Qualitative and quantitative assessment of degeneration of cervical intervertebral discs and facet joints.

Degeneration of intervertebral discs and facet joints is one of the most frequently encountered spinal disorders. In order to describe and quantify degeneration and evaluate a possible relationship between degeneration and biomechanical parameters, e.g., the intervertebral range of motion and intradiscal pressure, a scoring system for degeneration is mandatory. However, few scoring systems for the assessment of degeneration of the cervical spine exist. Therefore, two separate objective scoring systems to qualitatively and quantitatively assess the degree of cervical intervertebral disc and facet joint degeneration were developed and validated. The scoring system for cervical disc degeneration consists of three variables which are individually scored on neutral lateral radiographs: "height loss" (0-4 points), "anterior osteophytes" (0-3 points) and "endplate sclerosis" (0-2 points). The scoring system for facet joint degeneration consists of four variables which are individually scored on neutral computed tomography scans: "hypertrophy" (0-2 points), "osteophytes" (0-1 point), "irregularity" on the articular surface (0-1 point) and "joint space narrowing" (0-1 point). Each variable contributes with varying importance to the overall degeneration score (max 9 points for the scoring system of cervical disc degeneration and max 5 points for facet joint degeneration). Degeneration of 20 discs and facet joints of 20 patients was blindly assessed by four raters: two neurosurgeons (one senior and one junior) and two radiologists (one senior and one junior), firstly based on first subjective impression and secondly using the scoring systems. Measurement errors and inter- and intra-rater agreement were determined. The measurement error of the scoring system for cervical disc degeneration was 11.1 versus 17.9% of the subjective impression results. This scoring system showed excellent intra-rater agreement (ICC = 0.86, 0.75-0.93) and excellent inter-rater agreement (ICC = 0.78, 0.64-0.88). Surgeons as well as radiologists and seniors as well as juniors obtained excellent inter- and intra-rater agreement. The measurement error of the scoring system for cervical facet joint degeneration was 20.1 versus 24.2% of the subjective impression results. This scoring system showed good intra-rater agreement (ICC = 0.71, 0.42-0.89) and fair inter-rater agreement (ICC = 0.49, 0.26-0.74). Both scoring systems fulfilled the criteria for recommendation proposed by Kettler and Wilke. Our scoring systems can be reliable and objective tools for assessing cervical disc and facet joint degeneration. Moreover, the scoring system of cervical disc degeneration was shown to be experience- and discipline-independent.

Major vascular injury during anterior lumbar spinal surgery: incidence, risk factors, and management.

STUDY DESIGN: Retrospective chart review. OBJECTIVE: To examine the incidence of major vascular injury during anterior lumbar spinal surgery, attempt to identify predisposing risk factors, and to discuss management techniques. SUMMARY OF BACKGROUND DATA: Major vascular injury can be a catastrophic complication of anterior lumbar spinal surgery. METHODS: Current procedural terminology codes were used to identify the occurrence of major vascular injury, defined as injury to the iliac vessels, vena cava, and aorta. Once identified, the office record, hospital chart, operative note, and diagnostic test results were reviewed in detail. RESULTS: Three hundred forty-five operations were performed on 338 patients. Incidence of major vascular complication was 2.9% (10 of 345). There were 9 injuries of the common iliac vein and a single aortic injury. Risk factors identified in patients with major vascular injury were current or previous osteomyelitis or discogenic infection (n = 3), previous anterior spinal surgery (n = 2), spondylolisthesis (n = 2; 1 isthmic Grade II, 1 iatrogenic Grade II), large anterior osteophyte (n = 2), transitional lumbosacral vertebra (n = 1), and anterior migration of interbody device (n = 1). Lateral venorrhaphy by suture (n = 6) and hemoclip application (n = 2) was augmented by topical agents, which constituted the sole method of repair on 1 occasion. Magnetic resonance venography demonstrated iliac vein thrombosis in 1 patient. CONCLUSION: Current or previous osteomyelitis or discogenic infection, previous anterior spinal surgery, spondylolisthesis, osteophyte formation, transitional lumbosacral vertebra and anterior migration of interbody device point to an increased risk of vascular injury during anterior lumbar spinal surgery. Careful handling of the vascular structures and liberal use of topical hemostatic agents can lead to control of hemorrhage and preservation of vascular patency. Routine postoperative surveillance for proximal deep vein thrombosis, by magnetic resonance venography of the pelvic veins and inferior vena cava, should be performed after venorrhaphy.

