Showing papers in "Spine in 1981"

Operative results and postoperative progression of ossification among patients with ossification of cervical posterior longitudinal ligament.

Abstract: Although the pathogenesis of ossification of the cervical posterior longitudinal ligament (OPLL) has not yet been clarified, it has come to be widely recognized that severe cervical myelopathy or radiculopathy is caused by OPLL. Fifty-three cases who were operated on for OPLL with myelopathy or radiculopathy in our clinic over the past 16 years were followed up. A recovery rate of approximately 70% was observed. Postoperative progressions of the ossification were observed among 75% of the cases of continuous and mixed type but seldom among those with segmental and other types. As causative factors for these postoperative progressions of the ossification, the authors would like to advocate biological, structural, and mobility-related elements. We concluded that in the ossified stage it is desirable to apply anterior decompression for the segmental and other type, posterior decompression for the continuous and mixed type, and, if necessary, two-stage combined decompression for the mixed type.

Disc pressure measurements.

Abstract: By measurement of intradiscal pressure in vitro, the hydrostatic properties of the nucleus pulposus of normal lumbar intervertebral disc were proven. The hydrodynamic properties seem to exist also in the somewhat degenerated disc, but not in the more severely deranged ones. Intravitally-performed measurements of disc pressure over the last 20 years in more than 100 individuals have demonstrated how the load on the lumbar disc varies with the position of the subject's body and during the performance of various tasks, both in standing and in sitting. Compared with the pressure of load in the upright standing position, reclining reduces the pressure by 50-80%, while unsupported sitting increases the load by 40%, forward leaning and weight lifting by more than 100%, and the position of forward flexion and rotation by 400%. Large augmentations in pressure were also observed in subject performing various commonly prescribed strengthening exercises.

Epidemiologic aspects on low-back pain in industry.

Abstract: The role of epidemiology with respect to back pain in industry is to clarify the natural history and clinical course of the pain and to identify workplace factors and individual factors of importance. On the basis of knowledge obtained through epidemiologic research, preventive measures can be instituted and risk factors eliminated. This paper reviews epidemiological data accumulated over the past 30 years. The impact of back conditions on industry is emphasized.

Analysis of loads on the lumbar spine.

Abstract: This paper presents procedures to calculate the loads on the lumbar spine and the contraction forces in the trunk muscles that are likely to be produced by given physical activities.

Low-back pain associated with leg length inequality.

Abstract: The possible association between pelvic obliquity and low-back pain is investigated in low-back pain patients and a control population. A precise method of erect posture radiography is used to carefully measure leg length inequality in these two groups. An age-related response of the postural scolio

The relevance of torsion to the mechanical derangement of the lumbar spine.

Abstract: Cadaveric lumbar intervertebral joints were loaded simultaneously in torsion and compression, and load-deformation curves were obtained. These were repeated after each of the following structures were cut through in turn: the supra/interspinous ligaments, the apophyseal joint in compression, and the apophyseal joint in tension. From the differences in the curves, it was possible to deduce the role of each structure and of the intervertebral disc in resisting and limiting torsion. The results show that torsion of the lumbar spine is resisted primarily by the apophyseal joint that is in compression, although the intervertebral disc does play a major role. The capsular ligaments of the tension facet and the supra/interspinous ligaments are unimportant. The compression facet is the first of rotation in joints with nondegenerated intervertebral discs. Much greater angles are required to damage the intervertebral disc, so torsion seems unimportant in the etiology of disc degeneration and prolapse.

Back Pain in Industry: A Prospective Survey

Abstract: Eight hundred and two subjects employed in NW England have been interviewed and examined after episodes of back or sciatic pain, using a standardized procedure Data on recurrence of symptoms leading to further treatment or absence from work in the following two 12-month periods were obtained by postal questionary Residual pain in the leg and a number of positive clinical signs of return to work, longer sickness--absence for the current attack, and two or more previous attacks were all associated with recurrence or persistence of symptoms The prognosis also varied according to the cause of back pain, falls being associated not only with longer periods of absence in the current attack but with a higher rate of recurrence The results have underlined the significance of a thorough examination on return to work after back pain for the industrial medical officer, as well as the epidemiological importance of this phase in the natural history of back and sciatic pain

Estimation of vertebral rotation and the spinal and rib cage deformity in scoliosis by computer tomography.

