Showing papers in "Spine in 1992"

Surgery for lumbar spinal stenosis. Attempted meta-analysis of the literature.

Abstract: A meta-analysis was undertaken to determine the effects of surgery for lumbar spinal stenosis on pain and disability. Seventy-four journal articles met inclusion criteria and were independently reviewed by two readers. On average, 64% of patients treated surgically for lumbar spinal stenosis were re

Human lumbar vertebrae. Quantitative three-dimensional anatomy

Abstract: This study details the quantitative three-dimensional surface anatomy of human lumbar vertebrae based on a study of 60 vertebrae. The two lower vertebrae (L4 and L5) appeared to be transitional toward the sacral region, whereas the upper two vertebrae (L1 and L2) were transitional toward the thoracic region. Means and standard errors of the means for linear, angular, and area dimensions of vertebral bodies, spinal canal, pedicle, pars interarticularis, spinous and transverse processes were obtained for all lumbar vertebrae. This information provides a better understanding of the spine, and allows for a more precise clinical diagnosis and surgical management of spinal problems. The information is also necessary for constructing accurate mathematical models of the human spine.

Chronic Donor Site Pain Complicating Bone Graft Harvesting From the Posterior Iliac Crest for Spinal Fusion

Abstract: To explore the relationship between surgical approach and chronic posterior iliac crest donor site pain, 151 bone graft harvests with follow-up periods longer than 1 year were evaluated using a detailed questionnaire and follow-up clinical visits. There was no difference in the incidence of chronic donor site pain between harvests performed through the primary midline incision versus a separate lateral oblique incision (28 vs 31%). Twice as many donor sites harvested for reconstructive spinal procedures were reported as having chronic pain as compared with those harvested for spinal trauma, regardless of approach used (39 vs 18%). The association of chronic donor site pain with residual back pain was also greater in the spinal reconstructive group. Thus, it appears that incidence of chronic donor site pain is more dependent on diagnosis than on surgical approach.

The Distress and Risk Assessment Method. A simple patient classification to identify distress and evaluate the risk of poor outcome.

Abstract: The integration of physical and psychological assessment is frequently problematic. Psychological tests are often cumbersome and difficult to interpret. There would appear to be a need for a simple assessment method that would identify distress and help alert the clinician to the need for a more comprehensive assessment. The Distress and Risk Assessment Method is derived from a simple set of scales validated for use with patients with low-back pain. It offers a simple classification of patients into those showing no psychological distress, those at risk of developing major psychological overlay, and those clearly distressed. Four patient types can be identified on the basis of scores on two short questionnaires. The construction of the Distress and Risk Assessment Method is described and validity data (both clinical and psychological) are presented. The use of the Distress and Risk Assessment Method in the prediction of outcome of treatment is presented, and the paper concludes with general guidelines for its use.

Long-term follow-up of patients with untreated scoliosis. A study of mortality, causes of death, and symptoms.

Abstract: The mortality and causes of death in 115 patients (80 women), born 1902-1937, with untreated scoliosis were compared to the expected according to official Swedish statistics. Subgrouping for cause and onset of scoliosis was done. Fifty-five patients had died; 21 of respiratory failure and 17 of cardiovascular diseases. The mortality was significantly (P less than 0.001) increased. The increased risk was apparent at 40-50 years of age. The mortality was significantly increased in infantile (P less than 0.001) and juvenile (P less than 0.01) scoliosis but not in adolescent scoliosis. The mortality was also increased in post-polio scoliosis, scoliosis combined with rickets and scoliosis of unknown etiology indicating an increased mortality in idiopathic scoliosis. Among the surviving patients anti-hypertensive treatment was frequent (23 of 50).

Objective clinical evaluation of physical impairment in chronic low back pain.