Correlation of radiographic and MRI parameters to morphological and biochemical assessment of intervertebral disc degeneration.

UNLABELLED: Degenerative disc disease (DDD) is a common finding in MRI scans and X-rays. However, their correlation to morphological and biochemical changes is not well established. In this study, radiological and MRI parameters of DDD were assessed and compared with morphological and biochemical findings of disc degeneration. Thirty-nine human lumbar discs (L1-S1), age 19-86 years, were harvested from eight cadavers. Within 48 h postmortem, MRIs in various spin-echo sequences and biplanar radiographs of intact spines were obtained. Individual discs with endplates were then sectioned in the mid-sagittal plane and graded according to the morphological appearance. Samples from the nucleus of each disc were harvested for biochemical analysis including water and proteoglycan contents. On MRIs, T2-signal intensity, Modic changes, disc extension beyond the interspace (DEBIT), nucleus pulposus shape, annular tears, osteophytes and endplate integrity were graded. On radiographs, an independent observer classified the parameters disc height, endplate sclerosis, osteophytes, Schmorl's nodes, intradiscal calcifications and endplate shape. General linear-regression models were used for statistical analysis. Backward elimination with a 10% significance cut-off level was used to identify the most significant parameters, which then were summed to create composite scores for radiography, MRI and the combination of both methods. The grading was performed by three observers, and a reliability analysis using Cronbach's alpha model was used to control interobserver agreement. The three radiographic parameters height-loss, osteophytes and intradiscal calcifications correlated significantly with the morphological degree of degeneration (p<0.001, R2=642). Significant differences of even one morphological grade could also be differentiated in the composite radiological score (p<0.05), except at the extremes between grades 1 and 2 and grades 4 and 5. All MRI parameters correlated significantly with the morphological grade (p<0.05); however Modic changes, T2-intensity and osteophytes accounted for 83% of the variation in the data. T2-signal intensity correlated significantly with H2O and proteoglycan content (p<0.001), and was best for detecting highly degenerated discs. Regression showed that the combined score was better correlated with the morphological grade (p<0.001, R2=775) than either the composite radiographic (p<0.001, R2=642) or composite MRI (p<0.001, R2=696) alone. Based on the combined score, a backwards elimination of the regression was performed, in which the parameters Modic changes, and T2-intensity loss (MRI) as well as calcifications (X-ray) accounted for 87% of the variability. The interobserver validation showed a high correlation for all three scores (Cronbach's alpha values ranging from 0.95 to 0.97). CONCLUSION: Selective imaging parameters and a newly created scoring scheme were found to correlate with disc degeneration as determined in a morphological manner. Surprisingly, radiographic parameters were able to distinguish different stages of degeneration, whereas MRI could only detect advanced stages of disc degeneration. We conclude that X-rays may remain a cost-effective, non-invasive in vivo-grading method to detect early disc degeneration, and, combined with MRI, correlate best with morphological and biochemical assessment of disc degeneration.

[Occupational disease 2108. Degenerative changes of the cervical spine as a causality criterion in the assessment of discogenic diseases according to BeKV 2108]. / Berufserkrankung 2108. Degenerative Veränderungen der Halswirbelsäule als Kausalitätskriterium in der Begutachtung bandscheibenbedingter Erkrankungen gemäss BeKV 2108.

