1.Skin-to-epidural distance in the Southeast Asian paediatric population: multiethnic morphometrics and international comparisons.
Jolin WONG ; Serene Siu Tin LIM
Singapore medical journal 2019;60(3):136-139
		                        		
		                        			INTRODUCTION:
		                        			Paediatric epidurals can present technical challenges due to wide variations in age and weight among children, ranging from neonates to teenagers. This study evaluated the skin-to-epidural distance in the thoracic and lumbar regions to determine the relationship between age, weight and ethnicity and depth to the epidural space in our Singapore paediatric population.
		                        		
		                        			METHODS:
		                        			Data from the Acute Pain Service was prospectively collected over 16 years. Details included patient demographics, level of epidural performed and distance from skin to epidural space. Multivariable regression analysis was performed to determine the association of weight, age, ethnicity and gender with the depths to the thoracic and lumbar epidural spaces. A simple linear regression was calculated to predict the depth to both thoracic and lumbar epidural spaces based on body weight. Equations were formulated to describe the relationship between weight and depth of epidural space.
		                        		
		                        			RESULTS:
		                        			A total of 616 midline epidurals were studied. Regression analysis was performed for 225 thoracic epidurals and 363 lumbar epidurals. Our study revealed a clear correlation between skin-to-lumbar epidural distance and weight in children. The best correlation was demonstrated between skin-to-lumbar epidural distance and body weight (R = 0.729). This relationship was described by the formula: depth (mm) = (0.63 × weight [kg]) + 9.2.
		                        		
		                        			CONCLUSION
		                        			Skin-to-lumbar epidural distance correlated with weight in children. Our results highlighted the clinical significance of differences between Southeast Asian paediatric populations when compared to other populations.
		                        		
		                        		
		                        		
		                        			Adolescent
		                        			;
		                        		
		                        			Anesthesia, Epidural
		                        			;
		                        		
		                        			adverse effects
		                        			;
		                        		
		                        			methods
		                        			;
		                        		
		                        			Body Weight
		                        			;
		                        		
		                        			Child
		                        			;
		                        		
		                        			Child, Preschool
		                        			;
		                        		
		                        			Epidural Space
		                        			;
		                        		
		                        			anatomy & histology
		                        			;
		                        		
		                        			Female
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Infant
		                        			;
		                        		
		                        			Infant, Newborn
		                        			;
		                        		
		                        			Lumbar Vertebrae
		                        			;
		                        		
		                        			anatomy & histology
		                        			;
		                        		
		                        			Male
		                        			;
		                        		
		                        			Multivariate Analysis
		                        			;
		                        		
		                        			Pain Management
		                        			;
		                        		
		                        			methods
		                        			;
		                        		
		                        			Pediatrics
		                        			;
		                        		
		                        			methods
		                        			;
		                        		
		                        			Regression Analysis
		                        			;
		                        		
		                        			Singapore
		                        			;
		                        		
		                        			Skin
		                        			;
		                        		
		                        			anatomy & histology
		                        			;
		                        		
		                        			Thoracic Vertebrae
		                        			;
		                        		
		                        			anatomy & histology
		                        			
		                        		
		                        	
2.Effects of Danshensu on bone formation in ovariectomized rats.
Tao QU ; Ping ZHENG ; Chengwei YANG ; Xu LAN ; Tao ZHANG ; Hua LIU ; Shiyong WANG
Journal of Zhejiang University. Medical sciences 2016;45(6):587-591
		                        		
		                        			
		                        			                    
To investigate the effects of Danshensu on bone formation in ovariectomized rats.Thirty female SD rats were randomly divided into three groups with 10 rats in each:blank control group, model control group and Danshensu group. The osteoporosis model was induced by bilateral ovariectomy and rats in Danshensu group were fed with Danshensu 12.5 mg·kg·dby gavage after ostroporosis model induced. All animals were sacrificed after 90 days. The bone mineral density (BMD) of the whole body, femur and lumbar vertebra was measured by dual energy X-ray absorptiometry. The biomechanical properties of femur were measured by AG-IS mechanical universal testing machine. Serum osteocalcin and bone alkaline phosphates (BALP) levels were measured by ELISA. The number of osteoblasts of proximal femoral metaphysis was counted with light microscopy after HE staining.Compared with blank control group, BMD, biomechanical properties of femur, serum osteocalcin and BALP levels and the number of osteoblasts were decreased in model control group (<0.05 or<0.01). While compared with model control group, BMDs of the whole body, femur and lumbar vertebra, the elastic modulus, maximum load, yield strength, breaking point load of femur, the serum levels of osteocalcin and BALP, and the number of osteoblasts were significantly improved in Danshensu group (<0.05 or<0.01).Danshensu can improve bone quality by increasing bone density, improving biomechanical properties, promoting the expression of osteogenesis-related factors, and increasing the number of osteoblasts.
		                        		
