The relationship between facet joint osteoarthritis and disc degeneration of the lumbar spine: an MRI study

The role of MRI in assessing facet joint osteoarthritis is unclear. By developing a grading system for severity of facet joint osteoarthritis on MRI, the relationship between disc degeneration and facet joint osteoarthritis was determined. The accuracy of MRI in assessing facet joint osteoarthritis against CT was 94%. Under 40 years of age, the degree of disc degeneration varied among individuals. Over the age of 60, most of the discs were markedly degenerated. Under 40 years of age osteoarthritic changes in facet joints were minimal. Over the age of 60, variable degrees of facet joint osteoarthritis were observed but some facets did not show osteoarthritis. No facet joint osteoarthritis was found in the absence of disc degeneration and most facet joint osteoarthritis appeared at the intervertebral levels with advanced disc degeneration. Disc degeneration is more closely associated with aging than with facet joint osteoarthritis. The present study supports the hypothesis that “disc degeneration precedes facet joint osteoarthritis”, and also supports the concept that it may take 20 or more years to develop facet joint osteoarthritis following the onset of disc degeneration. Received: 1 March 1999 Revised: 27 May 1999 Accepted: 4 June 1999     

Disc degeneration of cervical spine on MRI in patients with lumbar disc herniation: comparison study with asymptomatic volunteers

An association between progression of cervical disc degeneration and that of lumbar disc degeneration has been considered to exist. To date, however, this association has not yet been adequately studied. Age-related changes in the cervical intervertebral discs were evaluated by magnetic resonance imaging (MRI) in patients with lumbar disc herniation, and compared with the MRI findings of healthy volunteers without lower back pain. The purpose of this study was to clarify whether the prevalence of asymptomatic cervical disc degeneration is higher in patients with lumbar disc herniation than in healthy volunteers. The study was conducted on 51 patients who were diagnosed as having lumbar disc herniation and underwent cervical spine MRI. The patients consisted of 34 males and 17 females ranging in age from 21–83 years (mean 46.9 ± 14.5 years) at the time of the study. The control group was composed of 113 healthy volunteers (70 males and 43 females) aged 24–77 years (mean 48.9 ± 14.7 years), without neck pain or low back pain. The percentage of subjects with degenerative changes in the cervical discs was 98.0% in the lumbar disc herniation group and 88.5% in the control group (p = 0.034). The presence of lumbar disc herniation was associated significantly with decrease in signal intensity of intervertebral disc and posterior disc protrusion in the cervical spine. None of the MRI findings was significantly associated with the gender, smoking, sports activities, or BMI. As compared to healthy volunteers, patients with lumbar disc herniation showed a higher prevalence of decrease in signal intensity of intervertebral disc and posterior disc protrusion on MRI of the cervical spine. The result of this study suggests that disc degeneration appears to be a systemic phenomenon.     

Temporo-spatial distribution of blood vessels in human lumbar intervertebral discs

While there is consensus in the literature that blood vessels are confined to the outer anulus fibrosus of normal adult intervertebral disc, debate continues whether there is a vascular in-growths into inner parts of the intervertebral disc during degeneration. We therefore tested the hypothesis that vascular in-growth is not a distinct feature of disc degeneration. The specific endothelial cell marker CD 31 (PECAM) was used to immunohistochemically investigate 42 paraffin-embedded complete mid-sagittal human intervertebral disc sections of various ages (0–86 years) and varying extent of histomorphological degeneration. Additionally, 20 surgical disc samples from individuals (26–69 years) were included in this study. In discs of fetal to infantile age, blood vessels perforated the cartilaginous end plate and extended into the inner and outer anulus fibrosus, but not into the nucleus pulposus. In adolescents and adults, no blood vessels were seen except for the outer zone of the anulus fibrosus adjacent to the insertion to ligaments. The cartilaginous end plate remained free of vessels, except for areas with circumscribed destruction of the end plate. In advanced disc degeneration, no vessels were observed except for those few cases with complete, scar-like disc destruction. However, some rim lesions and occasionally major clefts were surrounded by a small network of capillary blood vessels extending into deeper zones of the anulus fibrosus. A subsequent morphometric analysis, revealed slightly “deeper” blood vessel extension in juvenile/adolescent discs when compared to young, mature and senile adult individuals with significantly “deeper” extension in the posterior than anterior anulus. The analysis of the surgical specimens showed that only sparse capillary blood vessels which did not extend into the nucleus pulposus even in major disc disruption. Our results show that vascular invasion deeper than the periphery was not observed during disc degeneration, which supports the hypothesis that vascular in-growth is not a distinct feature of disc degeneration. This study was supported by a grant from the AO/ASIF Foundation Switzerland (00-B72) and a grant from the AO Spine (SRN 02/103).     

