Morphological study of styloid process of the temporal bone and its clinical implications.

The objective of this study was to study the morphometry of the styloid process of temporal bone and prevalence of elongated styloid process. The morphology of elongated styloid process along with its embryological and clinical importance are discussed. The present study included 110 human dry skulls which were procured from the bone collections of the department of anatomy. The styloid process was observed macroscopically on both sides of all the skulls, the elongations if any were noted. All the styloids were measured for their length, thickness at different levels and interstyloid distance at various levels. Out of 110 specimens, only 5 skulls (4.5%) exhibited the elongated styloid process. Among them, 3 skulls (2.7%) had unilateral elongation and 2 skulls (1.8%) had bilateral elongation of the styloid process. The mean length of the styloid process was 17.8±9.3 mm and 18.2±5.6 mm for the right and left sides, respectively. The prevalence of elongated styloid process in the present study was 4.5%. The clinical anatomy of this congenital variant is important to the neurosurgeon and radiologist, while interpreting the computed tomogram and magnetic resonance image scans. The morphological knowledge of elongated styloid process is clinically important since the course of the vertebral artery may be distorted in such situations.

Unique distribution by the peroneal nerves: a case report.

PURPOSE: Among the branches of common peroneal nerve, the superficial peroneal provides cutaneous innervation to major part of the dorsum of the foot and deep peroneal nerve supplies the skin over the first interdigital cleft region. METHODS: The present rare case was observed during routine dissection of leg for undergraduate students, in a 52-year-old male, formalin fixed cadaver. RESULTS: The superficial peroneal nerve provided solely motor branches to peroneus longus and brevis, whereas cutaneous branches were provided by deep peroneal nerve. In the lower one-third of the leg deep peroneal nerve divided into medial and lateral branches. The medial branch supplied tibialis anterior and the lateral branch supplied skin of medial three and half toes. Moreover, the sural nerve supplied the skin of lateral one and a half toes. CONCLUSION: Awareness of this type of variations in the course of nerves helps to alert the surgeons when there are complaints of atypical or unique pain in that particular region.

Occipital condyle morphometry and incidence of condylus tertius: phylogenetic and clinical significance.

PURPOSE: The objectives were to study the morphometry of occipital condyles and to find the incidence of third occipital condyle in Indian skulls. MATERIALS AND METHODS: In the present study, 140 occipital condyles from 70 dry skulls were analysed. The length, width, height of occipital condyles, the anterior and posterior intercondylar distances was measured. RESULTS: The average length, width and height of occipital condyle were 21.9 mm, 11.26 mm and 10.2 mm respectively. The average anterior and posterior intercondylar distances were 18.7 mm and 38.7 mm respectively. Among our specimens, 2 skulls (2.86%) had a third occipital condyle. CONCLUSION: We believe that the data of the present study may provide anatomical reference to neurosurgeons and thus help in surgical procedures around the craniovertebral junction. The clinical and phylogenetic significance of the third occipital condyle has been discussed.

Foramina on the zygomatic bone: its clinical significance.

AIM: To study the anatomy of zygomatico-orbital, zygomatico-facial and zygomatico temporal foramina in south Indian population. MATERIALS AND METHODS: 50 dry adult skulls of south Indian origin were studied. The number of ZO, ZF and ZT were recorded on each side. The distances of these foramina to the nearest palpable bony points, infero-lateral angle of the orbit and infra-orbital foramen were measured using Vernier's calipers. RESULTS: Variable number of ZO and ZF foramina, ranging from 0 to 4 was seen. Single ZO foramen in 56% and 44%, double in 6% and 12%, absent in 38% and 44% on right and left sides were seen. Distance of ZO foramen from inferolateral angle of orbit was 9+2.51 mm and 7.8+1.74 mm on right and left side respectively. The mean distance from infraorbital foramen was 29.93+2.76 mm and 30.19+ 3.52 mm on right and left side respectively. Single ZF foramen in 40% and 42%, double in 10% and 8%, 3 in 4% on right side and 4 in 2% on left sides were seen. In the remaining 46% and 48% of bones, the ZF foramen was absent. Mean distance from inferolateral angle of orbit was 8.05+2.68 and 9.15+2.11 mm respectively on the right and left side. Mean distance from infraorbital foramen was 25.45+4.35 mm and 25.42+4 mm respectively on right and left side. CONCLUSION: The location of ZO and ZF foramen can be population specific and knowledge of its location is important during stabilization of zygomatic fractures, in endoscopic subperiosteal facelift.