		                        		
		                        		
		                        			Alkaline Phosphatase
		                        			;
		                        		
		                        			blood
		                        			;
		                        		
		                        			drug effects
		                        			;
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Biomechanical Phenomena
		                        			;
		                        		
		                        			drug effects
		                        			;
		                        		
		                        			Bone Density
		                        			;
		                        		
		                        			drug effects
		                        			;
		                        		
		                        			Cell Count
		                        			;
		                        		
		                        			Female
		                        			;
		                        		
		                        			Femur
		                        			;
		                        		
		                        			anatomy & histology
		                        			;
		                        		
		                        			cytology
		                        			;
		                        		
		                        			drug effects
		                        			;
		                        		
		                        			Lactates
		                        			;
		                        		
		                        			pharmacology
		                        			;
		                        		
		                        			Lumbar Vertebrae
		                        			;
		                        		
		                        			anatomy & histology
		                        			;
		                        		
		                        			drug effects
		                        			;
		                        		
		                        			Osteoblasts
		                        			;
		                        		
		                        			drug effects
		                        			;
		                        		
		                        			Osteocalcin
		                        			;
		                        		
		                        			blood
		                        			;
		                        		
		                        			drug effects
		                        			;
		                        		
		                        			Osteogenesis
		                        			;
		                        		
		                        			drug effects
		                        			;
		                        		
		                        			Osteoporosis
		                        			;
		                        		
		                        			drug therapy
		                        			;
		                        		
		                        			Ovariectomy
		                        			;
		                        		
		                        			Rats
		                        			;
		                        		
		                        			Rats, Sprague-Dawley
		                        			
		                        		
		                        	
3.Effects of icariin total flavonoids capsule on bone mineral density and bone histomorphometry in growing rats.
Yuhai GAO ; Fangfang YANG ; Huirong XI ; Wenyuan LI ; Ping ZHEN ; Keming CHEN
Journal of Zhejiang University. Medical sciences 2016;45(6):581-586
		                        		
		                        			
		                        			                    
To investigate the effect of icariin total flavonoids capsules (ITFC) on bone mineral density (BMD) and bone histomorphometry in growing rats and its anti-osteoporosis mechanism.Thirty female SD rats were randomly divided into 3 groups:normal control group, ITFC-1 group and ITFC-2 group. Rats in ITFC-1 group and ITFC-2 group were fed with 50 mg·kg·dor 100 mg·kg·dITFC, respectively, and those in normal control group were fed with equal volume of distilled water. The whole body BMD was measured after 4, 8 and 12 weeks, and BMDs of the right femur and lumbar vertebrae were measured after 12 weeks. The serum levels of tartaric acid phosphatase 5b (TRACP 5b) and bone alkaline phosphatase (BALP) were measured by ELISA. Bone morphometry was performed on the right tibia.There were no significant differences in the body weight increase between normal control group and two ITFC groups (all>0.05). There were also no significant differences in whole body BMDs after 4 and 8 weeks between normal control group and ITFC groups (all>0.05). After 12 weeks, the whole body BMD, BMD of bone, serum BALP level and trabecular area in ITFC-1 group and ITFC-2 group were significantly higher, trabecular separation was significantly lower than that in normal control group (all<0.05); and the trabecular width and the number in ITFC-2 group were also significantly higher, and serum TRACP 5b level was significantly lower than that in normal control group (all<0.05). The BMD of bone, serum BALP level, trabecular number and area in ITFC-2 group were significantly higher, and serum TRACP 5b level was significantly lower than that in ITFC-1 group (all<0.05).ITFC can prevent osteoporosis by increasing bone density and bone formation, decreasing bone resorption and improving microstructure of bone.
		                        		
