glenoid fossa including its shape, height, width, and articular surface area, version and inclination, in an attempt to define a standard classification that can be applied to surgical intervention. Nevertheless, no definitive consensus concerning the classification of these morphologies has been forthcoming, hence the need for this review. Following a consideration of these morphologies, the current state of knowledge regarding glenoid deformity in osteoarthritis, as well as its surgical management, is considered.

Thiel embalming: Quantifying histological changes in skeletal muscle and tendon and investigating the role of boric acid.

Cadaver preservation methods impact their utilization in anatomical research and teaching. Thiel-embalmed cadavers show flexibility, however, the cause remains poorly understood. This study aimed to (1) describe qualitative and quantitative histological differences between Thiel-embalmed and formalin-fixed skeletal muscle and tendon tissue; (2) investigate whether boric acid in Thiel solution is solely responsible for modification of tissues; and (3) explore whether the modifications observed could potentially explain the mechanisms underpinning flexibility of Thiel cadavers. Skeletal muscle and tendon samples were harvested from mice preserved using formalin, Thiel solution, or modified-Thiel solution (without boric acid). Using standard H&E and Gomori's trichrome histological methods, tissues were examined to determine whether differences were apparent between the preservative treatments. Differences were present between the Thiel and formalin-fixed tissues; formalin-fixed samples remained substantially more intact while Thiel-embalmed samples showed fiber fragmentation and lack of nuclei. The mean cell diameter of Thiel-embalmed muscle (24.4 µm) was significantly smaller (P < 0.005) than formalin-fixed muscle (40.7 µm). There was significantly greater (P < 0.005) fragmentation in Thiel-embalmed muscle (631.5 per 1 mm2 ) compared to formalin-fixed muscle (75.4 per 1 mm2 ). Samples embalmed using modified-Thiel showed a severe lack of integrity within internal tissue structure. This suggests that Thiel solution significantly alters tissue structure at cellular level, with quantitative data demonstrating measurable differences between Thiel and formalin-fixed specimens. While the precise mechanism for these alterations remains unknown, it is shown that boric acid is not the only component of Thiel responsible for degradation of internal tissue structure. Clin. Anat., 33:696-704, 2020. © 2019 Wiley Periodicals, Inc.

Examining changes in acromial morphology in relation to spurs at the anterior edge of acromion.

BACKGROUND: Although acromial morphology is classified as flat, curved, and hooked, whether the morphology is primary or acquired is debated. There have been no investigations on the effect of acromial spurs on acromial morphology. This study therefore aimed to evaluate acromial morphology in relation to spur formation at the anterior edge of the acromion. MATERIALS AND METHODS: Acromial morphology was investigated in 40 scapulae taken from 20 cadavers (10 male and 10 female), with a median age of 82 years (range 62-97 years). Ink prints of the anteroposterior aspect of the acromion were used to evaluate acromial slope angle and curvature height in relation to spur incidence, length, and shape at the anterior edge of the acromion. RESULTS: Differences were observed in acromial morphology and acromial curvature in relation to acromial spurs (incidence, size, and shape). A hooked acromion was observed as a primary structure in 25% of specimens, which increased to 43% when acromial spurs were involved. No differences were observed in relation to sex or side, while a significant correlation was observed between acromial curvature and the age of the specimens. CONCLUSION: Acromial spurs increase acromial curvature and therefore change acromion morphology. Nevertheless, it is concluded that a hooked acromion occurs as a primary formed structure. LEVEL OF EVIDENCE: Basic science study, anatomy, cadaver dissection.

Revisiting thoracic surface anatomy in an adult population: A computed tomography evaluation of vertebral level.

