Age-dependent correlation of low-back pain and lumbar disc degeneration

The prevalence of lumbar disc degeneration in subjects suffering from low-back pain (n = 207; age range 10–49 years) and in age-matched asymptomatic controls (n = 216) was investigated by magnetic resonance imaging. The percentage of subjects with degenerated discs increased with age; starting from the age of 15 years, this increase was more rapid in subjects with low-back pain. Concurrently, the number of degenerated discs was higher in the pain group than in controls. Lumbar disc degeneration manifests earlier and in a greater percentage of subjects with low-back pain than in asymptomatic controls.     

Magnetic resonance study of disc degeneration in young low-back pain patients

The correlation of roentgenographic findings, clinical history, and incipient disc degeneration (DD), diagnosed with magnetic resonance imaging, was analyzed in young patients with low-back pain (LBP). One or more lumbar discs were abnormal in 57% of the 20-year-old LBP patients (n = 75) and in 35% of the asymptomatic controls (n = 34) in MRI. Narrowed disc spaces and alterations attributed to lumbar Scheuermann's disease, shown on the radiographs, were always associated with DD in MRI. Such a strong relationship was not observed with transitional vertebrae, spondylolisthesis, spina bifida, or postural abnormalities. However, an increased weight, a positive straight leg raising test, and a reduced lumbar mobility was consistent with an increase in frequency of DD. Magnetic resonance imaging is a safe and sensitive method for studying the presence and etiologic factors of DD.     

The development of low-back pain after excision of a lumbar disc

One hundred and twenty consecutive patients who had primary excision of a lumbar disc at a single level for predominantly radicular symptoms were studied. Of these patients, eighty-seven (72 per cent) were available for comprehensive review. The duration of follow-up ranged from twenty-four to eighty-seven months (average, thirty-eight months). Radiculopathy was initially relieved in eighty-six (99 per cent) of the patients, although six patients (7 per cent) had recurrent herniation, which was successfully treated by reoperation. In an additional twelve patients (14 per cent), the operation was deemed a failure due to subsequent disabling low-back pain. Narrowing of the disc space was present radiographically in 98 per cent of the patients, but the amount of narrowing did not correlate with the degree of low-back pain, the age of the patient, or the length of time after operation. Factors predisposing to failure of the operation due to disabling low-back pain included coverage under Workmen's Compensation (p less than 0.00001), a history of more than fifteen pack-years of cigarette-smoking (average, one pack a day for fifteen years) (p less than 0.01), and an age of more than forty years (p less than 0.05).     

腰椎间盘病的人工椎间盘置换23例报告

[目的]探讨人工椎间盘置换治疗腰椎间盘病的疗效。[方法]对23例24节段腰椎间盘病,采用人工椎间盘置换,其中男13例(14节段),女10例;平均年龄45.2岁,累及L1、21例,L4、55例,L5S117例。以椎间盘突出症为主的椎间盘病19例,骶椎类肿瘤1例,因原椎节段椎间盘摘除术后6~8.5 a复发3例。[结果]23例平均随访4.2 a,患椎伸6.8°、屈6.7°,左右旋转17°,比术前患椎活动度伸4.1°、屈4.7,°旋转6.8°,有明显进步(P<0.05)。结合患者的满意度和JOA评价,疗效优(31~40)21例,良(21~30)1例,可(16~20)1例,无失败(<16),优良率96.2%。[结论]人工椎间盘置换术是替代腰椎间融合术和治疗腰椎间盘病的有效方法。     

The relationship of low-back pain to pregnancy and gynecologic factors

The association between low-back pain (LBP) and pregnancy and gynecologic factors was investigated in a retrospective cross-sectional study of 1,760 38- to 64-year-old women. The life-time incidence of LBP was 66% (incidence group) and the prevalence 35% (prevalence group). Eighty-six percent of the women had been pregnant, and 24% had suffered from LBP during pregnancy. Ten percent of the women in the incidence group and 15% of those in the prevalence group stated that their LBP had started during pregnancy. Fifty-one percent of the women in the prevalence group experienced an increase in their LBP during menstruation. For the purpose of an analysis of covariance, the population was divided by age into those aged 38 to 49 years and those 50 to 64 years of age. A higher number of abortions was found to be directly associated to LBP in 38- to 49-year-old women. In 50- to 64-year-old women, two variables were directly associated to LBP viz., a higher number of live births and a higher frequency of menopausal symptoms.     

