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302: Jackson RP, Becker GJ, Jacobs RR, Montesano PX, Cooper BR, McManus GE. The neuroradiographic diagnosis of lumbar herniated nucleus pulposus: I. A comparison of computed tomography (CT), myelography, CT-myelography, discography, and CT-discography. Spine 1989 Dec;14(12):1356-61 Published erratum appears in Spine 1990 Jan;15(1):59 
 
North Kansas City Hospital, Missouri. 
 
The accuracy of five imaging modalities for the diagnosis of lumbar herniated nucleus pulposus (HNP) is compared prospectively in 124 patients, all of whom underwent surgical exploration. All tests were read independently of each other and the level of confidence in each diagnosis was recorded. The results are based on negative (106) as well as positive (125) findings at the 231 disc sites (level and side) explored. Computed tomography-discography (disco-CT) was the most accurate test (87%) compared to 77% for CT-myelography (myelo-CT), 74% for CT, 70% for myelography, 64% for disc injection pain, and 58% for discography. The false positive rate was lower for disco-CT (19%) than for myelo-CT (24%), CT (24%), and myelography (30%). The false negative rate was also lower for disco-CT (8%) than for myelo-CT (22%), CT (29%), and myelography (30%). Disco-CT was the most accurate test (94%) in patients who had prior disc surgery compared with 81% for myelo-CT, 80% for CT, and 74% for myelography. Disco-CT was also the most accurate test for patients with foraminal HNP (91% compared with 71% for CT, 65% for myelo-CT, and 58% for myelography). Disc injection reproduced the patient's clinical pain pattern in only 36% of herniated discs. This test has high specificity (89%), but low sensitivity (43%). The risks from myelography followed by discography within a 72-hour period are similar to those reported for myelography alone. Disco-CT is the most accurate of these tests (P less than 0.05) for the diagnosis of lumbar HNP.(ABSTRACT TRUNCATED AT 250 WORDS) 
 
 
 
303: Jackson RP, Cain JE Jr, Jacobs RR, Cooper BR, McManus GE. The neuroradiographic diagnosis of lumbar herniated nucleus pulposus: II. A comparison of computed tomography (CT), myelography, CT-myelography, and magnetic resonance imaging. Spine 1989 Dec;14(12):1362-7  
 
North Kansas City Hospital, Missouri. 
 
The accuracy of computed tomography (CT), myelography, CT-myelography (myelo-CT) and magnetic resonance imaging (MRI) for the diagnosis of lumbar herniated nucleus pulposus (HNP) is compared prospectively in 59 patients, all of whom underwent surgical exploration. All tests were read independently of each other and the level of confidence in each diagnosis was recorded. The results are based on the negative (61) as well as positive (59) findings at the 120 disc sites (level and side) explored. Magnetic resonance imaging was the most accurate test (76.5%) compared with myelo-CT (76.0%), CT (73.6%), and myelography (71.4%). The false positive rate was lowest for MRI (13.5%) followed by myelography (13.7%), CT (13.8%), and myelo-CT (21.1%). The false negative rate was lowest for myelo-CT (27.2%) followed by MRI (35.7%), CT (40.2%), and myelography (44.1%). In that subset of 19 patients who had prior surgery, myelography was the most accurate means of diagnosing lumbar HNP (88.8%), followed by MRI (83.3%), myelo-CT (78.4%), and CT (72.6%). The false positive rates in these patients were 11.6% for myelography, 13.2% for MRI, 14.5% for CT, and 16.4% for myelo-CT; the false negative rates were 22.7% for MRI, 24.4% for myelography, 29.5% for myelo-CT, and 47.7% for CT. Magnetic resonance imaging compares very favorably with other currently available imaging modalities for diagnosing lumbar HNP. Magnetic resonance imaging is painless, has no known side effects or morbidity, no radiation exposure, and is noninvasive. The authors recommend it as the procedure of choice for the diagnosis of most lumbar disc herniations. 
 
 
 
304: Ketonen L, Gyldensted C. Lumbar disc disease evaluated by myelography and postmyelography spinal computed tomography. Neuroradiology 1986;28(2):144-9  
 
Five- and ten-millimeter-thick transverse axial computed tomography (CT) scans were obtained at lumbar disc spaces in 81 patients with suspected lumbar disc disease. Scans were obtained following metrizamide myelography. CT and myelography findings were compared and correlated with clinical and surgical findings. Postmyelography CT scan was superior to myelography in 68% since it was able to demonstrate even small herniations. It was especially valuable in the L5-S1 space where the wide epidural space can hide the disc herniation without it being demonstrated by myelography. Also other kinds of pathology which may simulate or complicate disc herniation were readily evaluated by postmyelography CT. Although noncontrast CT scans are usually diagnostic and sufficient, the improved anatomical details obtained by postcontrast CT scans, increase the diagnostic accuracy, and selected, complicated cases may need the CT study with intrathecal metrizamide. 
 
305: Masaryk TJ, Ross JS, Modic MT, Boumphrey F, Bohlman H, Wilber G. High-resolution MR imaging of sequestered lumbar intervertebral disks. AJR Am J Roentgenol 1988 May;150(5):1155-62  
 
Department of Radiology, University Hospitals of Cleveland, Case Western Reserve University, OH 44106. 
 
We retrospectively reviewed the MR examinations of 20 patients with surgically documented sequestered lumbar disks (free fragments). Sixteen of 20 cases demonstrated extradural masses that were distinct from the interspace of origin and had intermediate signal on T1-weighted images but increased signal on T2-weighted images. In 12 cases there was migration of the sequestered fragment. Sequestered disks that migrated away from the interspace had an irregular, oblong appearance, while those near the interspace were round in configuration. Additionally, the interspace of origin consistently demonstrated loss of signal on T2-weighted images when compared with intact lumbar disks. Sagittal 12-weighted images best depicted the absence of a high-signal pedicle contiguous with the interspace of origin in sequestered disks. These findings were applied to a prospective group of 20 patients undergoing lumbar diskectomy. There was an 89% sensitivity, 82% specificity, and 85% accuracy for MR in distinguishing sequestered disks from other forms of lumbar disk herniation. We conclude that high-resolution MR imaging is sensitive in detecting disk disease and specific in characterizing various subtypes of extradural defects. MR uses morphology as well as changes in signal intensity to make these distinctions. 
 
 
306: Modic MT, Masaryk T, Boumphrey F, Goormastic M, Bell G. Lumbar herniated disk disease and canal stenosis: prospective evaluation by surface coil MR, CT, and myelography. AJR Am J Roentgenol 1986 Oct;147(4):757-65  
 
Sixty patients with suspected lumbar herniated disk and/or canal stenosis were studied prospectively with surface coil MRI, CT, and/or myelography, and the results were compared with the surgically confirmed abnormality. Forty-eight patients had lumbar surgery at 62 levels. There were no negative explorations. Thirty-nine patients had a myelogram and CT. Thirty of the CTs were performed following the injection of metrizamide for myelography. Nine patients had a CT without intrathecal contrast material 1 to several days before the myelogram. Six patients had myelography only, and three patients had CT only. All studies were evaluated for the location and type of disease in a forced choice fashion. Independent of the surgically correlated levels, there was 86.8% agreement between the MR and CT studies in all patients at 151 levels and 87.2% agreement between MR and myelography at 218 levels. At the operative levels, there was 82.6% agreement between MR and surgical findings for both type and location of disease; 83% agreement between CT and surgical findings; and 71.8% agreement between myelography and surgical findings. There was 92.5% agreement when MR and CT were used jointly, and 89.4% agreement when CT and myelography were used jointly. The results of this study indicate that a technically adequate MR examination was equivalent to CT and myelography in the diagnosis of lumbar canal stenosis and herniated disk disease. CT and MR can be complementary studies, and surface coil MR can be viewed as an alternative to myelography. 
 
 
 
307: Moufarrij NA, Hardy RW Jr, Weinstein MA. Computed tomographic, myelographic, and operative findings in patients with suspected herniated lumbar discs. Neurosurgery 1983 Feb;12(2):184-8  
 
Fifty patients presenting with a suspected herniated lumbar intervertebral disc were evaluated with sector computed tomography (CT). Excluded from this series were patients with prior lumbar laminectomy or a clinical diagnosis of lumbar canal stenosis. Forty-six of the patients also underwent preoperative lumbar myelography. All patients subsequently underwent laminectomy. In 40 patients (80%), CT was positive. In the remaining 10 patients (20%), it was negative; in this group the myelogram correctly predicted the lesion in 8 (80%). Sector CT correctly predicted the nature of the lesion in 24 patients (48%), was incorrect in 14 (28%), and gave incomplete findings in 12 (24%). CT was most accurate when it demonstrated a disc protrusion as the only finding. In this group, sector CT correctly predicted the operative findings in 24 of 25 patients (96%). CT was less accurate when spondylitic compression was diagnosed. This study suggests that sector CT is a useful test in the evaluation of patients with sciatica and that, when a soft herniated disc is demonstrated on CT, myelography may be omitted. 
 
308: Schipper J, Kardaun JW, Braakman R, van Dongen KJ, Blaauw G. Lumbar disk herniation: diagnosis with CT or myelography. Radiology 1987 Oct;165(1):227-31  
 
The value of computed tomography (CT) and myelography as single investigations in the diagnostic evaluation of patients with radiating leg pain probably due to lumbar disk herniation (LDH) has been adequately demonstrated. However, the extent to which CT can replace myelography and the conditions in which the examinations should be combined and in which order are still uncertain. Results of CT scans and myelograms from 461 patients with symptoms of lumbar root compression, probably due to LDH, were evaluated and compared with surgical results, if available. The sensitivity of myelography exceeded that of CT (82% vs. 73%), but its specificity was lower (67% vs. 77%). The positive predictive value of myelography only slightly differed from that of CT (93% vs. 94%). These results were used to establish a sequential diagnostic work-up for patients with radiating leg pain. If, in this population with a high prior probability for surgery, CT had been the investigation of first choice in patients suspected of having LDH, the number of myelographic procedures performed could have been reduced by two-thirds. 
 
 
 
309: Slebus FG, Braakman R, Schipper J, van Dongen KJ, Westendorp-de Seriere M. Non-corresponding radiological and surgical diagnoses in patients operated for sciatica. Acta Neurochir (Wien) 1988;94(3-4):137-43 
 
Department of Neurosurgery, University Hospital Dijkzigt, Erasmus University Rotterdam, The Netherlands. 
 
One hundred and nine patients with radicular leg-pain underwent both computer-tomography and myelography and were subsequently operated upon. The diagnoses on computer-tomogram, myelogram and surgery failed to correspond in 41 cases. Stenosis of the bony spinal canal, scar formation, and an intra- or extraforaminal herniation were the most frequent causes of discrepancy in the diagnoses. In cases of spinal stenosis and previous disc surgery both computer-tomography and myelography have to be performed. Certain precautions taken during computer-tomography and myelography may reduce the number of discrepant findings. 
 
