Lumbar disc high-intensity zone: the value and significance of provocative discography in the determination of the discogenic pain source.
(25/1257)
Disagreement still exists in the literature as to the significance of the high-intensity zone (HIZ) demonstrated on magnetic resonance imaging (MRI) as a potential pain indicator in patients with low back pain. A prospective blind study was therefore conducted to evaluate the lumbar disc high-intensity zone with the pain provocation response of lumbar discography. Consecutive patients with low back pain unresponsive to conservative treatment and being considered for spinal fusion were subjected to MRI followed by lumbar discography as a pre-operative assessment. The discographer was blinded to the results of the MRI scans. We used the chi-squared test to analyse our results. Ninety-two HIZs were identified in 73 patients, mainly occurring at L4/5 (48%) and L5/S1 (35%). Significant correlation was found between abnormal disc morphology and the HIZ (P < 0.001). In morphologically abnormal discs (grades 3, 4 and 5), there was a significant correlation between the HIZ and exact or similar pain reproduction (P < 0.001). The sensitivity, specificity and positive predictive value for pain reproduction were high, at 81%, 79% and 87% respectively. The nature of the HIZ remains unknown, but it may represent an area of secondary inflammation as a result of an annular tear. We conclude from our study that the lumbar disc HIZ observed on MRI in patients with low back pain is likely to represent painful internal disc disruption. (+info)
A comparison of three methods for measuring thoracic kyphosis: implications for clinical studies.
(26/1257)
OBJECTIVES: To compare the Cobb technique for measuring kyphosis with an alternative Cobb method and a computer-assisted curve assessment technique, and to examine the influence of vertebral body and disc shape on kyphosis. METHODS: Kyphosis measurements were derived from 93 lateral spinal radiographs or sagittal computed tomography images of cadaveric spines, using: (i) a computer-assisted method for estimating radius of curvature; (ii) the traditional Cobb method; and (iii) an alternative Cobb method. Regression models were applied for agreement analyses, and to examine the relative contribution of vertebral body and disc shape on the extent of curvature. Results and conclusions. Strong associations existed between curvature and angle data derived from the three methods, confirming the clinical utility of these techniques for the quantification of thoracic kyphosis. However, the traditional Cobb method tended to overestimate kyphosis in the presence of vertebral body end-plate deformation. The degree of kyphosis was strongly reflective of the extent of deformity of the vertebral bodies, and to a lesser extent the shape of the thoracic discs. (+info)
Effects of holmium(HO)-YAG laser irradiation on rabbit lumbar discs.
(27/1257)
To study the effect of laser irradiation on normal lumbar discs, a 2100 nm Holmium (HO)-YAG laser irradiation was applied to the 83 lumbar discs of 23 adult rabbits. The extent of disc vaporization, the temperature changes in the surrounding tissues, and changes in the radiograph and MRI findings were assessed after laser irradiation. When laser irradiation was delivered to the discs, the disc weight decreased linearly with the increase in total laser energy, indicating steady vaporization of disc material. The temperature was highest at the site of the guide needle. Laser irradiation was delivered at 0.5 J/pulse or 1.4 J/pulse x 5 pulses/sec to the intervertebral discs, and radiographs and T2-weighted MRI of the irradiated discs were investigated at 1, 4, and at 12 weeks after irradiation. At 1 week after irradiation at 0.5 and 1.4 J/pulse, the radiographs showed a decrease in the disc height. At 12 weeks after irradiation at 0.5 J/pulse, the disc height had restored to normal, while the decrease was persistent after irradiation at 1.4 J/pulse. At 1 week after irradiation, MRI showed a decrease in the signal intensity of discs treated at 0.5 J/pulse, but the decrease was recovered at 12 weeks. After irradiation at 1.4 J/pulse, the decrease in signal intensity was also recovered by 12 weeks, but the recovery was less than the recovery after treatment at 0.5 J/pulse. Laser irradiation is applicable for the treatment of intervertebral discs, but it is necessary to select the optimal operating conditions. It may also be necessary to change the power of irradiation according to the pathological condition of the disc being treated. (+info)
The vertebral end-plate: what do we know?
(28/1257)
The vertebral end-plate is critical for maintaining the health of the intervertebral disc. This paper reviews the literature that relates to end-plate structure and development and describes how disc integrity is affected by changes associated with pathology and aging. A range of studies, including biomechanical, biochemical, surgical and histological is discussed to illustrate the important role of the end-plate in spinal function. (+info)
Load-displacement properties of the normal and injured lower cervical spine in vitro.
