Showing papers on "Lumbar vertebrae published in 1999"

Genetic influences on cervical and lumbar disc degeneration: A magnetic resonance imaging study in twins

Abstract: Objective Degenerative intervertebral disc disease is common; however, the importance of genetic factors is unknown. This study sought to determine the extent of genetic influences on disc degeneration by classic twin study methods using magnetic resonance imaging (MRI). Methods We compared MRI features of degenerative disc disease in the cervical and lumbar spine of 172 monozygotic and 154 dizygotic twins (mean age 51.7 and 54.4, respectively) who were unselected for back pain or disc disease. An overall score for disc degeneration was calculated as the sum of the grades for disc height, bulge, osteophytosis, and signal intensity at each level. A “severe disease” score (excluding minor grades) and an “extent of disease” score (number of levels affected) were also calculated. Results For the overall score, heritability was 74% (95% confidence interval [95% CI] 64–81%) at the lumbar spine and 73% (95% CI 64–80%) at the cervical spine. For “severe disease,” heritability was 64% and 79% at the lumbar and cervical spine, respectively, and for “extent of disease,” heritability was 63% and 63%, respectively. These results were adjusted for age, weight, height, smoking, occupational manual work, and exercise. Examination of individual features revealed that disc height and bulge were highly heritable at both sites, and osteophytes were heritable in the lumbar spine. Conclusion These results suggest an important genetic influence on variation in intervertebral disc degeneration. However, variation in disc signal is largely influenced by environmental factors shared by twins. The use of MRI scans to determine the phenotype in family and population studies should allow a better understanding of disease mechanisms and the identification of the genes involved.

The efficacy of active rehabilitation in chronic low back pain. Effect on pain intensity, self-experienced disability, and lumbar fatigability.

Abstract: Study Design. A randomized study comparing the results of active rehabilitation and passive control treatment in patients with chronic low back pain with follow-up at 6 months and 1 year. Objectives. To study the efficacy of active rehabilitation on pain, self-experienced disability, and lumbar fatigability. of Background Data. Exercises in an outpatient setting are widely used for the treatment of chronic low back pain. The efficacy of the active rehabilitation approach has been documented in randomized control studies, but these studies have seldom been focused on lumbar fatigability, which is now recognized as a frequent problem among patients with chronic low back pain. Methods. Fifty-nine middle-aged patients (37 men and 22 women) with nonspecific chronic low back pain were randomly assigned to 12 weeks' active rehabilitation or to a passive control treatment (massage, thermal therapy). Pain and disability index, low back pain intensity (visual analog scale, 100 mmi, and the objectively assessed lumbar muscle fatigability (spectral electromyogram, mean power frequency slope [MPF SLOPE ]) in a new 90-second submaximal isoinertial back endurance test were recorded before and after the interventions and at 6-month and 1-year follow-up visits. Results. Results of repeated measures multivariate analysis of variance indicated that back pain intensity (visual analog scale) and functional disability (pain and disability index score) decreased, and lumbar endurance (MPF SLOPE ) improved significantly more (P < 0.05) in the active rehabilitation group than in the passive control treatment group, when measured at a 1-year follow-up examination. The group difference in visual analog scale and pain and disability index changes became even more significant at the end of 1 year. The change in lumbar endurance was significantly greater in the active rehabilitation group than in the passive control treatment group at the 6-month follow-up, but not at the 1-year follow-up. Conclusions. The active progressive treatment program was more successful in reducing pain and self-experienced disability and also in improving lumbar endurance than was the passive control treatment. However, the group difference in lumbar endurance tended to diminish at the 1-year follow-up.

False-positive findings on lumbar discography. Reliability of subjective concordance assessment during provocative disc injection.