 
310: Szypryt EP, Twining P, Wilde GP, Mulholland RC, Worthington BS. Diagnosis of lumbar disc protrusion. A comparison between magnetic resonance imaging and radiculography. J Bone Joint Surg Br 1988 Nov;70(5):717-22  
 
Spinal Research Unit, Harlow Wood Orthopaedic Hospital, Mansfield, Nottinghamshire, England. 
 
Forty-two consecutive patients with suspected lumbar disc protrusions were studied prospectively to compare the diagnostic accuracy of low-field strength MRI with that of radiculography. Thirty patients subsequently underwent surgical exploration at 33 levels and the operative findings were compared to both methods of diagnostic imaging. All patients had MRI studies, whilst 29 patients also had radiculography. Both studies were evaluated without prior knowledge of the clinical signs, operative findings or the results of other imaging techniques. MRI predicted the correct diagnosis in 29 of the 33 levels explored, an accuracy of 88%. All discs proven to be abnormal demonstrated a reduced signal from the nucleus pulposus. There were two false positive results and two doubtful cases but no false negatives. Radiculography predicted the correct diagnosis in 24 of 32 levels explored, an accuracy of 75%. There were two false positive results, five doubtfuls and one false negative. The overall accuracy when both tests were considered rose to 94%. Of the remaining 12 patients all except one showed good correlation between the MRI and radiculographic findings. These results indicate that low field strength MRI is slightly better than radiculography in diagnosing lumbar disc protrusions. 
 
 
 
312: Bell GR, Rothman RH, Booth RE, Cuckler JM, Garfin S, Herkowitz H, Simeone FA, Dolinskas C, Han SS. A study of computer-assisted tomography. II. Comparison of metrizamide myelography and computed tomography in the diagnosis of herniated lumbar disc and spinal stenosis. Spine 1984 Sep;9(6):552-6  
 
One hundred twenty-two patients with surgically confirmed pathology consisting of either herniated lumbar disc, spinal stenosis, or both were included in this investigation. For each of these patients, preoperative metrizamide myelography and computerized tomography were performed. Each myelogram and CT scan was read blindly so that the neuroradiologist interpreting the study had no knowledge of the patient's surgical pathology, clinical examination, nor any knowledge of the interpretation of the other preoperative test. A painstaking attempt was made to describe precisely both the exact nature of the preoperative myelogram and CT scan interpretations. The correlations between the preoperative interpretation of each test and the observed surgical findings then were analyzed statistically. Based upon this analysis, myelography was found to be more accurate than computed tomography in the diagnosis of herniated lumbar disc (83% vs. 72%). In the diagnosis of spinal stenosis, myelography was slightly more accurate than computed tomography (93% vs. 89%). Based upon the results of this study, the authors conclude that metrizamide myelography is more accurate than computed tomography in the diagnosis of both herniated lumbar disc and spinal stenosis and remains the diagnostic study of choice for these conditions. Furthermore, metrizamide myelography gives the added advantage of visualizing the thoracolumbar junction and, thus, affords the opportunity to diagnose occult spinal tumors. 
 
 
313: Bolender NF, Schonstrom NS, Spengler DM. Role of computed tomography and myelography in the diagnosis of central spinal stenosis. J Bone Joint Surg Am 1985 Feb;67(2):240-6  
 
In order to evaluate radiographic methods for diagnosing central lumbar stenosis, we reviewed the computed tomography scans and myelograms of twenty-four patients who underwent surgical decompression for central lumbar stenosis. In the diagnosis of central lumbar stenosis, the measurement of the anterior-posterior diameter of the osseous canal by computed tomography was less reliable than the measurement of the dural sac by myelography. The dimensions of the canal derived from computed tomography provided a correct diagnosis in 20 per cent of the patients, while myelography was accurate 83 per cent of the time. The effectiveness of computed tomography was improved when the cross-sectional area of the dural sac was measured. We suggest that a narrow dural sac, demonstrated by myelography or by computed tomography, reliably indicates central spinal stenosis. 
 
 
 
314. Epstein NE, Epstein JA, Carras R, Hyman RA. Far lateral lumbar disc herniations and associated structural abnormalities. An evaluation in 60 patients of the comparative value of CT, MRI, and myelo-CT in diagnosis and management. Spine 1990 Jun;15(6):534-9  
 
Department of Surgery, North Shore University Hospital, Manhasset, New York. 
 
The management of 60 patients with far lateral lumbar disc herniations operated on over a 5-year period are presented. These lesions were located superiorly within the neural foramens beneath or distal to the facet joints. The type of surgery performed in 43 of 60 (72%) of these patients was significantly altered by the presence of diffuse and lateral recess stenosis. This was better appreciated on the myelogram and myelo-CT (M-CT) studies than with the noncontrast CT and MRI examinations alone. Myelo-CT findings were particularly valuable in assessing patients who had previous surgical procedures. 
 
 
 
315. Herkowitz HN, Garfin SR, Bell GR, Bumphrey F, Rothman RH. The use of computerized tomography in evaluating non-visualized vertebral levels caudad to a complete block on a lumbar myelogram. A review of thirty-two cases. J Bone Joint Surg Am 1987 Feb;69(2):218-24  
 
In thirty-two patients who demonstrated a complete or almost complete block on a lumbar myelogram, computerized tomography of the non-visualized vertebral levels caudad to the block was performed prior to surgical intervention. The purpose of this study was to evaluate the clinical value of computerized tomography in detecting a lesion that is caudad to the level of a myelographic block. For twenty-three patients the cause of the myelographic block was stenosis of the spine; for five patients, a combination of stenosis of the spine and herniation of a disc; for one patient, herniation of a disc between the fourth and fifth lumbar vertebrae alone; for two patients, arachnoiditis; and for one patient, kyphosis secondary to fracture. A total of fifty vertebral levels that could not be visualized because of the block were evaluated. Thirty (60 per cent) of the non-visualized vertebral levels, in nineteen (59 per cent) of the thirty-two patients, demonstrated stenosis of the spine or a herniated disc that was confirmed at the time of surgical treatment. The value of computerized tomography for the evaluation of the vertebral levels caudad to the level of a complete or almost complete block on a lumbar myelogram was threefold. First, it provided visualization of the vertebral levels that could not be evaluated by the myelography. Second, the findings on computerized tomography provided information that was essential for preoperative planning and it removed the so-called exploratory element from the operative procedure.(ABSTRACT TRUNCATED AT 250 WORDS) 
 
316. Modic MT, Pavlicek W, Weinstein MA, Boumphrey F, Ngo F, Hardy R, Duchesneau PM. Magnetic resonance imaging of intervertebral disk disease. Clinical and pulse sequence considerations. Radiology 1984 Jul;152(1):103-11  
 
Sixty-five patients were examined with magnetic resonance imaging (MR) to determine what combination of operator-selectable controls would result in a thorough examination of the intervertebral disks. There were 20 normal subjects, 8 with degenerative lumbar disk disease, 27 with both degeneration and herniation, 5 with stenosis of the spinal canal, and 5 with disk space infection. T2 was significantly longer in the normal nucleus pulposus than in the degenerated disk. Based on plots of in vivo signal intensity vs. repetition time (TR) for various echo times (TE), a sagittal 30-msec. TE and a 0.25-sec. TR were used for anatomical delineation and rapid localization, while sagittal and/or axial 120-msec. TE/3-sec. TR images were used to evaluate the cerebrospinal fluid and disk. Comparison with radiographs, high-resolution CT scans, and myelograms showed that MR was the most sensitive for identification of degeneration and disk space infection, separating the normal nucleus pulposus from the annulus and degenerated disk. Herniation, stenosis of the canal, and scarring can be identified as accurately with MR as with CT or myelography. 
 
 
317. Schnebel B, Kingston S, Watkins R, Dillin W. Comparison of MRI to contrast CT in the diagnosis of spinal stenosis. Spine 1989 Mar;14(3):332-7  
 
Kerlan-Jobe Orthopedic Clinic, Inglewood, California. 
 
Retrospectively, the MR (magnetic resonance) and contrast CT (computed tomography examinations of 41 patients (123 segments) were objectively scored to evaluate spinal stenosis and disc degeneration. Five categories to evaluate stenosis included the facet joint, foramina, central canal, disc on sagittal section, and disc on axial section. In addition, the ability to demonstrate spondylolysis was compared. The examinations were interpreted by a single observer blinded to the results. Comparisons show 96.6% agreement between MR and contrast CT in the diagnosis of spinal stenosis. Magnetic resonance showed disc degeneration in 74 of 123 segments, while CT showed disc degeneration disease in 27 of 123 segments. Spondylolysis was recognized at three segments on both MR and CT. In conclusion, MR and contrast CT are comparable in their abilities to demonstrate spinal stenosis, and MR is more sensitive in demonstrating disc degeneration. 
 
 
 
318. Schonstrom NS, Bolender NF, Spengler DM. The pathomorphology of spinal stenosis as seen on CT scans of the lumbar spine. Spine 1985 Nov;10(9):806-11  
 
This study examines different morphologic measurements in the evaluation of patients with lumbar spinal stenosis. Preoperative CT scans from 24 patients who underwent surgery for central lumbar stenosis were analyzed. No correlation was observed between the size of the bony spinal canal and the size of the dural sac. A new measurement, the transverse area of the dural sac, is introduced. Normal values are provided. Correlation between the cross-sectional area of the dural sac and the anteroposterior diameter of the dural sac was excellent. 
 
 
 
319. Stockley I, Getty CJ, Dixon AK, Glaves I, Euinton HA, Barrington NA. Lumbar lateral canal entrapment: clinical, radiculographic and computed tomographic findings. Clin Radiol 1988 Mar;39(2):144-9  
 
         Problem Back Unit, Northern General Hospital, Sheffield. 
 
The radiculographic and computed tomographic findings in those nerve roots compressed by lumbar lateral canal entrapment have been assessed in a prospective series of 44 patients in whom such entrapment was found at surgery. The radiological procedures were reported by radiologists who were unaware of the clinical findings. Radiculography was performed in 41 of the patients and enabled the site or sites of entrapment to be correctly predicted in 62% of patients undergoing primary decompression and in 42% of patients undergoing revision surgery. Computed tomography (CT) was performed in 24 of the patients and enabled entrapment to be correctly predicted in 75% of the patients in both groups. We conclude that computed tomography is superior to radiculography in demonstrating lumbar lateral entrapment, and should usually be reserved for patients in whom operation or other intervention is warranted on clinical grounds. Otherwise false positive results may occur, especially in elderly patients, although the true incidence of false positive results in this condition is not known and has not been assessed in this study. 
 