(29/1257)
The objective of this study was to determine which discoligamentous structures of the lower cervical spine provide significant stability with regard to different loading conditions. Accordingly, the load-displacement properties of the normal and injured lower cervical spine were tested in vitro. Four artificially created stages of increasing discoligamentous instability of the segment C5/6 were compared to the normal C5/6 segment. Six fresh human cadaver spine segments C4-C7 were tested in flexion/extension, axial rotation, and lateral bending using pure moments of +/- 2.5 Nm without axial preload. Five conditions were investigated consecutively: (1) the intact functional spinal unit (FSU) C5/6; (2) the FSU C5/6 with the anterior longitudinal ligament and the intertransverse ligaments sectioned; (3) the FSU C5/6 with an additional 10-mm-deep incision of the anterior half of the anulus fibrosus and the disc; (4) the FSU C5/6 with additionally sectioned ligamenta flava as well as interspinous and supraspinous ligaments; (5) the FSU C5/6 with additional capsulotomy of the facet joints. In flexion/extension, significant differences were observed concerning range of motion (ROM) and neutral zone (NZ) for all four stages of instability compared to the intact FSU. In axial rotation, only the stage 4 instability showed a significantly increased ROM and NZ compared to the intact FSU. For lateral bending, no significant differences were observed. Based on these data, we conclude that flexion/extension is the most sensitive load-direction for the tested discoligamentous instabilities. (+info)
A systematic literature review to identify the best method for a single level anterior cervical interbody fusion.
(30/1257)
The goal of this systematic literature review was to determine, for patients with degenerative disc disease, which method of single-level anterior cervical interbody fusion using the anterior approach gives the best clinical and radiological outcome. The number of new techniques for obtaining a solid fusion has increased rapidly, but the rationale for choosing between different techniques is unclear. Randomised comparative studies on anterior cervical interbody fusions were identified in a sensitive Medline, Cochrane and Current Contents database search. Two independent reviewers evaluated the articles that met the selection criteria, using a checklist. The search yielded eight randomised, controlled trials for the systematic literature review. Three of these studies were judged to be of sufficient quality with regard to methodology and the information provided. In the three articles, five different treatment methods were investigated, four of which were interbody fusions. Fusion rates varied between 28% for an allograft method and 63% for a discectomy-alone method. In one study, kyphosis varied from 40% to 62% between treatments. Good clinical outcome (disability, pain and symptoms) ratings varied from 66% to 82%. A meta-analysis to determine the best method for an anterior interbody fusion could not be performed due to the heterogeneity of the methods reported and because no standard outcome parameter was used. From this systematic literature review, a gold standard for the treatment of degenerative disc disease could not be identified. (+info)
Outcome scores in degenerative cervical disc surgery.
(31/1257)
Forty-six consecutive patients with neck pain and arm radiculopathy were treated with anterior cervical discectomy and fusion. All patients had neurological symptoms corresponding to a herniated disc and/or spondylosis at one or two cervical levels, verified by magnetic resonance imaging. The patients were stabilized with an anterior graft and randomized to either fixation with a CSLP plate or no internal fixation. Preoperatively and 2 years postoperatively the patients filled in a questionnaire that included a modified Million Index, a modified Oswestry Index and the Zung Depression Scale. They were also asked to register their pain in the arm and in the neck on a vertical visual analogue scale (VAS). At the 2-year follow-up, an unbiased observer graded the patients' clinical outcome using Odom's criteria. A test-retest procedure was carried out to examine the questionnaire reproducibility. In the group that was operated at one level, there was no significant improvement in any of the scores. Nevertheless, 81% of the patients were satisfied with the outcome of the surgery. All scores improved in the group operated at two levels. The pain in the neck and arm, as measured on a VAS, decreased in both groups. The improvement in arm pain was significantly more pronounced in patients operated with a plate at two levels compared to those who were operated without a plate. At the 2-year follow-up, patients with an excellent or good result according to Odom's criteria had a lower Million Index (P < 0.0005), Oswestry Index (P < 0.0005), and Zung (P = 0.024) score, than the group classified as fair or poor. There was a significant correlation (P < 0.0001 for all scores) between the test and retest results. We conclude that the modified Million Index and Oswestry Index are clinically useful tools in the evaluation of outcome after degenerative cervical disc surgery. The clinical benefits of plate fixation were minimal. The outcome after surgery, measured with the Oswestry Index, Million Index and VAS for arm and neck pain, seems to correlate well with the classification of outcome by Odom. (+info)
Postoperative pancreatitis may occur following surgery in regions remote from the pancreas and the biliary tree. Though uncommon, it carries a high mortality rate. Pancreatitis complicating spinal surgery is extremely rare. This report describes a case of acute pancreatitis following an anterior lumbar interbody fusion and discusses the possible mechanisms of pancreatic cellular injury. (+info)