Showing papers on "Lumbar vertebrae published in 1994"

Mechanical behavior of the human lumbar and lumbosacral spine as shown by three-dimensional load-displacement curves

Abstract: The lumbar region is a frequent site of spinal disorders, including low-back pain, and of spinal trauma. Clinical studies have established that abnormal intervertebral motions occur in some patients who have low-back pain. A knowledge of normal spinal movements, with all of the inherent complexities, is needed as a baseline. The present study documents the complete three-dimensional elastic physical properties of each lumbar intervertebral level from the level between the first and second lumbar vertebrae through the level between the fifth lumbar and first sacral vertebrae. Nine whole fresh-frozen human cadaveric lumbar-spine specimens were used. Pure moments of flexion-extension, bilateral axial torque, and bilateral lateral bending were applied, and three-dimensional intervertebral motions were determined with use of stereophotogrammetry. The motions were presented in the form of a set of six load-displacement curves, quantitating intervertebral rotations and translations. The curves were found to be non-linear, and the motions were coupled. The ranges of motion were found to compare favorably with reported values from in vivo studies.

Clinical Features of Patients with Pain Stemming from the Lumbar Zygapophysial Joints: Is the Lumbar Facet Syndrome a Clinical Entity?

Abstract: Study DesignThis study is a prospective cross-sectional analytic study.ObjectivesThe authors determined the prevalence and clinical features of patients with pain stemming from the lumbar zygapophysial joints.Summary of Background DataPrevious studies have demonstrated a wide range of prevalence for

Total en bloc spondylectomy for solitary spinal metastases.

Abstract: We have developed a technique for total en bloc spondylectomy through a posterior approach and now report our experience of 20 patients with a solitary or localised metastasis in the thoracic or lumbar vertebrae. There are two steps: an en bloc laminectomy, followed by en bloc resection of the vertebral body with an oncological wide margin and the insertion of a vertebral prosthesis. Pain was relieved in the 17 patients who could be assessed; 11 of the 15 patients with a neurological deficit were much improved, impending paralysis being prevented in 5 patients. There have been no local recurrences. Nine patients are at present alive with a mean follow up of 17.4 months.

Increasing rates of cervical and lumbar spine surgery in the United States, 1979-1990.

Abstract: Study DesignData from annual national surveys of hospitalizations were used to review trends.ObjectivesThe trends in rates of hospitalizations with cervical and lumbar spine surgery were examined among persons ≥25 years old.Summary of Background DataPrelimlnary analysis of national survey data indic

Bone mineral density and vertebral compression fracture rates in ankylosing spondylitis.

Abstract: OBJECTIVE--To examine the relationship between disease severity and bone density as well as vertebral fracture risk in patients with ankylosing spondylitis (AS). METHODS--Measurements were taken for bone mineral density (BMD) and vertebral fracture rates in 87 patients with AS. BMD was measured at the hip (femoral neck -FN), lumbar spine (L1-L4-LS) and for the whole body using a hologic-QDR-1000/W absorptiometer. An algorithm based on normal female ranges of vertebral heights was used to define a fracture as occurring when two vertebral ratios were each three standard deviations below the calculated mean of the controls. RESULTS--Patients with AS had significantly lower FN-BMD in proportion to disease severity (based on a Schober index) and disease duration. LS-BMD was also reduced in early disease, but in patients with advanced AS it had increased considerably. Nine vertebral fractures (10.3%) were identified which was considerably higher than expected when compared with a fracture of 1.9% in a control population of 1035 females of a similar age range. Patients with AS with fractures were significantly older, more likely to be male, had longer disease duration and more advanced spinal limitation with less mobility. There was no significant reduction in lumbar spine or femoral neck bone density in the fracture group. CONCLUSIONS--Vertebral fractures that result from osteoporosis are a feature of longstanding AS. BMD used as a measure of osteoporosis of the spine in advanced AS is unreliable probably as a result of syndesmophyte formation and does not predict the risk of vertebral fracture. Alternative sites such as the neck of the femur should be used for sequential assessment of BMD in AS.