Accessory transverse foramina in the cervical spine: incidence, embryological basis, morphology and surgical importance.

AIM: To study the incidence of accessory foramina transversaria in cervical spine and to analyze them morphologically with emphasize on their embryological and surgical importance. MATERIAL AND METHODS: The study included 363 human cervical vertebrae which were procured from the bone collections of the Department of Anatomy. The foramen transversarium was observed macroscopically on both sides of all the vertebras, the accessory foramina were noted. RESULTS: Out of 363 specimens, only 6 (1.6%) vertebrae showed the accessory foramina. Among them 5 (1.4%) vertebra had double foramina and only 1 (0.3%) vertebra showed three foramina. Only 1 (0.3%) vertebrae showed the foramen on both sides and the remaining 5 (1.4%) had unilateral foramina. Among the unilateral, 4 were present on the right side and only 1 was on the left side. No vertebrae showed the absence of foramen transversarium. CONCLUSION: The present study observed the accessory foramina transversarium in 1.6% of cases. The unilateral presence was more common than the bilateral. The surgical anatomy of these variations is important for the neurosurgeons and radiologists for interpreting the computed tomogram and magnetic resonance image scans. Their morphological knowledge is clinically important since the course of the vertebral artery may be distorted in such situations.

Morphometry of A1 segment of the anterior cerebral artery and its clinical importance.

BACKGROUND AND AIM: Anterior cerebral artery, one of the terminal branches of the internal carotid artery is an important vessel taking part in the formation of circle of Willis. It supplies a large part of the medial surface of the cerebral hemisphere containing the areas of motor and somatosensory cortices of the lower limb. Aim of this study was the morphometry of A1 segment of the anterior cerebral artery. MATERIALS AND METHODS: 93 formalin fixed brain specimen of either sex and of Indian origin were studied. The mean length, mean external diameter and the anomalies present in A1 segment of the vessel were studied in detail and photographed. RESULTS: The mean length of A1 segment of the vessel was 14.49+/-0.28 mm and 14.22+/-0.22 mm on right and left side respectively. The mean external diameter of the vessel on right and left side was 2.12+/-0.07 mm and 2.32+/-0.06 mm respectively. Narrowing, aneurysm formation, buttonhole formation and median anterior cerebral artery were the anomalies seen with an occurrence of 15.05%, 5.37%, 3.22% and 12.9%, respectively. The above anomalies did not have any sex or side predilection. CONCLUSION: Knowledge of morphometry of the vessel will be of use to neurosurgeons while performing the shunt operation, in assessing the feasibility of such operations and in the choice of patients. From this study we infer that the morphometry of anterior cerebral artery varies in different population and that the neurosurgeons operating should have a thorough knowledge of the possible variations.

Anatomy of plantaris muscle: a study in adult Indians.

AIM: The plantaris muscle (PM) and its tendon is subject to considerable variation in both the points of origin and of insertion. The present study was carried out to fi nd the different types of origin, insertion and possible variations of the PM in the population of southern costal region of India. MATERIALS AND METHODS: 52 embalmed (Formalin fixed) cadaver lower limbs of 26 males (age ranged 48-79 years, mean age 68 years) were dissected, to study the origin and insertion of PM. Various dimensions (length and width) of plantaris muscle belly and its tendon were also measured. RESULTS: Three types of origin and equal number of insertion were noticed in the present study. The PM took origin from type I: Lateral Supracondylar ridge, Capsule of Knee joint and Lateral head of gastrocnemius in 73.07% cases; type II: Capsule of Knee joint and Lateral head of gastronemius in 5.76% cases; type III: Lateral Supracondylar ridge , Capsule of Knee joint , Lateral head of gastrocnemius and fibular collateral ligament in 13.46% cases. The plantaris tendon was inserted into type I: to the flexor retinaculum of foot in 28.84% cases; type II: independently to the os calcaneum in 36.53% cases; type III: to the tendocalcaneus at various levels in 26.92% cases. In four lower limbs (7.69%) the plantaris muscle was completely absent. Additionally the length and width of the plantaris muscle and its tendon were measured to know any side difference. There were no statistically significant differences between the measurements of left and right side (p>0.05). CONCLUSION: Present study will help the surgeons while attempting various surgical procedures in and around the posterior aspect of knee involving plantaris.