Abstract: STUDY DESIGN Experimental disc injections in subjects with no history of low back symptoms. OBJECTIVE To determine in an experimental model the reliability of patients' subjective interpretation of pain concordancy during provocative disc injection. BACKGROUND Discography in the evaluation of low back pain relies on a patient's subjective assessment of pain magnitude and quality during disc injection. Reproduction of significant pain on disc injection, which is similar to patients' usual pain, is believed to prove that the disc injected is the source of the patient's low back pain. In the current study, this hypothesis was tested in a controlled setting on patients with known nonspinal pain in a common referral area of discogenic pain. METHODS Patients with no history of low back pain were recruited to participate in a study of discography. Patients scheduled to undergo posterior iliac crest bone graft harvesting for nonthoracolumbar procedures were evaluated with lumbar radiography, magnetic resonance imaging, and psychometric testing. Two to 4 months after bone graft harvesting, patients underwent lumbar discography by strict blinded protocol. Patients were asked to compare the sensations elicited at discography to their usual back/buttock pain since bone graft harvesting. Pain was rated as 0-5 on a pain thermometer and concordancy was rated as none, dissimilar, similar, or exact. RESULTS Eight subjects completed the study, and 24 discs were injected. Of the 14 disc injections causing some pain response, 5 were believed to be "different" (nonconcordant) pains (35.7%); 7 were "similar" (50.0%), and 2 were "exact" pain reproductions (14.3%). The presence of anular disruption predicted concordant pain reproduction (P < 0.05). Of 10 discs with anular tears, injection of 5 elicited pain that was similar to or an exact reproduction of pain at the iliac crest bone graft harvest sites. By the usual criteria for positive discography, 4 of the 8 patients (50%) would have been classified as positive. In these patients, the pain on a single disc injection was very painful, and the pain quality was noted to be exact or similar to the usual discomfort. All subjects had a negative control disc. CONCLUSIONS The findings of this study demonstrate that patients with no history of low back pain who had undergone posterior iliac bone graft harvesting for nonlumbar procedures often experienced a concordant painful sensation on lumbar discography with their usual gluteal area pain. Thus, the ability of a patient to separate spinal from nonspinal sources of pain on discography is questioned, and a response of concordant pain on discography may be less meaningful than often assumed.

The use of an injectable, biodegradable calcium phosphate bone substitute for the prophylactic augmentation of osteoporotic vertebrae and the management of vertebral compression fractures.

Abstract: STUDY DESIGN A biomechanical study comparing two materials for augmentation of osteoporotic vertebral bodies and vertebral bodies after compression fracture. OBJECTIVES To compare an injected, biodegradable calcium phosphate bone substitute with injected polymethylmethacrylate bone cement for strengthening osteoporotic vertebral bodies and improving the integrity of vertebral compression fractures. SUMMARY OF BACKGROUND DATA Injection of polymethylmethacrylate bone cement into fractured vertebral bodies has been used clinically. However, there is concern about thermal damage to the neural elements during polymerization of the polymethylmethacrylate bone cement as well as its negative effects on bone remodeling. Biodegradable calcium phosphate bone substitutes have been studied for enhancement of fixation in fractured vertebrae. METHODS Forty fresh osteoporotic thoracolumbar vertebrae were used for two separate parts of this study: 1) injection into osteoporotic vertebrae: intact control (n = 8), calcium phosphate (n = 8), and polymethylmethacrylate bone cement (n = 8) groups. Each specimen then was loaded in anterior compression until failure; 2) injection into postfractured vertebrae: calcium phosphate (n = 8) and polymethylmethacrylate bone cement (n = 8) groups. Before and after injection, the specimens were radiographed in the lateral projection to determine changes in vertebral body height and then loaded to failure in anterior bending. RESULTS For intact osteoporotic vertebrae, the average fracture strength was 527 +/- 43 N (stiffness, 84 +/- 11 N/mm), 1063 +/- 127 N (stiffness, 157 +/- 21 N/mm) for the group injected with calcium phosphate, and 1036 +/- 100 N (stiffness, 156 +/- 8 N/mm) for the group injected with polymethylmethacrylate bone cement. The fracture strength and stiffness in the calcium phosphate bone substitute group and those in the polymethylmethacrylate bone cement group were similar and significantly stronger than those in intact control group (P < 0.05). For the compression fracture study, anterior vertebral height was increased 58.5 +/- 4.6% in the group injected with calcium phosphate and 58.0 +/- 6.5% in the group injected with polymethylmethacrylate bone cement as compared with preinjection fracture heights. No significant difference between the two groups was found in anterior vertebral height, fracture strength, or stiffness. CONCLUSION This study demonstrated that the injection of a biodegradable calcium phosphate bone substitute to strengthen osteoporotic vertebral bodies or improve vertebral compression fractures might provide an alternative to the use of polymethylmethacrylate bone cement.