 
 
320. Voelker JL, Mealey J Jr, Eskridge JM, Gilmor RL. Metrizamide-enhanced computed tomography as an adjunct to metrizamide myelography in the evaluation of lumbar disc herniation and spondylosis.Neurosurgery 1987 Mar;20(3):379-84  
 
Eighty patients with operatively proven lumbar disc herniation or lumbar spondylosis were preoperatively evaluated with metrizamide myelography followed by metrizamide-enhanced computed tomography (CT). The x-ray films were reviewed without knowledge of the operative findings, and the patients were subdivided into those with disc extrusions, spondylosis, or recurrent abnormalities. For the group as a whole, CT was correct in 82% and myelography was correct in 77%. Both CT and myelography together were accurate in 91%, a significant improvement (P less than 0.02). The authors conclude that, if both studies are performed, the percentage of cases correctly diagnosed is increased. Therefore, both metrizamide myelography and metrizamide-enhanced CT should be obtained in selected cases. A review of the literature is included. 
 
321. Zlatkin MB, Lander PH, Hadjipavlou AG, Levine JS. Paget disease of the spine: CT with clinical correlation. Radiology 1986 Jul;160(1):155-9  
 
Thirty-six patients with pagetic involvement of the spine were evaluated clinically and by computed tomography (CT). Pagetic phase, modeling expansion, degree and site of spinal stenosis, and pagetic facet joint arthropathy were recorded for each involved vertebral segment. CT demonstrated spinal stenosis in 20 patients, 11 of whom exhibited spinal stenosis on plain films. Twenty-one patients had symptoms of neck or back pain, with associated neurologic dysfunction in 13. Spinal stenosis was present in 81% of the symptomatic patients and 20% of the asymptomatic patients. Severe pagetic facet arthropathy was present in 17 of the symptomatic patients. We conclude that spinal stenosis is an important cause of vertebral pain and neurologic dysfunction. 
 
322. Powell MC, Wilson M, Szypryt P, Symonds EM, Worthington BS. Prevalence of lumbar disc degeneration observed by magnetic resonance in symptomless women. Lancet 1986 Dec 13;2(8520):1366-7  
 
302 women aged 16-80 without symptoms of spinal disease had their lumbar intervertebral discs examined by magnetic resonance. The prevalence of one or more degenerate discs increased linearly with age but disc degeneration was already present in over one-third of women aged 21-40; these young women may prove to be at special risk of disc prolapse later in life. The high prevalence of symptomless disc degeneration must be taken into account when magnetic resonance is used for assessment of spinal symptoms. 
 
 
 
323. Weinreb JC, Wolbarsht LB, Cohen JM, Brown CE, Maravilla KR. Prevalence of lumbosacral intervertebral disk abnormalities on MR images in pregnant and asymptomatic nonpregnant women. Radiology 1989 Jan;170(1 Pt 1):125-8  
 
          Department of Radiology, New York University Medical Center, NY 10016. 
 
The prevalence of lumbosacral intervertebral disk bulge and herniation on sagittal magnetic resonance (MR) images was determined in 45 pregnant subjects and 41 asymptomatic nonpregnant women of childbearing age. MR technique differed for the pregnant and nonpregnant groups. Fifty-three percent of pregnant and 54% of nonpregnant women had an abnormal disk (bulge or herniation) at one or more levels (L3-4, L4-5, or L5-S1). The difference was not statistically significant. There was also no significant difference in the distribution of outcomes among the 45 pregnant subjects, 17 parous nonpregnant women, and 24 nulliparous women. The results suggest that lumbosacral disk bulges or herniations are common in women of childbearing age, whether pregnant or not, and that, contrary to an earlier report, pregnant women do not have an increased prevalence of disk abnormalities. 
 
 
 
327. Walsh TR, Weinstein JN, Spratt KF, Lehmann TR, Aprill C, Sayre H Lumbar discography in normal subjects. A controlled, prospective study. J Bone Joint Surg Am 1990 Aug;72(7):1081-8  
 
             Department of Orthopaedic Surgery, University of Iowa Hospitals and Clinics, Iowa City 52242. 
 
Major advances in the techniques of discography since 1968, in conjunction with major strides in the evaluation of pain in recent years, prompted a study in which Holt's work on the specificity of discography was replicated and extended. For the present study, seven patients who had low-back pain and ten volunteers who had been carefully screened, with a questionnaire and a physical examination, to ensure that they had no history of problems with the back, had an injection at three levels, and all sessions were videotaped. After each injection, the participant was interviewed about the pattern and intensity of the pain, and then the discs were imaged with computed tomography. Five raters, who were blind to the condition of the participant, graded each disc as normal or abnormal on the basis of findings on magnetic resonance images that had been made before the injection and computed tomography (discography) were done. There was only one disagreement between the ratings that were made on the basis of the magnetic resonance images and those that were made on the basis of the discograms. Each participant's pain-related response was evaluated independently by two raters who viewed the videotapes of the discography. Inter-rater reliability was 0.99, 0.93, and 0.88 for the evaluation of intensity of the pain, pain-related behavior, and similarity of the pain to pain that the subject had had before the injection. In the asymptomatic individuals, the discogram was interpreted as abnormal for 17 per cent (five) of the thirty discs and for five of the ten subjects.(ABSTRACT TRUNCATED AT 250 WORDS) 
 
 
327.1 Carragee EJ, Tanner CM, Yang B, Brito JL, Truong T. False-positive findings on lumbar discography. Reliability of subjective concordance assessment during provocative disc injection. Spine 1999 Dec 1;24(23):2542-7  
 
             Stanford University School of Medicine, California, USA. 
 
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. 
 
327.2 Carragee EJ. Is lumbar discography a determinate of discogenic low back pain: provocative discography reconsidered. Curr Rev Pain 2000;4(4):301-8  
 
          Stanford University School of Medicine, R-171 Orthopedic Surgery, Stanford, CA 94305, USA.  
 
Provocative lumbar discography was investigated in a series of clinical studies at the Stanford University of Medicine, Stanford, CA. This work demonstrated that pain intensity during disc injection is strongly influenced by the subject's emotional and psychological profiles, chronic pain behavior, and ongoing compensation claims whether the patient has any back pain illness or not. Pain reproduction was also primarily related to penetration of the dye through the outer annulus and could not reliably be used to confirm the location of the pain source. 
 
327.3 Carragee EJ, Chen Y, Tanner CM, Hayward C, Rossi M, Hagle C. Can discography cause long-term back symptoms in previously asymptomatic subjects? Spine 2000 Jul 15;25(14):1803-8  
 
Departments of Orthopedic Surgery, Stanford University School of Medicine, Stanford, California 94305, USA.  
 
STUDY DESIGN: A prospective controlled study of patients without low back pain observed after experimental lumbar discography. OBJECTIVES: To determine whether discography may cause long-term low back symptoms in selected patients. BACKGROUND: Lumbar discography is generally considered safe, although controversial, with few complications. There is little information on long-term follow-up of asymptomatic patients after experimental discography. METHODS: Twenty-six patients without pre-existing low back pain were observed for 1 year after lumbar discography to determine the effects of lumbar discography in three experimental groups: 10 patients who had remote cervical spine surgery with excellent results (pain-free group); 10 patients who had the same surgery with poor results (chronic pain group); and 6 patients who had primary somatization disorders. Two control groups were also observed: a group of patients with somatization disorder who were similarly evaluated but without discography, a group of patients with low back pain observed for 1 year after discography without surgery. RESULTS: In the three experimental groups (no back pain before discography) no subject with normal psychometric testing had persistent pain after discography (0/11), whereas 6 (40%) of 15 with abnormal psychometric test results reported significant new low back pain. None of the pain-free group (0/10), 20% of the chronic neck pain group (2/10), and 66% of the somatization group (4/6) continued to have significant back pain 1 year after injection. Psychological testing and occupational disability strongly predicted continued pain after discography. The control groups had no significant change in low back symptomatology during the year of observation. CONCLUSION: Discography in a subject group without low back pain but with significant emotional and chronic pain problems may result in reports of significant back pain for at least 1 year after injection. Subjects with normal psychometric test results had no reports of significant long-term back pain after discography. 
 
327.4  Carragee EJ, Tanner CM, Khurana S, Hayward C, Welsh J, Date E, Truong T, Rossi M, Hagle C. The rates of false-positive lumbar discography in select patients without low back symptoms. Spine 2000 Jun 1;25(11):1373-80; discussion 1381  
 
Department of Orthopedic Surgery, Stanford University School of Medicine, California 94305, USA.  
 
STUDY DESIGN: Experimental disc injections in subjects with no history of low back symptoms. OBJECTIVE: To determine in an experimental setting the relative pain response and pain-related behavior in selected subjects without a history of low back pain undergoing lumbar discography. This study aimed to select a study population that more closely represented patients undergoing discography in clinical practice. SUMMARY OF BACKGROUND DATA: Previous work has shown that in young, healthy men with little degenerative disc disease and no history of low back problems, discographic injections usually did not cause significant pain. This group differed from the patients who usually undergo discographic evaluation in clinical practice. Most clinical patients are older, have significant degenerative disc disease, have behavioral changes associated with chronic pain, and often have confounding psychosocial troubles. The authors undertook to study discography in subjects without low back pain but with clinical profiles similar to patients undergoing discography in clinical practice. METHODS: Twenty-six individuals, mean age 43 years, with no history of low back pain had lumber discography according to the strict protocol of Walsh et al. Of these, 10 were pain-free; 10 had chronic neck and arm pain, but no low back symptoms; and 6 had primary somatization disorders without low back symptoms.- RESULTS: Significant positive pain response and pain-related behavior with discography were found in 10% of the pain-free group, in 40% of the chronic cervical pain group, and in 83% of the somatization disorder group completing the injections. Twenty-four subjects had negative control discs. Discs with annular disruption were more likely to be painful on injection, particularly in those individuals with ongoing compensation issues, chronic pain, or abnormal psychological testing.- CONCLUSION: If strict criteria are applied, the rate of false-positive discography may be low in subjects with normal psychometric profiles and without chronic pain. Significantly painful injections were very common in subjects with annular disruption and chronic pain or abnormal psychometric testing. 
 