An anomalous left external jugular vein draining into right subclavian vein: a case report

Knowledge of the varying drainage patterns of superficial veins of head & neck, in particular, jugular veins are not only important for anatomists but also for the surgeons operating at this level and to clinicians in general. The variations are important for interventional radiologists too who perform transjugular procedures, such as port implantations and the transjugular intrahepatic portosystemic shunt or selective venous samplings. Results of recent studies report that the superficial veins, especially the external jugular vein (EJV), is been increasingly utilized for cannulation to conduct diagnostic and therapeutic procedures. We report a very unusual presentation of external jugular vein on left side of an embalmed male cadáver. Embryological evaluations of the anomaly was done and compared with available literature which showed that the observed variation is rare.

El conocimiento de los diferentes patrones de drenaje de las venas superficiales de la cabeza y cuello, en particular, las venas yugulares no sólo son importantes para anatomistas, sino también para los cirujanos que operan a este nivel y para los médicos en general. Las variaciones son importantes también para los radiólogos intervencionistas, quienes realizan procedimientos transyugulares, así como implantaciones portales y portosistémicas transyugulares intrahepáticas o derivación venosa selectiva. Resultados de estudios recientes informan que la venas superficiales, especialmente la vena yugular externa, es cada vez más utilizada para la canulación en diagnósticos y procedimientos terapéuticos. Se reporta una muy inusual variación anatómica de la vena yugular externa del lado izquierdo, presente en un cadáver embalsamado de sexo masculino. Fueron realizadas evaluaciones embriológicas de la anomalía y se compararon con la literatura mostrando que se trata de una variación rara.

Hypoplastic posterior tibial artery and the enlarged peroneal artery supplying the posterior crural region: a rare variation / Artéria tibial posterior hipoplásica e a artéria peroneal aumentada suprindo a região crural posterior: uma variação rara

Arterial variations of distal parts of lower extremities are well-documented and can be demonstrated with the help of Doppler ultrasound or by arteriography. However, absence or variation of posterior tibial artery is considered a rare finding. We present a case of hypoplastic posterior tibial artery that terminated by supplying soleus muscle. The variant arterial supply to the sole was provided by the enlarged peroneal artery that continued as the lateral plantar artery. The awareness of these variations is important to vascular surgeons while performing arterial reconstructions in femorodistal bypass graft procedures, and also to orthopedists during surgical clubfoot release.

Variações arteriais de partes distais dos membros inferiores estão bem documentadas e podem ser demonstradas com o auxílio de ultra-sonografia Doppler ou por arteriografia. Entretanto, a ausência ou variação da artéria tibial posterior é um raro achado. Apresentamos um caso de artéria tibial posterior hipoplásica que terminava suprindo o músculo solear. Esse suprimento arterial variante foi fornecido pela artéria peroneal aumentada que continuava como artéria plantar lateral. Estar consciente dessas variações é importante para cirurgiões vasculares ao realizarem reconstruções arteriais em procedimentos de derivação femorodistal, bem como para ortopedistas durante correção cirúrgica do pé torto.

A variant of Buhler's arc formed by the unusually long dorsal pancreatic artery.

The knowledge of anatomical variations of the vascular junction between the celiac trunk and superior mesenteric artery is surgically significant. A case of unusually long dorsal pancreatic artery that originated from the common hepatic artery and directly anastomosed with the middle colic artery thus forming a rarely reported variant of Bühler's arcade is presented (Fig. 1, Ref. 14).

A cadaveric study of the testicular artery in the South Indian population.

INTRODUCTION: The male gonadal arteries, namely the testicular arteries, may vary at their origin and arise from the renal artery, suprarenal artery or lumbar artery. They may also be doubled, tripled or even quadrupled and may arise as a common trunk. With the advent of new intra-abdominal operative and laparoscopic techniques, the anatomy of the gonadal vessels has assumed much more importance. Therefore, a study was designed to assess the percentage of normal and aberrant origin and course of the testicular artery in the Indian population. METHODS: The posterior abdominal walls of 34 male cadavers (68 sides) were dissected and studied for the variations in the origin and course of the testicular arteries. RESULTS: In 85.3 percent of the cases, the male gonadal artery was normal in origin, number and course. However, in the remaining 14.7 percent, various anomalies in the testicular artery were noted. CONCLUSION: The variations in the testicular arteries are attributed to their embryological origin. A deep knowledge of these variations and their relations to the adjacent structures is very important in avoiding the complications in operative surgery.