A randomized prospective study of posterolateral lumbar fusion. Outcomes with and without pedicle screw instrumentation.

Abstract: Study design A prospective evaluation of the clinical and radiographic outcomes of 71 patients who underwent lumbar fusion, with or without transpedicular instrumentation. The patients completed a questionnaire that determined pain relief, medication use, return to work, and overall satisfaction with surgery. Objectives To explore the effect, if any, of instrumentation on the outcome of lumbar fusion surgery, according to reports of the patients, and whether there is a correlation between the radiographic determination of a solid fusion and the same patient-reported outcome. Summary of background data The literature on this topic reports pseudarthrosis rates from 0% to 57% and good to excellent results from 56% to 95%. These studies provide no clear-cut recommendations concerning the effect of added lumbar instrumentation on patient-reported outcome in a prospective manner using concurrent control subjects. Methods The patients were randomized to groups with and without instrumentation after deciding to undergo a lumbar fusion and consenting to enter the study. Radiographs were obtained and questionnaires filled out at 6 weeks, 6 months, 1 year, and 2 years after surgery. Results There was no statistical difference in patient-reported outcome between the two groups. There was a slight nonsignificant trend toward increased radiographic fusion rate in the group with instrumentation that did not correlate with an increased patient-reported improvement rate. Conclusions These results do not provide data that indicate a benefit in outcome from added instrumentation in elective lumbar fusions.

The distribution, determinants, and clinical correlates of vertebral osteophytosis: a population based survey.

Abstract: OBJECTIVE: Vertebral osteophytes are a characteristic feature of intervertebral disc degeneration. There are, however, few population data concerning the occurrence of and clinico-biological correlates of vertebral osteophytes in both the dorsal and lumbar spine. Our purpose was to determine the frequency and distribution of anterior osteophytes in the thoracic and lumbar spine, and their relationship with both various putative risk factors, including physical activity and obesity, and self-reported back pain. METHODS: Men and women aged 50 years and over were recruited from primary care based registers in 5 UK centers. They were invited to attend for an interviewer administered lifestyle questionnaire, assessment of height and weight, and lateral spinal radiographs. Lateral spinal radiographs were evaluated by a single observer for the presence of osteophytes from T4 to L5 using a semiquantitative score (grade): 0 = none, 1 = doubtful, 2 = mild, 3 = moderate, 4 = severe. Based on these data 2 summary statistics were derived: the maximum osteophyte grade at any vertebral level (MAX), and the sum of the osteophyte grades at the individual vertebral levels (TOT). RESULTS: In total, 681 women, mean age 63.3 years, and 499 men, mean age 63.7 years, were studied; 84% of men and 74% of women had at least one vertebral level with a grade 1 or higher osteophyte. Both the sum of the individual grades (TOT) and the proportion of subjects with MAX > or =2 were greater in men than in women in both the dorsal and lumbar spine, and both increased with age. The pattern of spinal involvement was similar in the sexes, with osteophytes occurring most frequently at T9-10 and L3. Increasing body mass index was associated with more frequent osteophytes at both dorsal and lumbar spine, although the relationship was stronger at the dorsal spine. Heavy physical activity, particularly in young adult life, was associated with osteophytosis in men. Self-reported back pain, both ever and in the past year, was linked with lumbar osteophytes in men. CONCLUSION: The distribution within the spine in our study and the relationship with heavy physical activity points to mechanical factors being important in pathogenesis of vertebral osteophytosis. Prospective studies are needed to explore the types of physical activity that increase susceptibility to vertebral osteophytosis. In men, osteophytes affecting the lumbar spine are associated with back pain.