退变性腰椎滑脱中腰椎-骨盆结构参数的特点分析

目的:分析退变性腰椎滑脱(degenerative lumbar spondylolisthesis,DLS)中腰椎-骨盆结构特点及其在退变性腰椎滑脱症中的意义。方法:对2015年4月至2017年1月收治的45例单纯退行性L_4,5节段腰椎滑脱患者(滑脱组)的临床资料进行回顾性分析,并与同期50例(对照组)体检资料齐全的健康者进行比较。通过影像学资料对受试者的腰椎-骨盆结构参数进行统计分析,分析DLS患者的脊柱-骨盆特点。观察退变性腰椎滑脱患者椎间盘及关节突关节退变特点。利用Spearson分析各观察项目之间的相关性。结果:滑脱组L_4,5关节突关节角、腰椎前凸角、骨盆入射角、骨盆倾斜角、骶骨倾斜角为(36.5±11.2)°、(44.2±7.3)°、(66.5±11.6)°、(22.2±10.0)°、(33.4±11.3)°。对照组L_4,5关节突关节角、腰椎前凸角、骨盆入射角、骨盆倾斜角、骶骨倾斜角为(44.4±8.2)°、(36.7±8.5)°、(55.4±13.2)°、(14.4±7.0)°、(42.3±13.1)°,滑...     

Review of existing grading systems for cervical or lumbar disc and facet joint degeneration

The aim of this literature review was to present and to evaluate all grading systems for cervical and lumbar disc and facet joint degeneration, which are accessible from the MEDLINE database. A MEDLINE search was conducted to select all articles presenting own grading systems for cervical or lumbar disc or facet joint degeneration. To give an overview, these grading systems were listed systematically depending on the spinal region they refer to and the methodology used for grading. All systems were checked for reliability tests and those recommended for use having an interobserver Kappa or Intraclass Correlation Coefficient >0.60 if disc degeneration was graded and >0.40 if facet joint degeneration was graded. MEDLINE search revealed 42 different grading systems. Thirty of these were used to grade lumbar spine degeneration, ten were used to grade cervical spine degeneration and two were used to grade both. Thus, the grading systems for the lumbar spine represented the vast majority of all 42 grading systems. Interobserver reliability tests were found for 12 grading systems. Based on their Kappa or Intraclass Correlation Coefficients nine of these could be recommended for use and three could not. All other systems could neither be recommended nor not be recommended since reliability tests were missing. These systems should therefore first be tested before use. The design of the grading systems varied considerably. Five grading systems were beginning with the lowest degree of degeneration, 37, however, with the normal, not degenerated state. A 5-grade scale was used in six systems, a 4-grade scale in 24, a 3-grade scale in eight and a 2-grade scale in three systems. In 15 cases the normal, not degenerated state was assigned to grade 0, in another 15 cases, however, this state was assigned to grade 1. This wide variety in the design of the grading systems makes comparisons difficult and may easily lead to confusion. We would therefore recommend to define certain standards. Our suggestion would be to use a scale of three to five grades, to begin the scale with the not degenerated state and to assign this state to grade 0.An erratum to this article can be found at     