		                        		
		                        		
		                        			Alkaline Phosphatase
		                        			;
		                        		
		                        			blood
		                        			;
		                        		
		                        			drug effects
		                        			;
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Bone Density
		                        			;
		                        		
		                        			drug effects
		                        			;
		                        		
		                        			Bone Resorption
		                        			;
		                        		
		                        			drug therapy
		                        			;
		                        		
		                        			Cancellous Bone
		                        			;
		                        		
		                        			anatomy & histology
		                        			;
		                        		
		                        			Dose-Response Relationship, Drug
		                        			;
		                        		
		                        			Female
		                        			;
		                        		
		                        			Femur
		                        			;
		                        		
		                        			anatomy & histology
		                        			;
		                        		
		                        			Flavonoids
		                        			;
		                        		
		                        			pharmacology
		                        			;
		                        		
		                        			Lumbar Vertebrae
		                        			;
		                        		
		                        			anatomy & histology
		                        			;
		                        		
		                        			Osteogenesis
		                        			;
		                        		
		                        			drug effects
		                        			;
		                        		
		                        			Osteoporosis
		                        			;
		                        		
		                        			prevention & control
		                        			;
		                        		
		                        			Rats
		                        			;
		                        		
		                        			Rats, Sprague-Dawley
		                        			;
		                        		
		                        			growth & development
		                        			;
		                        		
		                        			Tartrate-Resistant Acid Phosphatase
		                        			;
		                        		
		                        			blood
		                        			;
		                        		
		                        			drug effects
		                        			;
		                        		
		                        			Tibia
		                        			;
		                        		
		                        			anatomy & histology
		                        			
		                        		
		                        	
4.Bone-length measurement at low back and its application.
Chinese Acupuncture & Moxibustion 2015;35(6):573-576
		                        		
		                        			
		                        			By reviewing some acupuncture literature regarding the settings of bone-length measurement at low back, it was found out that ancient and modern descriptions were not consistent. In China current acupuncture textbook, it was mostly described as "the horizontal distance between inner borders of two scapulas was 6 cun". However, after analysis, it was believed that this setting was not reasonable in the clinical application of acupuncture, and it was agreed with the opinion that "midpoint of inner borders of two scapulas when scapulas are in abduction position" should be taken as bone-length measurement of low back. Besides, a self-made bone-length scale was applied to locate acupoint at low back, which could provide references for its standardized application manipulation.
		                        		
		                        		
		                        		
		                        			Acupuncture
		                        			;
		                        		
		                        			education
		                        			;
		                        		
		                        			Acupuncture Points
		                        			;
		                        		
		                        			Acupuncture Therapy
		                        			;
		                        		
		                        			Back
		                        			;
		                        		
		                        			anatomy & histology
		                        			;
		                        		
		                        			Books
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Lumbar Vertebrae
		                        			;
		                        		
		                        			anatomy & histology
		                        			;
		                        		
		                        			chemistry
		                        			
		                        		
		                        	
5.Study on the morphology of sagittal of lumbar endplate in healthy adult.
Shuchao ZHAI ; Shibao LU ; Yong HAI ; Qingy WANG ; Nan KANG ; Yu WANG ; Chao KONG ; Wenzhi SUN
Chinese Journal of Surgery 2015;53(3):189-192
OBJECTIVETo provide a theoretical basis for designing of lumbar intervertebral disc prosthesis by collecting the data of the lumbar endplate morphology.
METHODSA total of 100 healthy adults were measured about the following parameters: lumbar lordosis, the Cobb angle of each segment, the concavity depth (ECD) of the endplate, the location of concavity apex (ECA) of the endplate. And a correlation analysis on lumbar lordosis and ECD, ECA was made, respectively.
RESULTSIn total, 100 volunteers were measured. The mean age of the volunteer was 40 years (range 20 - 50 years); the average depth of ECD was (2. 37 ± 1. 42) mm, the average location of ECA was (52. 21 ± 9. 70) %; the average depth of ECD of inferior endplate (IEP) was (2. 81 ± 1. 52) mm (0. 54 - 7. 60 mm), and the parameter of the superior endplate (SEP) was (1. 94 ± 1. 16)mm(0. 39 - 6. 10 mm). The average depth of ECD of the IEP was bigger than of the SEP for each lumbar vertebral body. Most of the location of ECA was at the back of the intervertebral body, the average location of ECA of IEP was (49. 60 ± 8. 78) % (22. 57% - 75. 58%), and the parameter of the SEP was (55. 03 ± 9. 90) % (16. 03% -75. 58%); the mean angle of lumbar lordosis was 39. 760 11. 25°(13. 8° - 72. 00°). There was no obvious correlation between the lumbar lordosis and the ECD (r -0. 193, P =0. 195), neither was the location of ECA(r =0. 080, P =0. 592).
CONCLUSIONMost of the location of ECA is at the back of the intervertebral body, the average depth of ECD is 2. 37 mm, the average location of ECA is 52. 21%.
Adult ; Humans ; Intervertebral Disc ; Lumbar Vertebrae ; anatomy & histology ; Lumbosacral Region ; anatomy & histology ; Middle Aged ; Prostheses and Implants ; Reference Standards ; Spine ; anatomy & histology ; Young Adult
6.Construction and analysis of a finite element model of human L4-5 lumbar segment.
Wentao YAN ; Gaiping ZHAO ; Xinguo FANG ; Haoxiang GUO ; Tong MA ; Yihui TU
Journal of Biomedical Engineering 2014;31(3):612-618
		                        		