Symptomatic Lumbar Facet Joint Synovial Cysts: Clinical Assessment of Facet Joint Steroid Injection after 1 and 6 Months and Long-term Follow-up in 30 Patients

Abstract: PURPOSE: To study the results of facet joint intraarticular steroid injections in patients with symptomatic lumbar facet joint synovial cysts. MATERIALS AND METHODS: Data from 30 patients (age range, 44–82 years; mean age, 67 years) with nerve root pain due to a lumbar facet joint synovial cyst and treated with facet joint steroid injection were retrospectively studied. On the basis of MacNab criteria, the clinical course of nerve root pain was evaluated after 1 (n = 30) and 6 (n = 28) months. Data from long-term follow-up (mean, 26 months) were also available in 14 nonsurgically treated patients. RESULTS: After 1 month, the nerve root pain outcome was excellent or good in 20 patients (67%) and fair or poor in 10 (33%). After 6 months, 10 (50%) of these 20 patients still had excellent or good results, and 18 (60%) of the 30 patients had a fair or poor clinical status, 14 of whom underwent surgery; two patients (7%) were lost to follow-up. Excellent and good results were maintained at further follow-up (ra...

Mechanical and morphological variation of the human lumbar vertebral cortical and trabecular bone.

Abstract: The nanoindentation technique was used to characterize the variation in the elastic modulus and hardness of human lumbar vertebral cortical and trabecular bone. The elastic modulus (and in most cases, the hardness as well) of axially aligned trabeculae cut in the transverse direction was significantly greater than in other orientations of vertebral cortical and trabecular bone. In all cases, the elastic modulus and hardness of bone in the load-bearing direction was greater than in corresponding bone types cut in the other directions. Scanning electron micrographs of cortical shell revealed the Haversian-like canal systems expected in secondary cortical bone, but it was difficult to differentiate by morphology cortical from trabecular bone in the human lumbar vertebrae.

Microendoscopic approach to far-lateral lumbar disc herniation.

Abstract: The purpose of this study was to determine the feasibility of performing far-lateral lumbar discectomy by using the microendoscopic discectomy (MED) technique. The authors studied 11 consecutive patients with unilateral, single-level radiculopathy secondary to far-lateral disc herniation. There were eight men and three women, with an average age of 43 years. In all patients magnetic resonance imaging and/or computerized tomography scanning documented far-lateral disc herniations. Six patients experienced motor deficits, nine patients sensory abnormalities, and five depressed reflexes. All patients complained of radicular pain, which failed to improve with conservative care. After induction of epidural anesthesia, single-level, unilateral percutaneous discectomies were performed using the MED technique. Five discectomies were performed at L3-4 and six at L4-5. There were four contained and seven sequestered disc herniations. All surgeries were performed on an outpatient basis. Follow up ranged from for 12 to 27 months. Improvement was shown in all patients postoperatively. Using modified Macnab criteria to assess results of surgery, there were 10 excellent results and one good result. None of the patients experienced residual motor deficits, four had residual decreased sensation, and one still had some degree of nonradicular pain. There were no complications. Although various open techniques exist for the treatment of far-lateral disc herniation, MED is unique in that far-lateral pathological entities can be directly visualized and removed via a 15-mm paramedian incision. The percutaneous approach avoids larger, potentially denervating and destabilizing procedures. The need for general anesthesia can be avoided, and surgery is performed on an outpatient basis, thereby reducing hospital cost and length of stay.

Lumbar osteotomy for correction of thoracolumbar kyphotic deformity in ankylosing spondylitis. A structured review of three methods of treatment

Abstract: Objectives—Three operative techniques have been described to correct thoracolumbar kyphotic deformity (TLKD) resulting from ankylosing spondylitis (AS) at the level of the lumbar spine: opening wedge osteotomy, polysegmental wedge osteotomies, and closing wedge osteotomy. Little knowledge exists on the indication for, and outcome of these corrective lumbar osteotomies. Methods—A structured review of the medical literature was performed. Results—A search of the literature revealed 856 patients reported in 41 articles published between 1945 and 1998. The mean age at time of operation was 41 years, male-female ratio 7.5 to 1. In 451 patients an open wedge osteotomy was performed. Polysegmental wedge osteotomies were performed in 249 patients and a closing wedge osteotomy in 156 patients. Most of the studies primarily focus on the surgical technique. Technical outcome data were poorly reported. Sixteen reports, including 523 patients, met the inclusion criteria of this study, and could be analysed for technical outcome data. The average correction achieved with each surgical techniques ranged from 37 to 40 degrees. Loss of correction was mainly reported in patients treated by open wedge osteotomy and polysegmental wedge osteotomies. Neurological complications were reported in all three techniques. The perioperative mortality was 4%. Pulmonary, cardiac and intestinal problems were found to be the major cause of fatal complications. Conclusion—Lumbar osteotomy for correction of TLKD resulting from AS is a major surgery. The indication for these lumbar osteotomies as well as the degree of correction in the lumbar spine has not yet been established. Furthermore, there is a need for a generally accepted clinical score that encompasses accurate preoperative and postoperative assessment of the spinal deformity. The results of this review suggest that the data from the literature are not suitable for decision making with regard to surgical treatment of TLKD resulting from AS. (Ann Rheum Dis 1999;58:399‐406)