颈椎人工椎间盘置换术后异位骨化与小关节退变程度的相关性研究

 目的 探讨颈椎人工椎间盘置换术后发生异位骨化（hetrotopicossification, HO）的原因及与颈椎小关节退变程度的相关性。方法 回顾性分析2009年5月至2012年5月采用Discover假体行颈椎人工椎间盘置换术的133例完整患者资料,男74例,女59例;年龄23~56岁,平均（42.63±4.15）岁;单节段109例,双节段24例。在颈椎X线片上测量术前及末次随访时手术节段活动度;在颈椎CT片上采用Park等颈椎小关节退变程度分级标准对小关节的退变程度进行分级;在颈椎侧位X线片上采用McAfee标准对异位骨化进行分级。统计不同随访时间节点手术节段异位骨化的发生率和分级。根据是否发生异位骨化将患者分为异位骨化组和无异位骨化组,并比较两组患者手术节段活动范围、术前小关节退变程度。结果 133例患者均获得随访,随访时间2.0~4.8年,平均2.9年。末次随访时,25例（18.80%,25/133）患者出现异位骨化,其中手术节段的活动度异位骨化组（6.8°±3.9°）明显小于无异位骨化组（9.1°±2.4°）,两者比较差异有统计学意义;异位骨化组患者术前颈椎小关节退变程度明显重于无异位骨化组。相关性分析结果显示术后异位骨化的发生与术前小关节退变呈正相关（r=0.683, P=0.033）。结论 颈椎人工椎间盘置换术后异位骨化的发生与术前患者小关节的退变具有相关性。术后发生异位骨化的患者术前颈椎小关节的退变程度明显重于未发生异位骨化的患者,异位骨化分级越高,术前小关节的退变越严重。     

The mechanical response of the lumbar spine to different combinations of disc degenerative changes investigated using randomized poroelastic finite element models

Degeneration of the intervertebral disc is related to progressive changes in the disc tissue composition and morphology, such as water loss, disc height loss, endplate calcification, osteophytosis. These changes may be present separately or, more frequently, in various combinations. This work is aimed to the biomechanical investigation of a wide range of clinical scenarios of disc degeneration, in which the most common degenerative changes are present in various combinations. A poroelastic non-linear finite element model of the healthy L4–L5 human spine segment was employed and randomly scaled to represent ten spine segments from different individuals. Six different degenerative characteristics (water loss in the nucleus pulposus and annulus fibrosus; calcification and thickness reduction of endplate cartilage; disc height loss; osteophyte formation; diffuse sclerosis) were modeled in 30 randomly generated models, 10 for each overall degree of degeneration (mild, moderate, severe). For each model, a daily loading cycle including 8 h of rest, 16 h in the standing position with superimposed two flexion–extension motion cycles was simulated. A tendency to an increase of stiffness with progressing overall degeneration was observed, in compression, flexion and extension. Hence, instability for mild degeneration was not predicted. Facet forces and fluid loss decreased with disc degeneration. Nucleus, annulus and endplate degeneration, disc height loss, osteophytosis and diffuse sclerosis all induced a statistically significant decrease in the total daily disc height variation, facet force and flexibility in flexion–extension. Therefore, grading systems for disc degeneration should include all the degenerative changes considered in this work, since all of them had a significant influence on the spinal biomechanics.     

Immunohistochemical identification of notochordal markers in cells in the aging human lumbar intervertebral disc

The fate of notochord cells during disc development and aging is still a subject of debate. Cells with the typical notochordal morphology disappear from the disc within the first decade of life. However, the pure morphologic differentiation of notochordal from non-notochordal disc cells can be difficult, prompting the use of cellular markers. Previous reports on these notochordal cell markers only explored the occurrence in young age groups without considering changes during disc degeneration. The aim of this study, therefore, was to investigate presence, localization, and abundance of cells expressing notochordal cell markers in human lumbar discs during disc development and degeneration. Based on pilot studies, cytokeratins CK-8, -18 and -19 as well as Galectin-3 were chosen from a broad panel of potential notochordal cell markers and used for immunohistochemical staining of 30 human lumbar autopsy samples (0–86 years) and 38 human surgical disc samples (26–69 years). In the autopsy group, 80% of fetal to adolescent discs (0–17 years) and 100% of young adult discs (18–30 years) contained many cells with positive labeling. These cells were strongly clustered and nearly exclusively located in areas with granular changes (or other matrix defects), showing predominantly a chondrocytic morphology as well as (in a much lesser extent) a fibrocytic phenotype. In mature discs (31–60 years) and elderly discs (≥60 years) only 25 and 22–33%, respectively, contained few stained nuclear cells, mostly associated with matrix defects. In the surgical group, only 16% of samples from young adults (≤47 years) exhibited positively labeled cells whereas mature to old surgical discs (>47 years) contained no labeled cells. This is the first study describing the presence and temporo-spatial localization of cells expressing notochordal cell markers in human lumbar intervertebral discs of all ages and variable degree of disc degeneration. Our findings indicate that cells with a (immunohistochemically) notochord-like phenotype are present in a considerable fraction of adult lumbar intervertebral discs. The presence of these cells is associated with distinct features of (early) age-related disc degeneration, particularly with granular matrix changes.     

