A Morphometric Study on Subaxial Cervical Pedicles of Thai People.

STUDY DESIGN: This study investigated the subaxial cervical pedicles from C3 to C7 to provide information for accurately transpedicular screw fixation in this region. OBJECTIVE: This study was evaluated the morphology of the subaxial cervical pedicle to determine the size and trajectory of screw fixation. SUMMARY OF BACKGROUND DATA: Cervical vertebrae are an important structure to protect the neurovascular structure. The cervical spine surgery using screw fixation is an effective method to treat the cervical spine instability. There have been many research morphological data of subaxial cervical vertebrae. However, no studies have reports on dried cervical vertebrae of Thai's people. METHODS: The measurement was conducted in 130 dried cervical vertebrae (C3-C7), including 61 males and 69 females. The measurement parameters were pedicle width (PW), pedicle length (PL), pedicle height (PH), pedicle axis length (PAL), pedicle transverse angle (PTA), and pedicle sagittal angle (PSA), which determined using ImageJ software. RESULTS: The results of morphological data of C3 to C7 was found that the mean of PW, PL, PH, PAL, PTA, and PSA that obtained from male were significantly higher than female excepted for PL (C7) and PTA (C3, C5). Except for the C6 PW, C3 PL, C4 to C5 to C7 PTA, and C4 PSA, there were no significant differences of these parameters between male and female. CONCLUSION: The appropriate pedicle screw size is 4.0 mm for C3 and C4, and 4.5 mm for C5 to C7. The results of this study are the useful information for cervical spine fixation while prevent the vascular and neurological injuries from the large screw causing pedicle breakage. LEVEL OF EVIDENCE: 3.

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.

Classification of portal vein tributaries in Thai cadavers including a new type V.

PURPOSE: To compare portal vein tributaries in Thai with Thompson classification. METHODS: In 211 Thai cadavers, abdominal regions were dissected to identify the portal veins and their tributaries. The subjects were classified into types based on modes of drainage of the left gastric and inferior mesenteric veins. Percentages of all types of venous drainage were counted. RESULTS: There are four types of portal tributaries as defined by Thompson, type I_47.87 %, type II_13.27 %, type III_7.58 %, and type IV_29.86 %. There were 1.42 % of whose inferior mesenteric veins entered the joining angle of the superior mesenteric and splenic veins, and were classified as type V. The left gastric vein mostly drained into the portal vein in 79.15 %, while the inferior mesenteric vein emptied into the splenic vein mainly in 55.45 %. CONCLUSIONS: A new variance of portal tributaries in Thai cadavers is reported. The variations of portal vein formations are critical for liver surgery and interventional radiological procedures.

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.

Awareness of the median sacral artery during lumbosacral spinal surgery: an anatomic cadaveric study of its relationship to the lumbosacral spine.

PURPOSE: The purpose was to investigate the median sacral artery (MSA) anatomical pathway in terms of its relationship to the lumbosacral spine. METHODS: The posterior wall and lumbosacral spine of 54 adult embalmed cadavers were dissected. The MSA emerging point was identified. The distance from its emerging point to the lateral border of the vertebral body was measured bilaterally. The pathway of the MSA from the emerging point to the sacral promontory was described together with the MSA length. All outcomes were independently measured by two observers. Statistics on obtained data were calculated. RESULTS: Most of the MSA emerging points were at the L5 vertebral body (94.4 %). The emerging point from the right and left lateral border of the L5 vertebral body was 3.31 ± 0.54 cm and 2.39 ± 0.51 cm, respectively. The MSA then lay along the middle one-third of the anterior surface of the lumbosacral junction. The mean length between the emerging point and the sacral promontory was 2.73 ± 0.97 cm. CONCLUSIONS: The MSA anatomy is important for prevention of intra-operative bleeding. For anterior lumbosacral surgery, the MSA should be identified and controlled before proceeding with the spinal surgery. For posterior bicortical sacral screw placement, the screw tip should be fluoroscopically checked to avoid inserting the screw tip into the mid sacral promontory. By first approaching the anterior sacral promontory, the surgeon will find the MSA within the middle one-third zone, and 2.47-2.99 cm cephalad to this, the iliac vessels. Knowledge of the MSA helps the surgeon to operate more safely.

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.

Occipitalization of the atlas: its incidence and clinical implications.

OBJECTIVE: The aim of the present study was to investigate the incidence of occipitalization of the atlas among Thai dried skulls, in order to contribute to baseline awareness of this condition. MATERIALS AND METHODS: The skulls of 633 adult Thais from the collection maintained in the Department of Anatomy, Faculty of Medicine, Khon Kaen University, Thailand, were examined for evidence of occipitalization of the atlas. The skulls were well-preserved and did not show any traits of craniofacial deformation. The skulls for which the age and sex were unknown were excluded from the analysis. From the cadaveric records on each individual, we learned that the skulls belonged to 373 men (age of decease between 25 and 90 years), and 260 women (age of decease between 28 and 92 years). RESULTS: Occipitalization of the atlas was detected in 2 skulls (0.32%). The first case was a male skull (54 years of age at decease), where the atlas was partially fused to the occipital bone. The second case was also a male skull (59 years of age at decease) showing complete fusion of the anterior arch of the atlas. CONCLUSION: The incidence of occipitalization of the atlas is low; however, if present this abnormality may cause a wide range of neurological problems. Knowledge of occipitalization of the atlas may be of substantial importance to orthopedists, neurosurgeons, physiotherapists and radiologists dealing with abnormalities of the cervical spine. Mistaken diagnoses have led to delayed treatment and at times adverse results.

A rare variation of posterior cord brachial plexus branching coexisting with the intercalated ectopic muscle.