		                        			
		                        			In the present study, a finite element model of L4-5 lumbar motion segment was established based on the CT images and a combination with image processing software, and the analysis of lumbar biomechanical characteristics was conducted on the proposed model according to different cases of flexion, extension, lateral bending and axial rotation. Firstly, the CT images of lumbar segment L4 to L5 from a healthy volunteer were selected for a three dimensional model establishment which was consisted of cortical bone, cancellous bone, posterior structure, annulus, nucleus pulposus, cartilage endplate, ligament and facet joint. The biomechanical analysis was then conducted according to different cases of flexion, extension, lateral bending and axial rotation. The results showed that the established finite element model of L4-5 lumbar segment was realistic and effective. The axial displacement of the proposed model was 0.23, 0.47, 0.76 and 1.02 mm, respectively under the pressure of 500, 1 000, 1 500 and 2 000 N, which was similar to the previous studies in vitro experiments and finite element analysis of other people under the same condition. The stress distribution of the lumbar spine and intervertebral disc accorded with the biomechanical properties of the lumbar spine under various conditions. The established finite element model has been proved to be effective in simulating the biomechanical properties of lumbar spine, and therefore laid a good foundation for the research of the implants of biomechanical properties of lumbar spine.
		                        		
		                        		
		                        		
		                        			Biomechanical Phenomena
		                        			;
		                        		
		                        			Finite Element Analysis
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Intervertebral Disc
		                        			;
		                        		
		                        			anatomy & histology
		                        			;
		                        		
		                        			Lumbar Vertebrae
		                        			;
		                        		
		                        			anatomy & histology
		                        			;
		                        		
		                        			Models, Anatomic
		                        			;
		                        		
		                        			Pressure
		                        			;
		                        		
		                        			Prostheses and Implants
		                        			;
		                        		
		                        			Range of Motion, Articular
		                        			;
		                        		
		                        			Rotation
		                        			
		                        		
		                        	
7.Are Spinal or Paraspinal Anatomic Markers Helpful for Vertebral Numbering and Diagnosing Lumbosacral Transitional Vertebrae?.
Nil TOKGOZ ; Murat UCAR ; Aylin Billur ERDOGAN ; Koray KILIC ; Cahide OZCAN
Korean Journal of Radiology 2014;15(2):258-266
		                        		
		                        			
		                        			OBJECTIVE: To evaluate the value of spinal and paraspinal anatomic markers in both the diagnosis of lumbosacral transitional vertebrae (LSTVs) and identification of vertebral levels on lumbar MRI. MATERIALS AND METHODS: Lumbar MRI from 1049 adult patients were studied. By comparing with the whole-spine localizer, the diagnostic errors in numbering vertebral segments on lumbar MRI were evaluated. The morphology of S1-2 disc, L5 and S1 body, and lumbar spinous processes (SPs) were evaluated by using sagittal MRI. The positions of right renal artery (RRA), superior mesenteric artery, aortic bifurcation (AB) and conus medullaris (CM) were described. RESULTS: The diagnostic error for evaluation of vertebral segmentation on lumbar MRI alone was 14.1%. In lumbarization, all patients revealed a well-formed S1-2 disc with squared S1 body. A rhombus-shaped L5 body in sacralization and a rectangular-shaped S1 body in lumbarization were found. The L3 had the longest SP. The most common sites of spinal and paraspinal structures were: RRA at L1 body (53.6%) and L1-2 disc (34.1%), superior mesenteric artery at L1 body (55.1%) and T12-L1 disc (31.6%), and AB at L4 body (71.1%). CM had variable locations, changing from the T12-L1 disc to L2 body. They were located at higher sacralization and lower lumbarization. CONCLUSION: The spinal morphologic features and locations of the spinal and paraspinal structures on lumbar MRI are not completely reliable for the diagnosis of LSTVs and identification on the vertebral levels.
		                        		