 
 
327.5  Carragee EJ, Paragioudakis SJ, Khurana S. 2000 Volvo Award winner in clinical studies: Lumbar high-intensity zone and discography in subjects without low back problems. Spine 2000 Dec 1;25(23):2987-92 
 
Division of Orthopaedic Spine Surgery, Stanford University, Stanford, California 94305, USA. Carragee@Leland.Stanford.Edu 
 
STUDY DESIGN: A prospective observational study of patients with low back pain and those without was performed. OBJECTIVE: To investigate the prevalence and significance of a high-intensity zone in a group of patients asymptomatic for low back pain, but who had known risk factors for lumbar disc degeneration. This asymptomatic group was compared with a symptomatic group of patients with respect to the presence of anular high-intensity zone and the pain response with discography. SUMMARY OF BACKGROUND DATA: Some authors have estimated the prevalence of a high-intensity zone in a group of symptomatic patients to be 86%. They have reported a strong correlation between a high-intensity zone and positive discography in patients with low back pain. Other investigators have reported evidence either supporting or discounting these findings. METHODS: Patients with low back pain and those without underwent physical examination, psychometric testing, plain radiograph, magnetic resonance imaging, and discography. The presence of a high-intensity zone, anular disruption, and positive discographic pain then were compared between the two groups. There were strict inclusion criteria for both groups. A total of 109 discs in 42 patients were evaluated in the symptomatic group and compared with 143 discs in 54 patients in the asymptomatic group. The presence of a high-intensity zone was determined by a standardized criteria on T2-weighted magnetic resonance images. Psychometric testing also was administered to each patient before discography. Standard discography was performed on all the patients, and the pain response was recorded using a visual analog scale according to the Walsh et al criteria. RESULTS: The prevalence of a high-intensity zone in the patient populations was 59% in the symptomatic group and 24% in the asymptomatic group. In the symptomatic group, 33 (30.2%) of 109 discs were found to have a high-intensity zone. In the asymptomatic group, 13 of 143 discs were found to have a high-intensity zone. In the symptomatic group, 72.7% of the discs with a high-intensity zone were positive on discography, whereas 38.2% of the discs without a high-intensity zone were positive. In the asymptomatic group, 69.2% of the discs with a high-intensity zone were positive on discography, whereas 10% of the discs without a high-intensity zone were positive. In the patients with normal psychometric testing, 50% of the discs with a high-intensity zone were positive on discography, as compared with 100% positive discography results in patients with abnormal psychometric testing or chronic pain. CONCLUSIONS: The presence of a high-intensity zone does not reliably indicate the presence of symptomatic internal disc disruption. Although higher in symptomatic patients, the prevalence of a high-intensity zone in asymptomatic individuals with degenerative disc disease (25%) is too high for meaningful clinical use. When injected during discography, the same percentage of asymptomatic and symptomatic discs with a high-intensity zone were shown to be painful. 
 
327.6  Carragee EJ, Alamin TF, Miller J, Grafe M. Provocative discography in volunteer subjects with mild persistent low back pain. Spine J. 2002 Jan-Feb;2(1):25-34 
 
Stanford University School of Medicine, Stanford, CA 94305, USA. carragee@leland.stanford.edu 
 
BACKGROUND CONTEXT: Whether discographic injections would be positive in subjects with benign persistent "backache" who are not seeking treatment is unknown. This information is important, because benign backache undoubtedly co-exists in patients with chronic low back pain (CLBP) illness that is not discogenic in origin. If these subjects had a high rate of positive discography, the high background incidence of common backache would allow many positive tests in patients in whom discogenic processes were unrelated to their severe CLBP illness. Conversely, if subjects with benign low back pain rarely if ever had significant concordant pain reproduction on disc injections, the basic tenet of discographic diagnosis would be strengthened. PURPOSE: To compare, using a strict experimental design, the relative pain and concordancy response to provocative discography in subjects with clinically insignificant "backache" and clinical subjects with CLBP illness considering surgical treatment. STUDY DESIGN: Comparison of experimental disc injections in subjects with persistent mild backache and those with chronic low back pain (CLBP) illness. PATIENT SAMPLE: Twenty-five subjects with mild persistent low back pain (LBP) were recruited for an experimental discography study. Subjects were recruited from a clinical study of patients having had cervical spine surgery. Inclusion criteria required that subjects not be receiving or seeking medical treatment for LBP, be taking no medications for backache, have no activity restrictions because of LBP, and have normal psychometric scores. To more closely approximate the pain behavior in CLBP illness, 50% (12) of the "backache" group were recruited with a chronic painful condition (neck/shoulder) unrelated to the low back. CLBP subjects, patients coming to discography for consideration of surgical treatment, were used as control subjects. OUTCOME MEASURES: Results of discography were determined using the criteria of Walsh et al.: pain response of 3 or greater, two or more pain behaviors, a negative "control" discographic injection, and a similar or exact concordancy rating. METHODS: Discography was performed on experimental subjects and control patients. Experienced raters, who were blinded to control versus experimental status of the subjects, scored the magnetic resonance image, discogram, psychometric tests and discography videotapes of the subjects' pain behavior. RESULTS: Thirteen of 25 volunteer subjects had pain rated as "bad" or worse with disc injection. There were 12 painful and fully concordant disc injections in 9 of these 25 "backache" subjects (36%). These injections met all the Walsh et al. criteria for a positive diagnosis of discogenic pain. All positive discs had annular disruption to or through the outer annulus. Of the 9 subjects with positive discograms, 3 had no chronic pain states and 6 did. All subjects with positive injections had negative control discs. In comparison, in 52 subjects with CLBP illness 38 (73%) had at least one positive disc injection. CONCLUSIONS: In a group of volunteer subjects with persistent "backache," 36% were found to have significant pain on disc injection, which is reported to be concordant with their usual pain. The presence of positive concordant pain responses and negative control discs in 33% of subjects without CLBP illness seriously challenges the specificity of provocative discography in identifying a clinically relevant spinal pathology. 
 
 
 
328: Crawshaw C, Frazer AM, Merriam WF, Mulholland RC, Webb JK. A comparison of surgery and chemonucleolysis in the treatment of sciatica. A prospective randomized trial. Spine 1984 Mar;9(2):195-8  
 
Fifty-two patients with unilateral sciatica caused by intervertebral disc herniation were selected on strict clinical and radiological criteria. All patients had failed to respond to conservative measures. Patients in this trial group randomly were allocated surgery or Chymopapain. During the same period, a further 71 patients, who were put forward for the trial, and did not fulfill the trial criteria, were offered Chymopapain as an alternative to surgery. Both groups were assessed at one month, three months, and one year--progress being recorded by clinical examination and visual analogs. The failure rate in the two Chymopapain groups were comparable, with 52% and 47%, but were significantly higher than the surgical group (11%). Surgery in the failed Chymopapain group frequently was delayed and unrewarding. Failures can be predicted at one month posttreatment, and early surgery may be indicated to prevent chronic scarring. 
 
 
329: Ejeskar A, Nachemson A, Herberts P, Lysell E, Andersson G, Irstam L, Peterson LE. Surgery versus chemonucleolysis for herniated lumbar discs. A prospective study with random assignment. 
Clin Orthop 1983 Apr;(174):236-42  
 
The results of removal of a disc hernia at the L4/L5 level were compared with those obtained by the injection of 4000 IU (2 ml) of chymopapain (Discase) in 29 consecutive patients randomly selected for either treatment. All exhibited severe incapacitating sciatica, and all had a myelogram demonstrating a definite disc hernia. The two groups of patients did not differ significantly with regard to age, sex, or length of history. The total time of general anesthesia was significantly shorter for the injected patients by 20 minutes (p less than 0.01), as was the length of hospitalization, by three days (p less than 0.05). Within five months, eight of the patients receiving chymopapain injections had to be operated on because of unrelieved symptoms. All had definite disc herniae, and in four, a free fragment was found. All patients were seen at the time of dismissal from the hospital and at six and 12 months after operation by an independent observer. Comparisons made at these intervals, following either surgery or chymopapain injection with or without subsequent surgery, did not reveal any significant differences, but the short-term results following either treatment alone significantly (p less than 0.01) favored the surgical approach. (portion of study was patients response to questions by surgeon vs. independent investigator two fold higher scores in response to surgeon than independent investigator) 
 
330: Fraser RD. Chymopapain for the treatment of intervertebral disc herniation. A preliminary report of a double-blind study. Spine 1982 Nov-Dec;7(6):608-12  
 
Sixty patients with unilateral sciatica resulting from lumbar intervertebral disc herniation were entered into a double-blind study. All patients had failed to respond to conservative management, and the diagnosis had been confirmed by metrizamide myelography. Following a randomized schedule, 30 patients had intradiscal injections of chymopapain and 30 patients had intradiscal injections of an equivalent volume of normal saline solution. Complete relief of sciatica was obtained in 63% of patients treated with chymopapain, compared with 27% of saline-injected patients. Six weeks after the injection, 73% of patients treated with chymopapain and 37% of patients treated with saline solution considered that the treatment was successful. The success rate at six months was 80% for patients treated with chymopapain and 57% for saline-injected patients. From the preliminary results of this study, chymopapain is recommended for the treatment of sciatica from intervertebral disc herniation when conservative measures have failed and before disc fragment excision is considered. 
 
331: Fraser RD. Chymopapain for the treatment of intervertebral disc herniation. The final report of a double-blind study. Spine 1984 Nov-Dec;9(8):815-8  
 
Sixty patients with unilateral sciatica resulting from lumbar intervertebral disc herniation were entered into a double-blind study. All patients had failed to respond to conservative management, and the diagnosis had been confirmed by metrizamide myelography. Following a randomized schedule, 30 patients had intradiscal injections of chymopapain, and 30 patients had intradiscal injections of an equivalent volume of normal saline solution. Two years after the injection, 77% of patients treated with chymopapain were assessed as moderately improved, compared with 47% of saline-injected patients. Fifty-seven percent of the chymopapain group were free of pain, compared with 23% in the saline group. Based on the late results of this study, chymopapain is recommended for the treatment of sciatica from intervertebral disc herniation when conservative measures have failed and before disc fragment excision is considered. 
 
 
 
332: Gogan WJ, Fraser RD. Chymopapain. A 10-year, double-blind study. Spine 1992 Apr;17(4):388-94 
 
Department of Orthopaedic Surgery and Trauma, Royal Adelaide Hospital, South Australia. 
 
Sixty patients with sciatica from lumbar intervertebral disc herniation were entered into a double-blind study. Following a randomized schedule, 30 patients were treated with intradiscal chymopapain and 30 patients with intradiscal normal saline. At 10 years, with the patients still unaware of the treatment given, 80% of the chymopapain patients regarded the injection to be successful, compared with 34% for the saline group (P = 0.0006). Laminectomy was required in 20% of the chymopapain patients, compared with 47% of the saline patients (P = 0.028). Seventy-seven percent of the chymopapain group was assessed by a blinded independent observer to be at least moderately improved, compared with 38% for the saline group (P = 0.004). The results of this double-blind study at 10 years demonstrate a sustained therapeutic effect of chymopapain in the treatment of patients with sciatica from lumbar intervertebral disc prolapse. 
 
333: Javid MJ, Nordby EJ, Ford LT, Hejna WJ, Whisler WW, Burton C, Millett DK, Wiltse LL, Widell EH Jr, Boyd RJ, Newton SE, Thisted R. Safety and efficacy of chymopapain (Chymodiactin) in herniated nucleus pulposus with sciatica. Results of a randomized, double-blind study. JAMA 1983 May 13;249(18):2489-94  
 
A double-blind, randomized trial was conducted to compare the efficacy of intradiskal injection of chymopapain (Chymodiactin) with injection of placebo in patients with a herniated lumbar disk. Patients were randomly assigned to either placebo or drug regimens and followed up for six months. The primary measure of performance was agreement by patient and surgeon that further intervention was not necessary. At any time that patient and investigator agreed that treatment had failed, the patient was classified as a failure and the treatment code was broken. Of 53 placebo-treated patients, 31 failed by this criterion. Of 55 drug-treated patients, 15 failed. Placebo-treated patients who failed were allowed to receive drug treatment, and 29 (91%) of 32 were treated successfully. This study demonstrates that chymopapain is more effective than placebo for treatment of patients with a herniated lumbar disk. 
 