To compare key thoracic anatomical surface landmarks between healthy and patient adult populations using Computed Tomography (CT). Sixteen slice CT images of 250 age and gender matched healthy individuals and 99 patients with lung parenchymal disease were analyzed to determine the relationship of 17 thoracic structures and their vertebral levels using a 32-bit Radiant DICOM viewer. The structures studied were: aortic hiatus, azygos vein, brachiocephalic artery, gastroesophageal junction (GEJ), left and right common carotid arteries, left and right subclavian arteries, pulmonary trunk bifurcation, superior vena cava junction with the right atrium, carina, cardiac apex, manubriosternal junction, xiphisternal joint, inferior vena cava (IVC) crossing the diaphragm, aortic arch and junction of brachiocephalic veins. The surface anatomy of all structures varied among individuals with no significant effect of age. Binary logistic regression analysis showed a significant association between individual health status and vertebral level for brachiocephalic artery (P = 0.049), GEJ (P = 0.020), right common carotid (P = 0.009) and subclavian arteries (P = 0.009), pulmonary trunk bifurcation (P = 0.049), carina (P = 0.004), and IVC crossing the diaphragm (P = 0.025). These observations differ from those reported in a healthy white Caucasian population and from the vertebral levels of the IVC, esophagus, and aorta crossing the diaphragm in an Iranian population. The differences observed in this study provide insight into the effect of lung pathology on specific thoracic structures and their vertebral levels. Further studies are needed to determine whether these are general changes or pathology-specific. Clin. Anat. 30:227-236, 2017. © 2017 Wiley Periodicals, Inc.

Surface anatomy of major anatomical landmarks of the neck in an adult population: A Ct Evaluation of Vertebral Level.

To compare the projectional surface anatomy of healthy individuals in an adult population with those with a thyroid mass, using computed tomography (CT). Sixteen slice CT images of 101 individuals were analyzed using a 32-bit Radiant DICOM viewer to establish the relationships among major anatomical landmarks in the neck and their vertebral levels. The structures investigated included: hard palate (HP), hyoid bone (HB) including body and lesser horns, soft palate (SP), thyroid gland (TG) (both superior and inferior poles), thyroid gland anteroposterior (APD) and superoinferior (SID) diameters, thyroid isthmus (TI) superoinferior dimension, epiglottis, vertebral arteries (right and left), and both right and left parotid glands (superior and inferior extents). The vertebral levels noted most frequently were: body of hyoid bone (C4, 42.71%); lesser horns of hyoid bone (C3, 36.46%); thyroid gland superior pole (C6, 31.25%); and thyroid gland inferior pole (T2, 30.2%). TG-ID, TG-APD, and TG-SID were not significantly different between males and females in the healthy group; however, there was a significant gender difference in thyroid gland inferior diameter in the pathology group [males 2.16(±1.16) vs. females 3.37(±1.30), P = 0.01, paired sample t-test]. Further studies are needed to determine whether neck pathology in those with a thyroid mass affects the dimensions of the thyroid gland. Moreover, the surface anatomy of the neck should be revisited using modern imaging techniques to address inconsistencies in anatomy and clinical reference texts. Clin. Anat. 30:781-787, 2017. © 2017Wiley Periodicals, Inc.

Variability in attachment of the coracoacromial ligament in relation with its morphology.

PURPOSE: The coracoacromial ligament (CAL) presents with variable morphology and plays a significant role in the development of subacromial impingement syndrome. Sectioning the CAL has been suggested to relieve impingement of the rotator cuff. The aim of the current study was to investigate the CAL attachment in relation with ligament morphology. MATERIALS AND METHODS: The CAL was investigated in 220 cadaveric shoulders from 58 males and 59 females, with a median age of 82 years (range 53-102 years). CALs were classified according to three factors: (1) number of bands present; (2) shape; and (3) attachment to the acromial and coracoid processes. RESULTS: 35 (16%) CALs had a single band, 84 (38%) two bands, and 101 (46%) three or more bands. CAL shape was either broadband (14: 6%), quadrangular (21: 10%), Y-shaped (84: 38%), or multiple-banded (101: 46%). More ligaments were attached to the medial aspect of the acromion (60%) and medial end of the coracoid (75%) than those restricted to the anterior edge of the acromion (40%) and posterior aspect of the coracoid (25%). Multiple-banded ligaments attached significantly more medially at the acromion and coracoid processes, while single band ligament attachments were restricted to the anterior edge of the acromion and posterior aspect of the coracoid process. CONCLUSION: The CAL has variable morphology and attachments with interconnections to different structures around the shoulder. CALs with a medial acromial attachment may narrow the subacromial space leading to further shoulder impingement.

Three-dimensional analysis of the proximal humeral and glenoid geometry using MicroScribe 3D digitizer.