Gender differences in vertebral sizes in adults : biomechanical implications

Abstract: PURPOSE: To determine if vertebral bone densities or vertebral body sizes contribute to gender differences in vertebral bone mass in adults MATERIALS AND METHODS: Cancellous and cortical bone densities and dimensions of three lumbar vertebrae in 25 women and 18 men were measured with quantitative computed tomography (CT) and statistically analyzed RESULTS: Neither cancellous nor cortical vertebral bone densities differed in healthy adults Vertebral bodies in women had lower cross-sectional areas (822 cm2 +/- 109 [standard deviation] versus 1098 cm2 +/- 125, P < 001) and volumes (2242 cm3 +/- 240 versus 3086 cm3 +/- 26, P < 001) These differences also were evident in men and women matched for age, weight, vertebral bone density, and vertebral body height Overall cross-sectional areas of vertebral bodies are 25% smaller in women than men Vertebral bone densities do not differ between sexes Estimates of mechanical stress within vertebral bodies are 30%-40% higher in women than men for equiva

Gender differences in vertebral body sizes in children and adolescents.

Abstract: PURPOSE: To determine whether differences in vertebral bone densities or sizes account for gender differences in skeletal mass during growth. MATERIALS AND METHODS: Quantitative computed tomography (CT) was used to measure the densities of cortical and cancellous bone and dimensions of the lumbar vertebral bodies in 196 healthy children and adolescents, ages 4-20 years. RESULTS: Neither cancellous nor cortical bone densities differed between boys and girls with age or level of sexual development. In contrast, the cross-sectional areas of the vertebral bodies were greater in boys than girls throughout childhood and adolescence. Even when prepubertal children were matched for chronologic age, bone age, height, and weight, the size of the vertebral bodies was 17% greater in boys. This disparity in vertebral body size increased with level of sexual development and was greatest at sexual maturity. CONCLUSION: Lower vertebral bone mass of women as compared with men may result from early gender differences in th...

Biomechanics of the lumbar spine in sagittal/lateral moments

Abstract: Study DesignThe nonlinear stress analysis of the antire ligamentous lumbar spine (L1-S1) in single flexion, extension, right lateral, and left lateral moments of up to 15 Nm was performed. In sagittal moments, both disc fiber angles of 27° and 30° were considered. Moreover, in extension moment, the

Continuous therapy with pamidronate, a potent bisphosphonate, in postmenopausal osteoporosis

Abstract: There is a need for effective and acceptable therapies for postmenopausal osteoporosis. The bisphosphonates show promise in this role, but the effects of the potent bisphosphonates in established osteoporosis have not yet been reported. We performed a 2-yr, randomized, double blind, placebo-controlled trial of pamidronate (150 mg/day) in 48 postmenopausal osteoporotic women. Bone mineral density of the total body, lumbar spine, and proximal femur was measured every 6 months by dual energy x-ray absorptiometry. Bone mineral density increased progressively in the total body (1.9 +/- 0.7%; P < 0.01), lumbar spine (7.0 +/- 1.0%; P < 0.0001), and femoral trochanter (5.4 +/- 1.3%; P < 0.001) in subjects receiving pamidronate, but did not change significantly in those receiving placebo. There were significant decreases in bone density at both the femoral neck (P < 0.02) and Ward's triangle (P < 0.01) in subjects taking placebo, which did not occur in the pamidronate group. The differences between the treatment groups were significant at all sites (0.0001 < P < 0.05) except Ward's triangle. Vertebral fracture rates were 13/100 patient yr in the pamidronate group and 24/100 patient yr in those receiving placebo (P = 0.07), and there was a nonsignificant trend toward height loss being less in those receiving pamidronate (P = 0.16). It is concluded that pamidronate is an effective therapy in postmenopausal osteoporosis.

