The vertebral pedicle is an important structure used as an implant site for spinal instrumentation surgery. Since precise anatomical knowledge of lumbar pedicles in vivo is essential for risk - free surgery, we analyzed Korean vertebrae with radiologic imaging techniques. The authors analayzed 500 pedicles from L1 to L5 vertebrae with computerized tomograms (CT) and simple radiograms taken from patient free of vertebral abnormality. Five morphometric parameters: transverse pedicle width, transverse pedicle angle, sagittal pedicle width, sagittal pedicle angle depth to anterior cortex were measured. The transverse diameter and angle of pedicle increased gradually from L1 to L5, while the sagittal diameter and angle decreased from L1 to L5. The depth to anterior cortex from posterior elements was longer along the pedicle axis than along axis parallel to midline.
Axis, Cervical Vertebra ; Humans ; Lumbar Vertebrae* ; Spine

OBJECTIVE: This study was undertaken to study pedicle morphology in Koreans to provide a reference guide in transpedicular screw fixation. METHODS: Pedicle measurements were obtained from 35 dried human lumbar columns(175 lumbar vertebrae). Anatomic evaluation was focused on pedicle transverse diameter, pedicle axis length and the distance from the pedicle axis point to the midline of the transverse process. Pedicle angle and vertebral body length also were measured. RESULT: In the transverse plan, pedicle diameter increased from L1(7.8mm) to L5(15.5mm). But in 20.0% of L1 and L2, its diameters was under 6.0mm. In the sagittal plan, it was not as constant and had similar diameter from L1 to L5. In the transverse plan, the pedicle angle increased from L1 to L5. But in the sagittal plan it decreased from L1 to L5. Also, the pedicle axis length did not show concordant change, but rather had similar length in lumbar vertebrae. In 15%, its length was under 45mm. CONCLUSION: These results suggest that using above 6mm diameter and 45mm length of screw for L1 and L2 can violate the pedicle and vertebrae. Above L4, the pedicle axis point was superior to the midline of the transverse process, below L4, it was inferior to the midline of the transverse process. This information may prove to be helpful when contemplating the placement of screws to the lumbar pedicles.
Axis, Cervical Vertebra ; Humans ; Lumbar Vertebrae* ; Spine

OBJECTIVE: To establish normative data for spinal canal AP diameter from cervical vertebra to sacrum in the Korean young and to assess the exposed spinal canal after laminectomy which was related with restenosis by post-laminectomy membrane formation. METHODS: From PET/CT, axial bone-window CT of 83 young adults (20-29 years) were obtained, and we measured AP diameters of C3, C5, C7, T1, T4, T8, T12, L1, L3, L5 and S1. We also measured exposed AP diameter of C3, C5, C7, T1 and T2 above imaginary line for laminectomy. RESULTS: The shortest mean AP diameter was at C5 (14.5+/-1.5 mm), and the longest was at S1 (17.4+/-2.3 mm). AP diameter increased from C3 (14.6+/-1.1 mm) to T1 (16.1+/-1.2 mm) at cervical spine. In the thoracic spine, the diameter gradually decreased from T1 (16.1+/-1.2 mm) to T8 (14.6+/-1.3 mm) and increased to T12 (16.7+/-1.2 mm). The diameter decreased from L1 (16.7+/-1.3 mm) to L3 (15.7+/-1.9 mm), and it increased to S1 (17.4+/-2.3 mm) at lumbar spine. Exposed AP diameter above imaginary line for laminectomy was the longest at C3 (4.8+/-1.2 mm) and gradually decreased to T1 (3.3+/-0.9 mm) and T2 (0 mm). CONCLUSIONS: Spinal AP diameter was the shortest in the mid-cervical area (C5) and increased to the upper thoracic area. From the upper thoracic vertebra, the diameter gradually decreased to the mid-thoracic vertebra (T8) and then increased to the lower thoracic vertebra. Lumbar vertebra also was similar with thoracic vertebra. Below T2, there was no exposed dural sac after laminectomy. This means that restenosis by post-laminectomy membrane formation can occur above T1.
Cervical Vertebrae ; Female ; Humans ; Laminectomy ; Lumbar Vertebrae ; Membranes ; Sacrum ; Spinal Canal ; Spine ; Thoracic Vertebrae ; Young Adult

Fibrous dysplasia is a benign disorder of bone primarily affecting young people from childhood through the third decade. It usually manifests as an enlargement of bones in and about the orbits or the the cranial vault. Whether localized or diffuse, it rarely involves the cervical spine. We report a case of fibrous dysplasia involving axis combined with atlantoaxial instability which was caused by odontoid process fracture. Transfacetal screw fixation augmented with Halifax interlaminar clamp technique was applied to obtain atlantoaxial stability. Postoperative course was unevenful and postoperative radiologic findings revealed favorable fixation of atlantoaxial joint. The pertinent literature on fibrous dysplasia and atlantoaxial instability is reviewed and discussed.
Atlanto-Axial Joint ; Axis, Cervical Vertebra ; Odontoid Process ; Orbit ; Spine*