Lumbar arthrodesis for the treatment of back pain

Abstract: Lumbar arthrodesis is a commonly performed operative procedure for the treatment of low-back pain; however, the indications, techniques, and results remain controversial and unclear. The frequency of spinal arthrodesis for the treatment of back pain is increasing in the United States, as are criticism of the procedure and the study of available information on its outcomes. The concept of spinal arthrodesis is based on experience with other regions of the body in which arthrodesis has been used to treat painful joints by eliminating motion. Initially, spinal arthrodesis was used for the treatment of infectious conditions, deformity, and trauma of the spine. On the basis of these successful experiences and because of technical advances in imaging, operative procedures, implants, and bone-grafting, the indications for spinal arthrodesis have been expanded in an attempt to control pain attributed to abnormal or unstable motion between one vertebra and an adjacent vertebra or pain due to mechanical degeneration of the intervertebral disc. Much information on arthrodesis of the lumbar spine has been published, but most investigators have used nonstandardized criteria for inclusion of patients who were operated on for various diagnoses and whose outcomes were assessed with nonvalidated methods. Nevertheless, careful review of the available data may assist in determining which treatments are reasonable, which are unreasonable, and which are (or should be) considered investigational155. Under ideal circumstances, spinal arthrodesis should be performed only after a specific pathoanatomical diagnosis has been identified as being responsible for the patient's symptoms. In addition, the natural history of the diagnosis and the appropriate timing of operative intervention should be understood. By limiting abnormal motion or removing the intervertebral disc, lumbar spinal arthrodesis can potentially minimize or eliminate the source of pain. Procedures that result in minimum disruption of tissue and restore the normal biomechanics and physiological …

Anterior osteosynthesis plate for lumbar vertebrae or sacral lumbar vertebra and instrument for positioning same

Abstract: The invention concerns an anterior osteosynthesis plate for lumbar vertebrae or sacral lumbar vertebra comprising: an elongated body with the following features: adapted to cover the anterior part of two consecutive vertebrae; having an anterior surface (6) and an opposite posterior surface (7); presenting two end zones linked by a connecting zone (11); and provided with two passage holes for anchoring screws. The invention is characterised in that the plate posterior surface (7) has a support plate (12, 13) designed to be urged in contact with the anterior surface of the vertebrae, the support plates (12, 13) being inclined to define between them, along a saggital plane (S), an obtuse angle (α) adapted to the relative angulation of the anterior part of the two vertebrae and mutually linked at the connecting zone by a concave extension (17), such that at least the posterior surface (7) of the body presents a concave profile in the saggital plane.

Degenerative lumbar stenosis: diagnosis and management.

Abstract: Degenerative lumbar stenosis is a common cause of disabling back and lower extremity pain among older persons. The process usually begins with degeneration of the intervertebral disks and facet joints, resulting in narrowing of the spinal canal and neural foramina. Associated factors may include a developmentally narrow spinal canal and degenerative spinal instability. Nonoperative management includes restriction of aggravating activities, physical therapy, and anti-inflammatory medications. If nonoperative treatment has failed, surgical treatment may be appropriate. Decompression should be performed so as to address all clinically relevant neural elements while maintaining spinal stability. If instability is present, autogenous intertransverse bone grafting is recommended. There may be an advantage to augmenting some of these procedures with internal fixation. Surgical success rates as high as 85% have been reported, but may be compromised by inadequate decompression, inadequate stabilization, or medical comorbidities. Short-term follow-up data indicate that operative management provides more effective relief than nonoperative treatment, but prospective studies comparing the effects of nonoperative and operative interventions on the long-term natural history of lumbar spinal stenosis are needed.