334: Revel M, Payan C, Vallee C, Laredo JD, Lassale B, Roux C, Carter H, Salomon C, Delmas E, Roucoules J, et al. Automated percutaneous lumbar discectomy versus chemonucleolysis in the treatment of sciatica. A randomized multicenter trial. Spine 1993 Jan;18(1):1-7  
 
Department of Rheumatology, Hopital Cochin, Paris, France. 
 
A randomized clinical trial was conducted to compare the results of automated percutaneous discectomy with those of chemonucleolysis in 141 patients with sciatica caused by a disk herniation; 69 underwent automated percutaneous discectomy and 72 were subjected to chemonucleolysis. The principle outcome was the overall assessment of the patient 6 months after treatment. Treatment was considered to be successful by 61% of the patients in the chemonucleolysis group compared with 44% in the automated percutaneous discectomy group. At 1-year follow-up, overall success rates were 66% in the chemonucleolysis group and 37% in the automated percutaneous group. Within 6 months of treatment, 7% of the patients in the chemonucleolysis group and 33% in the discectomy group underwent subsequent open surgery. The complication rates of both treatment groups were low, with the exception of a high rate of low-back pain in the chemonucleolysis group (42%). The results of this trial confirm previous controlled studies on chemonucleolysis and suggest that controlled studies should be carried out before automated percutaneous discectomy can be considered a useful intervention. 
 
335: Tullberg T, Isacson J, Weidenhielm L. Does microscopic removal of lumbar disc herniation lead to better results than the standard procedure? Results of a one-year randomized study. Spine 1993 Jan;18(1):24-7  
 
Department of Orthopaedic Surgery, St. Goran's Hospital, Stockholm, Sweden. 
 
Sixty patients with single-level lumbar disc herniation confirmed by computerized tomography were studied in a randomized prospective study. The aim was to see if there was any difference between the microscopic removal of a disc herniation and the standard procedure. All patients were operated on by the same surgeon by either method. They were all followed up by an impartial observer at 3 weeks, 2 months, 6 months, and 1 year. There were no differences between the groups regarding perioperative bleeding, complications, inpatient stay, time off work, or end result. The authors concluded that the decision to use the operating microscope may be left to the surgeon, because it had no effect on the short-term results or those at 1 year. 
 
 
 
336: van Alphen HA, Braakman R, Bezemer PD, Broere G, Berfelo MW. Chemonucleolysis versus discectomy: a randomized multicenter trial. J Neurosurg 1989 Jun;70(6):869-75 
 
Department of Neurosurgery, Free University Hospital, Amsterdam, The Netherlands. 
 
A randomized clinical trial was carried out to compare the results of open discectomy with those of chemonucleolysis in 151 patients suffering from a disc herniation at L4-5 or L5-S1. All patients fulfilled strict entry criteria; 78 patients underwent open discectomy and 73 were subjected to chemonucleolysis. An increase in radicular pain immediately after treatment was encountered in 16 patients (22%) in the chemonucleolysis group, as compared to none in the discectomy group. The efficacy of discectomy appeared to be definitely superior to that of chemonucleolysis. Within a follow-up period of 1 year, 18 patients (25%) required open discectomy following failed chemonucleolysis; two patients (3%) in the discectomy group needed a second operation. Open discectomy following previous chemonucleolysis was successful in only 44% of cases. Comparison of the final results of the two modes of treatment 12 months after the last intervention (including second treatment) did not reveal any significant differences. The duration of the preoperative symptoms, the level of disc herniation, and the leakage of contrast medium out of the disc appeared to be of no relevance to the final outcome. The complication rates in both treatment groups were low. 
 
337: Watters WC 3d, Mirkovic S, Boss J. Treatment of the isolated lumbar intervertebral disc herniation: microdiscectomy versus chemonucleolysis. Spine 1988 Mar;13(3):360-2  
 
Baylor College of Medicine, Houston, Texas. 
 
A long-term goal of spine surgeons has been to reduce the morbidity, cost, and recuperative period of primary lumbar disc surgery. In this paper, microdiscectomy and chemonucleolysis are evaluated and compared with respect to achieving these goals. Two groups of successive, noncompensation patients numbering 50 each were studied. All patients met standard clinical and imaging criteria for an isolated lumbar vertebral disk herniation. One group was treated with chemonucleolysis and the second with micodiscectomy. Average follow-up exceeded 3 years. While both treatment groups achieved the stated goal when compared with traditional laminectomy, the microdiscectomy groups demonstrated statistically superior treatment results, with reduced time to return to work, and fewer required subsequent surgical procedures. 
 
 
 
338: Weber H. The effect of delayed disc surgery on muscular paresis. Acta Orthop Scand 1975 Sep;46(4):631-42  
 
A prospective study was carried out in 280 patients suffering from sciatica caused by myelographically verified disc prolapse. The patients were divided into three groups according to the following criteria: 1. The doubtful group, selected at random. Patients with doubtful indications for surgery. Treated operatively or not--by drawing lots. 2. Non-operated group. Patients with moderate symptoms and/or continued improvement. 3. Operated group. Patients with imperative indications for surgery. The muscle strength of the lower limbs was measured during maximal isometric voluntary contractions in all the patients 2 weeks after admission. Approximately 50 per cent had paresis. Control examinations of these patients 1 year later showed that operative treatment gave no better prognosis than conservative treatment with regard to the motor function, neither in the group chosen at random nor in the selected groups. The causative factors are discussed. 
 
 
 
339  Weber H. Lumbar disc herniation. A controlled, prospective study with ten years of observation. Spine 1983 Mar;8(2):131-40  
 
Two hundred eighty patients with herniated lumbar discs, verified by radiculography, were divided into three groups. One group, which mainly will be dealt with in this paper, consisted of 126 patients with uncertain indication for surgical treatment, who had their therapy decided by randomization which permitted comparison between the results of surgical and conservative treatment. Another group comprising 67 patients had symptoms and signs that beyond doubt, required surgical therapy. The third group of 87 patients was treated conservatively because there was no indication for operative intervention. Follow-up examinations in the first group were performed after one, four, and ten years. The controlled trial showed a statistically significant better result in the surgically treated group at the one-year follow-up examination. After four years the operated patients still showed better results, but the difference was no longer statistically significant. Only minor changes took place during the last six years of observation. 
 
339.1  Weber H. The natural history of disc herniation and the influence of intervention. Spine 1994 Oct 1;19(19):2234-8; discussion 2233  
 
Department of Neurology, Ullevaal Hospital, Oslo, Norway. 
 
The natural history of lumbar disc herniation must be considered when evaluating the influence and outcome of intervention. The combination of clinical signs and symptoms and corresponding radiologic findings permits a more certain diagnostic conclusion compared with many other obscure back disorders. The relationship between low back pain and a herniated disc is unclear. Mechanical compression and chemical changes may be the source of nerve root symptoms. Studies have shown that the natural course of acute radiculopathy has a good prognosis. Bed rest, information, and analgesics usually are sufficient therapeutic measures. Prolongation of symptoms requires radiologic examination. The decision regarding continued conservative therapy versus surgical intervention must be evaluated. Chemonucleolysis and percutaneous nucleotomy are being used, but the indications are uncertain. 
 
340: Hoffman RM, Wheeler KJ, Deyo RA. Surgery for herniated lumbar discs: a literature synthesis. J Gen Intern Med 1993 Sep;8(9):487-96  
 
Medical Service, Seattle Veterans Affairs Medical Center, Washington. 
 
OBJECTIVE: To assess the risks and benefits of surgery for herniated lumbar discs (discectomy) and to evaluate the methodologic quality of the literature. DESIGN: Literature synthesis. STUDY SELECTION AND DATA ANALYSIS: A structured MEDLINE search identified studies of standard, microsurgical, or percutaneous discectomy. Eligible studies had adult subjects, sample sizes of > or = 30, clinical outcome data for > or = 75% of patients, and follow-up of > or = 1 year. Summary rates of successful outcomes, reoperations, and complications were obtained by a random-effects logistic regression model. Methodologic quality was assessed using established study design criteria. RESULTS: Eighty-one studies met inclusion criteria. Most had substantial design flaws and/or omitted important clinical data. Randomized trials of standard discectomy showed better short-term sciatica relief following surgery; 65% to 85% of patients reported no sciatica one year after surgery, compared with only 36% of conservatively treated patients. No data from randomized trials were available for microdiscectomy or percutaneous discectomy, although most outcomes appeared comparable to those of standard discectomy. Approximately 10% of discectomy patients underwent further back surgery, and rates increased over time. The rate of serious complications, including death and permanent neurologic damage, was less than 1%. CONCLUSIONS: Most studies were poorly designed and reported. Standard discectomy appears to offer better short-term outcomes than does conservative treatment, but long-term outcomes are similar. Discectomies are relatively safe procedures, though reoperations are common and increase over time. Decisions for elective surgery must balance faster pain relief against the risks and costs of surgery. 
 
341: Agre K, Wilson RR, Brim M, McDermott DJ. Chymodiactin postmarketing surveillance. Demographic and adverse experience data in 29,075 patients. Spine 1984 Jul-Aug;9(5):479-85  
 
Postmarketing surveillance data on 29,075 patients who received Chymodiactin (Smith Laboratories' formulation of chymopapain) intradiscal injections for a herniated lumbar intervertebral disc are summarized and tabulated. The serious adverse reactions reported include death, anaphylaxis, paraplegia, and discitis. Similar problems also have been reported for Discase (Baxter-Travenol's formulation of chymopapain). Of 11 deaths reported following Chymodiactin administration, only 3 appear to be related to the drug or procedure. Two of these three were due to anaphylaxis and the third to bacterial discitis with resultant meningitis. Paraplegia appeared to be primarily due to needle trauma or injection of contrast agent and enzyme into the subarachnoid space. Careful patient selection and needle placement are essential for avoiding serious problems. 
 
342: Alexander AH, Burkus JK, Mitchell JB, Ayers WV. Chymopapain chemonucleolysis versus surgical discectomy in a military population. Clin Orthop 1989 Jul;(244):158-65  
 
Department of Orthopaedic Surgery Naval Hospital, Oakland, CA 94627-5000. 
 
From 1983 to 1987, 100 consecutive patients with lumbar herniated nucleus pulposus were treated with either chymopapain chemonucleolysis (51 patients) or surgical discectomy (49 patients). The chymopapain-treated group was followed for an average of 16 months and the surgically treated group was followed for an average of 12 months. All patients had to be candidates for both procedures and were grouped for therapy based on their preference. The groups were similar in military duty status, history, age, gender, duration and character of symptoms, physical findings, and computed tomography/myelogram results. Satisfactory outcomes were achieved in 40 of 51 (78%) chymopapain-treated patients and in 39 of 49 (80%) surgically treated patients. Seventy-eight percent of the chymopapain group and 79% of the surgery group ultimately returned to full military duty. Of the nine initial chymopapain failures, eight were successfully treated with surgical discectomy. There were fewer complications, 4% versus 10%, in the chymopapain group. The authors now consider chemonucleolysis as the final conservative measure prior to surgery, rather than an alternative to surgical discectomy. 
 