OBJECTIVE: The purpose of this study was to investigate morphological change at the craniovertebral junction (CVJ) region using computed tomography. METHODS: A total of 238 patients were included in this study, and mean age was 47.8+/-21.3 months. Spinal canal diameter, Power's ratio, McRae line, antero-posterior C1 ring height, atlantoaxial joint space, C2 growth, epidural space from the dens (M-PB-C2) and longitudinal distance (basion to C2 lower margin, B-C2) were measured. The mean value of each parameter was assessed for individual age groups. The cohorts were then divided into three larger age groups : infancy (I) (< or =2 years), very early (VE) childhood (2-5 years) and early (E) childhood (5> or = years). RESULTS: Spinal canal diameter increased with age; however, this value did not increase with statistical significance after VE age. A significant age-related difference was found for all C2 body and odontoid parameters (p<0.05). Mean McRae line was 8.5, 8, and 7.5 mm in the I, VE, and E groups, respectively. The M-PB-C2 line showed up-and-down dynamic change during early pediatric periods. CONCLUSION: Expansion of the spinal canal was restricted to the very early childhood period (less than 5 years) in the CVJ region; however, the C2 body and odontoid process increased continuously with age. The above results induced a dynamic change in the M-PB-C2 line. Although C2 longitudinal growth continued with age, the McRae line showed relatively little change.
Atlanto-Axial Joint ; Cohort Studies ; Epidural Space ; Humans ; Odontoid Process ; Spinal Canal ; Spine*

OBJECTIVETo investigate the clinical value of different magnetic resonance (MR) pulse sequences in diagnosis of spinal metastatic tumor.

METHODSFifteen patients with clinically suspected spinal metastatic tumor were included in this study. These patients were with documented primary tumors. Four MR pulse sequences, T1-weighted spin echo (T1WI SE), T2-weighted fast spin echo (T2WI FSE), short time inversion recovery (STIR), and gradient echo 2-D multi echo data imaging combination (GE Me-2D) were used to detect spinal metastasis.

RESULTSFifteen vertebral bodies were entire involvement, 38 vertebral bodies were section involvement, and totally 53 vertebral bodies were involved. There were 19 focal infections in pedicle of vertebral arch, 15 metastases in spinous process and transverse process. Fifty-three vertebral bodies were abnormal in T1 WI SE and GE Me-2D, 35 vertebral bodies were found abnormal in T2WI FSE, and 50 vertebral bodies were found abnormal in STIR. The verges of focal signal of involved vertebral bodies were comparatively clear in T1WI SE, comparatively clear or vague in T2WI FSE, vague in STIR, and clear in GE Me-2D.

CONCLUSIONSGE Me-2D may be the most sensitive technique to detect metastases. So three sequences (T1WI SE, T2WI FSE, GE Me-2D) can demonstrate the early changes of spinal metastasis roundly.

Cervical Vertebrae ; diagnostic imaging ; Coccyx ; diagnostic imaging ; Humans ; Lumbar Vertebrae ; diagnostic imaging ; Magnetic Resonance Imaging ; methods ; Neoplasm Metastasis ; pathology ; Radiography ; Sacrum ; diagnostic imaging ; Sensitivity and Specificity ; Spinal Neoplasms ; pathology ; secondary ; Spine ; diagnostic imaging ; Thoracic Vertebrae ; diagnostic imaging

Air within the spinal canal called pneumorrhachis has been seen rarely. We report a case showing multiple air pockets in the paraspinal and epidural space with vacuum disc and review pathogenesis and treatment of pneumorrhachis.
Epidural Space ; Intervertebral Disc ; Pneumorrhachis* ; Spinal Canal ; Spine ; Vacuum*

Few morphometric data on the thickness and the inclination of vertebral lamina are found with its frequent involvement in many surgical procedures. The thickness in the middle of right vertebral lamina and the angle between the superior border of lamina and sagittal plane were measured in 90 dried vertebral columns. 1. The laminae of the cervical vertebrae were generally thin and they became gradually thicker down to the lumbar vertebrae. The lamina of the fifth lumbar vertebra was the thickest (9.4mm) and that of the fifth cervical was the thinnest (2.9mm). The thickest lamina appeared in second cervical, twelfth thoracic and fourth lumbar vertebrae in 71%, 44% and 36%, respectively. 2. The angles between superior border of long axes of the laminae and the sagittal plane were the widest in thoracic vertebrae, and narrower in lumbar, the narrowest in cervical vertebrae. The angle of eithth thoracic was the widest (59.8°) and that of the fifth lumbar was the narrowest (48.6°). Widest angle of lamina appeared in seventh cervical, sixth thoracic and fifh lumbar vertebra in 27%, 20% and 48%, respectively. 3. No significant differences were found in the thicknesses and the angles of inclination of vertebral laminae between males and females.
Adult* ; Cervical Vertebrae ; Female ; Humans ; Lumbar Vertebrae ; Male ; Spine ; Thoracic Vertebrae