		                        		
		                        		
		                        			Adolescent
		                        			;
		                        		
		                        			Adult
		                        			;
		                        		
		                        			Aged
		                        			;
		                        		
		                        			Aged, 80 and over
		                        			;
		                        		
		                        			Anatomic Landmarks/*anatomy & histology
		                        			;
		                        		
		                        			Aorta, Abdominal/anatomy & histology
		                        			;
		                        		
		                        			Diagnostic Errors
		                        			;
		                        		
		                        			Female
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Intervertebral Disc/anatomy & histology
		                        			;
		                        		
		                        			Lumbar Vertebrae/*anatomy & histology
		                        			;
		                        		
		                        			Lumbosacral Region
		                        			;
		                        		
		                        			Magnetic Resonance Imaging
		                        			;
		                        		
		                        			Male
		                        			;
		                        		
		                        			Mesenteric Artery, Superior/anatomy & histology
		                        			;
		                        		
		                        			Middle Aged
		                        			;
		                        		
		                        			Renal Artery/anatomy & histology
		                        			;
		                        		
		                        			Reproducibility of Results
		                        			;
		                        		
		                        			Sacrum/*anatomy & histology
		                        			;
		                        		
		                        			Spinal Cord/anatomy & histology
		                        			;
		                        		
		                        			Spine
		                        			;
		                        		
		                        			Young Adult
		                        			
		                        		
		                        	
8.Transverse Process and Needles of Medial Branch Block to Facet Joint as Landmarks for Ultrasound-Guided Selective Nerve Root Block.
Daehee KIM ; Donghyuk CHOI ; Chungyoung KIM ; Jeongseok KIM ; Yongsoo CHOI
Clinics in Orthopedic Surgery 2013;5(1):44-48
		                        		
		                        			
		                        			BACKGROUND: Selective lumbar nerve root block (SNRB) is generally accepted as an effective treatment method for back pain with sciatica. However, it requires devices producing radioactive materials such as C-arm fluoroscopy. This study evaluated the usefulness of the longitudinal view of transverse process and needles for medial branch block as landmarks under ultrasonography. METHODS: We performed selective nerve root block for 96 nerve roots in 61 patients under the guidance of ultrasound. A curved probe was used to identify the facet joints and transverse processes. Identifying the lumbar nerve roots under the skin surface and ultrasound landmarks, the cephalad and caudal medial branch blocks were undertaken under the transverse view of sonogram first. A needle for nerve root block was inserted between the two transverse processes under longitudinal view, while estimating the depth with the needle for medial branch block. We then injected 1.0 mL of contrast medium and checked the distribution of the nerve root with C-arm fluoroscopy to evaluate the accuracy. The visual analog scale (VAS) was used to access the clinical results. RESULTS: Seven SNRBs were performed for the L2 nerve root, 15 for L3, 49 for L4, and 25 for L5, respectively. Eighty-six SNRBs (89.5%) showed successful positioning of the needles. We failed in the following cases: 1 case for the L2 nerve root; 2 for L3; 3 for L4; and 4 for L5. The failed needles were positioned at wrong leveled segments in 4 cases and inappropriate place in 6 cases. VAS was improved from 7.6 +/- 0.6 to 3.5 +/- 1.3 after the procedure. CONCLUSIONS: For SNRB in lumbar spine, the transverse processes under longitudinal view as the ultrasound landmark and the needles of medial branch block to the facet joint can be a promising guidance.
		                        		
		                        		
		                        		
		                        			Adult
		                        			;
		                        		
		                        			Aged
		                        			;
		                        		
		                        			Aged, 80 and over
		                        			;
		                        		
		                        			Chronic Disease
		                        			;
		                        		
		                        			Female
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Low Back Pain/etiology/*therapy
		                        			;
		                        		
		                        			Lumbar Vertebrae/anatomy & histology/*ultrasonography
		                        			;
		                        		
		                        			Male
		                        			;
		                        		
		                        			Middle Aged
		                        			;
		                        		
		                        			Nerve Block/*methods
		                        			;
		                        		
		                        			Sciatica/etiology/*therapy
		                        			;
		                        		
		                        			Spinal Stenosis/complications/*diagnosis
		                        			;
		                        		
		                        			Zygapophyseal Joint/anatomy & histology/ultrasonography
		                        			
		                        		
		                        	
9.Changes in Spinal Canal Diameter and Vertebral Body Height with Age.
Kyung Hyun KIM ; Jeong Yoon PARK ; Sung Uk KUH ; Dong Kyu CHIN ; Keun Su KIM ; Yong Eun CHO
Yonsei Medical Journal 2013;54(6):1498-1504
		                        		