Systematic review of tests to identify the disc, SIJ or facet joint as the source of low back pain

Clinical practice guidelines state that the tissue source of low back pain cannot be specified in the majority of patients. However, there has been no systematic review of the accuracy of diagnostic tests used to identify the source of low back pain. The aim of this systematic review was therefore to determine the diagnostic accuracy of tests available to clinicians to identify the disc, facet joint or sacroiliac joint (SIJ) as the source of low back pain. MEDLINE, EMBASE and CINAHL were searched up to February 2006 with citation tracking of eligible studies. Eligible studies compared index tests with an appropriate reference test (discography, facet joint or SIJ blocks or medial branch blocks) in patients with low back pain. Positive likelihood ratios (+LR) > 2 or negative likelihood ratios (-LR) < 0.5 were considered informative. Forty-one studies of moderate quality were included; 28 investigated the disc, 8 the facet joint and 7 the SIJ. Various features observed on MRI (high intensity zone, endplate changes and disc degeneration) produced informative +LR (> 2) in the majority of studies increasing the probability of the disc being the low back pain source. However, heterogeneity of the data prevented pooling. +LR ranged from 1.5 to 5.9, 1.6 to 4.0, and 0.6 to 5.9 for high intensity zone, disc degeneration and endplate changes, respectively. Centralisation was the only clinical feature found to increase the likelihood of the disc as the source of pain: +LR = 2.8 (95%CI 1.4–5.3). Absence of degeneration on MRI was the only test found to reduce the likelihood of the disc as the source of pain: −LR = 0.21 (95%CI 0.12–0.35). While single manual tests of the SIJ were uninformative, their use in combination was informative with +LR of 3.2 (95%CI 2.3–4.4) and −LR of 0.29 (95%CI 0.12–0.35). None of the tests for facet joint pain were found to be informative. The results of this review demonstrate that tests do exist that change the probability of the disc or SIJ (but not the facet joint) as the source of low back pain. However, the changes in probability are usually small and at best moderate. The usefulness of these tests in clinical practice, particularly for guiding treatment selection, remains unclear. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Changes in paraspinal muscles and their association with low back pain and spinal degeneration: CT study

The objectives of the study were to evaluate the association between lumbar paraspinal muscle density, evaluated on computed tomography (CT) and age, sex and BMI; and to evaluate the association of those changes with low back pain (LBP) and spinal degeneration features in a community-based sample. This study was an ancillary project to the Framingham Study. A sample of 3,529 participants aged 40–80 years had a CT scan performed to assess aortic calcification. 187 individuals were randomly enrolled in this study. LBP in the last 12 months was evaluated using self-report questionnaire. Density (in Hounsfield units) of multifidus and erector spinae was evaluated on CT. The prevalence of intervertebral disc narrowing, facet joint osteoarthritis (FJOA), spondylolysis, spondylolisthesis and spinal stenosis were also evaluated. We used linear regression models to examine the association of paraspinal muscles density with age, sex, BMI, LBP, and spinal degeneration features. The results show that in our study, men have higher density of paraspinal muscles than women, younger individuals have higher density than older ones and individuals with lower weight have higher muscle density than overweight. No differences between individuals with and without LBP were found. Significant association was found between L4 multifidus/erector spinae density and FJOA at L4–L5; between multifidus at L4 and spondylolisthesis at L4–5; and between erector spinae at L4 and L5 with disc narrowing at L4–5 and L5–S1, respectively. We conclude that the paraspinal muscle density decreases with age, and increases BMI. It is associated with at some levels FJOA, spondylolisthesis and disc narrowing at the same level, but not associated with occurrence of LBP.     