Lumbar disc degeneration and atherosclerosis of the abdominal aorta.

Abstract: STUDY DESIGN This study analyzed the relationship of disc degeneration to atherosclerotic changes in the abdominal aorta and stenosis of the ostia of the lumbar and middle sacral arteries, 86 plain radiographs of lumbosacral spines, and the corresponding abdominal aortas were evaluated in connection with routine autopsy. RESULTS Disc degeneration, advanced atherosclerotic manifestations, and stenosis of the ostia of the lumbar and middle sacral arteries all increased with age (P < 0.001). After partial rank correlation analysis, keeping the effect of age constant, there was still a statistically significant association between the grade of disc degeneration and stenosis of the ostia of the arteries supplying the disc. The association was stronger at upper lumbar levels (0.001 < P < 0.01) than at lower ones (0.01 < P < 0.05). Furthermore, with complicated lesions in the abdominal aorta, disc degeneration at all lumbar levels increased. CONCLUSIONS Atherosclerosis in the abdominal aorta and especially stenosis of the ostia of segmental arteries may play a part in lumbar disc degeneration.

The value of the provocation response in lumbar zygapophyseal joint injections.

Abstract: OBJECTIVE To determine the relationship between pain provocation and the analgesic response in lumbar zygapophyseal joint blocks. DESIGN Consecutive patients undergoing intraarticular zygapophyseal joint blocks for the investigation of low back pain were included in this prospective study. SETTING The referred sample was from the metropolitan areas of New Orleans and San Francisco. PATIENTS Ninety patients with low back pain of > 3 months' duration and no history of lumbar surgery. INTERVENTIONS All patients underwent one or more intraarticular injections of radiographic contrast followed by lignocaine (lidocaine) 2% into zygapophyseal joints between L2-3 and L5-S1. Those with definite responses at one or more levels underwent confirmatory blocks using 0.5% bupivacaine. OUTCOME MEASURES Provocation of familiar pain and relief of pain after the injection of local anesthetic. Patients were assessed by an independent observer. RESULTS A total of 203 joints were studied. Adopting liberal criteria, either exact or similar reproduction of pain on the one hand correlated with either definite or complete relief of pain after a single, analgesic block on the other (p < 0.0001). However, when more stringent criteria were adopted, such as response to a confirmatory block using bupivacaine, there was no significant association. CONCLUSIONS This study calls into question the validity of pain provocation alone as a criterion standard in patients undergoing diagnostic lumbar zygapophyseal joint blocks.

Vertebral arthritis and physical activities in the prehistoric Southeastern United States

Abstract: Vertebral arthritis is examined in a prehistoric Native American sample from northwestern Alabama. Both osteophytosis (OP) of the vertebral bodies and osteoarthritis (OA) of the apophyseal facets are highest in the lumbar vertebrae, followed by the cervical and thoracic segments, although differences are much more striking in OP. OA is bilaterally asymmetric, with greater prevalence on the right side in the upper thoracic region. Much of the patterning seen in arthritis in this and other samples is due to the stresses imposed by spinal curvature and weight-bearing due to our erect posture. In addition, handedness is the probable cause of asymmetry in OA. However, the high levels of cervical OP are unexpected, and may be due to use of the tumpline in carrying burdens. © 1994 Wiley-Liss, Inc.

Morphometric study of the pedicles of thoracic and lumbar vertebrae in Koreans.

Abstract: Study DesignThe shape and size of the pedicles of the human spine differs within different races. The authors studied the diameters and angles of the spine pedicle from the T1 to Ls levels in Koreans. The following measurements were made 1) transverse diameter, 2) superoinferior diameter, 3) anterop

Comparison of smoking habits between patients with surgically confirmed herniated lumbar and cervical disc disease and controls.