Nerve root pressure in lumbar disc herniation.

Abstract: Study design The contact pressure between the nerve root and lumbar disc herniation was measured and compared with clinical features. Objective To assess levels of actual compression to the nerve root in clinical cases. Summary of background data Actual levels of pressure to the nerve root of lumbar disc herniation in clinical cases is unknown. Methods The study was performed on 34 patients who had lumbar disc herniation. All of them had been treated by open discectomy. After laminotomy, nerve root pressure was measured by inserting a transducer between the nerve root and the disc herniation. The magnitude of pressure was compared with clinical features. Results Nerve root pressures before discectomy were varied from 7 mm Hg to 256 mm Hg (mean, 53 mm Hg). After discectomy, the contact pressure was 0 mm Hg in all cases. There were no significant correlations between the magnitude of nerve root pressure and limits to the degree of straight leg raising, duration of symptoms, and age of the patients. However, the magnitude of the pressure in patients with neurologic deficits and trunk list was significantly higher than in the absence of these findings. Conclusions The contact pressure exerted by lumbar disc herniation on the nerve roots was recorded during surgical intervention, and the mean pressure was 53 mm Hg. The magnitude of nerve root pressure was not correlated with the degree of straight leg raising, but with the severity of neurologic deficits.

Surface strain distribution on thoracic and lumbar vertebrae under axial compression. The role in burst fractures.

Abstract: Study design The surface strain distribution on the thoracic and lumbar vertebrae during axial compressive loading was examined. Objectives To examine the general mechanical behavior of the thoracic and lumbar vertebrae to evaluate their role in burst fractures. Summary of background data Burst fractures are generally characterized by injury to the middle column and fracturing of the superior endplate. However, results in previous biomechanical investigations have not shown how these fractures are initiated during compression. Methods Twenty-one thoracic and lumbar vertebrae (5 T10, 10 L1, and 6 L4) with upper and lower vertebrae were studied. Three-axis rosette strain gauges were cemented to 11 sites on the vertebral surface. An axial compressive load was applied, and the strain was measured in each specimen. The strain recorded by each rosette gauge was converted into a tensile, compressive, and shear component. Results The highest tensile and compressive strain was recorded at the base of the pedicle. Shear strain in the vertebral body was significantly higher than that in the lamina at all three spinal levels. At L1 and L4, the tensile strain at the superior vertebral rim was higher than that at the inferior rim. Conclusions The high tensile and compressive strains found at the base of the pedicle of T10, L1, and L4 indicate that the base of the pedicle is the site of fracture initiation. The higher tensile strain at the superior vertebral rim of L1 and L4 supports the clinical observation of the thoracolumbar burst fractures.

Bone density changes in pregnant women treated with heparin: a prospective, longitudinal study

Abstract: Heparin plus aspirin significantly improves the live birth rate of women with primary antiphospholipid syndrome. Osteopenia is a major concern of long-term heparin therapy. We studied prospectively the bone mineral density (BMD) changes during pregnancy and the puerperium in 123 women with primary antiphospholipid syndrome treated with low-dose aspirin and subcutaneous low-dose heparin (46 women took unfractionated heparin and 77 took low-molecular-weight heparin). Lumbar spine, neck of femur and forearm BMD were measured, using dual energy X-ray absorptiometry, at 12 weeks gestation, immediately postpartum and 12 weeks postpartum. The mean heparin duration was 27 weeks (range 22-29). During pregnancy, BMD decreased by 3.7% (P < 0.001) at the lumbar spine and by 0.9% (P < 0.05) at the neck of femur with no significant change at the forearm. Lactation was associated with a significant decrease in the lumbar spine and neck of femur BMD. There was no significant difference in BMD changes between the two heparin preparations. No woman suffered a symptomatic fracture. Long-term heparin treatment during pregnancy is associated with a small but significant decrease in BMD at the lumbar spine and neck of femur. This decrease is similar to that previously reported to occur in untreated pregnancies.

The degree of decompressive relief and its relation to clinical outcome in patients undergoing surgery for lumbar spinal stenosis.

