Showing papers in "Spine in 1982"

A mechanistic classification of closed, indirect fractures and dislocations of the lower cervical spine.

Abstract: Closed, indirect fractures and dislocations of the lower cervical spine occur in families or groups within which there is a spectrum of anatomic damage to a cervical motion segment. This study of 165 cases demonstrates the various spectra of injury, called phylogenies, and develops a classification based on the mechanism of injury. The common groups are compressive flexion, vertical compression, distractive flexion, compressive extension, distractive extension, and lateral flexion. The probability of an associated neurologic lesion relates directly to the type and severity of cervical spine injury. With use of the classification, it is possible to formulate a rational treatment plan for injuries to the cervical spine.

Reciprocal angulation of vertebral bodies in a sagittal plane: approach to references for the evaluation of kyphosis and lordosis.

Abstract: In order to establish a sagittal plane curve reference table for standing subjects examined laterally, we determined an easily reproducible standard posture. A sample of 100 healthy subjects from 20 to 29 years of age, was chosen (43 women, 57 men). The reciprocal angulations of each vertebral body in relation to the others were fed into a digitalizer and studied by computer. The study particularly concerns maximum kyphosis, maximum lordosis, sacral base slopes, and the tilt of intermediate vertebral bodies. The dispersion of the results is remarkably wide and, within the extreme values, the distribution is irregular. Individual correlations of these values are often dispersed, but spinal morphotypology. For considerable lengths, average values cannot be used as norms, given the wide span of values. Only the extreme limits are useful for the appreciation of curves as excessive, insufficient, or inverted.

The clinical anatomy of the cervical dorsal rami.

Abstract: A detailed description of the anatomy of the cervical dorsal rami is provided on the basis of the past literature and independent studies on five cadavers. In particular, the anatomy of the upper cervical dorsal rami and the innervation of the cervical zygapophyseal joints are described. The clinical significance of the cervical dorsal rami is discussed in relation to headache, occipital neuralgia, and neck pain. The surgical anatomy of cervical facet denervation is discussed. The radiologic anatomy of the medial branches of the cervical dorsal rami is described, and target points suitable for diagnostic blocks or facet denervation are illustrated.

A Biomechanical Analysis of the Clinical Stability of the Lumbar and Lumbosacral Spine

Abstract: Eighteen Functional Spinal Units (FSU), representing three levels of human lumbar and lumbosacral spine, were tested using preload forces that corresponded to the clinical situation of a person lying supine or standing while subjected to maximum physiologic flexion or extension forces. Sagittal plane displacements were measured using linear variable differential transformers (LVDTs) and a MINC-11/03 minicomputer. Sequential transection of components in the posterlor­ to-anterior and anterior-to-posterior directions until failure occurred allowed measurements of the displacement sagittal plane translation and rotation of the Intact and transected FSU [Key words: lumbar spine, stability, flexion. extersion, preload]

Assessment of the progress of the back pain patient

Abstract: Fifteen subjective variables reflecting the severity of back pain, the circumstances exacerbating symptoms, and the impact of the problem on life style were scored on Visual Analogue Scales. It was possible to combine the results from these assessments to provide a global subjective index. Repeated measurements by the same observer showed a high degree of reproducibility, but when performed by separate observers discrepancies arose in certain questions. By improving certain questions and standardizing their presentation to the patient, a considerable improvement in the correlation of results between observers was obtained. Objective assessments of spinal motion and straight leg raising and a global objective index showed a high degree of intraobserver reproducibility. This technique was applied to a study of relief of back pain by lumbar corsets when it was found that there was significantly greater relief of back pain by a corset with a lumbar support than one without a spinal support. We conclude that the emphasis in assessing the progress of the back-pain patient must be on the subjective parameters, and the technique developed offers a useful method for reliably assessing patients and following their progress.

Physiologic strains in the lumbar spinal ligaments. An in vitro biomechanical study 1981 Volvo Award in Biomechanics.

