Estimating aspect ratio of the distal femur and proximal tibia in the Emirati population from MRI scans of the knee: a preliminary experience.

Size and shape of knee implants play an important role in the success of total knee arthroplasty. Several studies have identified anthropometric differences of the distal femur and proximal tibia between the genders and ethnicities. Ill-fitting prosthesis can cause overhang or under-fit resulting in persistence of pain, periprosthetic fracture and decreased range of motion. The purpose of this study was to estimate the aspect ratio of distal femur and proximal tibia in the Emirati population and determine whether gender differences exist within this group. Magnetic resonance imaging datasets of unilateral knees scans performed on adult Emirati patients at a tertiary care hospital were retrospectively examined. Knee parameters were obtained from 65 males and 46 females (n = 111). Females showed significantly smaller AP and ML dimensions of distal femur and lower aspect ratios compared to males (p < 0.001). Proximal tibial dimensions (AP and ML) of Emirati women are also significantly smaller compared to men. However, aspect ratio of proximal tibia did not show gender variation (p = 0.956) within the Emirati population. Emirati knees showed significant gender differences in bony dimensions and aspect ratio of the knee, and also have smaller aspect ratios when compared with most other population groups.

Prevalence of the additional head of quadriceps femoris in the South Indian population: a cadaveric and radiological study.

Quadriceps femoris is an extensor muscle in the anterior compartment of thigh and is traditionally taught to be composed of four heads. Recently, there is an increased interest in the occurrence of an additional muscle head of quadriceps femoris. But scientific knowledge regarding its incidence is lacking in the South Indian population. This study was done to confirm the presence of the additional head by routine anatomic dissection and radiological imaging techniques. Forty-one formalin fixed human cadaveric lower limbs were dissected and the morphology of the additional head was noted. Retrospective analysis of 88 MRI images of patients was done. The additional muscle head was present in 43.9% of the cadaveric lower limbs and was consistently located between the vastus lateralis and vastus intermedius. It originated from variable portions of the greater trochanter, intertrochanteric line, lateral lip of linea aspera and lateral surface of the shaft of femur and inserted either as a muscle belly or as an aponeurosis into the vastus intermedius (55.6%), vastus lateralis (22.2%) or directly into the base of the patella. It received its vascular supply from branches of the lateral circumflex femoral artery and was innervated by branches from the posterior division of the femoral nerve. In addition, the additional muscle head was identified by MRI and its incidence was reported to be 30.68% for the first time in living subjects. The result of this study provides additional information in understanding the morphology of the quadriceps femoris muscle.

Estimation of Anatomical Dimensions of the Thorax from Computed Tomography Images of the Adult and Pediatric Indian Population for Developing Optimal Radiological Protocols.

Purpose: Ionizing radiation has been extensively used for medical diagnosis since its discovery in 1895; however, excessive use can lead to deleterious effects. Prior knowledge on radiological protocols based on simulations would be a practical tool for optimal use of radiation. Materials and Methods: Scan length of the thorax was measured from computed tomography (CT) topographic images and cross-sections at three levels of the thorax were measured from tomographic images of 500 adults and 340 children who had undergone CT thorax examinations using Centricity workstation software. The effective diameter (ED) of the thorax was calculated from anterio-posterior (AP) and transverse anatomical dimensions. Results: A 17% increase in scan length was observed for 6-10 years age group compared to 0-5 years, whereas there was marginal increase for 11-15 years of age. A 11.5% increase was observed for 16-18 years compared to 11-15 years age group. The cross-sectional phantom dimensions were calculated from ED measurements obtained from three regions of the thorax. Conclusions: This study has provided age- and gender-specific reference scan lengths, AP and transverse dimensions and ED for radiological examinations of the thorax. This information is useful to develop age- and gender-specific preset protocols and fabricate phantoms of the thorax for the pediatric and adult Indian population.

Structured, functional histology practical modules: An answer to medical students' histology nightmare and the way forward for relevant histology instruction in the Indian undergraduate medical curriculum?