Abstract: The aim of this study was to investigate physical impairment in patients with chronic low back pain, to develop a method of clinical evaluation suitable for routine use, and to consider the relationship between pain, disability, and physical impairment. Twenty-seven physical tests were investigated. Permanent anatomic and structural impairments of spinal deformities, spinal fractures, surgical scarring, and neurologic deficits were excluded as not relevant to the patient with low back pain in the absence of nerve root involvement or previous surgery. Three consecutive 20-patient reproducibility studies were used to develop reliable methods of examination for 23 of the tests. Only four tests were excluded as unreliable: sacral angle, pelvic tilt, and separate lumbar and pelvic extension, none of which are part of routine clinical examination or have any proven relationship to disability. The remaining 23 physical tests were evaluated in 70 asymptomatic subjects and 120 patients with chronic low back pain. Passive knee flexion, passive hip flexion, hip flexion strength, hip abduction strength, pain reproduction on each of these tests, and the prone extension strength test were excluded because they were too closely related to nonorganic and behavioral responses to examination. Eight tests successfully discriminated patients with low back pain from normal subjects and were significantly related to self-report disability in activities of daily living: pelvic flexion, total flexion, total extension, lateral flexion, straight leg raising, spinal tenderness, bilateral active straight leg raising, and sit-up. Factor analysis failed to demonstrate an underlying statistical dimension of physical impairment. However, an empirical combination of total flexion, total extension, average lateral flexion, average straight leg raising, spinal tenderness, bilateral active straight leg raising, and sit-up provided an equally satisfactory alternative. Simple cut-offs from normal subjects made the scale simple and quick to use. This final scale successfully discriminated 78% of patients and normal subjects and explained 25% of the variance of disability, with a specificity of 86% and sensitivity of 76%. This scale provides an objective clinical evaluation that meets the criteria for evaluating physical impairment, yet is simple, reliable, and suitable for routine clinical use. It should, however, be emphasized that all the tests included in the final scale are measures of current functional limitation rather than of permanent anatomic or structural impairment. This raises questions about the physical basis of permanent disability due to chronic low back pain.

Scoliosis Research Society. Multicenter spine fracture study.

Abstract: This study consisted of 1,019 spinal fracture patients followed prospectively for 2 years. Sixty-four physicians from 12 countries participated. The purpose of the study was to determine: 1) the relationship between neurologic deficit and fracture type, level, and spinal canal compromise; 2) the neurologic outcome comparing surgical versus nonsurgical treatment and anterior versus posterior surgery; and 3) the relationship of pain to both kyphotic deformity and to surgical and nonsurgical treatment. The main findings of this study are as follows: 1) seat belts reduced the incidence of severe neurologic injury; 2) there was a higher incidence of neurologic deficit with fracture-dislocations and a higher incidence of neurologically intact patients with compression and flexion-distraction injuries; 3) there was a greater incidence of complete neurologic deficits caused by fractures at the spinal cord level, and a diminished incidence at the cauda equina level; 4) for burst fractures there was a weakly positive relationship between canal compromise and neurologic deficit, including bladder function; 5) surgical intervention led to a greater percentage of improved neurologic function than nonoperative treatment, but the rate of improvement was not statistically different; 6) anterior surgery was not more effective than posterior surgery in improving the neurologic function when function was assessed using the Frankel or Motor Index scales, but it was statistically significant when compared to the Manabe scale; 7) in patients who deteriorated before surgery and underwent surgery, there was a greater improvement neurologically, particularly for anterior surgery, compared to those patients treated nonoperatively or to the overall surgically treated group; 8) There was a statistically significant relationship between bladder function and fracture type, with an increased incidence of absent function seen with fracture-dislocations, of impaired function with burst fractures, and of intact bladder function with compression and flexion-distraction injuries; 9) anterior surgery was more beneficial in improving complete bladder impairment to partial impairment compared to posterior surgery; 10) a kyphotic deformity of greater than 30 degrees at 2-year follow-up was associated with an increased incidence of significant back pain; 11) patients who had surgery complained less of severe pain than those who were treated without surgery.

Biomechanical evaluation of four different posterior atlantoaxial fixation techniques.

Abstract: Biomechanical Evaluation of Four Different Posterior Atlantoaxial Fixation Techniques Dieter Grob;Joseph Crisco;Manohar Panjabi;Ping Wang;Jiri Dvorak; Spine

Internal intervertebral disc mechanics as revealed by stress profilometry.