Psychosocial factors influencing outcome in patients with low-back pain

A psychosocial analysis of 58 patients with low-back pain was conducted. Three groups of patients with different outcomes were delineated with distinctly different psychosocial profiles. Patients who recovered uneventfully had a better income, reported more satisfaction with hospitalization or medical personnel, and had prolonged pain-free periods. Patients with the worst outcomes in terms of poor work role adjustment and severe pain complaints were more likely to be immigrants from mainland China, to be engaged in heavy manual labor, to be involved in compensation claims for work-related injuries, manifested a high degree of anxiety and depressive symptoms, and were hostile toward medical personnel. An intermediate group of patients with adequate work role adjustment but severe to moderate levels of pain were characterized by being females with varying combinations of anxiety and depressive symptoms. A preliminary clinical interview guide for screening potential problematic patients was developed.     

Lumbar discography followed by computed tomography. Refining the diagnosis of low-back pain

Two hundred fifty patients with low-back pain who underwent lumbar discography followed by computed tomography (CT) are the subject of this prospective study. In 93% of the patients, these combined imaging techniques provided additional useful diagnostic information that affected patient management and the selection of treatment alternatives. Lumbar discography followed by CT proved valuable in determining the significance of equivocal or multiple level abnormalities, determining the type of disc herniation, defining surgical options, and evaluating the previously operated spine. In 94% of patients who had surgery, CT-discography correctly predicted the type of disc herniation as protruded, extruded, sequestrated, or internally disrupted. Computed tomography-discography may be more sensitive that magnetic resonance imaging (MRI) in the early stages of disc degeneration because 18 of 177 discs with a normal T2-weighted image were discographically abnormal and the CT-discogram revealed annular tears or radial fissuring. The radiographic morphology of the normal herniated and degenerative lumbar discs shown by CT-discography gives unique insight into the pathogenesis of disc degeneration. The complications that followed the 750 discograms were one case of urticaria and one disc space infection. Even with the availability of high resolution CT and MRI, lumbar discography remains the only pain provocation challenge to the lumbar disc.     

Relationship between low-back pain, muscle spasm and pressure pain thresholds in patients with lumbar disc herniation

It is not known whether or not muscle spasm of the back muscles presented in patients with sciatic scoliosis caused by lumbar disc herniation produces muscle pain and/or tenderness. Pressure pain thresholds (PPTs) of the lower back and low-back pain were examined in 52 patients (13 of 52 presenting sciatic scoliosis) with lumbar disc herniation who complained of radicular pain and in 15 normal subjects. PPTs were measured at five points bilaterally using an electronic pressure algometer. Low-back pain was evaluated using visual analogue scale (VAS) ratings. All patients complained of radicular leg pain and were divided into the following three groups according to the presence of and the region of low-back pain: no low-back pain group, low-back pain with no laterality group, and low-back pain dominantly on the herniation side group; the VAS rating on the side ipsilateral to the herniation side was higher than that on the contralateral side. In the normal subjects, there were no statistically significant differences between sides in mean PPTs at all sites examined. PPTs were not lower in the spasmodic side (concave side) than the convex side in patients with sciatic scoliosis. PPTs on the herniation side were significantly lower than those on the contralateral side in patients with low-back pain dominantly on the herniation side. Furthermore, the areas of low PPTs were beyond the innervation area of dorsal ramus of L5 and S1 nerve root. It was considered that not only the peripheral mechanisms but also the hyper excitability of the central nervous system might contribute in lowering PPTs of the lower back on the herniation side.     

Schmorl's nodes and low-back pain

Summary Magnetic resonance imaing (MRI) findings in cases with symptomatic and asymptomatic Schmorl's nodes have been analysed. In all symptomatic cases, the vertebral body marrow surrounding the Schmorl's node was seen as low signal intensity on T1-weighted images and as high signal intensity on T2-weighted images. It was confirmed by histological examination that the MRI findings indicated the presence of inflammation and oedema in the vertebral bone marrow. These MRI findings were not seen in asymptomatic individuals. Inflammatory changes in the vertebral body marrow induced by intraosseous fracture and biological reactions to intraspongious disc materials might cause pain. We postulate that after fracture healing and subsidence of inflammation, the Schmorl's nodes become asymptomatic, in analogy with old vertebral compression fractures. MRI is not only useful in detecting the recently developed Schmorl's nodes but also in differentiating between symptomatic and asymptomatic Schmorl's nodes.     

Lumbar disc herniation: social and demographic factors determining duration of disease

The study was set up to show whether certain social and demographic characteristics play any significant role in determining the duration of disease in patients with lumbar disc herniation. The study included 171 consecutive patients operated upon for the first time for lumbar disc herniation over a 1-year period. Records were made of each patient's age, sex, domicile (town, rural area), social group and employment status. For each patient, four dates were also recorded: onset of symptoms, referral to hospital, operation and recovery. On this basis six periods could be calculated. Statistical analysis was used to identify the relation between the social and demographic factors and the various time periods between the onset of symptoms and recovery. Being employed, especially in a higher social group, cuts down the period from onset of symptoms to recovery. This shortening in the total duration mainly takes place between onset of symptoms and referral to hospital. The influences of domicile, age and sex were of no statistical significance. The median of the total period from onset of symptoms to recovery was 224 days. Among patients operated upon for the first time for lumbar disc herniation, employment denoted faster referral to hospital and thus faster operation and recovery. Among those employed, the patients from higher social groups were referred quickest.     