Abstract: There have been numerous studies that implicate cigarette smoking as a risk factor for the development of back pain or disc disease. The purpose of this article is to review patients who underwent surgery for cervical or lumbar radiculopathy and to investigate the relationship between cigarette smoking and development of surgical disc disease. A cigarette smoking study of 205 surgical patients with lumbar and cervical disc diseases was done, with the surgical patients compared to 205 age-sex-matched inpatient controls during 1987-1988. This study was conducted at the Pennsylvania Hospital in Philadelphia, Pennsylvania. There were 163 patients with lumbar disc disease and 42 patients with cervical disc disease. The ratio of men to women was 1.5:1 for lumbar disc and 2.5:1 for cervical disc disease. Smoking history (current and ex-smokers) was strikingly increased in both prolapsed lumbar intervertebral disc (56% vs. 37% of controls, p = 0.00029) and cervical disc disease (64.3% vs. 37% of controls, p = 0.0025). Calculated relative risks for smokers were 2.2 for lumbar disc and 2.9 for cervical disc diseases. This association between cigarette smoking and disc disease was more significant when comparing between current smokers versus nonsmokers (p = 0.000011 for lumbar disc disease, and p = 0.00064 for cervical disc disease). Relative risks for current smokers were 3.0 for lumbar disc and 3.9 for cervical disc diseases. This correlation was significant for both males (p = 0.000068 for lumbar disc disease, p = 0.043 for cervical disc disease) and females (p = 0.018 for lumbar disc disease, p = 0.006 for cervical disc disease).(ABSTRACT TRUNCATED AT 250 WORDS)

Fractal signature analysis of macroradiographs measures trabecular organization in lumbar vertebrae of postmenopausal women

Abstract: High definition macroradiography was used to provide an image of the detailed structural organization of the cancellous bone in human lumbar vertebrae. The fractal signature analysis (FSA) method was used to quantify the horizontal and vertical trabecular organization recorded within the image. Comparison of the FSA of the posteroanterior and lateral macroradiographs in postmortem lumbar vertebrae showed that neither the superimposition of the neural arch nor the radiographic angle affected the trabecular measurement within the vertebral body. FSA analysis of the trabecular structure measured from the macroradiographs of lumbar vertebrae in two groups of postmenopausal women, with high and low bone mineral density (BMD), showed that the large vertical trabecular structures correlated with the women's body weight (P<0.01–0.03) and body mass index (P<0.005–0.05), the fine horizontal structures correlated with the women's age (P<0.005–0.05), and fine vertical trabecular structures were significantly greater (P<0.005–0.05) in the low compared with the high BMD group.

The relationship between intramuscular pressure of the paraspinal muscles and low back pain

Abstract: Study DesignThe relationship between lumbar intramuscular pressure and backache with degenerative lumbar spine diseases was examined. Lumbar intramuscular pressure in 102 patients with low back pain and in 20 normal adults was compared in different positions using Miller's microtip catheter transduc

Spinal arthritis and physical stress at Bronze Age Harappa

Abstract: This study examines joint changes in the vertebral skeleton in human remains excavated in 1987 and 1988 at Bronze Age Harappa, an urban center of the Indus Valley civilization. The sample consists of 23 complete skeletons from primary burial context, the partial remains of more than 69 other individuals, and hundreds of skeletal elements from secondary context, totalling 3,084 vertebral joint margins and articular surfaces. Marginal bone proliferation, pitting of articular surfaces, eburnation, and ankylosis were scored macroscopically for vertebral body margins and surfaces and posterior apophyseal facet joints. Marginal lipping is far more prevalent on the vertebral bodies than on the apophyseal facets and surface pitting is also more frequent on vertebral bodies although its expression is relatively low overall. Cervical vertebrae in this sample exhibit the same amount of marginal new bone and much more surface pitting of the vertebral bodies than do either thoracic or lumbar vertebrae; the cervical segment also exhibits the most severe expressions of both types of lesions. In addition, although the frequencies of cervical and lumbar posterior facet involvement are similar, the cervical facets exhibit much more severe lipping as well as the only cases of eburnation and ankylosis. Pitting of the posterior facets is most common in the lumbar segment, but the cervical examples are the only severe cases. It is proposed that the severe joint changes in the cervical spine result from trauma, perhaps accumulated microtrauma from activity stresses. There are no age or sex associated patterns in the frequency of arthritis although this result may be influenced by the small proportions of the total sample for which age and sex could be determined.

