Kinematic analysis of dynamic lumbar motion in patients with lumbar segmental instability using digital videofluoroscopy

The study design is a prospective, case–control. The aim of this study was to develop a reliable measurement technique for the assessment of lumbar spine kinematics using digital video fluoroscopy in a group of patients with low back pain (LBP) and a control group. Lumbar segmental instability (LSI) is one subgroup of nonspecific LBP the diagnosis of which has not been clarified. The diagnosis of LSI has traditionally relied on the use of lateral functional (flexion–extension) radiographs but use of this method has proven unsatisfactory. Fifteen patients with chronic low back pain suspected to have LSI and 15 matched healthy subjects were recruited. Pulsed digital videofluoroscopy was used to investigate kinematics of lumbar motion segments during flexion and extension movements in vivo. Intersegmental linear translation and angular displacement, and pathway of instantaneous center of rotation (PICR) were calculated for each lumbar motion segment. Movement pattern of lumbar spine between two groups and during the full sagittal plane range of motion were analyzed using ANOVA with repeated measures design. Intersegmental linear translation was significantly higher in patients during both flexion and extension movements at L5–S1 segment (p < 0.05). Arc length of PICR was significantly higher in patients for L1–L2 and L5–S1 motion segments during extension movement (p < 0.05). This study determined some kinematic differences between two groups during the full range of lumbar spine. Devices, such as digital videofluoroscopy can assist in identifying better criteria for diagnosis of LSI in otherwise nonspecific low back pain patients in hope of providing more specific treatment.     

Osteosarcoma of the lumbar spine--a case report]

Primary osteogenic sarcoma of the spine is a very rare tumor. A case of osteosarcoma of the lumbar spine in a 22-year-old man is presented. Diagnosis was obtained by an open biopsy. Tumor was resected. The clinical and radiological pre and postoperative findings are described.     

Reliability of computer-assisted lumbar intervertebral measurements using a novel vertebral motion analysis system

Background contextTraditional methods for the evaluation of in vivo spine kinematics introduce significant measurement variability. Digital videofluoroscopic techniques coupled with computer-assisted measurements have been shown to reduce such error, as well as provide detailed information about spinal motion otherwise unobtainable by standard roentgenograms. Studies have evaluated the precision of computer-assisted fluoroscopic measurements; however, a formal clinical evaluation and comparison with manual methods is unavailable. Further, it is essential to establish reliability of novel measurements systems compared with standard techniques.PurposeTo determine the repeatability and reproducibility of sagittal lumbar intervertebral measurements using a new system for the evaluation of lumbar spine motion.Study designReliability evaluation of digitized manual versus computer-assisted measurements of the lumbar spine using motion sequences from a videofluoroscopic technique.Patient sampleA total of 205 intervertebral levels from 61 patients were retrospectively evaluated in this study.Outcome measuresCoefficient of repeatability (CR), limits of agreement (LOA), intraclass correlation coefficient (ICC; type 3,1), and standard error of measurement.MethodsIntervertebral rotations and translations (IVR and IVT) were each measured twice by three physicians using the KineGraph vertebral motion analysis (VMA) system and twice by three different physicians using a digitized manual technique. Each observer evaluated all images independently. Intra- and interobserver statistics were compiled based on the methods of Bland-Altman (CR, LOA) and Shrout-Fleiss (ICC, standard error of measurement).ResultsThe VMA measurements demonstrated substantially more precision compared with the manual technique. Intraobserver measurements were the most reliable, with a CR of 1.53 (manual, 8.28) for IVR, and 2.20 (manual, 11.75) for IVT. The least reliable measurements were interobserver IVR and IVT, with a CR of 2.15 (manual, 9.88) and 3.90 (manual, 12.43), respectively. The ICCs and standard error results followed the same pattern.ConclusionsThe VMA system markedly reduced variability of lumbar intervertebral measurements compared with a digitized manual analysis. Further, computer-assisted fluoroscopic imaging techniques demonstrate precision within the range of computer-assisted X-ray analysis techniques.     