Abstract: Computer tomography (CT) presents a method of determining longitudinal axis vertebral rotation and vertebral, spinal, and rib case deformity. Different rotation angles, distances, and indexes are defined and discussed. Radiation risks were evaluated and considered exceedingly small when compared to the ordinary spinal anteroposterior radiograph. In a model study the mean difference between actual vertebral rotation and measured rotation was 0.3 degrees if the vertebrae were tilted up to 20 degrees in either the frontal or sagittal plane. This accuracy was lost if the vertebrae were tilted 20 degrees in both the frontal and the sagittal plane. Computer tomography can be used for evaluation of the vertebral rotation in the frontal plane.

Macroscopic and microscopic anatomy of the sacroiliac joint from embryonic life until the eighth decade.

Abstract: The macroscopic and microscopic anatomy of the sacroiliac joint from embryonic life until the eighth decade is presented to establish a baseline of normal anatomy for this joint. The literature concerning the anatomy of the joint was reviewed and found to be fragmentary and conflicting, particularly concerning the diarthroidial characteristics of the joint. From fetal life onward, the iliac cartilage surface is fibrocartilaginous, while the sacral surface is hyaline cartilage. Degenerative arthrosis of the joint commences at an early age, affecting the iliac cartilage to a greater extent than its sacral counterpart. These early degenerative changes in the sacroiliac joint may very well be a more common cause of low-back pain than previously thought.

Proteoglycans in Experimental Intervertebral Disc Degeneration

Abstract: An animal model of intervertebral disc degeneration induced surgically by ventral nuclear herniation in the rabbit produces morphologic changes of disc degeneration. Histologic characteristics and proteoglycan changes have been studied at various times after herniation. After injury, there was metaplasia into fibrocartilage originating from the cells along the margins of the annular wound, with proliferation of cells changing almost the entire disc space into fibrocartilage. A vertebral osteophyte occurred through an endochondral ossification sequence. Aggregating proteoglycans had two periods of repletion in the early course of degeneration. The water content of the disc was rapidly but only transiently restored in the first two days after herniation, whilst the changes in the total proteoglycan content of the disc paralleled these changes. Hyaluronic acid content decreased rapidly after herniation, but the size of the proteoglycan monomers did not change with degeneration. It is suggested that loss of confined fluid mechanics signals an abortive repair attempt rather than that of biochemical changes in proteoglycans initiate disc degeneration.

Three-dimensional architecture of lumbar intervertebral discs.

Abstract: Three-dimensional observations of the collagen framework of lumbar intervertebral discs by scanning electron microscopy confirmed that the fibrillar framework of the annulus and the cartilage end-plate was made of nucleus as a closed pack system. The cartilage end-plate was made of dense collagen framework aligned horizontally. There was no interconnection between the cartilage end-plate and the lamellar subchondral collagen. In places, the vascular channels ran directly at the end-plate. In the inner one third of the annulus, obliquely oriented fibrillar lamellae interconnected with the cartilage end-plate. In the outer two thirds, the fibrillar lamellae were formed from fibrillar bundles and were firmly anchored into the vertebral bodies. Architectural relationships between the disc and the vertebral bodies are discussed.

Spinal cord injury. Review of basic and applied research.

Abstract: This review examines, in a condensed manner, many of the major achievements related to spinal cord injury research during the last quarter century. Most of the advances have been made within the past 10 years. They include such basic and clinical tools as evoked potentials, regional and local spinal blood flows, neurophysiologic monitoring systems, and methods that detail the morphology and contents of cord tissue. Much of the experimentation conducted within the last 25 years has provided a better understanding and clinical therapeutic approach to the injured spinal cord than at any time before. Such work has exposed significant aspects in the biochemistry and vascular mechanics associated with trauma to the cord. A growing and intriguing area of spinal injury research lies in probing the factors related to neuronal plasticity and regeneration of the cord tissue. This review also examines the role of experimental animal models as well as the clinical and experimental therapies available for acute and chronic spinal cord injury.

The incidence of low-back pain in adult scoliosis.