Anterior decompression for late pain and paralysis after fractures of the thoracolumbar spine.

Abstract: Anterior decompression of the thoracic and lumbar spine is indicated for patients with trauma, infection, or tumor that causes compression of the neural tissues, resulting in an incomplete neurologic deficit. The complication of chronic pain, with or without paralysis, that results from fractures with canal compromise has received little attention. This study involved 45 patients who had anterior decompression for chronic pain or paralysis at an average of 4.5 years after having thoracolumbar fractures. Pain was improved in 41 of 45 patients, with complete relief in 30 and partial relief in 11. In 25 patients with neurologic deficit, 21 noted improvement, 14 of which improved one or more grades of the Eismont classification. No patient had an increase in pain or loss of neurologic function. Complications were few. Anterior decompression of the thoracolumbar spine for chronic pain after thoracolumbar fractures is a safe and effective treatment for patients with this uncommon and difficult problem.

Adult idiopathic lumbar scoliosis : a formula for prediction of progression and review of the literature

Abstract: Study DesignA retrospective study was conducted of patients with untreated adult-type idiopathic lumbar scoliosisObjectivesTo construct a mathematical formula that provides accurate progression of an idiopathic adult lumbar scoliosis using initial roentgenographic parametersSummary of Background D

Effect of lordosis on the position of the nucleus pulposus in supine subjects. A study using magnetic resonance imaging.

Abstract: Study Design - Healthy young women (N = 20) underwent magnetic resonance imaging while supine with their hips and knees flexed (flexed position) and supine with a lumbar roll under the low back (extended position). The posterior end anterior margins of the nucleus pulposus (MP) relative to posterior and anterior margins of the adjacent vertebral bodies were calculated from mid-sagittal T 2-weighted images to determine the position change of the NP as a function of two supine postures.Objectives - This study describes the effect of two commonly used supine postures on the position of the NP. Summary of Background Data - Management of patients with low back pain is often based on theorized positional changes of the NP during spinal extension and flexion, Date describing NP positional changes have not been reported for noninvesive measurements. Results - The distance of the posterior margin of the NP to the posterior margins of the adjacent vertebral bodies was greater in the extended compared with the flexed position. There was no difference in the anterior distance. Eight of the 20 subjects had at least one degenerative disc in the lower lumbar spine. The NFs of the degenerative discs did not move the same as normal discs. Conclusions - The use of a lumbar roll under the low back when supine causes an increase in the distance from the posterior margin of the NP to the posterior portions of the vertebral bodies in normal discs of healthy young females. Degenerative discs deform differently from non degenerative discs.