Abstract: Study Design. A cross-sectional, clinical study to evaluate surgical decompression of the stenotic area monitored by computed tomographic scan and its relation to clinical variables in patients operated on for lumbar spinal stenosis. Objective. To study in patients with lumbar spinal stenosis the influence of the degree of compressive relief on the patients' clinical outcome. of Background Data. The goal of surgical treatment in lumbar spinal stenosis is to decompress the stenotic area. Although the decompression should be adequate, there are no clear guidelines to determine the extent of necessary decompression. In fact, there is clinical evidence that there is a discrepancy between the surgical outcome in the patient with lumbar spinal stenosis and postoperative radiologic findings. Methods. In 92 patients with lumbar spinal stenosis who had had no prior back surgery, preoperative and postoperative computed tomographic scans were obtained to determine the degree of decompression. The postoperative scan findings were classified according to the degree of decompression into a no-stenosis group (n = 35), an adjacent-stenosis group (n = 27), and a residual-stenosis group (n = 30). The postoperative instability of the lumbar spine was investigated by functional radiography. The subjective disability of the patients was assessed using the Oswestry score and the severity of pain using the visual analog scale. Walking capacity was evaluated by a treadmill test. The patients' estimations of the results of surgery were classified into groups of satisfied patients and dissatisfied patients. Results. The mean Oswestry score in all 92 patients was 27.1, and mean walking capacity was 630 m. In the satisfied patients, the Oswestry score was 18.8 and in the dissatisfied patients, 34.9 (P < 0.0000). Walking capacity was 690 m and 594 m. respectively. There were 30 patients with postoperative spinal instability, but it had no influence on surgical outcome. There were no differences in the Oswestry score, walking capacity, and patients' satisfaction among the postoperative CT groups. In the linear regression analysis, the satisfied patient corresponded significantly with the Oswestry score. Conclusions. The satisfaction of the patients with the results of surgery was more important in surgical outcome than the degree of decompression detected on computed tomographic scan.

Contralateral recurrent lumbar disc herniation. Results of discectomy compared with those in primary herniation.

Abstract: STUDY DESIGN: The surgical outcomes of patients who underwent discectomy for contralateral recurrent herniation and primary herniation were evaluated. OBJECTIVE: To assess whether the clinical results in patients undergoing surgery for contralateral recurrent disc herniation may be as good as those reported after primary discectomy. SUMMARY OF BACKGROUND DATA: No retrospective or prospective investigation has been conducted on the surgical treatment of contralateral recurrent lumbar disc herniation. METHODS: Sixteen patients who underwent surgery for recurrent disc herniation at the same level as primary disc excision, but on the opposite side, were analyzed prospectively from the recurrence of contralateral radicular pain (Group 1). All patients had reported a satisfactory results after primary discectomy. Fifty consecutive patients who underwent disc excision during the study period, who did not report recurrent radicular pain, were analyzed for comparison (Group 2). Overall patient satisfaction, pain severity, functional outcome, and work status were evaluated. RESULTS: At the 2-year follow-up, the clinical outcome was rated as satisfactory in 14 of 16 patients in Group 1 and in 45 of 50 in Group 2 (P > 0.05). Twelve patients in Group 1 and 42 in Group 2 had resumed their work or daily activities at the same level as before the operation (P > 0.05). Radicular pain was significantly improved in both groups at the 6-month and 2-year follow-ups. At the 6-month follow-up, low back pain was significantly improved only in the patients in Group 2; however, at the 2-year follow-up, low back pain was significantly improved in both groups. CONCLUSIONS: Clinical results in patients reoperated on for contralateral recurrent lumbar disc herniation compare favorably with those reported after primary discectomy. The improvement of pain in the low back and lower limbs reported by the majority of patients 2 years after reoperation suggests that fusion is not needed in this patient population.

Implant for fusing lumbar vertebrae and method of using same

Abstract: An implant for intersomatic fusion of two adjacent vertebrae has a web plate and a pair of arms extending from ends of the web plate and imparting a U-shape to the implant. The arms forming with the web plate a space. Such implants are used to stabilize two adjacent vertebrae following resection of a disk between them and distraction of the two vertebrae to form between confronting faces of the vertebrae a gap through which the patient's spinal chord extends. The implants are inserted into the gap from the posterior to each side of the spinal chord and then the spaces defined between the arms are packed with bone chips. Such a procedure is, by comparison with the standard anterior approach, relatively noninvasive and therefore is much less expensive and difficult for the patient.