Abstract: To date no knowledge of the incidence of scoliosis in adults and its relationship to low-back pain is available. In order to arrive at an understanding of low-back pain in adult scoliosis, a study of 5000 intravenous pyelograms was performed. The incidence of lumbar and thoracolumbar curves was 2.9%. One hundred and fifty-nine of the 189 patients found to have scoliosis were contacted. The incidence of back pain was 59% (similar to that in the general population). Back pain was subdivided into mild (44%), moderate (49%), or severe (7%). The curve was subdivided into three categories: 10-24 degrees, 25-44 degrees, and 45+ degrees. Of the 82 idiopathic curves with pain, 64 were in group 1, 15 in group 2, and 3 in group 3. Forty-three percent had mild pain, 50% had moderate pain, and 7% had severe pain. As the degree of curvature increased, the severity of pain increased, especially for curves of more than 45 degrees. Patients without back pain tended to have smaller curves. the presence of facet sclerosis correlated with a history of pain in 64%. There was a high correlation between radiologic changes at the curve apex and pain. Age bore no relationship to the incidence of pain.

1980 Volvo award in clinical sciences. Assessment of patients with low-back pain by biplanar radiographic measurement of intervertebral motion.

Abstract: Abnormalities of intervertebral joint motion including hypermobility, reduced mobility, torsional abnormality, and displacement of the center of rotation have been associated with degenerative change. However, measurement of these signs in plane X-ray films is handicapped by the three-dimensional motion and geometry of the spine. This study aimed to relate three-dimensional motion of the joints to their pathological state. We have used biplanar radiography to measure intervertebral motion during voluntary movements by patients with low back pain. Primary (or intentional) and coupled motions were measured by a refined technique, along with disc shear and facet joint motion. Abnormalities were found, especially in the "coupled" motions which were related to narrowed disc space, and to proximity to previous fusions. There was asymmetry of motion specific to joints with herniated nucleus pulposus.

Scoliosis in the institutionalized cerebral palsy population.

Abstract: A prospective review of 272 institutionalized cerebral palsy residents was undertaken in order to determine the incidence and characteristics of neuromuscular scoliosis in this population. The types of cerebral palsy in the group consisted of 75% spastic, 8% dyskinetic, 4% ataxic, 8% mixed, and 5% undefined. There was a 64% incidence of roentgenographic scoliosis greater than 10 degrees. Two distinct curve patterns were determined with equal frequency, single and multiple. The significance of the curve patterns could not be determined. Scoliosis was most common in the spastic group with the highest incidence in the spastic quadriplegics. The incidence directly paralleled the severity of the neurologic deficit but also appeared to be aggravated by the effects of gravity when the individuals were artificially placed in the sitting position. There was a definite inverse relationship between the level of ambulation and scoliosis: the higher the level of ambulation the lower the incidence of scoliosis. Hip stability per se could not be correlated with the incidence of scoliosis. The most important factors in predicting scoliosis in this population are the presence of spasticity and the severity of the neurologic deficit.

The mechanism of the lumbar spine.

Abstract: The moments generated in the lumbar spine by a weight lifter are balanced by moments generated internally by muscles and by the intervertebral ligamentous structures including the disc. Unique real number solutions have been obtained by a optimization technique minimizing shear and penalizing excessive muscle power. The model faithfully reproduces the electromyographic responses and all known experimentally-determined values for muscle power and compression. The outputs can be used to calculate a realistic motion of the spine under various loads. The model suggests that in handling heavy loads, the stress at each intervertebral joint is identical and with maximal voluntary effort, the weight lifter does not exceed 67% of the ultimate strength of his tissues.

Gastrointestinal complications of spinal cord injury.

Abstract: The incidence, nature, and radiographic features of gastrointestinal complications encountered in a group of 567 consecutive spinal-cord-injury patients are reported. Eighty-seven episodes of gastrointestinal complications developed in 63 (11%) patients. During the first month postinjury, these complications consisted of ileus, gastric dilatation, the body cast syndrome, peptic ulcer disease, and pancreatitis. More chronically these patients presented with fecal impactions, peptic ulcer disease, the superior mesenteric artery syndrome, hepatitis, amyloidosis, and the precocious appearance of diverticulosis, hiatus hernia, and gastroesophageal reflux. Radiographic findings were diagnostic in the majority of cases and aided in the early diagnosis of these potentially life-threatening complications.

Apophyseal injection of local anesthetic as a diagnostic aid in primary low-back pain syndromes.

Abstract: Twenty-five out of 41 adult patients suffering from their first attack of acute low-back pain were subjected to local anesthetic injection into the maximally tender lumbar apophyseal joints under controlled conditions. Two clinical syndromes can be identified according to whether the patients responded to the facet injection or not. Various clinical differences were statistically significant and included a wider than normal spinal canal in the responding group. The clinical significance of these two distinct groups is discussed in detail.