343: Bouillet R. Treatment of sciatica. A comparative survey of complications of surgical treatment and nucleolysis with chymopapain. Clin Orthop 1990 Feb;(251):144-52  
 
Orthopedic Department, Institut Chirurgical de Bruxelles, Belgium. 
 
Chymopapain in the treatment of sciatica by chemonucleolysis has become widespread in the United States and Europe since the approval of this drug for general use by the Food and Drug Administration. Potentially, the increased use of this drug by surgeons with relatively little experience could be expected to cause an increase in the complication rate. This report analyzes the results of a questionnaire sent to surgeons in 316 departments who have recently treated a total of 43,662 patients with this technique. The complication rate was 3.7% (1606 incidents). Of these, 192 (0.45%) were severe. The study revealed that the frequency of severe allergic reactions is lower in Europe than in the United States. Twice the number of anaphylactic reactions occurred with local and neuroleptic anesthesia compared to local or general anesthesia alone. The risk of infectious discitis is low, but a strict sterile technique is mandatory. Neurologic complications were rare, but included 15 cauda equina, one meningeal hemorrhage, a case of epilepsy, and two cases of paraplegia. The rate of complications in this study is comparable to two previous studies; thus, the expected increase in complications has not occurred. For comparison, a survey of 2051 patients treated surgically showed a complication rate of 26% (534 incidents), including 86 (4.2%) severe complications. Among the surgically treated patients, there was a perioperative complication rate of 9.75% (200 incidents) and a postoperative complication rate of 14% (290 incidents), resulting in three deaths. Thus, the surgical treatment was responsible for six times the number of incidents and ten times more severe incidents than for patients treated by nucleolysis. 
 
345: Deyo RA, Cherkin DC, Loeser JD, Bigos SJ, Ciol MA. Morbidity and mortality in association with operations on the lumbar spine. The influence of age, diagnosis, and procedure. J Bone Joint Surg Am 1992 Apr;74(4):536-43  
 
Department of Medicine, University of Washington, Seattle 98195. 
 
We examined the rates of postoperative complications and mortality, as recorded in a hospital discharge registry for the State of Washington for the years 1986 through 1988, for patients who had had an operation on the lumbar spine. When patients who had had a malignant lesion, infection, or fracture are excluded, there were 18,122 hospitalizations for procedures on the lumbar spine, 84 per cent of which involved a herniated disc or spinal stenosis. The rates of morbidity and mortality during hospitalization, as well as the hospital charges, increased with the ages of the patients. The rate of complications was 18 per cent for patients who were seventy-five years or older. Nearly 7 per cent of patients who were seventy-five years old or more were discharged to nursing homes. Complications were most frequent among patients who had spinal stenosis, but multivariate analysis suggested that the complications associated with procedures for this condition were primarily related to the patient's age and the type of procedure. Complications, length of hospitalization, and charges were higher for patients who had had a spinal arthrodesis than for those who had not. Over-all, operations for conditions other than a herniated disc were associated with more complications and greater use of resources, particularly when arthrodesis was performed, than were operations for removal of a herniated disc. No data on symptoms or functional results were available. 
 
 
 
346: Herkowitz HN, Kurz LT. Degenerative lumbar spondylolisthesis with spinal stenosis. A prospective study comparing decompression with decompression and intertransverse process arthrodesis. J Bone Joint Surg Am 1991 Jul;73(6):802-8  
 
Department of Orthopaedic Surgery, William Beaumont Hospital, Royal Oak, Michigan. 
 
Fifty patients who had spinal stenosis associated with degenerative lumbar spondylolisthesis were prospectively studied clinically and radiographically to determine if concomitant intertransverse-process arthrodesis provided better results than decompressive laminectomy alone. There were thirty-six women and fourteen men. The mean age of the twenty-five patients who had had an arthrodesis was 63.5 years and that of the twenty-five patients who had not had an arthrodesis, sixty-five years. The level of the operation was between the fourth and fifth lumbar vertebrae in forty-one patients and between the third and fourth lumbar vertebrae in nine patients. The patients were followed for a mean of three years (range, 2.4 to four years). In the patients who had had a concomitant arthrodesis, the results were significantly better with respect to relief of pain in the back and lower limbs. 
 
346a: Fischgrund JS, Mackay M, Herkowitz HN, Brower R, Montgomery DM, Kurz LT. 1997 Volvo Award winner in clinical studies. Degenerative lumbar spondylolisthesis with spinal stenosis: a prospective, randomized study comparing decompressive laminectomy and arthrodesis with and without spinal instrumentation. Spine 1997 Dec 15;22(24):2807-12 
 
William Beaumont Hospital, Department of Orthopaedic Surgery, Royal Oak, Michigan, USA. 
 
STUDY DESIGN: This prospective study analyzed the influence of transpedicular instrumented on the operative treatment of patients with degenerative spondylolisthesis and spinal stenosis. OBJECTIVES: To determine whether the addition of transpedicular instrumented improves the clinical outcome and fusion rate of patients undergoing posterolateral fusion after decompression for spinal stenosis with concomitant degenerative spondylolisthesis. SUMMARY OF BACKGROUND DATA: Decompression is often necessary in the treatment of symptomatic patients who have degenerative spondylolisthesis and spinal stenosis. Results of recent studies demonstrated that outcomes are significantly improved if posterolateral arthrodesis is performed at the listhesed level. A meta-analysis of the literature concluded that adjunctive spinal instrumentation for this procedure can enhance the fusion rate, although the effect on clinical outcome remains uncertain. METHODS: Seventy-six patients who had symptomatic spinal stenosis associated with degenerative lumbar spondylolisthesis were prospectively studied. All patients underwent posterior decompression with concomitant posterolateral intertransverse process arthrodesis. The patients were randomized to a segmental transpedicular instrumented or noninstrumented group. RESULTS: Sixty-seven patients were available for a 2-year follow-up. Clinical outcome was excellent or good in 76% of the patients in whom instrumentation was placed and in 85% of those in whom no instrumentation was placed (P = 0.45). Successful arthrodesis occurred in 82% of the instrumented cases versus 45% of the noninstrumented cases (P = 0.0015). Overall, successful fusion did not influence patient outcome (P = 0.435). CONCLUSIONS: In patients undergoing single-level posterolateral fusion for degenerative spondylolisthesis with spinal stenosis, the use of pedicle screws may lead to a higher fusion rate, but clinical outcome shows no improvement in pain in the back and lower limbs. 
 
348: Katz JN, Lipson SJ, Larson MG, McInnes JM, Fossel AH, Liang MH. The outcome of decompressive laminectomy for degenerative lumbar stenosis. J Bone Joint Surg Am 1991 Jul;73(6):809-16  
Brigham and Women's Hospital, Robert B. Brigham Multipurpose Arthritis Center, Boston, Massachusetts 02115. 
 
The outcome of laminectomy for the relief of symptoms resulting from degenerative lumbar stenosis is not well established. Eighty-eight consecutive patients who had had a laminectomy for degenerative lumbar stenosis between 1983 and 1986 were studied. Eight of the patients had had a concomitant arthrodesis. The follow-up evaluation included a review of charts and standardized questionnaires that were completed by the patients. One year postoperatively, five patients (6 per cent) had had a second operation and five still had severe pain. By the time of the latest follow-up, in 1989, fifteen (17 per cent) of the original eighty-eight patients had had a repeat operation because of instability or stenosis; twenty-one (30 per cent) of the seventy patients who were evaluated by questionnaire in 1989 had severe pain. The factors found to be associated with a poor long-term outcome, defined as severe pain or the need for a repeat operation, or both, included co-existing illnesses (such as osteoarthrosis, cardiac disease, rheumatoid arthritis, or chronic pulmonary disease) (p = 0.004), the duration of follow-up (p = 0.01), and an initial laminectomy involving a single interspace (p = 0.04). We concluded that the long-term outcome of decompressive laminectomy is less favorable than has been previously reported, and that co-morbidity and a single-interspace laminectomy are risk factors for a poor outcome. 
 
 
 
348c: Katz JN, Stucki G, Lipson SJ, Fossel AH, Grobler LJ, Weinstein JN Predictors of surgical outcome in degenerative lumbar spinal stenosis. Spine 1999 Nov 1;24(21):2229-33  
 
Division of Rheumatology, Immunology, and Allergy, Brigham and Women's Hospital, Boston, Massachusetts, USA. jnkatz@bics.bwh.harvard.edu 
 
STUDY DESIGN: A prospective, observational study. OBJECTIVES: To identify outcome predictors of surgery for degenerative lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: Degenerative lumbar spinal stenosis is the most frequent indication for spine surgery in the elderly. More than 25% of surgical patients have a poor outcome, yet little is known about factors that predict the outcome of surgery. METHODS: Surgery was performed on 199 patients with degenerative lumbar spinal stenosis, and they were observed for 2 years after surgery in four referral centers. Surgery consisted of decompressive laminectomy with or without arthrodesis. Outcomes included validated measures of symptom severity, walking capacity, and satisfaction with the results of surgery. Potential predictors of outcome included sociodemographic factors and physical examination, as well as radiographic, psychological, social, and clinical history variables. RESULTS: The proportion of patients with severe pain decreased from 81% before surgery to 31% by 2 years afterward. The most powerful preoperation predictor of greater walking capacity, milder symptoms, and greater satisfaction was the patient's report of good or excellent health before surgery. Low cardiovascular comorbidity also predicted a favorable outcome. CONCLUSIONS: Patient's assessments of their own health and comorbidity are the most cogent outcome predictors of surgery for spinal stenosis. 
 
348b: Katz JN, Lipson SJ, Chang LC, Levine SA, Fossel AH, Liang MH. Seven- to 10-year outcome of decompressive surgery for degenerative lumbar spinal stenosis.. Spine 1996 Jan 1;21(1):92-8  
Departments of Rheumatology and Immunology, Brigham and Women's Hospital, Boston, MA, USA. 
 