Background: . It is often a challenge to make histology instruction relevant and interesting. We assessed whether structured, worksheet-based histology practical modules with emphasis on functional histology and clinical application, would improve the learning experience and help students focus on relevant functional and clinical correlates. Methods: . In eight practical sessions, 100 students worked as two groups, one group undergoing new intervention practical modules and another group undergoing the routine laboratory practical exercises as a control group. For every pair of laboratory practical exercises, the groups alternated. Spot tests administered in the following week assessed identification ability as well as application of knowledge. Feedback was collected in the form of written questionnaires from faculty and students, student focus group discussion and in-depth interviews. Analysis of test scores as well as feedback was done. Results: . Test scores were better following the intervention method when comparing the overall score as well as its subcomponents of identification and analysis-type questions (p<0.001). The weaker performers in the class as well as high achievers showed better test scores with the intervention method (p<0.001). Feedback from faculty and students reflected better student experience with the intervention method. Suggestions were made to improve the approach further. Conclusion: . Studying histology through structured modules, which emphasize functional and clinical correlates, appears to improve the identification and application ability of the student as well as the student experience.

Clinical anatomy of the inferior epigastric artery with special relevance to invasive procedures of the anterior abdominal wall.

INTRODUCTION: Injury to the inferior epigastric artery (IEA) has been reported following lower abdominal wall surgical incisions, abdominal peritoneocentesis and trocar placements at laparoscopic port sites, resulting in the formation of abdominal wall haematomas that may expand considerably due to lack of tissue resistance. The aim of this study was to localise its course in relation to standard anatomic landmarks and suggest safe areas for performance of invasive procedures. MATERIALS AND METHODS: Sixty IEAs of 30 adult cadavers (male = 19; female = 11) were dissected and the course of the IEA noted in relation to the mid-inguinal point, anterior superior iliac spine (ASIS) and umbilicus. RESULTS: The mean distance of the IEA from the midline was 4.45 ± 1.42 cm at the level of the mid-inguinal point, 4.10 ± 1.15 cm at the level of ASIS and 4.49 ± 1.15 cm at the level of umbilicus. There was an average of 3.3 branches per IEA with more branches arising from its lateral aspect. The IEA was situated within one-third (32%) of the distance between the midline and the sagittal plane through ASIS at all levels. CONCLUSION: To avoid injury to IEA, trocars can be safely inserted 5.5 cm [mean + 1 standard deviation (SD)] away from the midline (or) slightly more than one-third of the distance between the midline and a sagittal plane running through ASIS. These findings may be useful not only for laparoscopic procedures but also for image-guided biopsy, abdominal paracentesis, and placement of abdominal drains.

Topography of inferior epigastric artery relevant to laparoscopy: a CT angiographic study.

PURPOSE: The incidence of inferior epigastric artery (IEA) injury is 0.2-2 %. The aim of this study was to trace the position and course of the inferior epigastric artery in the anterior abdominal wall above the inguinal ligament at three important landmarks, i.e., at the mid-inguinal point, Anterior Superior Iliac Spine (ASIS) and umbilicus in abdominal CT Angiograms. The study also correlates the relationship of body build and the position of the inferior epigastric artery. METHODS: In 50 CT Abdominal angiograms, the course of the inferior epigastric artery was traced and distance between the artery and midline was measured at the above landmarks using measurement tool on the picture archival and communication system. The measurements were analyzed using SPSS version 16 and expressed as mean and standard deviation. Mann-Whitney test was used to compare the mean values and ratios in males and females. Linear regression was done to derive formulas by which the position of the inferior epigastric artery could be found. RESULTS: The mean distance of the inferior epigastric artery from the midline was 5.17 ± 0.93 cm at the level of mid-inguinal point, 4.57 ± 1.05 cm at the level of ASIS and 5.27 ± 1.17 cm at the level of umbilicus. There was a definitive predictive pattern in the course of the artery as seen in correlation and regression analysis. CONCLUSION: The security distance for safe trocar placement was 6 cm at the level of ASIS and 9 cm at the level of umbilicus. Preoperative IEA assessment is helpful in reducing injuries to IEA.