Abstract: A technique was developed for measuring the distribution of stress within loaded cadaveric intervertebral discs. A strain-gauged membrane mounted on the side of a 1.3-mm diameter needle was pulled through the disc at constant speed. The orientation of the membrane was changed by rotating the needle, so that profiles of vertical and horizontal components of compressive stress could be obtained. The measurements were reproducible and did not perturb the tissue to any significant extent. Stress profiles varied considerably between discs and were highly dependent on the severity of degenerative changes. They also showed that the mechanical behavior of individual disc tissues was dependent not only on their location, but also on the loading and loading history of the disc. The new insight into internal disc mechanics revealed by stress profilometry may lead to a greater understanding of the mechanisms of disc function and failure.

A universal model of the lumbar back muscles in the upright position

Abstract: A model of the lumbar back muscles was constructed incorporating 49 fascicles of the lumbar erector spinae and multifidus. The attachment sites and sizes of fascicles were based on previous anatomic studies, and the fascicles were modeled on radiographs of nine normal volunteers in the upright position. Calculations revealed that the thoracic fibers of the lumbar erector spinae contribute 50% of the total extensor moment exerted on L4 and L5; multifidus contributes some 20%; and the remainder is exerted by the lumbar fibers of erector spinae. At upper lumbar levels, the thoracic fibers of the lumbar erector spinae contribute between 70% and 86% of the total extensor moment. In the upright posture, the lumbar back muscles exert a net posterior shear force on segments L1 to L4, but exert an anterior shear force on L5. Collectively, all the back muscles exert large compression forces on all segments. A force coefficient of 46 Ncm-2 was determined to apply for the back muscles. These results have a bearing on the appreciation of the effects on the back muscles of surgery and physiotherapy.

The natural history of sciatica associated with disc pathology. A prospective study with clinical and independent radiologic follow-up.

Abstract: The purpose of this study was to assess the natural history of sciatica due to lumbosacral nerve root compromise and to evaluate the pathomorphologic changes that accompany the natural resolution of the disease. One hundred sixty-five consecutive patients, 114 males and 51 females, with an average age of 41 years (range, 17-72) and an average duration of symptoms of 4.2 months (range, 1-72) presenting with sciatica thought to be due to lumbosacral nerve root compromise were admitted to the study. The cornerstone of treatment was the serial epidural administration of steroid and local anesthetic by the caudal route on an outpatient basis. Lumbar epidural injection or periradicular infiltration at the appropriate level, confirmed under image intensifier, was the next step before considering surgical decompression. An average of three injections (range, 0-8) was received by each patient. Patients underwent clinical examination and computed tomography. Twenty-three patients (14%) underwent surgical decompression. The remainder were clinically assessed at 1 year after presentation, and 111 were rescanned at the appropriate levels. All conservatively managed patients made a satisfactory clinical recovery: average reduction of pain on the visual analog scale was 94% (range, 45-100), and 64 (76%) of the 84 disc herniations and 7 (26%) of the 27 disc bulges showed partial or complete resolution (chi-square = 20.27, P = 0.0001). Thus a high proportion of patients with discogenic sciatica make a satisfactory recovery with aggressive conservative management, and this recovery is accompanied by resolution of disc herniations in a significant number. Only a small proportion of patients needed surgical decompression.

Low back and neck/shoulder pain in construction workers: occupational workload and psychosocial risk factors. Part 1: Relationship to low back pain.

Abstract: The prevalence rate of musculoskeletal problems, especially low back pain and severe low back pain in a randomly selected sample of 1,773 construction workers was studied. Its relationship to physical and psychosocial factors was analyzed. The workers answered a postal questionnaire. Workload was measured by means of eight manual materials handling indices and ten psychosocial indices, based on results from factor analyses. The 1-year prevalence rate of low back pain was 54% and of severe low back pain 7%. The relationship to heavy manual materials handling differed with age in such a manner that it could be interpreted as a healthy worker effect. Between severe low back pain and both stooping or kneeling a dose-response relationship was found. The most prominent of the psychosocial factors associated with low back pain and severe low back pain were the stress index and the psychosomatic and psychic indices. The age-standardized prevalence rate ratio of low back pain was 1.6 (95% confidence interval 1.4-1.8) and for severe low back pain 3.1 (95% confidence interval 2.3-4), when workers reporting "high" stress were compared to workers reporting "low" stress.