Rotational hypermobility of disc wedging using kinematic CT: preliminary study to investigate the instability of discs in degenerated scoliosis in the lumbar spine

The number of patients showing lumbar degenerative scoliosis, including disc wedging, has increased, and examination of the mechanism of spinal nerve compression due to lateral and rotational mobility of the lumbar spine is necessary. Thirty-two patients with L4–L5 disc wedging but without antero- or retrospondylolisthesis and ten age-matched controls were examined. The angle of disc wedging and change in the angle between left and right bending were evaluated by anterior–posterior X-ray images of patients while they were in a standing position. The degree of disc degeneration and existence of vacuum phenomena were evaluated at the L4–L5 discs. Rotational mobility between maximal right and left rotation was examined by computed tomography (CT). Rotational mobility was measured using the spinal transverse processes of L4 and L5. The relationship between these factors was statistically evaluated using multivariate analysis and Spearman’s correlation test. There was a significant increase in the average rotational mobility of the L4–L5 disc-wedging group. In the L4–L5 disc-wedging group, the increased angle of disc wedging and change in the angle between left and right bending correlated with increased rotational mobility. The degree of disc degeneration did not affect rotational mobility. However, existence of vacuum phenomena increased the rotational mobility of the L4–L5 disc-wedging group. This is the first study to evaluate the rotational hypermobility of L4–L5 disc wedging in patients without antero- or retrospondylolisthesis using kinematic CT. Increases in the wedging angle and abnormal instability of lateral bending correlated with increased rotational mobility. For surgical planning of degenerative L4–L5 disc wedging, it is important to consider rotational hypermobility using kinematic CT or X-ray imaging findings of lateral bending.     

An analysis of wrist and forearm range of motion using the Dartfish motion analysis system

Study DesignClinical measurement.IntroductionWrist range of motion (ROM) is considered the universal measurement of success for both surgical and non-surgical treatments. A goniometer can be challenging for an individual to use by themselves, whereas the Dartfish app can analyze and provide immediate feedback to monitor and evaluate patients’ kinematic changes during recovery after injury.Purpose of StudyTo establish the validity and reliability of the Dartfish app measuring ROM to be used in clinical applications.MethodsTwelve healthy participants, (18-25 yrs) , with no previous history of wrist injuries, were recruited for this study. Flexion/extension, radial/ulnar deviation, and supination/pronation range of motion measures were collected using a goniometer (two-arm) and Dartfish video analysis. Statistical analyses, such as t-tests and the Pearson correlation coefficient, as well as reliability analyses, such as intraclass correlation coefficient (ICC) and Bland-Altman plots, were performed.ResultsThere was no significant difference between the goniometer and Dartfish ROM measurements except for ulnar deviation. The concurrent validity showed nearly perfect correlations between examiners using Dartfish with r-values in the range 0.90-0.99, and between examiner2 and the goniometer showed medium, large, and very large correlations since the values were in the range 0.418-0.829. The ICC for test-retest reliability had an excellent agreement that ranged from 0.993-0.999, and the ICC values for inter-observer reliability had good and excellent agreement, which were in the range 0.893-0.997.ConclusionOverall, the results demonstrated that the Dartfish app was a reliable and valid method to measure wrist and forearm ROM. A patient would be able to easily record their own ROM measurement videos and track their progress during their recovery without the need of their physician to track their progress.     