OBJECTIVES: To analyze the fracture type and adjacency of accompanied fractures in acute osteoporotic spinal compression fracture using whole spine sagittal MRI (WS-MRI), and to know the relation of sagittal vertical axis (SVA), body mass index (BMI), and lumbar bone mineral density (BMD). METHODS: From June 2007 to December 2010, 167 patients who had acute spinal compression fractures confirmed by WS-MRI divide in three groups. 82 patients (M/F : 25/57) who had acute fractures only were in group 1, 79 patients who had acute and old fractures were in group 2, and 20 patients who had acute fractures after vertebroplasy were in group 3. To analyze the fracture type and adjacency of accompanied fractures in acute osteoporotic spinal compression fractures which combined chronic fracture or vertebroplasty using the WS-MRI and compared with the control group who had no spinal fractures measured the SVA. In all groups, we measured BMI, and BMD. RESULTS: In WS-MRI, 31 patients in group 1 had L1 which was the most common fracture site. Twenty two patients had chronic fractures and more than 3 remote levels at the acute fracture site in group 2 and especially among there 14 patients have each level in cervicothoracic and lumbar vertebrae. In group 3 had old fracture and adjacent fracture was 14 and 11 patients. Compared with the control group, all groups had increased SVA, especially in group 2 which has acute and chronic compression fractures. They have no significantly difference of BMI in each group, but group 2 and 3 had a significant lower BMD than group 1. CONCLUSION: Fourteen patients of coexisting fractures in acute osteoporotic spinal compression fractures with WS-MRI which could be missed in the conventional MRI. Additionally this study suggests that longer SVA causes sagittal imbalance, and BMD is more relative than BMI in refractures of chronic compression fracture patients.
Axis, Cervical Vertebra ; Body Mass Index ; Bone Density ; Fractures, Compression ; Humans ; Lumbar Vertebrae ; Osteoporosis ; Spinal Fractures ; Spine ; Vertebroplasty

STUDY DESIGN: The relationships between aorta and thoracic vertebrae were analyzed by using MR images. OBJECTIVES: The purpose of this study was to provide information upon the thoracic aortic passage to prevent vascular compli-cations during anterior and posterior instrumentations for various spinal disorders and traumas. SUMMARY OF BACKGROUND DATA: A number of morphometric investigations have been performed on the thoracic vertebrae, but the anatomical relationship between aorta and the thoracic vertebral body has not been analyzed. METHODS: The MR images of 32 patients with normal thoracic vertebral column were obtained. The angle between the transverse axis of the thoracic vertebral body and the thoracic aorta, the diameter of the thoracic aorta and the closest distance between the thoracic vertebral body and the thoracic aorta from T2 to T12 were measured on axial MR images. RESULTS: The smallest angle between the transverse axis of the thoracic vertebral body and the line connecting the centers of the vertebral body and aorta was 6.8 degrees/3.7 degrees(male/female) in the T5-6 region and highest angle observed was 56.3 degrees/55 degrees in the T12 region. The angle decreased between T2 and T5-6 and then increased after T6. The mean external diameter of the thoracic aorta was 32.8 mm, and the largest diameter of the thoracic aorta was 24.7/25.4 mm (M/F) in the T4-5 region. The aortic arch was first seen in the T2 region and it formed an arch in the T3-4 region. The shortest distance between the thoracic vertebral body and the thoracic aorta wall was 0.8/0.7 mm in the T12 region and the greatest distance between the vertebral body and the aorta was 11.84/6.75 mm in the T2-3 region. CONCLUSION: From T4 to T8, the aorta is located just left lateral to the vertebral body. In this area, the aorta is jeopardized by a screw penetrating the vertebral body during anterior instrumentation, if the screw protrudes beyond the pedicle during posterior instrumentation. The surgeon should be familiar with the anatomical relationship between aorta and the vertebral column when planning a surgical procedure or the use of instrumentation in this region.
Aorta ; Aorta, Thoracic ; Axis, Cervical Vertebra ; Humans ; Magnetic Resonance Imaging* ; Spine ; Thoracic Vertebrae