Histology of the cricothyroid membrane: a clinical perspective.

Puncture of the cricothyroid membrane is a component of several clinical procedures. Among the several complications are the immediate risk of bleeding, long-term risk of subglottic stenosis and hoarseness of voice. Presence of blood vessels in the cricothyroid membrane has also been implicated in the extra-laryngeal spread of laryngeal cancers. Though various authors have described the attachments of the cricothyroid membrane, very few have studied its histology. We studied the histology of the cricothyroid membrane using hematoxylin and eosin, Mallory's trichrome and Verhoeff's special stain. The cricothyroid membrane was found to be continuous on its deeper aspect with the mucosa of the subglottic larynx and lined by pseudostratified ciliated columnar epithelium. The membrane was observed to be fibroelastic, containing equal proportions of collagen and elastic fibers and numerous fibroblast nuclei. Numerous blood vessels are seen traversing through the membrane, which probably connect intralaryngeal with other extralaryngeal vessels. These histological findings help to further understand the complications of cricothyroidotomy and spread of laryngeal cancer.

Comparison of the volar and medial approach in peripheral block of ulnar nerve at the wrist - a cadaveric study.

CONTEXT: Two standard approaches are described to block the ulnar nerve at wrist. These include a) the traditional Volar approach where the needle is inserted lateral to tendon of flexor carpi ulnaris (FCU) b) Medial approach where the needle is inserted posterior to the tendon of FCU. Caution must be exercised to avoid puncture of the ulnar artery and/or intraneural injection of the ulnar nerve in both the approaches. AIM: This study compares the volar and medial approach to the peripheral block of ulnar nerve at the wrist. The objective was two fold: a) to analyze the position of the ulnar nerve and the ulnar artery in relation to the Flexor Carpi Ulnaris tendon b) to assess the risk of injury to ulnar artery in both the volar and medial approach. SETTINGS AND DESIGNS: Twelve cadaveric upper limbs were used and both approaches compared by an observational study. MATERIALS AND METHODS: Two 18 G needles were inserted up to a depth of 7 mm using the standard volar and medial approach. The pattern of arrangement and positions of the ulnar artery and nerve in relation to FCU tendon were observed. The distance between the tip of needle and its proximity to the ulnar artery, and risk of injury were determined. Statistical analysis was done using SPSS for Windows, Version 16.0. Chicago, SPSS Inc. RESULTS: Three patterns of arrangement and position of the ulnar nerve and artery were observed. Puncture of ulnar artery was seen in 50% of cases in the volar approach as compared to no injury at all in the medial approach. The ulnar artery is highly liable to injury during the volar approach in type I and II and safe only in type III arrangement of ulnar artery. The medial approach showed no injury to the ulnar artery or nerve at a penetration depth of 7mm. CONCLUSION: The medial approach is safer compared to volar approach for peripheral block of ulnar nerve at wrist.

Ludwig Edinger (1855-1918): founder of modern neuroanatomy.

Ludwig Edinger, a German neurologist is considered as one of the founders of modern neuroanatomy. He was conferred the degree of Doctor of Medicine at the University of Strassburg. His observation of small living organisms under a microscope at an early age led him to study medicine. Edinger had many discoveries to his credit. He was the first to describe the ventral and dorsal spinocerebellar tracts, to distinguish between paleo-encephalon and neo-encephalon, and between paleo-cerebellum and neo-cerebellum. He coined the terms "gnosis" and "praxis," which were later adopted in psychological descriptions of agnosia and apraxia. He identified the Edinger-Westphal nucleus in 1885 and was the first to describe the syndrome of thalamic pain. Edinger worked with renowned clinicians and published a large number of papers. He founded the Neurological Institute at the Goethe University in Frankfurt, which is the oldest neurological Institute in Germany. Edinger was a rare combination of a profound scientist, a brilliant teacher, a fine artist, and a noted hypnotist. While at the height of his career, he underwent a surgery and died a few hours later. It was his last will that his brain should be dissected in his own institute. It showed extraordinarily well-developed occipital lobes as well as other unusual features.