1980 Volvo award winner in basic science. Nutritional pathways of the intervertebral disc. An experimental study using hydrogen washout technique.

Abstract: The pathways of material transfer to the intervertebral disc were studied in adult dogs by measuring diffusion of hydrogen molecules in the nucleus pulposus before and after disruption of the route through the annulus fibrosus and before and after disruption of the end-plate route. The interfaces was only in the central two-thirds of one side, caused significantly greater decrease in the rate of hydrogen washout than the disruption of the annulus route. Histologically, the bone-cartilage interface was frequently perforated by marrow cavity and vascular buds. These findings suggest that the end-plate route is a major pathway for material transfer to the intervertebral disc.

Some experimental observations of the influence of a single lumbar floating fusion on the remaining lumbar spine.

Abstract: Observations of the ranges of flexion of the lumbar interbody joints under standardized loading have been made before and after isolated floating fusions were performed. The observed effect was that the movement which had previously occurred at the free disc level was transferred preferentially to discs immediately adjacent to the fusion-usually, but not always, most of this movement being taken up by the disc immediately below the fusion. The implications of these observations for patients on whom a floating spinal fusion is to be performed are discussed. A clinical case is discussed in which a congenital fusion is associated with degeneracy of an immediately neighboring disc.

The back school

Abstract: The conceptual basis for formation of a Back School for low-back pain victims includes understanding the relationship of pain to increased mechanical stress. Existing research data were organized into four lessons to be given to back pain victims in the form of group education. Anatomy and physiology form the basis for practical applications in the conduct of physical activities.

The incidence of spondylolysis and spondylolisthesis in nonambulatory patients.

Abstract: Radiographs were obtained of the lumbosacral spines of 143 patients that had never walked. The frequency of spondylolysis and spondylolisthesis was determined, as well as that of other spinal abnormalities. The average age of the patients was 27 years, with a range of 11 to 93 years. The underlying diagnoses responsible for the nonambulatory status varied, but cerebral palsy predominated. No case of spondylolysis or spondylolisthesis was detected, and when compared to the 5.8% incidence in the general population, this finding is significant at the P less than 0.001 level. The incidences of spinal bifida (8.4%) and of transitional vertebrae (10.9%) are similar to those found in the general population. Scoliosis was found in 49% and vertebral body height was increased in 32.9%. Degenerative changes occurred in only 2.8%. These results support the theory that spondylolysis and isthmic spondylolisthesis represent a fatigue fracture resulting from activities associated with ambulation.

The Relation Between Bone Mineral Content, Experimental Compression Fractures, and Disc Degeneration in Lumbar Vertebrae

Abstract: The bone mineral content and the ultimate compressive strength were determined in 109 fresh lumbar vertebrae from 36 different subjects, 31 to 79 years of age. The degree of macroscopic disc degeneration and the types of fracture were determined. Three types of fracture-central, wedge and transverse-were found, but only under magnification and at simultaneous movements of the fracture segment. The central type of fracture was found predominantly in specimens with high bone mineral content surrounded by normal discs. The wedge type of fracture was consistent with lower bone mineral content and more severe disc degeneration.

Repeat lumbar surgery. A review of patients with failure from previous lumbar surgery treated by spinal canal exploration and lumbar spinal fusion.

Abstract: Thirty-six patients with chronic back and/or leg pain following previous lumbar surgery who underwent both spinal canal exploration and spinal fusion were subjected to retrospective review. The purpose was to determine the probability of success for this surgical approach. Twenty (56%) of the 36 patients had a satisfactory result. In 15 patients with multiple objective findings of an ongoing radiculopathy, 11 (73%) improved. Only nine (43%) of 21 patients improved if these preoperative criteria were absent. Analysis according to the type of surgery performed in the spinal canal demonstrated improvement in (a) 17 (74%) of 23 patients who had wide bony decompression, (b) eight (61%) of 12 patients who had discectomy, and (c) seven (47%) of 15 patients who had an extensive neurolysis. In 17 patients whose time interval between the previous operation and present reconstruction was greater than 18 months, 13 (76%) improved. Only seven (36%) of 19 patients with a shorter time interval improved. The presence of pseudarthrosis was a poor indication for repeat lumbar surgery. The number of previous lumbar surgeries may not necessarily preclude a satisfactory outcome. Solid fusion correlated highly with a satisfactory outcome. Best results are obtained when objective preoperative findings indicate the presence of a surgically correctable abnormality.

