Morphometric study and anatomical variation with its incidence of foramina transversaria on the lower cervical vertebrae / Estudio morfométrico y variación anatómica con la incidencia de forámenes transversos en las vértebras cervicales inferiores

SUMMARY: Anatomical variation of the foramina transversaria (FT) is associated with vertebral neurovascular symptoms and can cause complications after lower spine surgery, especially cervical pedicle screw (CPS) insertion. FT variation has been documented and classified in various populations, as this information can help increase cervical stability in subaxial vertebral surgery. Although the morphometry of the upper cervical spine in Thai populations has been reported, there have yet been no studies examining the features of FT. The FT of dried cervical spines (C3-C7; left and right side; n = 107, male = 53 and female = 54) were examined for morphological variation, and their anteroposterior (AP) and transverse (T) diameters were measured using a digital vernier caliper. Morphometric data and variations were compared by sex and lateral side. It was that the C3-C6 FT in both sexes were round, and the C7 FT was elliptical with an oblique right side. FT diameters did not differ significantly by sex except for the AP diameters of C6-C7 and for T diameters of C4 and C7. The left AP diameters of C3-C6 were significantly longer than the right, as were the T diameters of C4 and C7 FT. Additionally, T diameter was significantly longer than that of the AP, except that of the left C6 in male spines, which did not differ from the AP. Most FT examined were round. These findings should be considered in the provisional diagnosis of vertebral neurovascular symptoms caused by FT variation as well as that of neurovascular damage after cervical pedicle screw placement.

La variación anatómica del foramen transverso (FT) se asocia con síntomas neurovasculares vertebrales y puede causar complicaciones después de la cirugía de columna cervical inferior, especialmente la inserción de tornillos pediculares cervicales (TPC). La variación del FT se ha documentado y clasificado en varias poblaciones, ya que esta información puede ayudar a aumentar la estabilidad cervical en la cirugía vertebral subaxial. Aunque se ha informado sobre la morfometría de la columna cervical superior en poblaciones tailandesas, aún no se han realizado estudios que examinen las características de FT. Se examinó la variación morfológica del FT de vértebras cervicales secas (C3-C7; lado izquierdo y derecho; n = 107, hombres = 53 y mujeres = 54), y se midieron sus diámetros anteroposterior (AP) y transverso (T) usando un pie de metro digital. Se compararon datos morfométricos y variaciones por sexo y lado. Los FT de C3-a C6 en ambos sexos eran redondos, y el FT C7 era elíptico con el lado derecho oblicuo. Los diámetros del FT no difirieron significativamente por sexo excepto para los diámetros AP de C6- C7 y para los diámetros transversos de C4 y C7. Los diámetros AP izquierdos de C3-C6 eran significativamente más largos que los del lado derecho, al igual que los diámetros transversos de C4 y C7. Además, el diámetro transverso fue significativamente mayor que el AP, excepto el C6 izquierdo en las vértebras de hombres, que no difirió del AP. La mayoría de los FT examinados eran redondos. Estos hallazgos deben ser considerados en el diagnóstico provisional de síntomas neurovasculares vertebrales causados por la variación del FT, así como en el de daño neurovascular tras la colocación de tornillos pediculares cervicales.

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.

The invention of new anterior spinal instrumentation prototype: a structural analysis of KKU expandable cage.

OBJECTIVE: Report the invention and structural analysis of the new model of anterior spinal instrumentation (KKU expandable cage) that is expandable for space filling after vertebral body resection while simultaneously stabilize the upper vertebra with the lower vertebra, to tolerate the thoracolumbar physiologic load and augment the interbody arthrodesis of the spine. MATERIAL AND METHOD: The new model of expandable anterior spinal instrumentation, named KKU expandable cage, was invented and designed using the computer. The structural property of this instrumentation was tested and analyzed using the computer based structural analysis software. RESULTS: The KKU expandable cage made out of 316L stainless steel is 0.0301044 kg in mass and 3.76305 x 10(-6) m3 for volume. The outer diameter of the device is 23 mm and the height can expand from 20 mm to 35 mm for space filling after thoracolumbar vertebrectomy. The stress in the device after applying the maximal thoracolumbar physiologic compression load (1250N) is between 11692.7 N/m2 to 94.7266 x 10(6) N/m2, less than compression strength of the 316L stainless steel (170 x 10(6) N/m2). CONCLUSION: The stainless steel 316 L KKU expandable cage for anterior spinal instrumentation can withstand the maximal thoracolumbar physiologic compression load without failure whereas its expandable property enable it to fill and fit in the space reaching the height of 35 mm. Therefore, the insertion of this device into a space after thoracolumbar or lumbar corpectomy or vertebrectomy for the vertebral osteomyelitis or vertebral metastasis is appropriate. The device can also stabilize the spine and tolerate the maximal physiologic compression load of the thoracolumbar vertebrae. Therefore, the device helps decrease the need for bone graft or bone substitute in these patients.

KKU knee compression-rotation test for detection of meniscal tears: a comparative study of its diagnostic accuracy with McMurray test.

OBJECTIVE: The purpose of the present study was to compare the sensitivity, specificity and diagnostic accuracy of a new test, named "KKU Knee Compression-Rotation Test", with the most widely used examination, McMurray test. MATERIAL AND METHOD: Sixty-eight patients aged 18 to 39 years old were included in the present study. All of these patients were interviewed for their knee injury histories and examined with both KKU knee compression-rotation and McMurray tests preoperatively. For these clinical examination tests, the sensitivity, specificity, false positive, false negative and diagnostic accuracy rates were calculated and compared with the arthroscopic findings of these patients. RESULTS: The KKU knee compression-rotation test had sensitivity, specificity, and diagnostic accuracy for detection of meniscal tear as 86.27, 88.23, and 86.76% respectively, which superior to McMurray test that was 70.59, 82.35, and 73.53%. In addition, the KKU knee compression-rotation test had false positive and false negative rates of 11.76 and 13.73% less than the 17.65 and 29.41% of McMurray test. The combination of these two tests had diagnostic sensitivity of 90.20% and positive result of both tests suggested torn meniscus with the probability of 97.14%. CONCLUSION: The KKU knee compression-rotation test for detection of torn meniscus had better rates of diagnostic sensitivity, specificity, and accuracy than McMurray test. Therefore, the KKU knee compression-rotation test can be the first line screening examination for detection of torn meniscus. However, if the patient is tested by both the KKU knee compression-rotation and the McMurray tests, it will be a better screening test because a high sensitivity and positive result of both tests suggests a diagnosis of torn meniscus accurately.