Occipital emissary foramina in South Indian modern human skulls.

An occipital emissary foramen has been traditionally described as a foramen present in the squamous part of the occipital bone at the occipital protuberance transmitting a vein that connects the confluence of sinuses with the occipital vein. The present study was done on 221 South Indian adult modern human skulls of unknown sex in the Department of Anatomy, St John's Medical College, Bangalore, India. The foramen was observed in 21/221 (9.50%) skulls, 6/21 (28.57%) to the right of, 10/21 (47.61%) to the left of, and 2/21 (9.52%) on the External Occipital Crest. It was seen more often near the posterior margin of foramen magnum rather than at the External Occipital Protuberance as has been traditionally described. A new finding is that bilateral foramina were observed in 3 skulls (14.28%). The incidence was higher than seen in other Indian population. Since it is present near the foramen magnum in most cases, knowledge of the number and position of the foramen is important for suboccipital craniotomies. The extensive connections of the veins with cranial venous sinuses may lead to intracranial infections and vice versa.

Estimation of total length of humerus from its segments.

The aim of the present study was to calculate the total length of the humerus from its segments using linear, transverse and sagittal measures. One hundred and fifty dry adult unpaired humeri of both sides and of unknown sex from South India were studied. The humeri were divided into eight segments using salient bony points and muscular markings. The length of each segment was compared with the total length. These were subjected to statistical analysis. A high degree of correlation was found between segment length and total length and hence regression equations were calculated to estimate total length of humerus from each segment. The difference in measurements of the right and left sides was insignificant; hence single equations were calculated for all 150 bones. The length of the humerus and finally the stature of the individual could be calculated fairly accurately with an error of less than 2 cm. The results were compared with similar studies on other Indian populations. Calculation of total length from longer segments is comparable with other Indian populations, but if only shorter segments are available, new equations are needed for each population.

Subclavius posticus muscle: a case report

A rare case of subclavius posticus muscle observed in a male cadaver is reported here. Presence of such accessory muscles have been recognized as possible causes of neurovascular compression syndromes in this region. It has been suggested by several authors that presence of accessory muscles like subclavius posticus can be a potential cause of thoracic outlet syndrome.

Es reportado un caso raro de músculo subclavio posticus observado en un cadáver de sexo masculino. La presencia de tales músculos accesorios ha sido reconocida como posible causa de los síndromes de compresión neurovascular en esta región. Varios autores han sugerido que la presencia de músculos accesorios como subclavio posticus, puede ser una causa potencial del síndrome de salida torácica.

Variations in brachial plexus and the relationship of median nerve with the axillary artery: a case report.

BACKGROUND: Brachial Plexus innervates the upper limb. As it is the point of formation of many nerves, variations are common. Knowledge of these is important to anatomists, radiologists, anesthesiologists and surgeons. The presence of anatomical variations of the peripheral nervous system is often used to explain unexpected clinical signs and symptoms. CASE PRESENTATION: On routine dissection of an embalmed 57 year old male cadaver, variations were found in the formation of divisions and cords of the Brachial Plexus of the right side. Some previously unreported findings observed were; direct branches to the muscles Pectoralis Minor and Latissimus dorsi from C6, innervation of deltoid by C6 and C7 roots and the origin of lateral pectoral nerve from the posterior division of upper trunk. The median nerve was present lateral to axillary artery. The left side brachial plexus was also inspected and found to have normal anatomy. CONCLUSION: The probable cause for such variations and their embryological basis is discussed in the paper. It is also concluded that although these variations may not have affected the functioning of upper limb in this individual, knowledge of such variations is essential in evaluation of unexplained sensory and motor loss after trauma and surgical interventions to the upper limb.

Supratrochlear foramen of the humerus.

The presence of the supratrochlear foramen was studied in 150 dry adult humeri, of unknown sex from the Department of Anatomy, St John's Medical College, Bangalore: The dimensions of the foramen were measured. In bones where the foramen was absent, opacity or translucency of the septum was observed. A supratrochlear foramen was found in 28% of the total humerii. It was almost equal in number on both the sides (right, 27.9%; left, 27.8%). Most of the foramina were oval in shape, their transverse and vertical diameters being, on average, 6.92 mm and 4.64 mm, respectively. A translucent septum was seen in 66% of the bones, in 51.51% of right and in 48.48% of the left. Only nine bones had opaque septae (6%). The study was done on bones belonging to South Indians and the findings were compared with the data available on other races. The paper discusses the evolutionary aspects of the foramen in addition to its surgical and orthopedic significance.