Abstract: For understanding of the mechanical causes of low-back pain, knowledge of the biomechanics of the various spinal elements is essential. In this in vitro biomechanical study, in situ behavior of spinal ligaments of the L3-4 and L4-5 functional spinal units during physiologic activities was studied in a three-stage procedure. First, 72 load-displacement curves were obtained to determine the three-dimensional flexibility characteristics of the spinal units. Second, three-dimensional morphometric measurements were made of all the spinal ligament attachment points. Finally, a mathematical model was constructed to combine the flexibility and morphometric data and compute the ligament length changes and strains as functions of various spinal movements. In flexion movement, the interspinous and supra-spinous ligaments were found to be subjected to the highest strains, followed by the capsular ligaments and the ligamentum flavum. During extension, it is the anterior longitudinal ligament that has the maximum strain. In lateral bending, the contralateral transverse ligaments carried the highest strains, while the interspinous and supraspinous ligaments were relatively unstrained. In rotation, the capsular ligaments were by far the most strained ligaments.

Vertebral end-plate changes with aging of human vertebrae.

Abstract: The present study describes the sequential age changes within the growth and articular layers of the cartilaginous end-plates of vertebrae from humans varying in age from birth to 73 years. There is a gradual reduction in the width of the growth cartilage up to 16-20 years of age. During adulthood and progressing into old age (60-73 years), the end-plates consist of only articular cartilage which undergoes calcification followed by resorption and replacement by bone. Age changes are observed in the arterioles, capillaries, and venules found in the nutrient canals or spaces of the bone adjacent to the cartilage or disc. The calcification of the articular cartilage and vascular changes seen in the older vertebrae would impede the passage of nutrients from the blood to the disc proper. Collagen fibers are observed arising from the older vertebral end-plates to course into the midregion of the disc.

Neurologic complications of anterior cervical interbody fusion.

Abstract: Questionnaires regarding the neurologic complications of anterior cervical fusion were sent to 1358 neurosurgeons in 1974. There were 704 replies describing a total of 82,114 cases. Three hundred eleven major neurologic complications were reported in the entire series, including myelopathy. In addition, 70 detailed case reports were appended to the replies, making a separate analysis possible. Incidence of complications versus series size was tabulated.

The unstable burst fracture.

Abstract: Sixteen patients with "unstable" burst fractures of the thoracolumbar junction were treated with a modified posterolateral decompression and Harrington rod instrumentation. Preoperative computed tomography (CT) could assess the midsagittal diameter of the spinal canal and accurately localize the site of neural impingement. A surprisingly large proportion of cases had CT-demonstrated posterior element fractures which were missed using conventional radiographic modalities. The surgical goal was to provide the optimal environment for neurologic recovery. All 12 patients with neurologic deficits improved postoperatively, including five of eight patients with conus medullaris lesions who had full recovery. One-stage decompression-stabilization reduces the incidence of progressive kyphosis, neurologic deterioration, and mechanical back pain common in both conservative treatment and with wide laminectomy.

Scoliosis in the elderly: a follow-up study.

Abstract: A follow-up x-ray study of 554 subjects aged between 50 and 84 years has been carried out to determine the appearance, presence, and progression of scoliosis in the elderly and its relationship to osteoporosis and back pain. The subjects were chosen from a population group of 3600 subjects examined 7 to 13 years previously in the same investigators. Some degree of scoliosis was found in 70% of the subjects, and curves of 10 degrees or more in approximately 30%. Ten percent of the subjects had developed scoliosis de novo during the follow-up period. There was no direct relationship between the presence or progression of scoliosis and osteoporosis. There was no direct relationship between scoliosis and back pain or between scoliosis and degenerative changes in the spine. Since scoliosis in the elderly seldom becomes a clinical problem of significance, there would appear to be no valid reason for a more extensive study of the condition at this time.

The Galveston technique for L rod instrumentation of the scoliotic spine.