Percutaneous laser disc decompression. A new therapeutic modality.

Abstract: The authors present a new advance in the treatment of herniated disc disease using percutaneous Nd:YAG laser to vaporize a small portion of nucleus pulposus, thereby decompressing the disc. In vitro and in vivo animal data are presented. Three hundred seventy-seven magnetic resonance imaging or computed tomography scan-documented, herniated, nonsequestered lumbar intervertebral discs with corresponding clinical findings in 333 patients were so treated in an outpatient setting. The longest follow-up was 62 months, with a mean of 26 months. According to the Macnab criteria, there was a good to fair response in 261 patients (78.4%), and a poor response in 72 (21.6%); 166 patients experienced relief of pain during the procedure. One-third of repeat magnetic resonance imaging scans at 4-6 months postlaser treatment showed modest to moderate decrease of disc herniation.

Age and gender related normal motion of the cervical spine.

Abstract: The purpose of this study was to develop a clinical method for measuring three-dimensional motion of the cervical spine using the CA 6000 Spine Motion Analyzer (Orthopaedic Systems Inc., Hayward CA). Normal values for passive examinations of flexion-extension, lateral bending, rotation, rotation out of maximum flexion, and rotation out of maximum extension were obtained and analyzed for each gender in a group of 150 normal subjects. Gender classifications were further subdivided into age groups, with each decade containing asymptomatic volunteers. Values for each group were compared for differences with respect to age and gender differences. A detailed error analysis was also performed on the interobserver and intraobserver repeatability, differences between passive and active testing, and the use of different fixation devices. Significantly decreased motion differences were found between age groups within gender, and between gender groups in corresponding decades. Results of rotation out of maximum flexion suggest and support earlier conclusions that the rotation of the C1-C2 segment does not decrease with age, but rather increases slightly to perhaps compensate for the overall decreased motion in the lower segments.

Biomechanical analysis of lumbosacral fixation.

Abstract: The lumbosacral junction is perhaps the most difficult portion of the spine in which to obtain a solid fusion [1–11]. This is particularly true following reductions of spondylolisthesis [12]. Lumbar spine fusion techniques have continued to evolve since Hibbs and Albee first described their fusion methods for tuberculosis spine infections [13,14]. At present, instrumentation systems run a wide range of design to confer desirable biomechanical properties in hopes of increasing the success of spinal fusion while obviating the need for a postsurgical orthosis.

Pedicle screw instrumentation for thoracolumbar burst fractures and fracture-dislocations.

Abstract: Thirty-eight patients with unstable thoracolumbar and lumbar (T12–L5) spine fractures were treated with Cotrel-Dubousset pedicle screw instrumentation. They were followed for an average of 22.73 months (range 12–39). Measurements of canal compromise. wedge index, and kyphosis correction at follow-up

Laminoplasty versus subtotal corpectomy. A comparative study of results in multisegmental cervical spondylotic myelopathy.

Abstract: A comparative study of surgical results was used to determine the treatment of choice for multisegmental cervical spondylotic myelopathy. Forty-one patients who received subtotal corpectomy and strut grafting (SCS) and forty-two undergoing laminoplasty were followed up for at least 2 years after surgery. Regarding factors known to affect surgical prognosis (age at surgery, duration of symptoms, severity of neurologic deficit, anteroposterior canal diameter, transverse area of the cord at the site of maximum compression, number of levels involved), the two groups were statistically comparable with each other. The severity of neurologic deficits was assessed by the Japanese Orthopaedic Association scale. Results were evaluated in terms of postoperative score and recovery rate. The difference between the recovery rate and final score between the two groups was not statistically significant. Surgical complications were more frequent in the subtotal corpectomy and strut grafting group than in the laminoplasty group. The most frequent complications encountered in the subtotal corpectomy and strut grafting group were related to bone grafting. Spinal alignment worsened in six patients of the laminoplasty group, but none of them suffered from neurologic deterioration. Another disadvantage of subtotal corpectomy and strut grafting was the longer postoperative period of bed rest needed to secure graft stability. We conclude that laminoplasty should be the treatment of choice for multisegmental cervical spondylotic myelopathy when neurologic results, incidence of complications, and postoperative treatment are taken into consideration.