With the second amendment to the Ordinance on Occupational Diseases (BeKV) of 18 December 1992, discogenic diseases of the spine are included in the disease register of occupational diseases for the first time. If occupations that impose stress on the spine have been practised for many years, the possibility exists of recognizing degenerative diseases as an occupational disease. In assessment practice, the radiological data on the spine exposed to stress is compared with that of regions which are remote from the stress (cervical/thoracic spine). This pattern of the distribution of degenerative disease is then used as the basis for determining a causal relationship between the occupation causing the stress and disease of the axial skeleton. The pattern of degeneration of the cervical spine was investigated in two groups, one with ( n =153) and one without ( n =333) occupations that impose stress on the lumbar spine. A cumulative score of degenerative changes was elaborated and presented as a new classification. No differences were found between the groups with regard to either the frequency of occurrence, segmental distribution or severity of disease. In both groups, degenerative changes correlated with age. The prevailing assessment practice is discussed on the basis of these data.

Radiographic assessment of interbody fusion using recombinant human bone morphogenetic protein type 2.

STUDY DESIGN: A prospective randomized study investigated the radiographic progress of fusion at 6, 12, and 24 months in 42 patients who underwent a single-level anterior lumbar interbody fusion using cylindrical interbody fusion cages. OBJECTIVE: To determine the patterns and rates of osteoinduction associated with the use of recombinant human bone morphogenetic protein type 2 (rhBMP-2) and an absorbable collagen sponge carrier in anterior lumbar interbody fusion with a tapered cylindrical fusion device. SUMMARY OF BACKGROUND DATA: Studies have shown that rhBMP-2 used with allograft dowels increases the rate of interbody fusion by promoting osteoinduction and enhancing incorporation of the allograft. In a small series of human patients undergoing anterior lumbar interbody fusion with a tapered cylindrical fusion cage, rhBMP-2 has been shown to promote osteoinduction and fusion. METHODS: In this prospective nonblinded study, 42 patients were randomly divided into two groups. The investigational group underwent interbody fusion using two tapered cylindrical fusion cages (LT-CAGE) and rhBMP-2 on an absorbable collagen sponge, and a control group underwent the procedure, receiving the devices and autogenous iliac crest bone graft. Plain radiographs and computed tomographic scans were used to evaluate the pattern of osteoinduction in the interbody space and the progression of fusion 6, 12, and 24 months after surgery. RESULTS: All the patients who received rhBMP-2 showed radiographic evidence of osteoinduction in the interbody cages 6 months after surgery. The density in the cages had increased an average of 142 Hounsfield units by 6 months. At 12 months, the increase had reached 228.7 Hounsfield units New bone formation occurred in the disc space outside the cages by 6 months in 18 of the patients in the investigational group (18/22; 82%). By 24 months, all the investigational patients showed new formation outside the cages. In the autograft control group, the density in the cages increased an average of 42 Hounsfield units, and 10 patients (10/20; 50%) showed evidence of bone formation outside the cages. CONCLUSIONS: The use of rhBMP-2 is a promising method for facilitating anterior intervertebral spinal fusion in patients who have undergone anterior lumbar fusion surgery.

[Disk-related diseases of the lumbar spine as an example for the critical interaction between clinical diagnosis and occupational disease]. / Das Spannungsfeld zwischen klinischer Diagnose und anerkannter Berufskrankheit Dargestellt am Beispiel der bandscheibenbedingten Erkrankungen der LWS.

First an overview of the significance of musculoskeletal diseases in terms of national economy and social politics is given, and then the historical development of the occupational disease "disk-related spinal disorders" is outlined. The most important court decisions and the actual state of jurisprudence on this matter are summarized, emphasizing the questions which still have to be answered in the course of medical evaluation of a spinal occupational disease. Based on a joint research project on the spinal effects of whole-body vibrations, an analysis of lumbar X-rays is presented which aimed at detecting specific patterns of response corresponding to the respective extent of strain. In spite of a statistically significant relationship between the clinical diagnosis of a lumbar syndrome and the severity of the degenerative radiological changes on the one hand and vibration exposure on the other hand, the evaluation of the lumbar X-rays did not show any clear radiological pattern related to the exposure. Furthermore, starting points for prevention are discussed. With regard to whole-body vibration, the technical possibilities of reducing the amount of vibration load are still not completely exhausted. However, during preventive measures of occupational health usually carried out as medical screening examinations, the occupational health physician again will face some of the same problems which have already been met with respect to the medical evaluation. Thus, a suggestion is made to modify the traditional concepts of the Professional Industrial Associations on occupational diseases in order to take into account the peculiarities of disk-related spinal disorders.