Small keyhole transuncal foraminotomy for unilateral cervical radiculopathy

Summary Interbody fusion after anterior discectomy may lead to acceleration of degenerative changes at adjacent levels. Although the posterior approach preserves the motion segment, decompression of the nerve root is indirect if “hard disc prolaps” is the main cause. Recently, a technique of microsurgical anterior cervical foraminotomy for the treatment of radiculopathy with preservation of the segment mobility was published. In this study, we present this technique with several modifications. Thirteen patients – 5 men and 8 women with an average age of 49 years – with unilateral radiculopathy resistant to conservative treatment underwent microsurgical anterior foraminotomy via a small keyhole transuncal approach. The base of the uncinate process (UP) was directly drilled in the trajectory to the intervertebral foramen without destroying the disc tissue. The vertebral artery between the transverse process was not exposed. Furthermore, the functional anatomy of the uncovertebral joint remained largely intact. All patients experienced complete relief of radiating pain. A cervical collar was not used. Mean follow-up time was 19 months. The mobility of the operated segment was preserved in each patient. No instability of the cervical spine was seen. The microsurgical anterior foraminotomy via a small keyhole transuncal approach is safe, minimally invasive, and represents an effective method to treat unilateral cervical radiculopathy caused by disc prolaps and/or uncovertebral osteophytes. Additionally, the segment mobility is preserved and prevents the acceleration of degenerative changes at adjacent levels.     

Inter- and intraobserver reliability of the vertebral, local and segmental kyphosis in 120 traumatic lumbar and thoracic burst fractures: evaluation in lateral X-rays and sagittal computed tomographies

Evaluation of the kyphosis angle in thoracic and lumbar burst fractures is often used to indicate surgical procedures. The kyphosis angle could be measured as vertebral, segmental and local kyphosis according to the method of Cobb. The vertebral, segmental and local kyphosis according to the method of Cobb were measured at 120 lateral X-rays and sagittal computed tomographies of 60 thoracic and 60 lumbar burst fractures by 3 independent observers on 2 separate occasions. Osteoporotic fractures were excluded. The intra- and interobserver reliability of these angles in X-ray and computed tomogram, using the intra class correlation coefficient (ICC) were evaluated. Highest reproducibility showed the segmental kyphosis followed by the vertebral kyphosis. For thoracic fractures segmental kyphosis shows in X-ray “excellent” inter- and intraobserver reliabilities (ICC 0.826, 0.802) and for lumbar fractures “good” to “excellent” inter- and intraobserver reliabilities (ICC = 0.790, 0.803). In computed tomography, the segmental kyphosis showed “excellent” inter- and intraobserver reliabilities (ICC = 0.824, 0.801) for thoracic and “excellent” inter- and intraobserver reliabilities (ICC = 0.874, 0.835) for the lumbar fractures. Regarding both diagnostic work ups (X-ray and computed tomography), significant differences were evaluated in interobserver reliabilities for vertebral kyphosis measured in lumbar fracture X-rays (p = 0.035) and interobserver reliabilities for local kyphosis, measured in thoracic fracture X-rays (p = 0.010). Regarding both fracture localizations (thoracic and lumbar fractures), significant differences could only be evaluated in interobserver reliabilities for the local kyphosis measured in computed tomographies (p = 0.045) and in intraobserver reliabilities for the vertebral kyphosis measured in X-rays (p = 0.024). “Good” to “excellent” inter- and intraobserver reliabilities for vertebral, segmental and local kyphosis in X-ray make these angles to a helpful tool, indicating surgical procedures. For the practical use in lateral X-ray, we emphasize the determination of the segmental kyphosis, because of the highest reproducibility of this angle. “Good” to “excellent” inter- and intraobserver reliabilities for these three angles could also be evaluated in computed tomographies. Therefore, also in computed tomography, the use of these three angles seems to be generally possible. For a direct correlation of the results in lateral X-ray and in computed tomography, further studies should be needed.     