The effectiveness of manual therapy, physiotherapy, and treatment by the general practitioner for nonspecific back and neck complaints. A randomized clinical trial.

Abstract: In a randomized trial, the effectiveness of manual therapy, physiotherapy, continued treatment by the general practitioner, and placebo therapy (detuned ultrasound and detuned short-wave diathermy) were compared for patients (n = 256) with nonspecific back and neck complaints lasting for at least 6 weeks. The principle outcome measures were severity of the main complaint, global perceived effect, pain, and functional status. These are presented for 3, 6, and 12 weeks follow-up. Both physiotherapy and manual therapy decreased the severity of complaints more and had a higher global perceived effect compared to continued treatment by the general practitioner. Differences in effectiveness between physiotherapy and manual therapy could not be shown. A substantial part of the effect of manual therapy and physiotherapy appeared to be due to nonspecific (placebo) effects.

Modified Smith-Robinson procedure for anterior cervical discectomy and fusion.

Abstract: Fifty-one consecutive patients with cervical radiculopathy or spondylosis were treated with single or multilevel anterior discectomy and fusion using a modified Smith-Robinson procedure. There were 33 single-level fusions, 16 two-level fusions, and 2 three-level fusions. The three modifications included: 1) the endplates at the fusion level were completely removed with a high-speed bur to exposed bleeding cancellous bone in parallel planes; 2) the Caspar distractor (Aesculap, Burlingame, CA) was used to increase distraction and improve visualization; 3) the tricortical autologous iliac crest bone graft was placed in reverse position, that is, with the cortical cross-section facing posteriorly, creating a stabilizing strut in the middle column. With an average follow-up of 1 year, the fusion rate was 94% (67 of 71 levels). The single-level fusion rate was 97%, the two-level fusion rate was 94%, and the three-level fusion rate was 83%. Of the four nonunions, only two were symptomatic. Results by clinical examination revealed 36 (71%) excellent, 11 (21%) good, 3 (6%) satisfactory, and 1 (2%) poor outcomes. There were no significant disc collapses or extrusions. One patient had an increase in kyphotic deformity of > 5 degrees, none with > 10 degrees kyphosis. There were no wound infections or neurologic complications. The modified Smith-Robinson procedure for anterior cervical discectomy and fusion has led to the successful treatment of cervical radiculopathy and spondylosis with improved results and few complications.

Assessment of outcome in patients with low-back pain.

Abstract: The Low-Back Outcome Score has been devised as a new and accurate rating system for patients with low-back pain. Thirteen factors, such as pain, employment, sporting ability, rest required, and activities of daily living, were included; subjective opinion was excluded. Pain and active pursuits were weighted. Presentation of the score as a questionnaire, excluding examination findings, eliminated both interobserver variation and observer variation with time. The score was applied retrospectively in a follow-up study of conservatively treated patients and was found to be more comprehensive and more discriminating than the Oswestry Disability Score, the Waddell Disability Rating, or the Waddell Physical Impairment Rating. The Low-Back Outcome Score is recommended for further evaluation in future prospective studies in low-back pain.

Low back and neck/shoulder pain in construction workers: occupational workload and psychosocial risk factors. Part 2: Relationship to neck and shoulder pain.

Abstract: The prevalence rate of neck and shoulder trouble and considerable neck and shoulder pain in a randomly selected sample of 1773 construction workers were studied. The relationship to physical and psychosocial factors was analyzed. The workers answered a postal questionnaire. Workload was measured by means of eight manual materials handling indices and ten psychosocial indices, based on results from factor analyses. The 1-year prevalence rate of considerable neck and shoulder trouble was 56% and of neck and shoulder pain 12%. To work with hands above shoulder level showed a dose-response relationship to both neck and shoulder trouble and neck and shoulder pain. The psychosocial factors were more prominently associated with neck and shoulder trouble and neck and shoulder pain than the physical workload factors. The psychosocial indices; psychosomatic and psychic symptoms, stress and job satisfaction showed the highest age-standardized prevalence rate ratios for both neck and shoulder trouble and neck and shoulder pain.