Abstract: Many small details of technique are important for achieving an excellent quality L-rod instrumentation of the scoliotic spine. Herein the authors report specifics gleaned from their experience and discuss the basis for them. The optimum approach establishes correctability of the deformity prior to spinal instrumentation, provides secure internal fixation of the spine, and strives for a massive arthrodesis.

Vibration and the human spine.

Abstract: Vibrational effects have been found to be associated with increased frequency of low-back pain in various industries, and because of this the study herein reported was conducted to assess the physiologic response of the spinal system to sinusoidal vibrations. A device replicating industrial vibration was constructed and employed on healthy human volunteers to determine the stiffness, impedence, and resonant characteristics of the subjects. Three peaks of enhanced transmissibility corresponding to the resonant frequency of the spinal system were found. The greatest transmissibility of vibratory input occurs at the first resonant frequency (5Hz) where marked enhancement of vibrational input occurs as vibrations pass through the spinal system. A progressive stiffening of the system occurs in response to vibrational inputs of increasing frequency. The effects of posture, the Valsalva maneuver, and fatigue alter the normal response. Structures vibrated at the first resonant frequency have greater potential for damage.

Can the lumbar spine be crushed in heavy lifting

Abstract: Cadaveric lumbar intervertebral joints were wedged to simulate forward flexion and then compressed to failure. The compressive strengths of the young male specimens tested were compared with the forces calculated to act when average young men perform maximum lifts from the flexed posture. It is concluded that the spine has a considerable margin of safety when such lifts are performed.

Lumbar discectomy. Results with limited disc excision and selective foraminotomy.

Abstract: Fifty-four consecutive patients who underwent limited lumbar discectomy, based on specific objective criteria, were reviewed. Sixteen of these patients had a limited foraminotomy performed in addition to the limited discectomy. The postoperative results in these patients were good, and the fair to poor results appear to be related primarily to subjective factors, rather than to persistent objective impairment of neuromuscular function. These data do not support prior concern over an increased incidence of recurrent disc herniation with a limited discectomy. Lumbar discectomy performed with limited disc excision is a safe, effective, and reliable method for treating selected patients with herniated lumbar discs.

Laminoplasty for patients with compressive myelopathy due to so-called spinal canal stenosis in cervical and thoracic regions.

Abstract: The author reports detail of a simplified technique named laminoplasty, as an alternative to laminectomy that allows osteoplastic enlargement of the spinal canal in the cervical and thoracic spines. The postoperative spinal deformities from laminectomy can be prevented by employing this method since it promotes stable clinical results. The indications, technique, and results of the procedure are discussed in ten cases. The laminoplasty is recommended for compressive myelopathy due to narrowed spinal canal, especially in the cervical region. Clinical neurologic improvement tends to parallel the spinal canal enlargement achieved.

Chymopapain for the treatment of intervertebral disc herniation. The final report of a double-blind study.

Abstract: Sixty patients with unilateral sciatica resulting from lumbar intervertebral disc herniation were entered into a double-blind study. All patients had failed to respond to conservative management, and the diagnosis had been confirmed by metrizamide myelography. Following a randomized schedule, 30 patients had intradiscal injections of chymopapain, and 30 patients had intradiscal injections of an equivalent volume of normal saline solution. Two years after the injection, 77% of patients treated with chymopapain were assessed as moderately improved, compared with 47% of saline-injected patients. Fifty-seven percent of the chymopapain group were free of pain, compared with 23% in the saline group. Based on the late results of this study, chymopapain is recommended for the treatment of sciatica from intervertebral disc herniation when conservative measures have failed and before disc fragment excision is considered.

Segmental spinal instrumentation in the treatment of fractures of the thoracolumbar spine.

Abstract: A group of 14 patients with fractures of the thoracolumbar spine was studied. They were all treated with segmental spinal instrumentation as a primary procedure which afforded immediate rigid internal fixation of the spine and permitted mobilization without external support and immediate rehabilitation. Ancillary procedures to eliminate intramedullary obstructions were necessary for four patients before definitive segmental spinal instrumentation correction and stabilization. There were no complications attributable to the surgical procedure in this group of patients.