STUDY DESIGN: Retrospective review and prospective follow-up of 88 patients who had decompressive laminectomy with or without fusion from 1983 to 1986. OBJECTIVE: To determine the 7- to 10-year outcome of surgery for degenerative lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: There is limited information on the impact of surgery for lumbar spinal stenosis on symptoms, walking ability, and satisfaction, as well as reoperation. METHODS: Patients completed standardized questionnaires in 1993 that included items about reoperations, back pain, leg pain, walking capacity, and satisfaction with surgery. Associations between preoperative demographic and clinical variables and outcomes 7 to 10 years after surgery were evaluated in univariate and multivariate analyses. RESULTS: Average preoperative age was 69 years and eight patients received fusion. Of 88 patients in the original cohort, 20 (23%) were deceased and 20 (23%) had undergone reoperation by 7- to 10-year follow-up. Fifty-five patients answered questionnaires. Average duration of follow-up was 8.1 years. Thirty-three percent of the respondents had severe back pain at follow-up, 53% were unable to walk two blocks, and 75% were satisfied with the results of surgery. The severity of current spine-related symptoms was a stronger correlate of physical functional status at the time of follow-up than age or nonspinal comorbid conditions. CONCLUSIONS: Seven to 10 years after decompressive surgery for spinal stenosis, 23% of patients had undergone reoperation and 33% of respondents had severe back pain. Despite a high prevalence of nonspinal problems in this elderly cohort, spinal symptoms were the most important correlate of reduced functional status. 
 
349: Lee CK, deBari A Lumbosacral spinal fusion with Knodt distraction rods. Spine 1986 May;11(4):373-5  
 
Knodt distraction rods have been used in conjunction with lumbar spinal decompression and/or fusion to open the intervertebral foramen. A review was undertaken to evaluate the efficacy of the Knodt Rods in 24 patients with multiple level foramenal canal stenosis. All 24 patients were treated by wide decompressive laminectomy, foramenotomies and bilateral-lateral fusion. One half of those 24 patients were treated with supplemental Knodt Rods and the other half was treated without Knodt Rods. Pre- and post-operative radiologic and clinical results were compared between the two groups. Although there were definitive roentgenographic trends that Knodt Rods provided flexion of the spine and more opening of the intervertebral foramina, there was no significant clinical benefit from the use of the Knodt Rods compared with those without Knodt Rods. 
 
8 Prospective Studies needed 
 
350: White AH, von Rogov P, Zucherman J, Heiden D. Lumbar laminectomy for herniated disc: a prospective controlled comparison with internal fixation fusion. Spine 1987 Apr;12(3):305-7  
 
This is a controlled prospective study on a matched set of patients with herniated lumbar discs. Both groups received the same bilateral lumbar laminectomy and disc excision by the same surgeon. One group had the addition of an intertransverse fusion with internal fixation. Both groups were studied by an independent examiner at an average of 3 years postoperatively for success rate as determined by activity level, medication, subjective and objective evaluation. Both groups had similar age, sex, and occupational characteristics. No patient had prior surgical treatment or chemonucleolysis. Patients with associated lumbar spine problems such as stenosis, instability, or spondylolisthesis were excluded. Each patient had a positive clinical picture for a herniated lumbar disc, as well as a positive myelogram, venogram or computerized tomographic scan. Most had positive electromyograms. All patients received at least 3 months of conservative care. The 38 patients with fusion had a significantly longer mean time to return to work after surgery versus the 31 patients without fusion. Although the general success rate of both groups was 87%, the best results were in the nonfusion group. A total of 29% of nonfusions had excellent results whereas only 11% of the fusion group had excellent results. The conclusion is that fusions are not necessary and give less excellent results in simple laminectomy cases for herniated lumbar disc. 
 
351: Turner JA, Ersek M, Herron L, Haselkorn J, Kent D, Ciol MA, Deyo R. Patient outcomes after lumbar spinal fusions. JAMA 1992 Aug 19;268(7):907-11  
 
Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle 98195. 
 
OBJECTIVES--To determine success and complication rates for lumbar spinal fusion surgery, predictors of good outcomes, and whether fusion improves success rates of laminectomy for specific low back disorders. DATA SOURCES--English-language journal articles published from 1966 through April 1991, identified through MEDLINE searching (spinal fusion plus limiting terms), bibliography review, and expert consultation. STUDY SELECTION--Articles were selected only if they reported at least 1 year of follow-up data enabling the classification of clinical outcomes as satisfactory or unsatisfactory for at least 30 patients. DATA EXTRACTION--Two reviewers independently extracted data on patient characteristics, surgical methods, patient outcomes, and quality of study methods. DATA SYNTHESIS--Of 47 articles, there were no randomized trials. Four nonrandomized studies compared surgery with and without fusion for herniated disks; three found no advantage for fusion. On average, 68% of patients had a satisfactory outcome after fusion, but the range was wide (16% to 95%), and the satisfactory outcome rate was lower in prospective than in retrospective studies. The most frequently reported complications were pseudarthrosis (14%) and chronic pain at the bone graft donor site (9%). Clinical outcomes did not differ by diagnosis or fusion technique, but were worse in studies with a greater number of previously operated patients. CONCLUSIONS--For several low back disorders no advantage has been demonstrated for fusion over surgery without fusion, and complications of fusions are common. Randomized controlled trials are needed to compare fusion, surgery without fusion, and nonsurgical treatments in rigorously defined patient groups. 
 
351a: Turner JA, Ersek M, Herron L, Deyo R. Surgery for lumbar spinal stenosis. Attempted meta-analysis of the literature. Spine 1992 Jan;17(1):1-8  
 
       Dept of Psychiatry and Behavioral Sciences, University of Washington, Seattle. 
 
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 reported to have good-to-excellent outcomes. However, there was wide variation across studies in the percentage with good outcomes. Few patient characteristics were found to predict outcome. Major deficits in study design, analysis, and reporting were common, and these precluded firm conclusions. 
 
352: A longitudinal, prospective study of industrial back injury reporting. Bigos SJ, Battie MC, Spengler DM, Fisher LD, Fordyce WE, Hansson T, Nachemson AL, Zeh J. Clin Orthop 1992 Jun;(279):21-34  
 
Department of Orthopaedics, University of Washington, Seattle. 
 
The authors prospectively evaluated 3020 volunteers of the Boeing-Everett plant to assess risk factors that predispose workers to file industrial back injury claims. During four years of follow-up observation, more than 279 subjects reported acute back problems. The effect of the only predictive physical variable was explainable by a history of medical treatment. The most predictive individual factors were (1) job task dissatisfaction and (2) distress as reported on Scale 3 of the Minnesota Multiphasic Personality Inventory (MMPI). This data perhaps explains why the focus on purely physical and injury-related factors has met with little success in dealing with what has become the most expensive orthopedic problem. Clinically, nonphysical factors that significantly impact the reporting of back injuries may also affect patients' responses to medical treatment. 
 
352a: Bigos SJ, Battie MC, Fisher LD, Hansson TH, Spengler DM, Nachemson AL. A prospective evaluation of preemployment screening methods for acute industrial back pain. Spine 1992 Aug;17(8):922-6  
 
Department of Orthopaedics, University of Washington, Seattle. 
 
Preemployment screening methods have been ineffective in predicting those at risk, and in curbing the impact of back problems in industry. Such methods have centered on individual physical factors (capacities and clinical examination). This study evaluates commonly used physical examination measures and simple historical data for its ability to predict individuals at risk for future back injury reporting in the aircraft industry. In this study, once simple historical information about previous pain treatment was known, information gained from physical factors added no significant predictive value. 
 
352b: Krause N, Ragland DR, Fisher JM, Syme SL. Psychosocial job factors, physical workload, and incidence of work-related spinal injury: a 5-year prospective study of urban transit operators. Spine 1998 Dec 1;23(23):2507-16 
 
Division of Epidemiology, School of Public Health, University of California, Berkeley, USA. 
 
STUDY DESIGN: Five-year prospective cohort study of 1449 transit operators. OBJECTIVES: To investigate psychosocial job factors as predictors of work-related spinal injuries, controlling for current and past physical workload. SUMMARY OF BACKGROUND DATA: The association between psychosocial job factors and spinal disorders may be confounded by physical workload. A 1991 prospective study of Boeing workers found psychosocial but not physical factors to be associated with spinal injuries. However, data on physical workload were limited. Recent cross-sectional studies of transit drivers showed both physical and psychosocial factors to be independently associated with back and neck pain. This study was designed to test these findings prospectively. METHODS: Spinal injuries were ascertained from workers' compensation records, employment history from company records, and psychosocial factors from questionnaires. Logistic regression models adjusted for age, gender, height, weight, vehicle type, and current and past physical workload. RESULTS: During follow-up, 320 drivers reported a first spinal injury. Spinal injury was predicted by psychological job demands (odds ratio [OR], 1.50; 95% confidence interval [CI], 1.33-1.95); job dissatisfaction (OR, 1.56; 95% CI, 1.09-2.23); and the frequency of job problems (OR, 1.52; 95% CI, 1.02-2.26). Marginally significant associations were found for low supervisor support (OR, 1.30; 95% CI, 0.99-1.72) and female gender (OR, 1.49; 95% CI, 0.95-2.32). Compared with full-time work, part-time work was associated with a 2.7-fold reduced risk for spinal injury (OR, 0.37; 95% CI, 0.15-0.93). Cable car crews performing the heaviest physical labor had a threefold increased risk of spinal injury compared with bus drivers (OR, 3.04; 95% CI, 1.85-5.00). CONCLUSIONS: Physical workload and psychosocial job factors both independently predict spinal injury in transit vehicle operators. 
 
353: Eie N. Comparison of the results in patients operated upon for ruptured lumbar discs with and without spinal fusion. Acta Neurochir (Wien) 1978;41(1-3):107-13  
 
A comparative study of 259 patients operated on for ruptured lumbar discs, with and without spinal fusion, has been carried out. Simple removal of the herniated nucleus pulposus was performed in 119 patients while 68 were subjected to combined removal of the herniated disc material and lumbo-sacral fusion. During the first postoperative months the results were similar in the two groups, with a satisfactory result in 89 and 88 per cent of the cases respectively. During the following years a significant difference occurred between the groups. Severe pain recurred in 27% of the patients with simple removal of the herniated disc material and in 15% of those with the combined operation (P less than 0.01). The cause of the recurrence in the patients without fusion was disc herniation in 10% (at the same level in 7% and at a different level in 3%), and adhesions, or osteochondrosis with or without instability in 17%. In the patients with the combined operation the recurrences were caused by pseudoarthrosis in 9%, by disc herniation in 3%, and by other causes in 3%. At the final examination 6--7 years after the first operation, the results were still better in the fused patients, but the difference was no longer significant. Eighty-five per cent of the patients with the combined operation has a satisfactory result with regard to pain as compared with 76% in the other group. Thus, the results show that the combined operation gives better protection against recurrence of pain. However, it is a more extensive procedure and has complications of its own, and it should therefore mainly be used in young patients. 
 
354: Frymoyer JW, Hanley E, Howe J, Kuhlmann D, Matteri R. Disc excision and spine fusion in the management of lumbar disc disease. A minimum ten-year followup. Spine 1978 Mar;3(1):1-6  
 
Seventy-nine percent of 312 patients who underwent lumbar disc surgery were evaluated at least 10 years postoperatively (mean equal to 13.7 years). Residual back and nerve root symptoms and functional impairment were equally as common among the 143 patients who underwent fusion as they were among the 64 patients who did not. Thirty percent of the patients whose spines were fused and 37.7% of those patients whose spines were not fused were considered long-term failures because of persistent symptoms or the need for reoperation. Thirty-seven percent of the fusion patients had persistent graft donor site symptoms. Examined patients showed a high percentage of residual neurologic defects. An unexplained positive Trendelenburg sign was present in 14.8% of the fusion patients and in 18.2% of the patients whose spines were not fused. Although retrospective studies often have problems of accuracy, this analysis confirms other observations that midline spinal fusion offers few benefits in the management of lumbar disc disease. 
 