Mobility, strength, and fitness after a graded activity program for patients with subacute low back pain. A randomized prospective clinical study with a behavioral therapy approach

Abstract: Patients with nonspecific mechanical low back pain (n = 103), examined by an orthopaedic surgeon and a social worker, were randomized to an activity group (n = 51) and a control group (n = 52). Patients with defined orthopaedic, medical, or psychiatric diagnoses were excluded before randomization. No patients were excluded due to place of birth or difficulties in speaking or understanding the Swedish language. The purpose of the study was to compare mobility, strength and fitness after traditional care and after traditional care plus a graded activity program with a behavioral therapy approach. A graded activity program, with a behavioral therapy approach was given under the guidance of a physical therapist. The endpoint of the graded activity program was return to work. This program significantly increased mobility, strength, and fitness more than could be explained by only a time recovery effect, especially in males. The patients in the activity group returned to work earlier than did the patients in the control group. Spinal rotation, abdominal muscle endurance time and lifting capacity were significantly correlated to rate of return to work. Traditional care plus a graded activity program were superior to only traditional care, evaluated in terms of mobility, strength and fitness. The graded activity program proved to be a successful method of restoring occupational function and facilitating return to work in subacute low back pain patients. The patients in the graded activity program learned that it is safe to move, while regaining function.

Complications of lumbar spinal fusion with transpedicular instrumentation.

Abstract: Transpedicular screw fixation systems are coming into wide use as an adjunct to lumbar spinal fusion procedures. This 5-year series included 486 patients who underwent 533 variable screw placement precedures for diseal, degenerative, and spondylolytic problems. The wound infection rate was 2.6%: 0.6

Self-reported low back symptoms in urban bus drivers exposed to whole-body vibration.

Abstract: The prevalence of self-reported low back symptoms was investigated by a postal questionnaire in a group of 234 urban bus drivers exposed to whole-body vibration and postural stress and in a control group of 125 maintenance workers employed at the same bus municipal company. The average vertical whole-body vibration magnitude measured on the seat pan of the buses was 0.4 m/s2. After controlling for potential confounders, the prevalence odds ratios for the bus drivers compared to the controls significantly exceeded 1 for several types of low back symptoms (leg pain, acute low back pain, low back pain). The occurrence of low back symptoms increased with increasing whole-body vibration exposure expressed in terms of total (lifetime) vibration dose (years m2/s4), equivalent vibration magnitude (m/s2), and duration of exposure (years of service). The highest prevalence of disc protrusion was found among the bus drivers with more severe whole-body vibration exposure. Frequent awkward postures at work were also related to some types of low back symptoms. It is concluded that bus driving is associated with an increased risk for low back troubles. This excess risk may be due to both whole-body vibration exposure and prolonged sitting in a constrained posture. The findings of this study also indicated that among the bus drivers low back symptoms occurred at whole-body vibration exposure levels that were lower than the health-based exposure limits proposed by the International Standard ISO 2631/1.

The effect of lactate and pH on proteoglycan and protein synthesis rates in the intervertebral disc

Abstract: The intervertebral disc is the largest avascular tissue in the body. Its metabolism is mainly anaerobic, and thus lactate is produced at a significant rate. As a result the lactate concentrations in the center of the disc may be 8-10 times as high as in the plasma. The pH in the disc center is thus acidic. Because low values of pH are known to affect proteoglycan synthesis in other cartilages, the authors measured the effect of lactate levels and pH on 35S-sulphate and 3H-proline incorporation rates in the nucleus of bovine coccygeal discs and in human disc obtained during percutaneous nucleotomy. The maximum incorporation rate occurred at pH 7.2-pH 6.9. Here the rate was 40-50% greater than at pH 7.4. Below pH 6.8 the rate fell steeply, more so for sulphate than for proline. At pH 6.3 the sulphate incorporation rate was around 20 percent that at pH 7.4. The results indicate that proteoglycan synthesis rates in particular are sensitive to extracellular pH, and that the peak rate occurs around the level of pH seen in vivo. Factors that cause lactate levels to rise, such as a fall in O2 levels as the result of smoking or vibration (Holm and Nachemson, 1988) could lead to a fall in proteoglycan synthesis rates, ultimately leading to a fall in proteoglycan content and to disc degeneration.