表面钛涂层椎间融合系统治疗腰椎管狭窄症伴腰椎不稳症

目的 探讨应用解剖型表面钛涂层椎间融合系统治疗腰椎管狭窄症伴腰椎不稳症的临床疗效.方法 回顾总结2003年1月至2004年6月采用解剖型表面钛涂层椎间融合系统治疗腰椎管狭窄症伴腰椎不稳症46例,男19例,女27例;年龄53～71岁,平均62岁.融合节段:L3,4 5例,L4,5 29例,L5S1 10例,L3,4+L4,5 1例,L4,8+L5S1 1例.行后路椎管减压、椎体间融合术,均植入2枚解剖型表面微孔钛涂层实心融合器,全部加用椎弓根螺钉内固定并辅以后外侧植骨,椎间隙不予植骨.测量术后6、12及24个月时椎间隙高度丢失情况,融合节段稳定性以及融合器周围成骨情况并进行对比,采用JOA评分及Oswestry功能障碍指数进行临床疗效评定.结果 全部病例均得到随访,随访时间25～31个月,平均27个月.术后椎间隙高度得到满意恢复,随访中未发现有明显丢失,融合节段稳定性良好.JOA评分及ODI指数均显示临床疗效良好.2例出现术中硬脊膜撕裂,未有遗留神经症状.结论 解剖型表面钛涂层椎间融合器和既往的中空融合器相比,在提供稳定的融合环境的同时有利于新生骨的形成,有效地提高了融合率,应用于腰椎管狭窄症伴腰椎不稳症的治疗是安全,有效的方法.     

Posterolateral fusion of the lumbar and lumbosacral spine--a review of long term results

1. Long-term results of posterolateral lumbar and lumbosacral spinal fusion were evaluated in 40 patients who had been treated by this technique 10 years or more (mean: 14 years and 6 months). 2. In the clinical evaluation employing the criteria for assessment by the Japanese Orthopaedic Association (JOA score), the total score averaged 24.2 points. The roentgenographically assessed bone union rate was 93.2%. At the site of operation, the angular displacement was within 5 degrees and the horizontal displacement ranged from 0.7% to 1.4%. Thus, a long-term stability was confirmed. 3. Although age-related problems such as osteoporosis remain unsolved, the long-term results were so good that this technique can be recommended as a salvage operation in patients with an unstable spine or those requiring decompression from the posterior approach.     

Slump sitting X-ray of the lumbar spine is superior to the conventional flexion view in assessing lumbar spine instability

Background Context

Flexion radiographs have been used to identify cases of spinal instability. However, current methods are not standardized and are not sufficiently sensitive or specific to identify instability.

Evaluation of lumbar segmental instability in degenerative diseases by using a new intraoperative measurement system

OBJECT: In vivo quantitative measurement of lumbar segmental stability has not been established. The authors developed a new measurement system to determine intraoperative lumbar stability. The objective of this study was to clarify the biomechanical properties of degenerative lumbar segments by using the new method. METHODS: Twenty-two patients with a degenerative symptomatic segment were studied and their measurements compared with those obtained in normal or asymptomatic degenerative segments (Normal group). The measurement system produces cyclic flexion-extension through spinous process holders by using a computer-controlled motion generator with all ligamentous structures intact. The following biomechanical parameters were determined: stiffness, absorption energy (AE), and neutral zone (NZ). Discs with degeneration were divided into 2 groups based on magnetic resonance imaging grading: degeneration without collapse (Collapse[-]) and degeneration with collapse (Collapse[+]). Biomechanical parameters were compared among the groups. Relationships among the biomechanical parameters and age, diagnosis, or radiographic parameters were analyzed. RESULTS: The mean stiffness value in the Normal group was significantly greater than that in Collapse(-) or Collapse(+) group. There was no significant difference in the average AE value among the Normal, Collapse(-), and Collapse(+) groups. The NZ in the Collapse(-) was significantly higher than in the Normal or Collapse(+) groups. Stiffness was negatively and NZ was positively correlated with age. Stiffness demonstrated a significant negative and NZ a significant positive relationship with disc height, however. CONCLUSIONS: There were no significant differences in stiffness between spines in the Collapse(-) and Collapse(+) groups. The values of a more sensitive parameter, NZ, were higher in Collapse(-) than in Collapse(+) groups, demonstrating that degenerative segments with preserved disc height have a latent instability compared to segments with collapsed discs.     

In vivo elbow biomechanical analysis during flexion: three-dimensional motion analysis using magnetic resonance imaging

The purpose of this article is to evaluate in vivo 3-dimensional kinematics of the elbow joint during elbow flexion. We studied the ulnohumeral and radiohumeral joint noninvasively in 3 elbows in healthy volunteers using a markerless bone registration algorithm. Magnetic resonance images were acquired in 6 positions of elbow flexion. The inferred contact areas on the ulna against the trochlea tended to occur only on the medial facet of the trochlear notch in all of the elbow positions we tested. The inferred contact areas on the radial head against the capitellum occurred on the central depression of the radial head in all of the tested elbow positions except for 135 degrees flexion, where the anterior rim of the radial head articulates with the capitellum.     