颈椎曲度和活动度参数的影响因素

 目的 探讨颈椎曲度和活动度的测量参数及影响因素。方法 回顾性分析2012年1月至2013年6月,212位正常志愿者的颈椎标准侧位、前屈位、后伸位X线片,男84位,女128位;年龄20~79岁,以10年为一组,分成6组;颈椎间盘退变程度依据颈椎9分法,分为4组。影像资料由3名脊柱外科医生分3次运用Mimics软件测量。测量参数包括C2~C7曲度及椎间各节段和整体活动度。对颈椎曲度和整体活动度的关系进行Pearson 相关性分析,对年龄、性别和间盘退变三个因素进行多重线性回归分析。组内相关系数（ICC）评估测量者组内和组间一致性。结果 C₂~C₇曲度为21.40°±12.15°,C₂~C₇整体活动度为 63.59°±15.37°。性别对颈椎曲度的影响有统计学意义（回归系数=-2.472,P＜ 0.05）。性别和年龄两因素对颈椎整体活动度的影响有统计学意义（回归系数=3.863和-6.463,P＜0.05）。性别对C_2,3、C_5,6两个节段活动度的影响有统计学意义;年龄对C₂~C₇所有五个节段活动度的影响有统计学意义;间盘退变对C_4,5、C_5,6和C_6,7三个节段活动度的影响有统计学意义。颈椎曲度与颈椎整体及后伸活动度无明显相关性（r=-0.106和0.215,P＞0.05）,但与前屈活动度呈负相关（r=-0.401,P＜0.05）。颈椎曲度、整体活动度和节段活动度的测量结果均具有很高的组内一致性（ICC=0.97,0.96~0.97;ICC=0.91,0.90~0.92;ICC=0.89,0.87~0.91）和组间一致性（ICC=0.94,0.92~0.95;ICC=0.89,0.86~0.91;ICC=0.83,0.79~0.86）。结论 性别是颈椎曲度的影响因素,性别和年龄两因素是颈椎整体活动度的影响因素,性别、年龄和间盘退变程度是颈椎节段活动度的影响因素。     

Muscone Protects Vertebral End-plate Degeneration by Antiinflammatory Property

Most chronic neck pain is the result of degeneration of the cervical spine. IL-1β may play an important role in intervertebral disc degeneration. This being the case, inhibiting IL-1β could provide a therapeutic approach for reducing or preventing disc degeneration. Muscone reportedly relieves pain and suppresses inflammation. Therefore, we asked whether muscone, a potent antiinflammatory agent, could reduce proinflammatory cytokines in vitro (end-plate cartilage cultures) and end-plate degeneration in vivo (a rat model that induces intervertebral disc degeneration). In vitro, muscone reversed IL-1β-induced upregulation of IL-1β, tumor necrosis factor α, cyclooxygenase 2, inducible nitric oxide synthase, matrix metalloproteinase 13, aggrecanase 2, and nitric oxide and downregulation of Col2α1 and aggrecan. Pretreatment with muscone (6.25, 12.5, 25 μmol/L) inhibited the IL-1β-induced phosphorylation of extracellular signal-regulated kinases 1/2 and c-Jun N-terminal kinase in a dose-dependent manner. In vivo, muscone inhibited the expression of prostaglandin E2, 6-keto-prostaglandin F1α, IL-1β, and tumor necrosis factor α and recovered the structural distortion of the degenerative disc. Our findings suggest muscone is a promising agent for treating intervertebral disc degeneration through its antiinflammatory effects.     

Validity and interobserver agreement of a new radiographic grading system for intervertebral disc degeneration: Part II. Cervical spine

A new radiographic grading system for a more objective assessment of lumbar intervertebral disc degeneration has been described and tested in Part I of this study. The aim of the present Part II of the study was to adapt this system to the cervical spine, and to test it for validity and interobserver agreement. Some modifications of the grading system described in Part I were necessary to make it applicable to the cervical spine. Its basic structure, however, stayed untouched. The three variables Height Loss, Osteophyte Formation and Diffuse Sclerosis first have to be graded individually. Then, the Overall Degree of Degeneration is assigned on a four-point scale from 0 (no degeneration) to 3 (severe degeneration). For validation, the radiographic degrees of degeneration of 28 cervical discs were compared to the respective macroscopic ones, which were defined as real degrees of degeneration. The interobserver agreement was determined between one experienced and one unexperienced observer using the radiographs of 57 cervical discs. Quadratic weighted Kappa coefficients () with 95% confidence limits (95% CL) were used for statistical evaluation. The validation of the new version of the radiographic grading system showed a moderate agreement with the real, macroscopic overall degree of degeneration (=0.599, 95% CL 0.421–0.786). In 64% of all discs the real overall degree of degeneration was underestimated but never overestimated. This underestimation, however, was much less pronounced and the Kappa coefficients were significantly higher for the three variables: Height Loss, Osteophyte Formation, and Diffuse Sclerosis separately. The agreement between the radiographic ratings of the experienced and the unexperienced observer was substantial for the overall degree of degeneration (=0.688, 95% CL 0.580–0.796), almost perfect for the variable, Height Loss, moderate for Osteophyte Formation and fair for Diffuse Sclerosis. In conclusion, we believe that the new version of the radiographic grading system is a sufficiently valid and reliable tool to quantify the degree of degeneration of individual cervical intervertebral discs. In comparison to the version for the lumbar spine described in Part I, however, a slightly higher tendency to underestimate the real overall degree of degeneration and somewhat higher interobserver differences have to be expected.Part I of this article can be found at http://dx.doi.org/10.1007/s00586-005-1029-9     

