Surachai Sae-Jung

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.

Prevention of peridural fibrosis using a cyclooxygenase-2 inhibitor (nonsteroidal anti-inflammatory drug) soaked in absorbable gelatin sponge: an experimental comparative animal model.

Study Design. Experimental study. Objective. To evaluate the efficacy and safety of peridural parecoxib-soaked absorbable gelatin sponge, and cellulose membrane on peridural fibrosis prevention in an animal model. Summary of Background Data. Postoperative peridural fibrosis is one of the causes of failed back surgery syndrome. Nonsteroidal anti-inflammatory drugs inhibit the inflammatory response, while an absorbable gelatin sponge or cellulose membrane interposes between the dura and the paraspinal muscle to staunch the surgical bleeding. These mechanisms may prevent peridural fibrosis. Methods. Forty L5–L6 laminectomized adult Sprague-Dawley rats were randomly allocated into 4 groups. The high parecoxib group received 6 mg of parecoxib soaked into an absorbable gelatin sponge placed over the dura. The low parecoxib group was given 2 mg of parecoxib soaked into an absorbable gelatin sponge. The dura in the cellulose group was covered with a cellulose membrane, while the control group received normal saline drip before surgical wound closure. All rats were killed at 6 weeks for histopathological assessment. The fibroblast density, inflammatory cell density, fibrous adherence, and adverse events were quantified. The obtained results were analyzed statistically. Results. The respective mean fibroblast density in the high parecoxib, low parecoxib, cellulose, and control groups was 217.77 ± 51.76, 317.51 ± 126.92, 321.80 ± 90.94, and 328.48 ± 73.41 cells/mm2, while the respective mean inflammatory cell density was 539.65 ± 236.52, 910.17 ± 242.59, 1011.84 ± 239.30, and 1261.78 ± 319.68 cells/mm2. The mean fibroblast and inflammatory cell densities of the high parecoxib group were significantly lower than the control. The high parecoxib group also showed statistically less fibrous adherence than low parecoxib, cellulose, and control groups. Conclusion. The high-dose parecoxib-soaked absorbable gelatin sponge can prevent peridural fibrosis without complications. The low-dose parecoxib and cellulose membrane provided no significant benefit vis-à-vis prevention of peridural fibrosis, as adduced from the lack of any statistically significant difference between the test and control rats. Level of Evidence: N/A

Interrater Reliability of the Postoperative Epidural Fibrosis Classification: A Histopathologic Study in the Rat Model

Study Design Agreement study. Purpose To validate the interrater reliability of the histopathological classification of the post-laminectomy epidural fibrosis in an animal model. Overview of Literature Epidural fibrosis is a common cause of failed back surgery syndrome. Many animal experiments have been developed to investigate the prevention of epidural fibrosis. One of the common outcome measurements is the epidural fibrous adherence grading, but the classification has not yet been validated. Methods Five identical sets of histopathological digital files of L5-L6 laminectomized adult Sprague-Dawley rats, representing various degrees of postoperative epidural fibrous adherence were randomized and evaluated by five independent assessors masked to the study processes. Epidural fibrosis was rated as grade 0 (no fibrosis), grade 1 (thin fibrous band), grade 2 (continuous fibrous adherence for less than two-thirds of the laminectomy area), or grade 3 (large fibrotic tissue for more than two-thirds of the laminectomy area). A statistical analysis was performed. Results Four hundred slides were independently evaluated by each assessor. The percent agreement and intraclass correlation coefficient (ICC) between each pair of assessors varied from 73.5% to 81.3% and from 0.81 to 0.86, respectively. The overall ICC was 0.83 (95% confidence interval, 0.81-0.86). Conclusions The postoperative epidural fibrosis classification showed almost perfect agreement among the assessors. This classification can be used in research involving the histopathology of postoperative epidural fibrosis; for example, for the development of preventions of postoperative epidural fibrosis or treatment in an animal model.

Percutaneous release of the A1 pulley using a modified Kirschner wire: a cadaveric study

Purpose. To evaluate the outcome of percutaneous release of the A1 pulley in 40 cadaveric fingers using a modified Kirschner wire. Methods. A 2.5-mm-diameter Kirschner wire measuring >12 cm in length was used. One end of the wire was sharpened into a ‘J’ shape using a grinder. The J-shaped tip featured a blunt, elongated lower tip, a sharp J-shaped curve, and a blunt upper tip. Completeness of A1 pulley release and injuries to the A2 pulley, flexor tendon, and neurovascular structures were evaluated in 40 cadaveric fingers. Results. Complete release of the A1 pulley was achieved in 8 index, 7 middle, 8 ring, and 8 little fingers, whereas incomplete release of the distal part was noted in 2 index, 2 middle, 2 ring, and one little fingers; release was missed in one middle and one little fingers. Injury to the A2 pulley was noted in 2 index fingers; the injury was minimal and limited to the proximal 2 mm of the A2 pulley. There was no flexor tendon or digital nerve injury in any finger.