		                        			
		                        			PURPOSE: All structures of the spine, including the spinal canal, change continuously with age. The purpose of this study was to determine how the spinal canal of the lumbar spine changes with age. The L4/5 is the most common site of spinal stenosis and has the largest flexion-extension motion, whereas the T5/6 has the least motion. Therefore, we measured the spinal canal diameter and vertebral body height at T5, T6, L4, and L5 with age. MATERIALS AND METHODS: This was a retrospective study of aged 40 to 77 years. We reviewed whole spine sagittal MRIs of 370 patients with lumbar spinal stenosis (LSS) (Group 2) and 166 herniated cervical disc (HCD) (Group 1). Each group was divided into four age groups, and demographic parameters (age, gender, height, weight, BMI), the mid-spinal canal diameter, and mid-vertebrae height at T5, T6, L4, L5 were compared. Within- and between-group comparisons were made to evaluate changes by age and correlations were carried out to evaluate the relationships between all parameters. RESULTS: Height, weight, and all radiologic parameters were significantly lower in Group 2 than Group 1. Group 1 did not show any differences, when based on age, but in Group 2, height, weight, and T6, L4, and L5 height were significantly decreased in patients in their 70's than patients in their 40's, except for spinal canal diameter. Age was associated with all parameters except spinal canal diameter. CONCLUSION: Vertebral height decreased with age, but spinal canal diameter did not change in patients with either LSS or HCD. Mid-spinal canal diameter was not affected by aging.
		                        		
		                        		
		                        		
		                        			Adult
		                        			;
		                        		
		                        			Age Factors
		                        			;
		                        		
		                        			Aged
		                        			;
		                        		
		                        			Cervical Vertebrae/anatomy & histology
		                        			;
		                        		
		                        			Female
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Intervertebral Disc Displacement/pathology
		                        			;
		                        		
		                        			Lumbar Vertebrae/*anatomy & histology
		                        			;
		                        		
		                        			Male
		                        			;
		                        		
		                        			Middle Aged
		                        			;
		                        		
		                        			Retrospective Studies
		                        			;
		                        		
		                        			Spinal Canal/*anatomy & histology
		                        			;
		                        		
		                        			Spinal Stenosis/pathology
		                        			
		                        		
		                        	
10.Assessing validation of dual fluoroscopic image matching method for measurement of in vivo spine kinematics.
Jian-Qiang BAI ; Yong-Cheng HU ; Li-Qing DU ; Jing-Liang HE ; Kai LIU ; Zhong-Jun LIU ; Qun XIA
Chinese Medical Journal 2011;124(11):1689-1694
BACKGROUNDAccurate knowledge of the spinal structural functions is critical to understand the biomechanical factors that affect spinal pathology. Many studies have investigated the human vertebral motion both in vitro and in vivo. However, determination of in vivo motion of the vertebrae under physiologic loading conditions remains a challenge in biomedical engineering because of the limitations of current technology and the complicated anatomy of the spine.
METHODSFor in vitro validation, a human lumbar specimen was imbedded with steel beads and moved to a known distance by an universal testing machine (UTM). The dual fluoroscopic system was used to capture the spine motion and reproduce the moving distance. For in vivo validation, a living subject moved the spine in various positions while bearing weight. The fluoroscopes were used to reproduce the in vivo spine positions 5 times. The standard deviations in translation and orientation of the five measurements were used to evaluate the repeatability of technique. The accuracy of vertebral outline matching with metallic marks matching technology was compared.
RESULTSThe translation positions of the human lumbar specimen could be determined with a mean accuracy less than 0.35 mm and a mean repeatability 0.36 mm for the image matching technique. The repeatability of the method in reproducing in vivo human spine six degrees of freedom (6DOF) kinematics was less than 0.43 mm in translation and less than 0.65° in rotation. The accuracy of metallic marks and vertebral outline matching did not show significant difference.
CONCLUSIONSCombining a dual fluoroscopic and computerized tomography imaging technique was accurate and reproduceable for noninvasive measurement of spine vertebral motion. The vertebral outline matching technique could be a useful technique for matching of vertebral positions and orientations which can evaluate and improve the efficacy of the various surgical treatments.
Biomechanical Phenomena ; Fluoroscopy ; methods ; Humans ; In Vitro Techniques ; Lumbar Vertebrae ; anatomy & histology ; physiology ; Middle Aged ; Spine ; anatomy & histology ; physiology
            
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