A biomechanical study of posterolateral lumbar fusion using a three-dimensional nonlinear finite element method

Biomechanical analyses under compressive load, flexion, and extension torque were performed, using a nonlinear three-dimensional finite element method, to evaluate stability in posterolateral fusion. Effects of facet fusion and disc denucleation on posterolateral fusion were also examined. Using an initially prepared L4–5 motion segment model, we prepared a denucleation model, posterolateral fusion models classified by presence or absence of denucleation and facet fusion, and an interbody fusion model. In the denucleation model, rigidity was less than in the normal model, and maximum rigidity was analyzed for the interbody fusion model. The effect of denucleation on posterolateral fusion was also analyzed. Taking into account the instability of the anterior elements, including the intervertebral disc, appears to be clinically important. In the posterolateral fusion model under compressive load, the axis of rotation moved principally toward the fusion mass, and axial displacement and flexion rotation were induced. Sagittal rotation angles under flexion and extension torque were 1.5°–2.3° at a maximum moment of 15 N-m, demonstrating elasticity of posterolateral fusion. When combined with facet fusion, posterolateral fusion yielded increase of load transfer across the lamina and decrease of rotation angle of about 10% under flexion-extension torque. Adjunctive clinical use of facet fusion should permit more solid posterolateral fusion. Received for publication on Dec. 4, 1997; accepted on Oct. 26, 1998     

Rotational instability of the patella on radiographic images

Summary In the period from 1980 to 1981, knee joint radiographs were made in 82 patients following the clinical diagnosis of patellar chondropathy. A total of 119 knee joints with patellar chondropathy and 45 with no specific complaints on the contralateral side, in addition to a control cohort consisting of 28 persons, i.e., 56 knee joints with no complaints, were evaluated. Tangential radiographic images of the patellae enabled us to measure directly the rotation of the patella around the axis perpendicular to its center. It could be established that all healthy patellae underwent medial rotation between 45 and 60 degrees of knee flexion which was maintained up to 90 degrees, whereas the affected knee joints did not rotate.     

Rotational instability of the patella on radiographic images

In the period from 1980 to 1981, knee joint radiographs were made in 82 patients following the clinical diagnosis of patellar chondropathy. A total of 119 knee joints with patellar chondropathy and 45 with no specific complaints on the contralateral side, in addition to a control cohort consisting of 28 persons, i.e., 56 knee joints with no complaints, were evaluated. Tangential radiographic images of the patellae enabled us to measure directly the rotation of the patella around the axis perpendicular to its center. It could be established that all healthy patellae underwent medial rotation between 45 and 60 degrees of knee flexion which was maintained up to 90 degrees, whereas the affected knee joints did not rotate.     