PURPOSE: To understand the geometry of the proximal humerus and glenoid fossa to facilitate the design of components used in shoulder arthroplasty. The aim is to evaluate the geometry of the proximal humerus and glenoid fossa and their relationship using a MicroScribe 3D digitizer. METHODS: Scans and measurements were obtained from 20 pairs of dry proximal humeri and scapulae [10 female and 10 male cadavers: median age 81 years (range 70-94 years)] using a MicroScribe 3D digitizer and Rhinoceros software. RESULTS: Means (±SD) of humeral inclination, medial wall angle of the bicipital groove, and radius of the humeral head values were 135 ± 11°, 39 ± 19°, and 14 ± 3 mm, respectively. Means (±SD) of glenoid height and width were 35 ± 4 and 26 ± 4 mm, while the means (±SD) of the angles of glenoid inclination, retroversion, and rotation were 87 ± 32°, 96 ± 10°, and 9 ± 6°, respectively. A significant difference in glenoid height (P ≤ 0.002) and width (P ≤ 0.0001) was observed between males and females, despite them having almost an identical radius of the humeral head, glenoid inclination, retroversion, and angle of rotation. There was also a significant difference (P ≤ 0.01) in the angle of glenoid retroversion between the right and left sides. CONCLUSIONS: Using a MicroScribe 3D digitizer, the glenoid fossa was observed to be significantly smaller in females than males; furthermore, there was a difference in glenoid retroversion between the right and left sides.

Evaluation of the coracoid and coracoacromial arch geometry on Thiel-embalmed cadavers using the three-dimensional MicroScribe digitizer.

BACKGROUND: Understanding the geometry of the coracoid and coracoacromial arch will improve surgical intervention in shoulder surgery. METHODS: Thirty pairs of scapulae from 20 female and 10 male deceased donors, average age of 82 years (range, 62-101 years), were scanned and measurements taken using the 3-dimensional (3D) MicroScribe digitizer (Immersion Corp, San Jose CA, USA) and Rhino software (McNeel North America, Seattle, WA, USA). RESULTS: The following mean angles were determined: coracoid slope, 44° ± 11°; coracoid deviation, 35° ± 6°; coracoid root to glenoid, 115° ± 14°; coracoid head to glenoid, 110° ± 11°; scapular spine angle, 35° ± 6°; and coracoacromial angle, 63° ± 9°. The following mean distances were also determined: coracoid height, 10 ± 3 mm; coracoacromial distance, 42 ± 7 mm; coracoacromial arch height, 20 ± 5 mm; and coracoid (anterior, 29 ± 6 mm; middle, 20 ± 4 mm; posterior tip, 18 ± 6 mm) to the glenoid fossa. The coracoid root-to-glenoid angle was significantly correlated with the coracoacromial angle. In addition, coracoid slope was significantly correlated with coracoid root-to-glenoid angle and also with coracoid deviation. Left shoulders had a significantly higher coracoid-to-glenoid angle (P < .029) than right shoulders. Women had a significantly higher coracoid root-to-glenoid angle than men (P < .042), and men had a significantly higher coracoid deviation (P < .011), anterior (P < .006) and posterior coracoid-to-glenoid distances (P < .03), and coracoacromial arch height (P < .07) than women. CONCLUSIONS: This is the first time that the 3D MicroScribe digitizer has been used to evaluate the geometry of the coracoacromial arch and coracoid process.

How well do contoured superior midshaft clavicle plates fit the clavicle? A cadaveric study.

BACKGROUND: Given the degree of variation in clavicular morphology, 4 clavicle plating systems were examined for their congruity as superior, midshaft, anatomic clavicle (SMAC) plates in a cadaveric study. METHODS: SMAC plates from 4 manufacturers were applied to 79 dry right human clavicles. Two systems offered multiple (4) variations of plates (MP), 1 offered two variations (TP), and 1 had a single plate (SP). Two examiners applied and clamped the best-fitting plate from each system onto each of the 79 clavicles and then graded them: 1, poor fit; 2, good fit; and 3, anatomic fit. Each examiner repeated the process to assess intraobserver and interobserver reliability. The scores were averaged to produce a final score for each system for each clavicle. RESULTS: The MP systems scored the highest (32%-37% anatomic, 54%-63% good, 5%-8% poor), followed by the TP system (30% anatomic, 53% good, 17% poor), and finally the SP system (9% anatomic, 59% good, 32% poor). Of note, clavicular length significantly correlated with a higher degree of conformity in all plating systems (Spearman rank correlation P < .05 for each system). In clavicles longer than 150 mm, the MP and TP systems performed identically, with the SP system close behind. Contouring of the plate is needed in 73% of cases overall. CONCLUSION: Plating systems with multiple plate shape variations are more advantageous when dealing with smaller-sized clavicles, typically in females. However, when dealing with larger clavicles, there was no real difference.