Clinical efficacy of imaging modalities in the diagnosis of low-back pain disorders

This review provides methodological background and some guidelines for the evaluation of imaging modalities for the lumbar spine and reviews the current literature on the basis of different levels of efficacy which consider standards beyond technical quality or diagnostic accurracy. From a MEDLINE search, 672 articles (1985–1995) were retrieved which focused on the development or application of imaging modalities for lumbar spinal disorders. The papers were categorized according to different efficacy levels at which the imaging modalities were assessed. This review has demonstrated that the vast majority of reports evaluate imaging studies for the lumbar spine only at the technical efficacy level. A minor proportion of the articles focus on the evaluation at the level of diagnostic accuracy. Articles which assess imaging studies on a higher level of efficacy (e.g., diagnostic and therapeutic impact, patient outcome and costbenefit analysis) are sparse. This review has outlined frequent methodological flaws in patient selection and design of imaging studies for the lumbar spine. The spine specialist should therefore become very critical in the interpretation of those studies and pay attention to patient selection and spectrum, choice of the reference standard, sample size, various forms of biases, and the reasoning behind clinical recommendations in order to improve his patient care.This work was supported by a grant from the Swiss Foundation for Grants Medicine and Biology (to N. Boos)     

The relation between biomechanical and psychological factors in patients with low-back pain

Behavioral factors are increasingly being recognized for their role in determining the course and outcome of low-back disorders. This paper examines the relation between behavioral variables, which include psychological symptoms and pain tolerance, and biomechanical variables. The majority of the 89 patients tested could be classified into two groups. One group was intolerant of pain and showed reduced spinal mobility, restricted straight leg raising, and altered flexor-extensor muscle balance. The other group was more tolerant of pain and did not show restriction of motion or muscle imbalance. Spinal mobility was also related to psychological symptoms. A model is proposed which points to a feedback between spinal motion and the patient's ability to cope with pain as one mechanism that determines return to a functional range of motion.     

Epidemiology and impact of low-back pain

Disorders of the lumbar spine are among the most common medical problems in western countries, affecting up to 80% of people at some time during their lives. The epidemiology and impact of six specific disorders of the lumbar spine are reviewed. These include prolapsed discs, disc degeneration, osteoarthrosis of the apophyseal joints, fractures and dislocations of vertebrae, osteoporosis, and spondylolisthesis. Various mechanical factors contribute to the causation of most of these disorders, but other underlying pathologic mechanisms are important as well. In light of the great impact of these conditions on society and on individuals, it is concluded that there is a considerable need for a greater allocation of resources for improvement in methods of prevention, diagnosis, and treatment.     

Lumbar disc degeneration: epidemiology and genetics

Research conducted over the past decade has led to a dramatic shift in the understanding of disc degeneration and its etiology. Previously, heavy physical loading-often associated with occupation-was the main suspected risk factor for disc degeneration, which was commonly viewed as a wear-and-tear phenomenon exacerbated by the precarious nutritional status of the disc. However, results of studies on twins suggest that physical loading specific to occupation and sport plays a relatively minor role in disc degeneration. Recent research indicates that heredity has a dominant role in disc degeneration, which would explain the variance of up to 74% seen in adult populations that have been studied to date. Since 1998, genetic influences have been confirmed by the identification of several gene forms associated with disc degeneration. This research is paving the way for a better understanding of the biologic mechanisms through which disc degeneration occurs, including specific interactions between genes and environment. Research into disc degeneration and genetics has become more limited by phenotypes or definitions and measures of disc degeneration than by DNA analysis. Standardized, universally accepted definitions of disc degeneration are lacking, in part due to limited knowledge of the process. The measurements that are selected depend on the method used to evaluate the disc and are often qualitative ordinal rating scales, lacking in precision. Although it is generally agreed that disc degeneration is common, the prevalence of specific findings is unclear. A review of the epidemiology of disc degeneration reveals wide-ranging prevalence estimates for various signs of disc degeneration in samples of the general population and in patients with back symptoms. The extreme variations in prevalence rates are likely largely due to inconsistencies in the definitions and measurements of disc degeneration. Such inconsistencies and inaccuracies impede epidemiologic research on disc degeneration.     

Lumbar disc herniation: microsurgical approach

Lumbar microdiscectomy IS an effective and time-tested neurosurgical procedure. Appropriate patient selection is as important as surgical technique in ensuring good outcome. As with any operation, mastery of the relevant anatomy is paramount. We offer the following illustrations to help surgeons appreciate this anatomy: specifically, the relationship between the interspace, the nerve root, and the pedicle as seen during a microdiscectomy.