基于CT三维重建的上颈椎三维活动度在体测量研究

目的:采用CT三维重建的方法测量健康成年人上颈椎寰枕关节、寰枢关节的各个方向上的活动度及其耦合运动,以及颈椎病患者上颈椎最大旋转位的三维活动度,并作对比分析,同时验证所使用的测量方法的可靠性。方法:2014年1月至2015年6月,选取20个健康成年受试者(健康成年组),其中男11例,女9例,年龄22～26(24.0±1.2)岁;26个颈椎病患者(颈椎病组),其中男24例,女2例,年龄36～72(52.8±8.6)岁。采集健康成年人中立位、最大右侧旋转位、最大右侧侧屈位及最大屈曲位、最大背伸位5个位置的及颈椎病患者中立位、最大右侧旋转位上颈椎(含枕骨大孔)的CT图像。利用软件Mimics将所得CT重建为三维图像。在各个椎体(或枕骨)上选取明显的解剖标志点进行标注,根据所标注的解剖标志点建立局部坐标系,局部坐标系即代表了所在椎体的位置及方向。利用Pro/Engineer及MATLAB软件运算出上位椎体(或枕骨)相对下位椎体的活动度及颈部整体三维活动度,并比较颈椎病组和健康成年组差异。因解剖标志点识别有人为差异,选取两名实验员进行3次测量,用组内相关系数(组内ICC)和组间相关系数(组间ICC)验证实验方法的可靠性。结果:可靠性验证结果:组内ICC、组间ICC结果均在0.90以上,测量方法有很高的可靠性;健康成年组上颈椎三维活动度:最大右侧旋转位时,寰枕关节有(-6.8±1.5)°的耦合左侧屈和(8.9±2.0)°的耦合背伸活动,其余3个位置寰枕关节各方向活动度均很小,最大为(5.3±2.6)°;最大右侧旋转位时寰枢关节右旋(37.9±5.1)°,占整个颈椎活动度[(72.4±5.0)°]的52.34%,其余3个位置寰枢关节仍以旋转活动最为突出;上位椎体(或枕骨)相对下位椎体的平移距离均很小。颈椎病患者颈椎整体平均轴向旋转角度[(62.0±3.4)°]较健康成年组明显下降,但寰枕关节、寰枢关节的平均轴向旋转角度比较健康成年组没有明显差异(P0.05)。结论:(1)基于CT三维重建的方法能够很好的描述颈椎的这种复杂的三维运动,并且有很高的可靠性。(2)上颈椎运动是一个复杂的三维运动过程,各个方向活动时均附带有其他方向上的耦合运动。(3)颈椎病患者最大旋转位上颈椎旋转方向的活动度较健康成年人没有明显变化。     

USS钉棒系统内固定结合椎体间植骨融合术治疗退行性腰椎不稳症

目的探讨USS钉棒系统内固定结合椎体间植骨融合术治疗退行性腰椎不稳症的疗效。方法对78例退行性腰椎不稳症患者采用USS钉棒系统内固定结合椎体间植骨融合术治疗。采用Oswestry功能障碍指数与JOA下腰痛评分对患者手术前和术后1年随访期进行评分;摄片观察植骨融合情况并统计术后内固定失败（钉棒松动、折断）的发生率。结果 6例术后出现顽固轻微手术区胀痛。所有患者均得到随访,时间13~36个月。术后3个月患者腰背痛明显缓解,术后半年基本可以恢复正常日常生活。随访期内无钉棒松动、折断发生。术后6~8个月骨性融合。术后1年,Oswestry功能障碍指数较低,JOA下腰痛评分较高,与术前比较差异有统计学意义（P〈0.05）。腰椎功能改善总有效率达100%。结论 USS钉棒系统内固定结合椎体间植骨融合术治疗退行性腰椎不稳症临床疗效满意。     

Stress analysis of the lumbar disc-body unit in compression. A three-dimensional nonlinear finite element study

It has been argued that a clarification of the mechanical causes of low-back pain requires a knowledge of the states of stress and strain throughout the lumbo-sacral spine. Since a purely experimental approach cannot provide this information, analytical model studies, to supplement measurements, are called for. In the present study, a general three-dimensional finite element program has been developed and applied for the analysis of the lumbar L2-3 disc-body unit. The analysis accounts for both the material and the geometric nonlinearities and is based on a representation of the annulus as a composite of collagenous fibers embedded in a matrix of ground substance. The geometry of the model analyzed is based on in vitro measurements. The validity of the model and the analysis procedure has been established by a comparison of those predictions that are also amenable to direct measurements, eg, the response of the disc-body unit to compressive load in terms of axial displacement, disc bulge, end-plate bulge, and intradiscal pressure. The states of stress and strain have then been computed in the cancellous bone, cortical shell, and the subchondral endplate of the intervertebral body and in the annulus fibers and ground substance of the disc when the unit is subjected to a compressive load. The results indicate that for a normal disc with an incompressible nucleus, the most vulnerable elements under compressive load are the cancellous bone and the end-plate adjacent to the nucleus space. On the other hand, for a degenerated disc, simulated in an extreme fashion by assuming it to be void of the nucleus, the analysis predicts the annulus bulk material to be also susceptible to failure. The annulus fibers do not appear to be vulnerable to rupture when the disc-body unit is subjected to pure compressive force.     