354a: Frymoyer JW, Matteri RE, Hanley EN, Kuhlmann D, Howe J. Failed lumbar disc surgery requiring second operation. A long-term follow-up study. Spine 1978 Mar;3(1):7-11  
 
Forty-five patients who had lumbar disc surgery 10 or more years previously, and had required a second operative procedure, have been evaluated. Failures occurred up to 16 years after the first operation, and were most commonly due to pseudoarthrosis in the patients who underwent spinal fusion initially, and to recurrent disc lesions at the same level as previous surgery in the patients who did not have fusion. The clinical and functional results in the second group of patients who required a second procedure were comparable to those of patients who required only a single procedure. In contrast, patients who had undergone spinal fusion who required a second procedure had significantly worse clinical and functional results, both in comparison to the patients who did not undergo fusion as well as to patients who had had fusion as a single procedure. The only predictable, demonstrable source of failure was acquired spondylolysis. Frequently, repair of pseudoarthrosis did not lead to symptomatic relief. These data suggest that spinal fusion, when it fails, has a significantly worse prognosis than simple disc excision in the management of lumbar disc disease. 
 
355: Schofferman J, Anderson D, Hines R, Smith G, White A. Childhood psychological trauma correlates with unsuccessful lumbar spine surgery. Spine 1992 Jun;17(6 Suppl):S138-44  
 
San Francisco Spine Institute, Daly City, California. 
 
In a retrospective study of 86 patients who underwent lumbar spine surgery, patients who had three or more of a possible five serious childhood psychological traumas (risk factors) had an 85% likelihood of an unsuccessful surgical outcome. Conversely, in patients with a poor surgical outcome, the incidence of these traumas was 75%. In the group of 19 patients with no risk factors, there was only a 5% incidence of failure. This study shows that a highly significant correlation exists between unsuccessful lumbar spine surgery and a history of childhood traumas. Although recognition of predictors for unsuccessful outcome can be useful in avoiding surgery in patients whose indications for surgery are borderline, the greater challenge is to help the patient who, despite being at high psychological risk for negative outcome, has severe spinal pathology that will likely require surgery. In such cases, psychiatric treatment is critical. In the group of 19 patients with no risk factors, single-level laminectomies and discectomies were performed on 6 patients. The other 13 cases were complex, involving a combination of repeat surgeries (n = 4) fusions (n = 3), and/or multilevel laminectomies and discectomies (n = 11). 
 
356: Vaughan PA, Malcolm BW, Maistrelli GL. Results of L4-L5 disc excision alone versus disc excision and fusion. Spine 1988 Jun;13(6):690-5  
 
Toronto Hospital for Sick Children, Ontario. 
 
We evaluated the results of 85 patients having L4-L5 disc excision (52 having disc excision alone, and 33 having disc excision and fusion) using the Smiley-Webster scale at an average follow-up of 7.3 years. Both groups (fusion and nonfusion) were comparable except that the nonfusion group had a significantly higher percentage of patients with a history of chronic back pain and degenerative changes on their initial radiographs. The fusion group had significantly better results compared with the nonfusion group (85% satisfactory results versus 39% satisfactory results). The most common cause of unsatisfactory results in the fusion group was pseudarthrosis (two) while progressive degenerative disc disease (18) and recurrent disc prolapse (eight) were the most common cause of unsatisfactory results in the nonfusion group. The overall reoperation rate was 9.4% (13.5% in the nonfusion group, and 3% in the fusion group. 
 
357x: Waddell G, Newton M, Henderson I, Somerville D, Main CJ. A Fear-Avoidance Beliefs Questionnaire (FABQ) and the role of fear-avoidance beliefs in chronic low back pain and disability. Pain 1993 Feb;52(2):157-68  
 
Orthopaedic Department, Western Infirmary, Glasgow, Scotland UK. 
 
Pilot studies and a literature review suggested that fear-avoidance beliefs about physical activity and work might form specific cognitions intervening between low back pain and disability. A Fear-Avoidance Beliefs Questionnaire (FABQ) was developed, based on theories of fear and avoidance behaviour and focussed specifically on patients' beliefs about how physical activity and work affected their low back pain. Test-retest reproducibility in 26 patients was high. Principal-components analysis of the questionnaire in 210 patients identified 2 factors: fear-avoidance beliefs about work and fear-avoidance beliefs about physical activity with internal consistency (alpha) of 0.88 and 0.77 and accounting for 43.7% and 16.5% of the total variance, respectively. Regression analysis in 184 patients showed that fear-avoidance beliefs about work accounted for 23% of the variance of disability in activities of daily living and 26% of the variance of work loss, even after allowing for severity of pain; fear-avoidance beliefs about physical activity explained an additional 9% of the variance of disability. These results confirm the importance of fear-avoidance beliefs and demonstrate that specific fear-avoidance beliefs about work are strongly related to work loss due to low back pain. These findings are incorporated into a biopsychosocial model of the cognitive, affective and behavioural influences in low back pain and disability. It is recommended that fear-avoidance beliefs should be considered in the medical management of low back pain and disability. 
 
358: Bigos SJ, Battie MC, Spengler DM, Fisher LD, Fordyce WE, Hansson TH, Nachemson AL, Wortley MD. A prospective study of work perceptions and psychosocial factors affecting the report of back injury. Spine 1991 Jan;16(1):1-6  
Department of Orthopaedics, University of Washington, Seattle. 
 
A longitudinal, prospective study was conducted on 3,020 aircraft employees to identify risk factors for reporting acute back pain at work. The premorbid data included individual physical, psychosocial, and workplace factors. During slightly more than 4 years of follow-up, 279 subjects reported back problems. Other than a history of current or recent back problems, the factors found to be most predictive of subsequent reports in a multivariate model were work perceptions and certain psychosocial responses identified on the Minnesota Multiphasic Personality Inventory (MMPI). Subjects who stated that they "hardly ever" enjoyed their job tasks were 2.5 times more likely to report a back injury (P = 0.0001) than subjects who "almost always" enjoyed their job tasks. The quintile of subjects scoring highest on Scale-3 (Hy) of the MMPI were 2.0 times more likely to report a back injury (P = 0.0001) than subjects with the lowest scores. The multivariate model, including job task enjoyment, MMPI Scale-3, and history of back treatment, revealed that subjects in the highest risk group had 3.3 times the number of reports in the lowest risk group. These findings emphasize the importance of adopting a broader approach to the multifaceted problem of back complaints in industry and help explain why past prevention efforts focusing on purely physical factors have been unsuccessful. 
 
359: Skovron ML, Szpalski M, Nordin M, Melot C, Cukier D. Sociocultural factors and back pain. A population-based study in Belgian adults. Spine 1994 Jan 15;19(2):129-37  
 
Hospital for Joint Diseases, New York University School of Medicine, New York. 
 
A population-based survey of approximately 4000 adults in Belgium, a bi-cultural country with a uniform health care system, explored the relationships of socio-cultural and employment factors to the reported experience of low back pain (LBP). Predictors of 1) history of LBP, 2) first LBP, and 3) daily LBP were examined by multiple logistic regression analysis. Thirty-three percent of the population had current LBP, including 5% experiencing their first episode; 26% had past but not current LBP, and 41% had never had LBP. Increasing age (OR > 2.0, P = .000) and female gender (OR 2.16, P = .000) were associated with history of LBP; only gender (OR 1.40, P = .02) was associated with first episode; neither was associated with daily LBP. Language was associated with history (OR 1.80, P = .000) and first occurrence (OR 1.77, P = .000) but not daily LBP. Among those employed, work dissatisfaction was associated with history of LBP (OR > 2.4, P = .02) and daily LBP (OR 3.85, P = .02), but not with first episode. The results suggest that sociocultural factors influence the expression of LBP, but not the risk of chronicity once LBP is reported, and that work satisfaction may not be causally related to LBP, but may intervene along with type of occupation in the possibility of continuing employment once LBP is present. Prospective studies are needed to confirm these results and elucidate causal relationships. 
 
359a: Szpalski M, Nordin M, Skovron ML, Melot C, Cukier D. Health care utilization for low back pain in Belgium. Influence of sociocultural factors and health beliefs. Spine 1995 Feb 15;20(4):431-42  
 
Centre Hospitalier Moliere, Longchamp, Brussels, Belgium. 
 
STUDY DESIGN. A population-based survey was undertaken. OBJECTIVES. To describe health care utilization for low back pain (LBP) in a culturally diverse society with universal access to health care; to describe how LBP chronicity influences health care utilization; and to describe how sociocultural and demographic factors and health beliefs influence health care utilization. METHODS. A probability sample of approximately 5,000 Belgian adults stratified by gender, age, social class, and habitat was surveyed by trained interviewers. Information on demographics, health beliefs, frequency of LBP, and health care utilization was elicited. Statistical analysis was conducted by means of univariate and multivariate logistic regression. Analysis was restricted to 2,660 respondents with history of LBP. RESULTS. Of subjects with LBP, 38% reported daily LBP. Sixty-three percent had seen a health professional for the most recent episode; 11% had been on bed rest. Forty-four percent had at sometime undergone radiography; three and a half percent had ever undergone spinal surgery. Eighty-six percent considered themselves in good health. Controlling for LBP frequency, all forms of health care utilization examined were associated with health beliefs. CONCLUSIONS. LBP frequency, health beliefs, and sociocultural factors influence health care behaviors and utilization among adults with a history of LBP in a society with universal access to health care. The association of history of spinal surgery with reports of daily LBP suggests that spinal surgery has failed, at least partly, to relieve LBP. 
 
360: Wiltse LL, Rocchio PD. Preoperative psychological tests as predictors of success of chemonucleolysis in the treatment of the low-back syndrome. J Bone Joint Surg Am 1975 Jun;57(4):478-83  
 
Pre-injection psychological test scores, surgeon ratings, and patient biographical data were evaluated as predictors of success of chymopapain injection therapy in 130 patients who would otherwise have been treated by laminectomy. Three psychological tests were administered to each patient: the Minnesota Multiphasic Personality Inventory, the Cornell Medical Index, and the Quick Test (a measure of mental ability). In addition, the surgeons rated their patients on a five-point scale immediately after injection relative to their suitability for injection therapy and at one year relative to the objective and symptomatic results. The MMPI hysteria and hypochondriasis scales and the surgeon's rating of the psychogenic component of the patient's pain were predictive of the result of chemonucleolysis. The patient's biographical data which consisted of age, sex, marital status, occupation, and education were not related to postoperative outcome. 
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