Flexion creep deformation and hysteresis in the lumbar vertebral column.

Abstract: Fresh lumbar vertebral columns from nine male subjects aged from six to 61 years were tested for creep deformation and hysteresis. The standard test applied a load of 3.5 kg for one hour through a weight and pulley circuit. Additional tests used 1 kg and 5.5 kg for varying periods of time. The four oldest columns showed a pronounced decrease in the range of flexion movement but a consistent increase in the flexion creep deformation. Hysteresis recovery on load removal was more prolonged and less complete in the older lumbar columns than in the young.

Discitis following removal of intervertebral disc.

Abstract: Thirty-three patients with discitis following removal of an intervertebral disc and treated at the Orthopaedic Hospital of the Invalid Foundation in Helsinki, Finland, are reported. The incidence of discitis in this series extending over a period of 16 years (1960-1975) was 0.75%. The appearance of the disease paralleled mainly the frequency of postoperative infections at the hospital in general. Two-thirds of the patients were treated conservatively, while additional surgical treatment was needed for the others. At average follow-up 7.5 years later, most patients showed advanced symptoms from the back, and increased degenerative changes were observed on roentgenograms. About one-half of the patients had retired from regular work. Preoperative prophylaxis, early diagnosis, and appropriate management of the disease is especially urgent to overcome and inhibit the consequences of postoperative discitis.

Analysis and quantitative myoelectric measurements of loads on the lumbar spine when holding weights in standing postures.

Abstract: Ten subjects executed a number of weight-holding and force-resisting work tasks while standing either upright or with their trunks in 30 degrees of forward flexion. All tasks involved sagitally symmetric body configurations and were performed isometrically. A simple calculation scheme was devised to predict the lumbar trunk muscle contraction forces and the lumbar spine compression forces required for execution of each task. The myoelectric activity was recorded quantitatively at eight sites over the lumbar trunk muscles and at four sites over the abdominal muscles. Good correlation was found between the predicted muscle contraction forces and the myoelectric activities.

Manipulation for chronic neck pain. A double-blind controlled study.

Abstract: Twenty-one with symptomatic cervical spondylosis or nonspecific neck pain were given an amnesic dose of diazepam before manipulation of the cervical spine Eighteen patients served as controls and also received diazepam but no manipulation Results were obtained in a randomized, double-blind fashion Statements of outcome by patients and mean visual analog scales for pain and activity showed no significant differences between manipulation and control groups, though both tests favored manipulation Control subjects subsequently treated by manipulation showed no consistent favorable response Questionnaires dealing with personality, life events, social and medical histories, etc, provided no correlations with outcome, nor did radiographic findings Diffuse local tenderness correlated with high pain scores after treatment The authors conclude that the value of a single manipulation of the cervical spine has not been established and that further exploration of indications is needed The use of intravenous diazepam should be considered because it allows a double-blind experimental design

A new technique for intraoperative monitoring of spinal cord function: multichannel recording of spinal cord and subcortical evoked potentials.

Abstract: A new technique for intraoperative monitoring of spinal cord function is described. Evoked potentials to peripheral nerve stimulation are recorded with interspinous ligament needles from below and from two or more levels above the surgery. Simultaneously subcortical potentials are recorded with scalp electrodes from cervical-scalp derivations. Simultaneous recordings from multiple levels (below and above the surgical procedure) permit reliable differentiation between technical problems and alteration of cord function due to the surgical procedure. The interspinous ligament technique for recording of spinal potentials has significant advantages over previous monitoring techniques. One case in which monitoring during surgery detected a reversible acute spinal cord dysfunction is described.

Scoliosis and cor pulmonale.