Ulnar nerve cutaneous distribution in the palm: Application to surgery of the hand.

The ulnar nerve (UN) was classically described as supplying most of the intrinsic muscles of the hand, and the cutaneous innervation of the ulnar one and half digits, by dividing into superficial sensory and deep motor branches in Guyon's canal. Variations of this pattern have been reported in the literature. This study investigated the cutaneous distribution of the UN in the palm following the dissection of 144 cadaveric hands. The UN was examined and the distances from branching points of the superficial branch to the proximal edge of the pisiform were measured. The UN bifurcated (80.4%) into one deep trunk and one superficial trunk, which further divided distally into the proper digital (PDN) and common digital (CDN) nerves or trifurcated (19.6%) into one deep trunk, a PDN and a CDN in Guyon's canal. It received fibers from the median nerve in four cases and from the dorsal branch of the UN in six cases. A classification scheme based on the nerves contributing to the sensory innervation of the ulnar side of the palm was suggested. Understanding the cutaneous distribution of the UN in the palm and appreciating possible communicating branches can help clinicians to assess hand pathologies better and avoid injuries during surgical interventions.

The sensory distribution in the dorsum of the hand: anatomical study with clinical implications.

The sensory distribution in the dorsum of the hand was investigated in 150 formalin-fixed hands with the aim of outlining the most common innervation pattern of the superficial branch of the radial nerve (SBRN), dorsal branch of the ulnar nerve (DBUN) and the lateral antebrachial cutaneous nerve (LABCN). Although variable, the most common pattern found was SBRN innervation to the dorsal surface of the lateral 2½ digits and DBUN innervation to the dorsal surface of the medial 2½ digits. Dual innervation due to communicating branches or nerves overlapping was found in 41 cases. All-radial supply to the dorsum of the hand was found in ten cases. The LABCN was closely associated, and occasionally overlapped, with the SBRN. There were significant differences in the sensory distribution of the dorsum of the right and left hands of the same cadaver. The sensory distribution in the dorsum of the hand is variable; however, understanding the most common innervation pattern and appreciating the possible variations to this pattern is important to avoid errors in interpretation of conduction velocity studies, misdiagnosis of nerve pathology signs and symptoms and inappropriate treatments.

The origin variability of the iliolumbar artery and iatrogenic sciatica.

The iliolumbar artery (ILA) is a standard branch from the posterior trunk of the internal iliac artery. It is the only pelvic artery ascending from pelvic cavity. Current study comprises 171 cadavers dissection to assess the origin variability of ILA. The present study identified the incidence of the ILA origin variability in Caucasian population which also clarified the iliolumbar variability in males and females. The current study shows that the ILA arises from the common iliac artery in 2%, from the external iliac artery in 0.3% and from the internal iliac artery in 13.8% either from its dorsal or dorsomedial aspects in 1 and 12.8%, respectively. The common, external and internal iliac arteries are defined as a high (early) origin and occurred in 16.1%. The posterior trunk of the internal iliac artery is the most common origin of the ILA found to be in 77.9%. Occasionally, it also arose from the superior gluteal artery (0.7%) and the sciatic artery (0.3%). Furthermore, the ILA arises from the anterior trunk indirectly as from the inferior gluteal artery in 0.3%. The ILA arising from the superior or inferior gluteal artery or from the sciatic artery is defined as a low (delayed) origin and occurred in 1.3%. In contrast, the ILA was 4.7%. Consequently, variability of the ILA leads to vascular variability of the lumbosacral trunk of the sciatic nerve. Clinicians have to be aware of these variations to avoid unnecessary ligation to prevent sciatic neuropathy.

Liver displacement during ventilation in Thiel embalmed human cadavers - a possible model for research and training in minimally invasive therapies.