1980 Volvo award in biomechanics. Measurement of the distribution of axial stress on the end-plate of the vertebral body.

Abstract: The distribution of axial stress on the end-plate of the vertebral body has been measured by the aid of miniature piezoelectric pressure transducers in specimens of motion segments of the human vertebral column. The results indicate that the stress distribution depends essentially on the state of degeneration of the intervertebral disc and on the relative position of the adjacent end-plates. Furthermore lumbar and thoracic motion segments show a different behaviour. The measured results relate to the problem of the stress dependent deformation of the growing vertebra, the codfish shape of the osteoporotic vertebra and to the mechanism of degeneration of the intervertebral disc.

Significance of lumbar spondylolysis in college football players.

Abstract: We reviewed the records of 506 consecutive college football players over an eight-year period. Of these athletes, 135 (27%) had low-back pain. Because of persistent low-back symptoms, 58 players had roentgenograms of the lumbosacral spine; 12 cases of lumbar spondylosis were observed. From the 58 players for whom roentgenograms were available, two groups were compared with respect to time lost from games and practices. One group (N = 8) had low-back pain complaints with lumbar spondylosis. The randomly selected control group (N = 12) had low-back pain with no evidence of spondylolysis on roentgenograms. There was no significant difference in time loss between these two groups (4.8% versus 4.0%). It appears that lumbar spondylolysis is of minimal clinical significance over a short (four-year) period. The long-term implications of lumbar spondylolysis are clearly important but are not addressed in this study.

The shoulder abduction test in the diagnosis of radicular pain in cervical extradural compressive monoradiculopathies.

Abstract: The authors have observed a series of patients with cervical monoradiculopathies due to extradural compressive disease in whom clinical signs included relief of radicular pain with abduction of the shoulder. Of 22 patients requiring myelography for unremitting radicular pain, 15 experienced relief of pain with shoulder abduction. Thirteen patients showing this sign required surgery and all achieved a good result. Two patients were relieved with additional conservative measures. Pain relief obtained with this maneuver seems to occur by decreasing tension on the nerve root. This shoulder abduction relief sign has not been commonly elicited in the past, and the authors wish to bring attention to its value as an indicator of significant cervical extradural radicular compressive disease.

Scheuermann's kyphosis--long-term results of Milwaukee braces treatment.

Abstract: A review of 203 patients with Scheuermann's kyphosis is presented. The modified Milwaukee brace was used in 62 patients. Thirty-nine patients wore the brace for an average of 18 months. The pretreatment kyphosis averaged 62 degrees, and the curve at the completion of brace treatment averaged 41 degrees. Follow-up of more than 18 months after brace wear showed an average 15 degrees loss of correction. Wedging of the vertebral bodies improved from 7.9 degrees to 6.8 degrees with brace treatment. To provide permanent correction, vertebral wedging must improve to approximately 5 degrees. Most patients will require full-time brace wear of longer than 18 months to effect this improvement in vertebral wedging. The brace can improve kyphotic curves greater than 75 degrees.

Biomechanics of lumbosacral dural sac - a study of flexion-extension myelography

Abstract: Measurements were performed on 40 lateral lumbar myelograms in flexion and extension with the object of analyzing changes in position and shape of the dural sac in spinal movements. There proved to be an anterior displacement of the entire lumbar dural sac in lumbar extension, most likely caused by shortening and thickening of the flaval ligaments. In addition, the anterior dural surface was indented at the L3-4 and L4-5 interspaces by posterior bulging of the discs in extension. This encroachment was partially compensated by dural bulging into areas with a rich and compressible venous plexus: behind the vertebral bodies and the L5-S1 disc. While the patterns of dural movements showed individual variations, these trends were found in all diagnostic and anatomic subgroups. One subgroup (with root involvement at L4-5) showed marked dorsal encroachment upon the dural sac in extension at the same level. The clinical implications of these findings are discussed.

Transitional lumbosacral discs. probability of herniation.

Abstract: The charts and roentgenograms of 200 patients operated upon for lumbar disc herniations were reviews. Among them, there were 42 persons in whom a lumbosacral transitional vertebra existed. The discs beneath these vertebra varied in appearance. A descriptive classification for the four disc types is proposed. In none of the 42 patients were there myelographic evidence of herniation of such a disc. In five instances, such disc were surgically inspected, and no protrusion was uncovered. Before transitional discs are operated upon, the proof of herniation should be incontrovertible.