Multiple supernumerary muscles of the arm and its clinical significance.

During routine cadaveric dissection of the flexor compartment of the right arm, multiple supernumerary muscles were observed in a 56-year-old male cadaver. There were three supernumerary muscles took taking origin independently from the humerus distally to the insertion of coracobrachialis muscle. The upper two supernumerary muscles were attached to the common tendon of the biceps brachii muscle and considered as its additional heads. The third supernumerary muscle passed between the biceps brachii and brachialis muscles, then crossed obliquely the brachial artery and median nerve nearing cubital fossa to get inserted in to the radial side of the humeral head of the pronator teres. The clinical significance of the above variations is discussed (Fig. 1, Ref. 16).

An anomalous left external jugular vein draining into right subclavian vein.

Knowledge of the varying drainage patterns of superficial veins of head & neck, in particular, jugular veins are not only important for anatomists but also for the surgeons operating at this level and to clinicians in general. The variations are important also for interventional radiologists, who perform trans-jugular procedures, such as port implantations and trans-jugular intra-hepatic porto-systemic shunts or selective venous samplings. Results of recent studies report that the superficial veins, especially the external jugular vein, have been increasingly utilized for cannulation to conduct diagnostic and therapeutic procedures. We report a very unusual left-sided presentation of external jugular vein in an embalmed male cadaver. Embryological evaluations of the anomaly was done & compared with available literature, which showed that the observed variation is rare (Fig. 1, Ref. 12).

A rare variation of the profunda femoris vein in the popliteal fossa.

The profunda femoris artery is normally accompanied by a profunda femoris vein (deep femoral vein), which begins at the adductor magnus with various tributaries and drains into the femoral vein at the femoral triangle. Very rarely, the profunda femoris vein establishes communication with the popliteal vein. We present an anomalous profunda femoris vein in a 62-year-old male cadaver whose vein was located in the popliteal fossa as a direct communicating channel between the popliteal vein and the femoral vein.

The mendosal suture of the occipital bone: occurrence in Indian population, embryology and clinical significance.

The occipital bone is ontogenetically and functionally unique when compared to the other bones of the skull in humans and other mammalian cousins. The occipital bone develops from six ossification centers; any defect in the ossification process will give rise to mendosal suture (accessory suture) and conditions like posterior plagiocephaly. There is a paucity of literature regarding the mendosal suture and further more, its report in Indian population is not known. The present study was conducted to find out the occurrence of mendosal suture in the Indian dry skulls. Fifteen specimens (3%) were found to have these sutures out of five hundred (500) skulls examined. Nine (3.1%) samples are of male skulls out of two hundred ninety (290) and six (2.85%) samples are that of female skulls out of two hundred ten (210). The mendosal suture ran close to the superior nuchal line in all specimens and traveled medially from the lambdoidal suture. The length of the sutures ranged from 0.8 cm to 2.6 cm (1.88 cm) on the right side and 1.4 cm to 2.9 cm (1.94 cm) on the left side respectively in male skulls; and 0.7 cm to 2.8 cm (1.55 cm) on the right side and 1 cm to 2.4 cm (1.42 cm) on the left side, respectively, in female skulls. The origin of mendosal suture from the lambdoidal suture was 5.7 cm to -6.3 cm (5.98 cm) from the tip of the mastoid process on the right side and 5.6 to -6.3 cm (6 cm) on the left side, respectively, in male skulls; and 5.4 cm to -5.8 cm (5.58 cm) on the right side and 5.4 cm to -5.6 cm on the left side respectively in female skulls. The occurrence and clinical significance of the present study is discussed.

Cadavers as teachers in medical education: knowledge is the ultimate gift of body donors.

In most of the medical colleges in India, unclaimed bodies from various mortuaries reach the dissection hall; and here, the body donors club has yet to gain the desired dimensions. In spite of all the adverse circumstances, the cadaver and the dissection both have survived the most rigorous test of pedagological fitness--the test of time. Today, many of the Western countries have long donor waiting lists where cadavers are acquired as anatomical gifts or through body donor programmes. Thailand's approach to body donors offers a role model for resolving the present situation. The spirit of volunteerism reflects the drastic shift in public perception and a global change in approach is needed in the present time.