Identification of the correct lumbar level using passive intersegmental motion testing

This study aimed to assess the accuracy and agreement between examiners when attempting to identify a single lumbar spinal level using passive intersegmental motion testing, a technique commonly used by physical therapists. Thirty-five adults were examined independently by an experienced and a novice clinician. Each examiner was asked to identify and note the interspace between the fifth lumbar vertebra and the first sacral vertebra, and to mark it. The mark was invisible to the second clinician asked to identify the same lumbar interspace. The true level was then identified by fluoroscopic imaging and was correct in 54-57% of cases. Interobserver agreement was poor. A significant learning effect was found for the experienced examiner, with proportionately more correct levels identified during the second part of the study (79%) when compared to the first (31%). The results show that intersegmental motion testing is a relatively unreliable method of identifying the correct spinal level.     

Kinematics of the lumbar spine in trunk rotation: in vivo three-dimensional analysis using magnetic resonance imaging

In vivo three-dimensional (3D) kinematics of the lumbar spine has not been well evaluated by the conventional methods because of their methodological limitations, while 3D intervertebral motions have been quantitatively determined by cadaver studies. We thus developed a novel 3D analyzing system for the relative motions of individual vertebrae using 3D magnetic resonance imaging (MRI) and analyzed in vivo 3D intervertebral motions of the lumbar spine during trunk rotation. Ten healthy volunteers underwent 3D MRI of the lumbar spine in nine positions with 15° increments during trunk rotation (0°, 15°, 30°, 45°, and maximum). Relative motions of the lumbar spine were calculated by automatically superimposing a segmented 3D MRI of the vertebra in the neutral position over images of each position using the voxel-based registration method. These 3D motions were represented with 6 degrees of freedom by Euler angles and translations on the coordinate system. The mean axial rotation of ten healthy volunteers of each lumbar spinal segment in 45° trunk rotation to each side ranged from 1.2° to 1.7°. Coupled flexion with axial rotation was observed at the segments from L1/2 to L5/S1. Coupled lateral bending of the segments from L1/2 to L4/5 was in the opposite direction of the trunk rotation, while that of T12/L1 and L5/S1 was in the same direction. The direction of the coupled lateral bending in the present study was different from that in the previous cadaver study only at L4/5. This difference might result from the non-load state of the supine position in the current study and/or the non-physiological state in the cadaver study. Our system has two limitations: (1) the study was conducted with each volunteer in the supine position, and (2) because the rotation device regulated trunk rotation, trunk rotation might not have been physiological. In vivo 3D intervertebral motions of the lumbar spine during trunk rotation were evaluated using our novel motion analysis system. These data may be useful for the optimal orthopaedic management of lumbar spinal disorders. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

In vivo three-dimensional wrist motion analysis using magnetic resonance imaging and volume-based registration.

This study represents a new attempt to non-invasively analyze three-dimensional motions of the wrist in vivo. A volume-based registration method using magnetic resonance imaging (MRI) was developed to avoid radiation exposure. The primary aim was to evaluate the accuracy of volume-based registration and compare it with surface-based registration. The secondary aim was to evaluate contributions of the scaphoid and lunate to global wrist motion during flexion-extension motion (FEM), radio-ulnar deviation (RUD) and radial-extension/ulnoflexion, "dart-throwing" motion (DTM) in the right wrists of 12 healthy volunteers. Volume-based registration displayed a mean rotation error of 1.29 degrees +/-1.03 degrees and a mean translation error of 0.21+/-0.25 mm and was significantly more accurate than surface-based registration in rotation. Different patterns of contribution of the scaphoid and lunate were identified for FEM, RUD, and DTM. The scaphoid contributes predominantly in the radiocarpal joint during FEM, in the midcarpal joint during RUD and almost equally between these joints during DTM. The lunate contributes almost equally in both joints during FEM and predominantly in the midcarpal joint during RUD and DTM.