Caudal Epidural Blocks for Elderly Patients with Lumbar Canal Stenosis

Abstract: Objective: To determine the efficacy of caudal epidural blocks (CEB) in relieving pain and the duration of pain relief with CEB in elderly patients suffering from degenerative lumbar canal stenosis (LCS). Design: This study was a descriptive, prospective study with a 10-month follow-up. Participants and Setting: Thirty patients, 76 ± 6.7 years of age, with leg discomfort with or without back pain and with LCS documented by magnetic resonance imaging (MRI) within 1 year of the study, were recruited from the outpatient clinic of the Cleveland Clinic Florida. None of the subjects had received CEB or surgery for their leg discomfort and none had relief of pain by analgesics alone. Measurements and Interventions: Subjects received a total of three doses of 0.5% Xylocaine with 80 mg Depo-Medrol into the caudal epidural space through the sacral hiatus at weekly intervals. The Roland 5-point pain rating scale was utilized before and at 2-month intervals up to 10 months after the CEB was administered. MRI was used to identify the degree of LCS. Results: The degree of LCS on admission was moderate in 66.7% (n = 20) of the patients, mild in 23.3% (n = 7), and severe in the remaining 10% (n = 3). Patients had LCS involving 2.4 ± 0.49 lumbar vertebrae. The degree of LCS is directly correlated with the pain level before CEB. After CEB, the pain level changed from 3.43 ± 0.82 to 1.5 ± 0.86 (P < 0.0000), with a significant relief of pain up to 10 months (the end of observation). The duration of pain relief ranged from 4 to 10 months (P < 0.0001). Conclusion: CEB offers significant pain relief and appears to be a reasonable therapeutic option among elderly patients with LCS. This alternative seems particularly important among patients with poor response to drug therapy and who are either poor surgical risks or who have refused surgery.

Bone mineral density in ankylosing spondylitis. DEXA comparison of control subjects with mild and advanced cases

Abstract: We have used dual-energy X-ray absorptiometry to measure bone mineral density (BMD) in patients with ankylosing spondylitis comparing 41 healthy control subjects and 33 patients with either mild or advanced ankylosing spondylitis. A Norland XR-28 bone densitometer was used to measure the BMD of the lumbar spine and that of the head, trunk, arms, femoral neck, Ward's triangle, legs, pelvis, and total body. Mild ankylosing spondylitis was defined as that showing no or incipient syndesmophytes between L1 and L5 vertebrae: we studied 16 men of mean age 37 years and six women of mean age 37 years. Advanced ankylosing spondylitis, in 11 men of mean age 42 years, showed a bamboo spine with bridging syndesmophytes across all disc spaces between L1 and L5. The mean BMD of the lumbar spine was significantly different in the patients and control subjects of the same sex (0.01 < p < 0.05, analysis of variance), being significantly reduced compared with control subjects in mild disease (0.001 < p < 0.01, t-test) and significantly increased in advanced disease over control subjects (0.01 < p < 0.05; t-test) and over patients with mild disease (0.001 < p < 0.01; t-test). The relevance of these findings to the aetiology and pathogenesis of spinal deformities and other complications in ankylosing spondylitis is discussed.

The growth of the lumbar vertebral canal.

Abstract: Study Design This study examines the growth and development of the lumbar spinal canal with emphasis on early life. Objective Changes in dimensions of the canal were investigated throughout life. Summary of Background Data Seven hundred and fifteen lumbar vertebrae were examined from the Spitalfield Collection of Skeletons at the Natural History Museum, London. Methods Ummagnified silhouette pictures were taken of the canals with a specially designed photographic box. Computerized image analysis provided the accurate measurements. Results Regarding the midsagittal diameter and the cross-sectional area, the cranial four lumbar vertebrae were already fully matured in infants. At L5 there was significant increase up to 4 years of age when the midsagittal diameter was even larger than in the adult. The interpedicular diameter significantly increased at L1 until 10 years of age, at the other levels until adulthood, as did the perimeter at L4 and L5 until 14 years of age. The shape of the canal was assessed by measuring the circularity, the 'trefoilness' and the situation of the centroid. The first measurement significantly decreased with age, the trefoilness increased until adulthood, and the centroid of the canal approached the vertebral body. In spines with spina bifida occulta, the lumbar canal was significantly larger proximal to the lesion than in the unaffected spines. Conclusion The lumbar spinal canal exhausts its growth potential by infancy as regards the midsagittal diameter and the cross-sectional area. Thus, in the case of delayed development, it is not capable of catch-up growth.

Lumbar intervertebral disc transfer. A canine study.