During a dissection of the brachial plexus we found a rare variation of left posterior cord branching coexisting with an unusual intercalated ectopic muscle. This muscle originated from the shoulder joint capsule at the lesser tubercle on insertion of the subscapularis then pierced between the brachial plexus, enclosed by two roots of the radial nerve, and inserted into the upper part of the latissimus dorsi muscle. The variant posterior cord divided into two roots; a thin lateral and thick medial root. The lateral root gave off the thoracodorsal nerve that penetrated and also innervated the ectopic muscle. The medial root gave off five nerve branches; two upper subscapular, one lower subscapular, one axillary and one terminal branch. A terminal branch fused with the lateral root to form a loop enclosing the ectopic muscle then continued as the radial nerve. This type of variation may be useful to interpret unexplained clinical signs and symptoms and provided additional knowledge to surgeons who perform brachial plexus surgery.

The right ovarian artery arising from the right inferior phrenic artery: a case report.

OBJECTIVE: To report a case of the right ovarian artery arising from the right inferior phrenic artery. MATERIAL AND METHOD: The authors carried out the standard dissection survey of 810 embalmed female cadavers between 1983 and 2010. RESULTS: The authors encountered a case of the right ovarian artery arising from the right inferior phrenic artery in a donated cadaver aged 53 years at decease. CONCLUSION: With the advent of intra-abdominal laparoscopic techniques, the anatomy of the ovarian artery has assumed much more importance.

Duplicated axillary arch muscles arising from the latissimus dorsi.

Many origins and insertions of an axillary muscular slip (also known as Langer's or axillary arch muscles) have been documented previously. In this report, we found duplicated axillary arch muscles (two variant muscular slips) originating from the inferolateral border of the right side latissimus dorsi muscle. Obviously, these axillary arch muscles can be distinguished as short and long muscular strips. While the origin was the same, the short muscular slip inserts into the fascia covering on the pectoralis minor, whereas the longer one inserts on/into the aponeurosis of pectoralis major. For the surgery in the axillary region, this rare variation should be considered a cause of surgical interventions.

Incidence of the accessory internal thoracic artery and its safety area in the thoracic wall.

OBJECTIVE: To provide the incidence, origin, size and the safety area of the accessory internal thoracic artery (AITA) in the fourth intercostal space. MATERIAL AND METHOD: One hundred and thirty two thoracic cages were dissected and examined for the presence of AITA. The origin, course, diameter and location in the fourth intercostal space of detected AITA were investigated. RESULTS: AITA with diameter ranging from 0.6 to 3.05 (mean = 1.76 +/- 0.69) millimeters existed in 10 of 132 (7.58%) cadavers. They originated from the upper part of the internal thoracic artery, close and inferior to the subclavian artery (0-3 cm, mean = 2.4 +/- 0.78) and ran inferolaterally on the deep surface of the thoracic wall and ended in the second to the sixth intercostal spaces. Most of them ended in the fifth intercostal spaces (28.57%). The artery was present bilaterally in 4 cases (3.03%) and unilaterally in 6 cases (4.55%). Most of these arteries were located close to the midaxillary line (0-3 cm, mean = 1.73 +/- 1.18) in the fourth intercostal space which is endangered in several surgical procedures such as thoracoscopy. CONCLUSION: Even the incidence of AITA is low (7.57%) but when present, it is endangered in thoracic surgical procedures. The safety area of AITA for surgical procedures in the fourth intercostal space is at least 3 centimeters anterior to the midaxillary line.

Left sided inferior vena cava: a case report.

OBJECTIVE: To report a case of left sided inferior vena cava (IVC). MATERIAL AND METHOD: The authors carried out the standard dissection survey of939 embalmed cadavers between 1974 and 2008. RESULTS: The authors encountered a case of left sided IVC in a male donated cadaver aged 65 years at decease. The IVC formed behind the left common iliac artery at the L5 vertebra and coursed proximally on the left of the aorta until it reached the left renal vein and then crossed anterior to the abdominal aorta to assume the normal right side. At the point of crossing, it received the left renal vein. The right renal vein emptied into the IVC on the right side. CONCLUSION: In the era of laparoscopic urological surgery, preoperative diagnosis of this uncommon but important entity is essential to prevent unwarranted surgical mishaps.

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.

Shape of the lingula and its localization by panoramic radiograph versus dry mandibular measurement.

BACKGROUND: To evaluate the incidence of lingula shapes in Thai adult mandibles and to compare the accuracy of panoramic radiograph measurement with the dry mandible measurements for localizing the position of the lingula. METHODS: Seventy-two dry adult mandibles (144 sides) from 52 males and 20 females of Thai origin were classified as triangular, truncated, nodular or assimilated. Twenty-three mandibles, composed of both first molar and canine on the same side (33 sides), were selected for distance measurement. The ten distances from the lingula to the anterior, posterior ramus, to the coronoid notch and lower border of the mandible were measured on the dry mandibles and compared with the same distances on panoramic radiographs. The distribution of the lingula shape is described. Paired t test and correlation were used to evaluate the accuracy of panoramic radiographs in localizing the position of the lingula. RESULTS: Truncated lingula were most commonly found (68 sides or 47%). Nodular, triangular and assimilated shapes were found in 33 (23%), 24 (17%) and 19 subjects (13%), respectively. The distance differences between the panoramic radiograph measurement and the dry mandible measurement were statistically significant (P < 0.01). The positive correlations between the panoramic and dry skull measurements were high (0.59-0.91). CONCLUSIONS: The lingula has different shapes in different populations. In adult Thai mandibles, the truncated lingula shape is most common. Panoramic radiographs present not only the position but also the shape and number of lingula and mandibular foramen. There is a high concordance between the measured distances in panoramic radiography and dry mandibles.

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.