Classification and incidence of pterion patterns of Thai skulls / Clasificación e incidencia de los patrones de pterion en cráneos de Tailandia

SUMMARY: The pterion, a landmark for neurosurgery, is the weakest part of the skull owing to relatively thin bone. Variant patterns of pterion can confuse the clinicians during diagnosis of the lateral skull fractures in emergency situations. Thedifferent pterion types of many races have been reported but not of Thais. In this study; therefore, we investigated the incidence of sutural pterion patterns on of Thai skulls. The infratemporal fossa of 110 sides from 55 dried skulls identified as Thais were observed and classified for individual pterion types. The results showed that the pterion patterns can be classified into 4 types; spheno-parietal (87.27 %), fronto-temporal (4.55 %), uni-epipteric (6.36 %), and multi-epipteric (1.82 %) types. It was found that the spheno-parietal type was dominant in males (61.81 %) than in females (25.45 %). The majority of the skulls showed bilateral symmetry (85.45 %) in all types and the unilateral ones were far less (14.55 %). In bilateral pterion incidence, the spheno-parietal type was approximately 93.61 % while the uni-epipteric type was not found. Moreover, the bilateral multi-epipteric type was found only in one female skull (2.13 %). These findings will be useful for the radiologists and the neurosurgeons concerning lateral skull fractures in emergency diagnosis.

RESUMEN: El pterion es un punto de referencia para la neurocirugía, y es la parte más débil del cráneo debido a estar conformado por hueso relativamente delgado. Los diversos patrones de pterion pueden confundir a los clínicos durante el diagnóstico de fracturas laterales de cráneo en situaciones de emergencia. Con excepción de los tailandeses, diferentes tipos de pterion se han reportado en muchas razas. hemos investigado la incidencia de diversos patrones de pterion en cráneos de Tailandia. Analizamos 110 fosas infratemporales, correspondientes a 55 cráneos secos del Noreste de Tailandia y se clasificaron de acuerdo al tipo de pterion. Los resultados mostraron que el pterion puede clasificarse en 4 tipos: esfeno-parietal (87,27 %), fronto-temporal (4,55 %), epiptérico (3,63 %) y multi-epiptérico (1,81 %). Se encontró que el tipo esfeno-parietal tuvo mayor incidencia en hombres (61,81 %) que en mujeres (25,45 %). Además, la incidencia de simetría bilateral (85,45 %) fue mayor que la unilateral (14,55 %). A nivel bilateral, el tipo esfeno-parietal fue de 93,61 %, mientras que el tipo epiptérico no se observó. Por otra parte, el tipo multiepiptérico fue encontrado bilateralmente en un solo cráneo femenino (2,13 %). Esta incidencia puede ser utilizada como un conocimiento básico para los radiólogos tailandeses sobre las fracturas laterales del cráneo en un diagnóstico de emergencia.

Incidence of unusual formation of the median nerve in Thai-Northeast embalmed cadavers / Incidencia de la formación inusual del nervio mediano en cadáveres embalsamados del noreste de Tailandia

This study aimed to investigate the incidence of unusual formation of the median nerve in Thai cadavers. Two hundred and ninety-two upper limbs were dissected and observed. The results showed that 5 out of 292 (1.71 %) arms had unusual splitting of median nerve that supplied the flexor arm muscles. Concomitantly, the musculocutaneous nerve was absent. In 4 out of 5 variant arms (80 % or 1.37 % of total upper limbs), each median nerve was unusually formed by 3 roots; the first and second roots were from lateral cord and the third one from medial cord. The union of the second lateral and medial roots to become a median nerve distantly extended in the arm. The second lateral roots gave off small muscular branches to the upper part of flexor arm muscles. Knowledge of such anatomical variations is helpful for surgeons in performing of brachial plexus surgery.