Response to steroid and duration of radicular pain as predictors of surgical outcome.

Abstract: Prolonged structural compromise of spinal nerve roots can lead to chronic changes that surgical decompression might not be able to reverse. In this study, it was hypothesized that if there were a reversible structural pain component, a steroid injected into the patient's symptomatic nerve root should provide temporary pain relief and that these patients should have a favorable surgical outcome. It also was hypothesized that duration of radicular symptoms would correlate inversely with surgical outcome. For postoperative relief of radicular pain, the results showed that patients with pain lasting less than 1 year had a positive surgical result (89%), regardless of response to steroid. Patients with pain lasting more than 1 year and who have had a positive response to steroid injected into the symptomatic nerve root (roots) had a positive surgical outcome of 85%. Patients who did not respond to the steroid and had pain for more than 1 year (95%) generally had a poor surgical outcome. Although the poor outcome in the last group might be explained in some cases by an inadequate structural correction, inadequate stabilization, or functional reasons, the majority of these failures represented irreversible changes in the neural structures.

The treatment of osteoporotic posttraumatic vertebral collapse using the kaneda device and a bioactive ceramic vertebral prosthesis

Abstract: Twenty-two patients with neurologic deficit due to delayed posttraumatic vertebral collapse after osteoporotic compression fractures of the thoracolumbar spine underwent anterior decompression and reconstruction with bioactive Apatite-Wollastonite containing glass ceramic vertebral prosthesis and Kaneda instrumentation. Eighteen patients previously had minor trauma that resulted in a mild vertebral compression fracture without any neurologic involvement and were either conservatively treated or not treated at all. Four had no history of back injury. The preoperative neurologic status was incomplete paralysis in all patients. The average age at surgery was 66 (53-79) years. The average follow-up was 34 (20-58) months after surgery. All patients had returned to their daily living with neurologic recovery and stable spine. This type of anterior procedure is effective in the osteoporotic patients and there was a very low incidence of instrumentation failure and very low morbidity.

Human disc phospholipase A2 is inflammatory.

Abstract: Human discs have been demonstrated to contain high levels of phospholipase A2. As the enzyme responsible for the liberation of arachidonic acid from membranes, this enzyme has a theoretical inflammatory potential. Herniated lumbar discs have a higher level of phospholipase A2 than do normal discs. The purpose of this study was to evaluate the inflammatory capability of purified human disc phospholipase A2. Phospholipase A2 extracted and purified from human disc was found to be inflammatory. Its inflammatory capability was directly related to its ability to function enzymatically. When the enzyme was treated with parabromophenacyl bromide (p-BPB) to specifically alkylate the active site histidine and block catalytic activity, the ability of the modified protein to produce edema was markedly reduced. Careful regulation of the activity of this enzyme is important in vivo because its inflammatory potential could result in disc degeneration and nerve injury.

Use of the International Classification of Diseases (ICD-9-CM) to identify hospitalizations for mechanical low back problems in administrative databases.

Abstract: Large administrative databases are increasingly valuable tools for health care research. Although increased access to these databases provides valuable opportunities to study health care utilization, costs and outcomes and valid and comparable results require explicit and consistent analytic methods. Algorithms for identifying surgical and nonsurgical hospitalizations for "mechanical" low back problems in automated databases are described. Sixty-six ICD-9-CM diagnosis and 15 procedure codes that could be applied to patients with mechanical low back problems were identified. Twenty-seven diagnosis and two procedure codes identify hospitalizations for problems definitely in the lumbar or lumbosacral region. Exclusion criteria were developed to eliminate nonmechanical causes of low back pain, such as malignancies, infections, and major trauma. The use of the algorithms is illustrated using national hospital discharge data.