Abstract: Twenty patients with cor pulmonale due to scoliosis and associated spine deformities seen at the Twin Cities Scoliosis Center in the past 20 years have been reviewed. The average age was 37 years. The average scoliosis was 135 degrees and ranged from 90 degrees to 200 degrees. Fifteen patients were placed in halo traction, nine of whom went on to surgical stabilization. Of the nine patients having surgical treatment, five had postpoliomyelitis curves, two had congenital, one had infantile idiopathic, and one had frontometaphyseal dysplasia. The best results were in the postpoliomyelitis group, with an average pretreatment vital capacity of 595 cc and posttreatment vital capacity of 1071 cc; the average PaO2 increased from 55 to 64 mm Hg, and the average PaCO2 decreased from 52 to 43 mm Hg. The only death in the postpoliomyelitis group occurred six years postoperatively. Of the four nonpoliomyelitis patients having surgery, only one survived, the patient with frontometaphyseal dysplasia. The difference between the poliomyelitis and nonpoliomyelitis groups was striking. Patients with cor pulmonale due to spine deformity should have careful evaluation and a trial of halo traction. If the vital capacity improves, the PaO2 increases, and the PaCO2 decreases, then surgical stabilization can often be successfully accomplished. If these parameters do not improve in traction, then surgical treatment can be abandoned.

Lumbar spine structural changes associated with leg length inequality.

Abstract: Radiographic asymmetric structural changes in the lumbar spine, which appear to be correlated with pelvic obliquity and the consequent postural lumbar scoliosis, are described in nonacute low-back-pain patients with (i) a leg length difference of greater than 9 mm and (ii) no leg length difference (0-3 mm). With leg length inequality, concavities in the end-plates of lumbar vertebral bodies, wedging of the fifth lumbar vertebrae, and traction spurs appear. No relationship to symptoms is suggested.

Trunk asymmetries in a Belgian school population.

Abstract: Two hundred seventy schoolchildren attending Belgian town schools were screened for trunk asymmetries. The present investigation confirms a wide prevalence of clinically evident asymmetries of the trunk. In the large majority of cases, the asymmetries were accompanied by a measurable rib hump and/or lumbar prominence, which have to be considered in scoliosis screenings. Age and sex do not have a clinically demonstrable influence on the degree and laterality of asymmetry in the school population examined. A height discrepancy of shoulders, scapulae, and iliac crests not exceeding 1 cm and a discrepancy in the depth of the waist triangles not exceeding 1.5 cm are so frequency that they must be considered as physiologic. The same applies to the rib hump (not exceeding 8 mm) and the lumbar prominence (not exceeding 5 mm). As in idiopathic scoliosis, the rib hump is predominantly situated on the right, especially in girls in the prepubertal period.

The effect of Harrington instrumentation on the longitudinal axis rotation of the apical vertebra and on the spinal and rib-cage deformity in idiopathic scoliosis studied by computer tomography.

Abstract: The effects of Harrington instrumentation on the longitudinal axis rotation of the vertebra, the kyphosis-lordosis, and the rib-cage deformity were investigated by computer tomography in 33 patients. No significant derotation was achieved. The sagittal diameter of the rib cage was reduced significantly with distraction rod instrumentation and further by additional application of a compression rod. The rib hump was reduced significantly only with distraction rod instrumentation. The obtained results indicate that despite instrumentation, the spine preserves an almost unchanged peripheral position in the rib cage.

Segmental spinal instrumentation: a preliminary report of 40 consecutive cases.

Abstract: Two groups of patients with complex scoliosis problems are presented. The majority of patients had neurogenic scoliosis. Thirty patients (Group A) had Harrington instrumentation with segmental wiring and were immobilized postoperatively. Instrument stability was best when sacral fixation was not required. Pseudarthrosis was especially likely when there was deficiency of posterior elements. Ten patients (Group B) had double L rod instrumentation, and six had no postoperative immobilization. Correction was maintained except in two patients with kyphotic curves. There were transient neurologic complications in both groups, nerve root contusion being the most common (four cases). It is concluded that segmental instrumentation provides significant improvement in stability over conventional Harrington instrumentation. The advantages of added stability must be weighed against the increased potential for neurologic complications.