Este estudio tuvo como objetivo investigar la incidencia en la formación inusual del nervio mediano en cadáveres tailandeses. Se disecaron y observaron 292 miembros superiores. En 5 casos (1,71 %) se presentó una división inusual del nervio mediano que suministraba los nervios para los músculos flexores del brazo. Concomitantemente, el nervio musculocutáneo estaba ausente. En 4 de los 5 casos (80 % o 1,37 % del total de los miembros superiores), cada nervio mediano se formó por 3 raíces; la primera y segunda raíces procedían del fascículo lateral y la tercera del fascículo medial. La unión de la segundas raíces lateral y medial formaban el nervio mediano distalmente en el brazo. Las segundas raíces laterales daban pequeños ramos musculares a la parte superior de los músculos flexores del brazo. El conocimiento de tales variaciones anatómicas es útil para los cirujanos en la realización de la cirugía del plexo braquial.

Incidence of metopism in adult Thai skulls / Incidencia de metopismo en cráneos tailandeses adultos

The persistent metopic suture on adult skull (also known as metopism) can confuse the clinicians during diagnosis of the frontal bone fractures in emergency conditions. The incidences of metopism have been documented in many populations except in Thais. Therefore, this study was aimed to determine the incidence of metopism in adult Thai skulls. The identified 706 Thai dried skulls (481 males and 225 females) were carried out for metopic suture observations. The results showed that 53 skulls (7.51%) were present of the metopic sutures. The metopism observed could be classified into major two types (complete metopic suture (20 skulls [2.83%]) and incomplete metopic suture (33 skulls [4.67%]). For the incomplete metopic suture could be further classified into two subtypes, bregma-incomplete metopic suture and nasion- incomplete metopic suture. This incidence maybe a basic information for Thai radiologists to concern about metopic suture in emergency diagnosis of frontal bone fractures.

La persistencia de la sutura metópica en el cráneo adulto (también conocido como metopismo) puede provocar confusión en los médicos durante el diagnóstico de las fracturas de los huesos frontales en situaciones de emergencia. La incidencia de metopismo se ha documentado en muchas poblaciones, excepto en individuos tailandeses. Por lo tanto, este estudio tuvo como objetivo determinar la incidencia de metopismo en cráneos tailandeses adultos. Se identificaron 706 cráneos secos (481 hombres y 225 mujeres) y se llevó a cabo la observación de ls sutura metópica. Los resultados mostraron que en 53 cráneos (7,51%) estaba presente la sutura metópica. Según nuestras observaciones, el metopismo podría ser clasificado en dos tipos principales: sutura metópica completa (20 cráneos [2,83%]) y sutura metópica incompleta (33 cráneos 4,67%). A su vez, la sutura metópica incompleta podría ser clasificada en dos subtipos: sutura metópica incompleta "bregma" y sutura metópica incompleta "nasion". Consideramos que la indicedencia de metopismo registrado en este trabajo configura una información de relevancia para los radiólogos tailandeses en relación a la sutura metópica y el correcto diagnóstico en la emergencia de fracturas óseas frontales.

Version of femoral neck: a cadaveric dried bone study / Versión del cuello femoral: estudio cadavérico sobre huesos secos

The aim of this study was to measure the version of femoral neck on dried Thai human femora. The version of femoral neck varies widely. It is important to know the version of femoral neck in a particular population to undertake successful femoral neck reconstructive surgery. Paired 216 dried femora of adult Thais from the bone collection maintained in the Department of Anatomy at the Faculty of Medicine, Khon Kaen University, Thailand, were used to measure the version of femoral neck. The mean+SD femoral anteversion (FNA) was 16.21+5.24 degrees. The 95% confidence interval of FNA was from 15.48 to 16.94 degrees. The 95% confidence intervals of male and female average FNA were 14.75 to 16.90 and 15.59 to 17.59 degrees respectively. There was no significance difference of the FNA between males and females in both anteversion and retroversion groups. The average male FNA showed no statistical difference to average female anteversion. The 95% confidence intervals of males and females average retroversion were -8.22 to -4.80 and -7.71 to -4.47 degrees respectively. The average male retroversion showed no statistical difference to average female retroversion. The overall 95% confidence interval of femoral neck anteversion and retroversion were 15.48 to 16.94 degrees and -7.33 to -5.27 with no significant difference between males and females. These degrees of FNA must be considered when the femoral neck reconstructive surgery is planned.