Percutaneous Biopsy of the Thoracic and Lumbar Spine: Transpedicular Approach under Fluoroscopic Guidance

Abstract: Eighteen patients with vertebral lesions located in the thoracic or lumbar spine underwent percutaneous biopsy performed via a transpedicular approach under fluoroscopic guidance. This technique led to an accurate diagnosis in 16 cases (89%). No complications were encountered. For percutaneous lumbar and thoracic vertebral biopsy, the transpedicular approach is a safe and accurate alternative to the posterolateral approach.

Ten- to 15-year outcome of surgery for lumbar disc herniation: radiographic instability and clinical findings.

Abstract: The most appropriate treatment for radiculopathy associated with disc pathology is still controversial. Since 1934, surgical treatment has consisted of hemilaminectomy and removal of the herniated material. Many authors believe that these procedures may cause degenerative spondylosis and vertebral instability. Several surgical methods have been proposed, but the long-term effects are still being debated. In addition there appear to be few well-designed outcome studies on the management of this disease. In the present study, 150 patients were selected for surgery with strict criteria and all treated with the standard technique. The series was evaluated by subjective analyses (Roland questionnaire; 120 patients), objective examinations (68 patients – 56.6%) and radiographic studies including dynamic views (analyzed by the Taillard and Boxall methods) to establish the presence of vertebral instability (50 patients – 41.6%). The subjective and objective analyses showed a high rate of good results. Radiographic studies showed vertebral instability in 30 cases, but only 9 were symptomatic. Recurrences were not observed and only a few patients suffered from leg pain. The standard procedure for lumbar disc herniation showed good results at 10- and 15-year follow-up.

Recurrent pain after lumbar discectomy: the diagnostic value of peridural scar on MRI.

Abstract: The association between peridural scarring and recurrent pain after lumbar discectomy is much debated. A recently published study found that patients with extensive peridural fibrosis were 3.2 times more likely to experience recurrent radicular pain than those with less extensive scarring. This finding may lead to an overestimation of peridural fibrosis in clinical practice. In a retrospective study we analyzed the records of 53 patients who underwent a lumbar MRI because of recurrent pain after first unilateral microdiscectomy. Patients were classified as those with radicular or non-radicular pain according to history and clinical findings. The diagnosis was confirmed by spinal anesthetic block. The extension of scarring was compared between the two groups of patients. The amount of epidural fibrosis was examined on contrast-enhanced MRI in axial slices subdivided into four quadrants. The amount of fibrosis was divided into four stages in each affected quadrant. We found no differences regarding the amount of peridural fibrosis between patients with radicular pain and patients with non-radicular pain. We conclude that the extent of peridural scarring as defined by MRI is of minor value in the differential diagnosis of recurrent back and leg pain after lumbar microdiscectomy.

Mechanism of change in the orientation of the articular process of the zygapophyseal joint at the thoracolumbar junction

Abstract: The orientation of the superior articular processes in thoracic and lumbar vertebrae differs. The present study was undertaken to investigate the possible mechanism for the change from a posterolaterally facing superior articular surface in the thoracic region to a posteromedially facing curved articular surface in the lumbar region. The material of the study consisted of dry macerated bones of 44 adult human vertebral columns. The orientation of the superior articular process and its relation to the mamillary tubercle (process) was examined between T9 and L5 vertebrae in each column. An abrupt change from the thoracic to lumbar type of articular process was observed in 3 columns (7%). Forty-one (93%) columns showed a gradual change extending over either 2 or 3 successive vertebrae. The present study suggests that the change in the orientation of the superior articular process, from the coronal to the sagittal plane (sagittalisation), occurs due to the change in the direction of weight transmission through zygapophyseal joints at the thoracolumbar junction. It was observed that the gradual sagittalisation of the superior articular process in the transitional zone brought it close to the mamillary tubercle which eventually fused with it. Thus the study suggests that the characteristic posteromedially facing concave superior articular process of lumbar vertebrae may have formed because of the fusion of the articular process and the mamillary tubercle.