Respiration-related movement of organs is a complication in a range of diagnostic and interventional procedures. The development and validation of techniques to compensate for such movement requires appropriate models. Human cadavers embalmed with the Thiel method remain flexible and could provide a suitable model. In this study liver displacement during ventilation was assessed in eight Thiel embalmed cadavers, all of which showed thoracic and abdominal motion. Four cadavers displayed realistic lung behaviour, one showed some signs of pneumothorax after prolonged ventilation, one had limited filling of the lungs, and two displayed significant leakage of air into the thorax. A coronal slice containing the largest section through the liver was imaged with a real-time Fast Gradient Echo (FGR) MRI sequence: Craniocaudal displacement of the liver was then determined from a time-series of slices. The maximum liver displacement observed in the cadavers ranged from 7 to 35 mm. The ventilation applied was comparable to tidal breathing at rest and the results found for liver displacement are similar to values in the literature for respiratory motion of the liver under similar conditions. This indicates that Thiel embalmed cadavers have potential as a model for research and training in minimally invasive procedures.

Piriformis and obturator internus morphology: a cadaveric study.

Preservation of piriformis during exposure of the hip joint via a posterior approach may result in a lower rate of dislocation following total hip arthroplasty. The aim of this study was to identify anatomical variations in the tendons of piriformis and obturator internus which could inform piriformis sparing approaches to the hip. Twenty-nine proximal femora from 15 cadavers, 5 male and 10 female aged 65-79 years, were examined. Tendon crossing angles, location and mode of insertion to the greater trochanter and the extent of fusion between tendons prior to insertion were noted. The mean (and associated standard deviation) of the vertical and horizontal widths of the piriformis tendon were 4.78 ± 1.31 mm and 7.35 ± 1.74 mm, respectively. The mean (and associated standard deviation) of the vertical and horizontal widths of the obturator internus tendon were 6.87 ± 1.61 mm and 5.72 ± 1.38 mm, respectively. The mean distances of the anterior and posterior margins of the piriformis tendon insertion from the posterior limit of the greater trochanter, defined as a percentage of the anteroposterior length of the greater trochanter, were 63.3% ± 9.4% and 43.0% ± 9.4%, respectively. Equivalent mean distances for the obturator internus insertion were 73.0% ± 6.6% and 55.9% ± 7.0%, respectively. On the basis of the relationship between the piriformis and obturator internus tendons in terms of the angle and point at which they cross, in addition to any degree of tendon fusion, four classifications were identified. This study shows that the most posterior margins of the piriformis and obturator internus attachments are located more than one-third of the way along the greater trochanter, suggesting that current osteotomies would not include these external rotators in the majority of cases.

Virtual reality haptic human dissection.

This project aims to create a three-dimensional digital model of the human hand and wrist which can be virtually 'dissected' through a haptic interface. Tissue properties will be added to the various anatomical structures to replicate a realistic look and feel. The project will explore the role of the medical artist and investigate the cross-discipline collaborations required in the field of virtual anatomy. The software will be used to train anatomy students in dissection skills before experience on a real cadaver. The effectiveness of the software will be evaluated and assessed both quantitatively as well as qualitatively.

Virtual reality haptic dissection.

This project aims to create a three-dimensional digital model of the human hand and wrist which can be virtually 'dissected' through a haptic interface. Tissue properties will be added to the various anatomical structures to replicate a realistic look and feel. The project will explore the role of the medical artist, and investigate cross-discipline collaborations in the field of virtual anatomy. The software will be used to train anatomy students in dissection skills, before experience on a real cadaver. The effectiveness of the software will be evaluated and assessed both quantitatively as well as qualitatively.

Arterial supply to the sciatic nerve in the gluteal region.

The arterial supply to the sciatic nerve was investigated in 20 human lower limbs (10 right, 10 left) from 20 cadavers (14 females, aged 84 +/- 9.6 years, range 66-95 years: 6 males, aged 80 +/- 8.2 years, range 70-90 years). In all limbs examined at least 1 sciatic artery could be identified supplying the sciatic nerve in the gluteal region. In total 28 sciatic arteries were identified, of which 14 arose from the medial circumflex femoral artery, 11 from the inferior gluteal artery, 2 from the first perforating artery, and 1 from the internal pudendal artery. In 5 limbs, 2 sciatic arteries were observed, being independent branches from the medial circumflex femoral and inferior gluteal arteries in 4 limbs and separate branches of the medial circumflex femoral artery in 1 limb. In 1 limb, 4 sciatic arteries were observed: 1 from the inferior gluteal artery, 2 from the medial circumflex femoral artery, and 1 from the first perforating artery. In the remaining 14 limbs a single sciatic artery was observed, which in one case arose from the internal pudendal artery, a previously unreported observation.