[Is lumbar disk disease an occupational disease? Scientific background, radiological findings, and medical legal interpretations]. / Die Berufskrankheit 2110. Wissenschaftliche Grundlagen, radiologisches Erscheinungsbild und Begutachtungskriterien.

AIM: It should be cleared whether or not the interpretation of lumbar disk disease as an occupational disease is justifiable. Which disc changes follow whole-body vibration and can they be distinguished from those which occur constitutionally while aging? METHOD: Orthopedic meta-analysis of epidemiological and occupational studies concerning the influence of whole- body vibration. RESULTS: Reliable studies are rare. Severe methodological problems limit the interpretation of difficult relationships. The role of age when working influences begin as well as the stress and behaviour of exposed persons away from the work-place before and while working with whole-body vibration is not known. There is no study which could be called exact according orthopedic criteria. It is therefore not evident that whole-body vibration causes lumbar disc disease. CONCLUSIONS: After whole-body vibration similar to long term heavy lifting an earlier beginning of disk degeneration in X-ray-studies can be observed. This leads to prevalence differences, which diminish with increasing age. Deviation to the left of the prevalence curve lasts for five to ten years. Whole-body vibration leads to a topographic modification of disk degeneration of the lumbar spine. After long duration exposition an increased amount of spondylotic changes at the thoracolumbar junction and the middle half of lumbar spine can be observed (up to the upper plate of the fourth vertebral body). This can be explained by biomechanic means: whole-body vibration caused by tractor driving and similar long-term exposures leads to traction of the disks of the lower thoracic spine and the upper and middle parts of lumbar spine.

Quantitative assessment with SPECT imaging of stress injuries of the pars interarticularis and response to bracing.

The evaluation and management of acute spondylolysis remains unclear in part because of outcome data that are primarily subjective. The aim of this study was to evaluate and monitor these patients objectively using quantitative single-photon emission computed tomography (SPECT). Thirty-four patients were so observed clinically between 1987 and 1996 and were studied with an initial and at least one follow-up SPECT scintigram. Initial radiographs and planar bone scans failed to demonstrate the pars lesion in 53 and 19% of the patients, respectively. The average SPECT ratio before brace treatment was 1.45. After treatment, this ratio significantly decreased to 1.27 (p = 0.03). A subset of patients remained symptomatic at follow-up. Their reduction in SPECT ratio averaged only 2.8% as compared with 13% for the remainder of the patients (p = 0.01). Patients diagnosed and braced in the early, more active stage of the condition (with greater intensity on SPECT) had more predictable symptom relief. An initial SPECT ratio of >1.5 was associated with complete symptom resolution after brace treatment. Patients treated with activity restriction only (>3 months) before bracing were more likely to have persistent symptoms and more modest improvement on SPECT (p = 0.01). These data, which use SPECT scintigraphy, support prompt treatment with brace immobilization for acute spondylolysis in children and adolescents.

[Significance of revision of the occupational illness legislation for evaluating intervertebral disk damage]. / Die Bedeutung der Erweiterung der Berufskrankheitenverordnung für die Beurteilung von Bandscheibenschäden.