Abstract: STUDY DESIGN Degenerative lumbar disc disease has been implicated as a cause of low back pain. Current treatment options for low back pain involve nonphysiologic fusion of the involved segments and have variable success rates. This is an experimental study of lumbar intervertebral disc transplantation using a canine surgical model. OBJECTIVES This study evaluated the feasibility of lumbar disc transplantation and its effects on disc metabolism and morphology. METHOD Eight mature mongrel dogs underwent disc transfer surgeries, in which the L2-L3 and L4-L5 intervertebral discs, with a small segment of adjacent superior and inferior vertebral body, were removed and transposed. The transplanted disc were stabilized by plates or by a flexible cable wire construct using Songer cables (DANEK, Inc., Memphis, TN). Unrestricted activity was allowed postoperatively. At 4 months, the spines were harvested, and the transplanted discs were evaluated biochemically and histologically. Intervening nontransplanted discs served as viable controls and thrice-frozen discs served as nonviable controls. Cell viability was assessed by measuring proteoglycan synthesis and DNA content. RESULTS Proteoglycan synthesis (35S uptake normalized to DNA content) was maintained in transplanted anulus fibrosus tissue, but was decreased in nucleus pulposus samples (P < 0.05). DNA content was not altered significantly in the transplanted discs. Histologic analysis of the transplanted discs showed revascularization and remodeling of the bone adjacent to the disc and preservation of the lamellar architecture of the anulus fibrosus. The transplanted nucleus pulposus samples had chondrocyte-like cells present, but the staining characteristics of the nucleus material was variable. The contour of the transplanted disc endplates was irregular in all specimens. CONCLUSIONS The structure and function of autograft intervertebral discs were maintained after disc transfer surgery; the transplant discs, however, were not completely normal in either their morphology or their metabolic functioning.

Lumbar traction: a review of the literature.

Abstract: Lumbar traction is commonly used to treat patients with back pain. Typically, clinicians rely on expert opinion in making decisions about when and how to implement lumbar traction. The purpose of this paper was to review current knowledge of lumbar traction and to identify what, if any, empirical evidence supports the expert opinions. This review found that whereas the mechanical effects of lumbar traction are well substantiated, the results of studies examining clinical effectiveness are conflicting. The failure to conclusively demonstrate the clinical benefit of lumbar traction may be related to the varied diagnostic categories and treatment techniques employed in the studies. Of the 10 types of lumbar traction described in the literature, static and intermittent mechanical traction are the two most commonly used. Indications, contraindications, and treatment techniques for these two types of traction are discussed. Based on the findings of this review, further study is needed to determine optimal treat...

Increase of motion between lumbar vertebrae after excision of the capsule and cartilage of the facets. A cadaver study.

Abstract: Seventeen fresh segments of cadaveric lumbar spines were tested in flexion, extension, and axial rotation. The resulting angular rotations were measured with the use of a goniometer and a three-dimensional system of video analysis. Measurements of flexibility were made, in order, in the intact spine; after decompression (bilateral total laminectomies, partial medial facetectomies, and foraminotomies); after excision of the capsule and cartilage of the facets; and after cancellous bone had been packed into the facet defects. Decompression resulted in a slight increase in the sagittal and axial ranges of motion. Subsequent excision of the capsule and cartilage of the facets, as in preparation for an arthrodesis of the facets, resulted in a significant increase in both the sagittal (5.7 +/- 2.9 degrees, mean and standard deviation) (p < 0.001) and the axial (1.4 +/- 0.9 degrees) (p < 0.01) ranges of motion compared with the motion in the intact specimen and with the motion in the specimen after only decompression had been done (p < 0.01 and p < 0.05, respectively). Packing of bone in the facets did not significantly reduce motion. It was calculated that the increase in the sagittal range of motion after excision of the capsule and cartilage of the facets would increase the tensile strain in a graft between the transverse processes of the fourth and fifth lumbar vertebrae (18 +/- 1 per cent tensile strain [mean and 95 per cent confidence interval] for the intact vertebrae and 25 +/- 1 per cent for the vertebrae in which the facets had been excised).