El objetivo fue medir el cuello femoral en fémures humanos de tailandeses adultos. La versión del cuello femoral es muy variable. Es importante conocer la versión de cuello femoral en una población en particular para llevar a cabo con éxito una cirugía reconstructiva. Se utilizaron 216 fémures secos de adultos tailandeses obtenidos de la colección del Departamento de Anatomía de la Facultad de Medicina de la Universidad de Khon Kaen, Tailandia. La anteversión femoral (AFM) media+DE fue de 16,21±5,24. El intervalo de confianza del 95% de la AFM fue entre 15,48 a 16,94. El promedio de intervalos de confianza del 95% en hombres y mujeres fue desde 14,75 a 16,90 y 15,59 a 17,59, respectivamente. No hubo diferencia significativa entre hombres y mujeres en ambos grupos de anteversión y retroversión. La AFM promedio en hombres no mostró diferencia significativa con la anteversión media de las mujeres. Se observó un promedio de -8,22 a -4,80 y -7,71 a -4,47 en el 95% de los intervalos de confianza entre hombres y mujeres, respectivamente. La retroversión promedio en hombres no mostró ninguna diferencia significativa con la retroversión media en las mujeres. Estos grados de AFM deben ser considerados en la planificación de una cirugía reconstructiva del cuello femoral.

Aortic bifurcation: a cadaveric study of its relationship to the spine.

BACKGROUND: Vascular injuries are the main complication of the anterior approach to the lumbosacral spines. One of the key procedural steps is the identification and gentle manipulation of the aortic bifurcation to prevent the vascular injury and provide the adequate exposure during anterior lumbosacral operation. OBJECTIVE: The present study was to determine the level of abdominal aortic bifurcation in Thai cadavers. MATERIAL AND METHOD: The abdominal aortic bifurcation was studied on 187 cadavers (132 men, 55 women). The average ages of the cadavers were 67.3 +/- 0.8 years (range from 30 to 88 years). The accurate site of the abdominal aortic bifurcation was determined by the relationship of the bifurcation with the level of neighbor lumbosacral spine. RESULTS: The abdominal aorta descended and bifurcated into two common iliac arteries at the level of L4 vertebra in 131 cases (70.1%), at the fourth lumbar intervertebral disc in 23 cases (12.3%), and at the level of L5 vertebra in 33 cases (17.6%). CONCLUSION: The precise location of aortic bifurcation is useful for surgeons in the anterior approach of the lumbosacral spine to prevent harmful vascular injury.

Thicknesses of the iliac crest appropriate for anterior cervical interbody fusion grafts.

Autogenous tricortical iliac crest bone graft is the most widely used for the anterior cervical interbody fusion procedure. The authors performed systematic measurements to delineate the thickest areas of the iliac crest, so that surgeons would know where to select the appropriate grafts for cervical interbody fusion. The Department of Anatomy, Faculty of Medicine, Khon Kaen University, supplied 232 iliac crests (116 left; 116 right) dried hip bones donated by 67 Thai males and 49 Thai females. The deceased averaged 59 years of age (range, 26-86). The thickest part of the iliac crest extended from 3 to 5 cm posterior to the ASIS and ranged between 15.59 and 17.02 mm. These regions have an appropriate thickness for harvesting graft material.

An anatomical study of anomalous renal pedicle.

Typically, the renal pedicle is located at the renal hilum, such that the renal vein is anterior to the renal artery, which in turn is anterior to the renal pelvis. Objective: Student dissection of cadavers to observe typical anatomy and observe variations that may occur. Methods: The Gross Anatomy Laboratory, Faculty of Medicine, Khon Kaen University. Results: A total of 180 Thai cadavers were dissected in anatomical practice, during the years 1998 to 2000. Anomalous renal pedicles were found in the cadavers of a 49 year-old female and a 80 year-old male. In the female, the anomalous renal pedicle presented on both the left and right sides. Both the renal pelvises were anterior to the renal vessels. We also found supernumerary renal arteries. The male had only a right anomalous renal pedicle, in which the right renal pelvis lay anterior to the right renal vessel. Variations of the renal arteries were found in this case as well. Conclusion: These observations are important so that during surgery, care be taken in retroperitoneal operations, especially pyelolithotomy.