Effectiveness of posterior tension band fixation in the thoracolumbar seat-belt type injuries of the young population

The effects of different parameters on the mechanical behaviour of the lumbar spine were in most cases determined deterministically with only one uncertain parameter varied at a time while the others were kept fixed. Thus most parameter combinations were disregarded. The aim of the study was to determine in a probabilistic finite element study how intervertebral rotation, intradiscal pressure, and contact force in the facet joints are affected by the input parameters implant position, implant ball radius, presence of scar tissue, and gap size in the facet joints. An osseoligamentous finite element model of the lumbar spine ranging from L3 vertebra to L5/S1 intervertebral disc was used. An artificial disc with a fixed center of rotation was inserted at level L4/L5. The model was loaded with pure moments of 7.5 Nm to simulate flexion, extension, lateral bending, and axial torsion. In a probabilistic study the implant position in anterior–posterior (ap) and in lateral direction, the radius of the implant ball, and the gap size of the facet joint were varied. After implanting an artificial disc, scar tissue may develop, replacing the anterior longitudinal ligament. Thus presence and absence of scar tissue were also simulated. For each loading case studied, intervertebral rotations, intradiscal pressures and contact forces in the facet joints were calculated for 1,000 randomized input parameter combinations in order to determine the probable range of these output parameters. Intervertebral rotation at implant level varies strongly for different combinations of the input parameters. It is mainly affected by gap size, ap-position and implant ball radius for flexion, by scar tissue and implant ball radius for extension and lateral bending, and by gap size and implant ball radius for axial torsion. For extension, intervertebral rotation at implant level varied between 1.4° and 7.5°. Intradiscal pressure in the adjacent discs is only slightly affected by all input parameters. Contact forces in the facet joints at implant level vary strongly for the different combinations of the input parameters. For flexion, forces are 0 in 63% of the cases, but for small gap sizes and large implant ball radii they reach values of up to 533 N. Similar results are found for extension with a maximum predicted force of 560 N. Here the forces are mainly influenced by gap size, implant ball radius and scar tissue. The forces vary between 0 and 300 N for lateral bending and between 0 and 200 N for axial torsion. The parameters that have the greatest effect in both loading cases are the same as those for extension. Intervertebral rotation and contact force in the facet joints depend strongly on the input parameters studied. The probabilistic study shows a large variation of the results and likelihood of certain values. Clinical studies will be required to show whether or not there is a strong correlation of parameter combinations that cause high facet joint forces and low back pain after total disc replacement.     

Modic改变与下腰椎三关节复合体退变相关性的回顾性分析

目的探讨Modic改变(modic changes,MCs)与下腰椎三关节复合体退变的相关性。方法选择2016年3月~2020年6月在本院住院治疗的231例腰椎间盘突出症(lumbar disc herniation,LDH)患者进行分析,观察MCs的发生率、椎间盘的Pfirmann分级和小关节退变分级(Weishaupt分级)的关系。结果MCs总发生率为45.31%(296/693),L_3-4、L_4-5、L₅-S₁节段MCs发生率分别为25.11%(58/231)、54.11%(125/231)和48.92%(113/231),组间差异存在统计学意义(P<0.05)。L_3-4、L_4-5和L₅-S₁节段MCsⅠ型、Ⅱ型和Ⅲ型病变节段的椎间盘退变程度均高于无MCs病变节段(P<0.05)。L_3-4节段MCsⅢ型与无MCs患者的小关节退变差异存在统计学意义(P<0.05)。L_4-5和L₅-S₁节段MCsⅡ型患者与无MCs患者的小关节退变差异存在统计学意义(P<0.05)。结论MCs与三关节复合体退变存在相关性,主要表现在MCs不同类型均与腰椎间盘退变分级相关,MCsⅡ型与腰椎小关节退行性病变相关。     