Version of Femoral Neck: A Cadaveric Dried Bone Study

El objetivo fue medir el cuello femoral en femures humanos de tailandeses adultos. La version del cuello femoral es muy variable. Es importante conocer la version de cuello femoral en una poblacion en particular para llevar a cabo con exito una cirugia reconstructiva. Se utilizaron 216 femures secos de adultos tailandeses obtenidos de la coleccion del Departamento de Anatomia de la Facultad de Medicina de la Universidad de Khon Kaen, Tailandia. La anteversion 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 anteversion y retroversion. La AFM promedio en hombres no mostro diferencia significativa con la anteversion media de las mujeres. Se observo 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 retroversion promedio en hombres no mostro ninguna diferencia significativa con la retroversion media en las mujeres. Estos grados de AFM deben ser considerados en la planificacion de una cirugia reconstructiva del cuello femoral.

Chitosan Pad, Cellulose Membrane, or Gelatin Sponge for Peridural Bleeding: An Efficacy Study on a Lumbar Laminectomized Rat Model

Study Design Experimental study in an animal model. Purpose This study aims to evaluate the hemostatic properties of four common hemostatic materials including the chitosan clot pad, absorbable gelatin sponge, cellulose membrane, and gauze on peridural bleeding using a rat model. Overview of Literature Intraoperative bleeding during spinal surgery can lead to morbidities. Hemostatic materials have been developed, but the efficacy of these materials on peridural bleeding remains unclear. Methods Forty 8-week-old Sprague-Dawley rats were used in this study. Under adequate anesthesia, each rat was posteriorly dissected to their L5 and L6 spinous processes. Bleeding from muscles and soft tissue dissections was stopped before lumbar bone cutting. Immediately after the L5–L6 laminae were cut and removed, the rats were randomly allocated to receive one of the abovementioned hemostatic materials. All hemostatic materials were placed over the raw surface of cut bone and dura and changed every 60 seconds. The procedure was stopped when there was no further bleeding. Time to staunching and amount of bleeding were recorded for statistical analysis. Results The respective mean±standard deviation hemorrhage volume and time for the cellulose membrane, gelatin sponge, chitosan pad, and gauze were 1.19±0.44, 1.03±0.72, 0.96±0.57, and 1.98±0.62 mL, respectively, and 2.9±0.6, 2.1±0.6, 1.7±0.5, and 2.9±1.0 minutes, respectively. The overall bleeding volumes for the cellulose membrane, gelatin sponge, and chitosan pad were significantly lower than the overall bleeding volume for gauze. Conclusions Chitosan clot pads, gelatin sponges, and cellulose membranes have better hemostatic properties than gauze. The chitosan pad had the lowest average bleeding volume, followed by gelatin sponge and cellulose membrane.

Clinical correlation of cervical myelopathy and the hyperactive pectoralis reflex.

Study Design: A diagnostic study. Objective: To validate the correlation between hyperactive pectoralis reflex and the level of cervical myelopathy. Summary of Background Data: The hyperactive pectoralis reflex was proposed to be present in patients with spinal cord compression at the C2–3 and/or C3–4 level. Nevertheless, in a validation study on the correlation of various hyperactive reflexes and the cervical myelopathic level, this particular reflex was not evaluated. Methods: All patients presenting with cervical myelopathy between August 2009 and June 2012 were included in this study. Each patient underwent neurological examination for cervical myelopathy focusing on the examination of pathologic reflexes, including the hyperactive pectoralis reflex. We recorded the presence or absence of these reflexes and the level of cervical myelopathy as detected on magnetic resonance imaging. We used the level of spinal cord compression—cranial to C4 of the vertebral body—as the reference level to validate a hyperactive pectoralis reflex. Results: The study included 95 cervical myelopathy patients: 33 patients had most of their compressed cervical cord somewhere above the C4 vertebral body. The hyperactive pectoralis reflex for cervical myelopathy at this level had a respective sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of 84.8%, 96.7%, 26.67, and 0.16. Conclusions: The high sensitivity and specificity of the hyperactive pectoralis reflex is very useful for screening and diagnosis of the cervical myelopathic level when it is above the C4 vertebral body.