QUESTION: Are there any radiological criterions which are able to indicate the profession related disease No. 2108? METHODS: The medical documents and x-rays of the whole spine of 390 back pain patients who applied for a profession related disease of the spine were evaluated. Those patients who fulfilled the professional claims for acknowledgement of the profession related disease were compared to those who didn't fulfill these conditions. RESULTS: Concerning the segmental alterations of the cervical and the lumbal spine specific allocation frequencies were found. The dominance of L3/4 in the comparison group was conspicuous. Looking at the allocation frequencies of the cervical and lumbal disc alterations in view of affection heaviness it was obvious, that the predominating slight alterations mainly were located in the central parts of the cervical and the lumbal spine whereas bad alterations mainly were found in the lower parts. Regarding this matter test and comparison groups behaved the same way. Looking at the allocation frequencies concerning single respectively multiple alterations it was found that in the comparison group single respectively bisegmentale alterations could be recognized even in duplicate than in the test group in which the multiple alterations were dominant. The comparison of the cervical and the lumbal spine regarding chondrotic? spondylotic, slight and bad alterations in all mentioned features the next deeper located segment was affected particularly in the test group. Therefore a distal shift of the chondrotic alterations could be recognized. In case of the spondylotic affections it was the other way round: a cranial shift was conspicuous. CONCLUSION: After doing heavy labour for years only a few isolated multiple affections of the lumbal spine are found. On the strength of this fact the proof of exclusively in the lumbal spine located alterations doesn't allow the acknowledgement of a profession related disease. However, a distal shift of osteochondrotic alterations respectively a cranial shift of spondylotic affections in the lumbal spine is suspicous for being job-related. L3/4 takes a very special place in the differential diagnosis of profession related disease of the spine. In the test group this part of the lumbal spine showed bad alterations much more frequent. The affection of L3/4 pleads against a considerable participation of mechanical influences and therefore against a profession related disease. Singular or bisegmental disc affections are out of question for being a profession related disease because these alterations are seen much more frequent in the comparison than in the test group.

Neuroradiologic and electrophysiologic assessment of cervical spondylotic amyotrophy.

Dissociated motor loss due to cervical spondylosis and disc herniation was evaluated in 10 patients who presented with left deltoid paresis in the absence of sensory deficits or myelopathy. All of these cases underwent cervical anterior decompression. Based on magnetic resonance imaging, computed tomography myelography, and computed tomography discography, patients were divided into two pathologic types: The first showed focal bony spur and disc herniation with axial cord rotation and nerve root compression, and the second demonstrated ventral cord flattening. Electrophysiologic studies included evoked spinal potentials, motor evoked potentials, and evoked muscle action potentials. Motor evoked potentials, recorded epidurally from the ventral aspect of the thecal sac and the nerve root within the anterior discectomy or vertebrectomy sites, proved clinically most useful. Combining the latest available neuroradiologic and electrophysiologic information, 4 types of neural injury associated with deltoid pareses were identified in the 10 patients. The first included isolated C5 nerve root lesions; the second, C6 nerve root lesions; the third, both C5 and C6 nerve root lesions, and finally, intrinsic cord pathology.

Assessment of a single lumbar spine radiograph in low back pain.

The lumbosacral spine radiographs of 200 patients with unexplained low back pain and without neurological signs were reviewed. The purpose of the study was to determine whether significant diagnostic information would be lost by replacing the standard three film series with a single radiograph, either in the lateral or antero-posterior projection. The contribution of the coned lumbosacral junction view was also assessed. The results show that a single lateral radiograph is diagnostically satisfactory and would have the added advantages of reducing patient radiation dose and radiographic workload.

Cervical spinal cord injury without evidence of fracture or dislocation. An assessment of the radiological features.

An analysis of plain X-ray films, tomography and myelography in 30 patients with proven cervical spinal cord injury, whose X-ray films were negative, has been performed. Features considered were the sagittal diameter of the spinal canal, associated cervical spondylosis, soft tissue changes, mobility studies and the value in cases of cervical injury of two recently described radiological signs. The only consistent feature in the majority of patients was a large posterior osteophytic spur in the lower cervical spine. No other radiological feature was found to be of particular value in diagnosis.