Evaluation of a new virtual-reality training simulator for hysteroscopy

Background  To determine realism and training capacity of HystSim, a new virtual-reality simulator for the training of hysteroscopic interventions. Methods  Sixty-two gynaecological surgeons with various levels of expertise were interviewed at the 13^th Practical Course in Gynaecologic Endoscopy in Davos, Switzerland. All participants received a 20-min hands-on training on the simulator and filled out a four-page questionnaire. Twenty-three questions with respect to the realism of the simulation and the training capacity were answered on a seven-point Likert scale along with 11 agree–disagree statements concerning the HystSim training in general. Results  Twenty-six participants had performed more than 50 hysteroscopies (“experts”) and 36 equal to or fewer than 50 (“novices”). Four of 60 (6.6%) responding participants judged the overall impression as “7 – absolutely realistic”, 40 (66.6%) as “6 – realistic”, and 16 (26.6%) as “5 – somewhat realistic”. Novices (6.48; 95% confidence interval [CI] 6.28–6.7) rated the overall training capacity significantly higher than experts (6.08; 95% CI 5.85–6.3), however, high-grade acceptance was found in both groups. In response to the statements, 95.2% believe that HystSim allows procedural training of diagnostic and therapeutic hysteroscopy, and 85.5% suggest that HystSim training should be offered to all novices before performing surgery on real patients. Conclusion  Face validity has been established for a new hysteroscopic surgery simulator. Potential trainees and trainers assess it to be a realistic and useful tool for the training of hysteroscopy. Further systematic validation studies are needed to clarify how this system can be optimally integrated into the gynaecological curriculum.     

A comparison of outcomes of cervical disc arthroplasty and fusion in everyday clinical practice: surgical and methodological aspects

Randomised controlled trials (RCTs) of cervical disc arthroplasty vs fusion generally show slightly more favourable results for arthroplasty. However, RCTs in surgery often have limited external validity, since they involve a select group of patients who fit very rigid admission criteria and who are prepared to subject themselves to randomisation. The aim of this study was to examine whether the findings of RCTs are verified by observational data recorded in our Spine Center in association with the Spine Society of Europe Spine Tango surgical registry. Patients undergoing fusion/stabilisation or disc arthroplasty for degenerative cervical spinal disease were selected for inclusion. They completed a questionnaire pre-operatively and at 12 and 24 months follow-up (FU). The questionnaire comprised the multidimensional Core Outcome Measures Index (COMI; 0–10 scale) and, at FU, questions on global outcome and satisfaction with treatment (5-point scales, dichotomised to “good” and “poor”), re-operation and patient-rated complications. The surgeon completed a Spine Tango Surgery form. The outcome data from 266 (208 fusion, 58 arthroplasty) out of 284 eligible patients who had reached 12 months FU, and 169 (139 fusion, 30 arthroplasty) out of 178 who had reached 24 months FU, were included. Patients with cervical disc arthroplasty were younger [46 (SD 8) years vs 56 (SD 11) years for fusion; P < 0.05], had less comorbidity (P < 0.05), more often had only mono-segmental pathology (69% arthroplasty, 47% fusion) and only one type of degenerative pathology (69% arthroplasty, 46% fusion). Surgical complication rates were similar in each group (arthroplasty, 1.5%; fusion, 2.6%). The reduction in the COMI score was significantly greater in the arthroplasty group (at 12 months, 4.8 (SD 3.0) vs 3.7 (SD 2.9) points for fusion, and at 24 months 5.1 (SD 2.8) vs 3.8 (SD 2.9) points; each P < 0.05). In the arthroplasty group, a “good” global outcome was recorded in 90% patients (at 12 months) and 93% (at 24 months); in the fusion group the figures were 80 and 82%, respectively (group differences at each timepoint, P > 0.09). Satisfaction with treatment was similar in both groups (89–93%), at each timepoint. In multiple regression analysis, treatment group was of borderline significance as a unique predictor of the change in COMI at FU (P = 0.059 at 12 months, P = 0.055 at 24 months) in a model in which known confounders (age, comorbidity, number of affected levels) were controlled for. Being in the arthroplasty group was associated with an approximately 1-point greater reduction in the COMI score at FU. The results of this observational study appear to support those of the RCTs and suggest that, in patients with degenerative pathology of the cervical spine, disc arthroplasty is associated with a slightly better outcome than fusion. However, given the small size of the difference, its clinical relevance is questionable, especially in view of the a priori more favourable outcome expected in the arthroplasty group due to the more rigorous selection of patients.