It is questionable whether an annular tear (AT) is a predictor for accelerated degeneration of the intervertebral discs. The aim of the present study was to answer this question via a matched case–control study design that reliably eliminates potential confounders.
Materials
Presence or absence of AT, defined as a hyperintense lesion within the annular fibrosus on T2-weighted non-contrast MRI images, was documented in 450 intervertebral lumbar discs of 90 patients who could be followed up for at least 4 years with MRI. Discs with an AT (n = 36) were matched 1:1 to control discs according to the level, degree of initial disc degeneration on MRI (both Pfirrmann grade median 4, range 3–4), age (59.5 ± 15.0 versus 59.3 ± 14.6 years), BMI (26.7 ± 4.4 versus 26.9 ± 4.4 kg/m2) and interval to the follow-up MRI (4.8 ± 0.9 versus 5.1 ± 0.8 years). The degree of disc degeneration after a minimum of 4 years was graded on the follow-up MRI in both groups according to the Pfirrmann classification.
Results
One-fourth (25 %) of the 36 discs with an AT on the initial MRI exam progressed in degeneration. This was similar to the rate of the matched control discs with no AT, in which also around one-fourth (22 %) showed a progression of degeneration (p = 1.00), also without any difference in the degree of degeneration.
Conclusion
Discs with a Pfirrmann grade >2 with an AT, defined by a hyperintense signal intensity on MRI, are not prone to accelerated degeneration if compared to discs without an AT. Therefore, the presence of an AT per se does not predict accelerated disc degeneration. 相似文献
The aim of this study was to determine the relationship between the apparent diffusion coefficient (ADC) and lumbar intervertebral disc degeneration using diffusion-weighted magnetic resonance imaging (DWI).
Materials and methods
Using a 3 T magnetic resonance scanner, DWI of the lumbar spine was assessed in 109 patients, with a total of 545 lumbar discs analyzed. Apparent diffusion coefficient values were recorded for each disc, and all discs were visually graded by two independent observers using Pfirrmann’s grading system. Apparent diffusion coefficient values of disc were tested by correlation with qualitative clinical grading of degeneration severity, patient age, and sex. Correlations were investigated using Pearson’s and Spearman’s rank correlation analysis, and multiple regression analysis.
Results
Intervertebral disc degeneration was negatively correlated with ADC values of all levels (Spearman’s correlation coefficient ranged from ?0.381 to ?0.604, p < 0.001). There was a significant negative association between age and ADC values at all spinal levels (Pearson’s correlation coefficient ranged from ?0.353 to ?0.650, p < 0.001). When stepwise regression models were analyzed, both disc degeneration and age remained negatively associated with ADC values at each lumbar level (standardized coefficients ranged from ?0.231 to ?0.505, p < 0.01 and standardized coefficients ranged from ?0.179 to ?0.523, p < 0.05 respectively).
Conclusion
Apparent diffusion coefficient values obtained using DWI can assess lumbar intervertebral disc degeneration, and the ADC values were negatively correlated with the degree of disc degeneration. 相似文献
To investigate differences in functional intervertebral disk (IVD) characteristics between low back pain (LBP) patients and controls using T2-mapping with axial loading during MRI (alMRI).
Methods
In total, 120 IVDs in 24 LBP patients (mean age 39 years, range 25–69) were examined with T2-mapping without loading of the spine (uMRI) and with alMRI (DynaWell® loading device) and compared with 60 IVDs in 12 controls (mean age 38 years, range 25–63). The IVD T2-value was acquired after 20-min loading in five regions of interests (ROI), ROI1-5 from anterior to posterior. T2-values were compared between loading states and cohorts with adjustment for Pfirrmann grade.
Results
In LBP patients, mean T2-value of the entire IVD was 64 ms for uMRI and 66 ms for alMRI (p?=?0.03) and, in controls, 65 ms and 65 ms (p?=?0.5). Load-induced T2-differences (alMRI–uMRI) were seen in all ROIs in both patients (0.001?>?p?<?0.005) and controls (0.0001?>?p?<?0.03). In patients, alMRI induced an increase in T2-value for ROI1-3 (23%, 18% and 5%) and a decrease for ROI4 (3%) and ROI5 (24%). More pronounced load-induced decrease was detected in ROI4 in controls (9%/p?=?0.03), while a higher absolute T2-value was found for ROI5 during alMRI in patients (38 ms) compared to controls (33 ms) (p?=?0.04).
Conclusion
The alMRI-induced differences in T2-value in ROI4 and ROI5 between patients and controls most probably indicate biomechanical impairment in the posterior IVD regions. Hence, alMRI combined with T2-mapping offers an objective and clinical feasible tool for biomechanical IVD characterization that may deepen the knowledge regarding how LBP is related to altered IVD matrix composition.
Graphical abstract
These slides can be retrieved under Electronic Supplementary Material.
To investigate whether axial loading of the spine during MRI (alMRI) instantaneously induces changes in biochemical disc features as reflected by altered quantitative T2 values in patients with chronic low back pain (LBP).
Methods
T2 mapping was performed on 11 LBP patients (54 lumbar discs) during the conventional unloaded MRI and subsequent alMRI. Each disc was divided into five volumetric regions of interests (ROIs), anterior annulus fibrosus (AF) (ROI 1), the interface anterior AF-nucleus pulposus (NP) (ROI 2), NP (ROI 3), the interface NP-posterior AF (ROI 4), and the posterior AF (ROI 5). The mean T2 values for each ROI were compared between MRI and alMRI and correlated with degeneration grade (Pfirrmann), disc angle, and disc level.
Results
With alMRI, T2 values increased significantly in the whole disc as well as in various parts of the disc with an increase in ROI 1–3 and a decrease in ROI 5. The changes in T2 values correlated to degeneration grade, changes in disc angle, and lumbar level.
Conclusion
alMRI instantaneously induces T2-value changes in lumbar discs and is, thus, a feasible method to reveal dynamic, biochemical disc features in patients with chronic LBP.
To determine if adolescent athletics increases the risk of structural abnormalities in the lumbar spine.
Methods
A retrospective review of patients (ages 10–18) between 2004 and 2012 was performed. Pediatric patients with symptomatic low back pain, a lumbar spine MRI, and reported weekly athletic activity were included. Patients were stratified to an “athlete” and “non-athlete” group. Lumbar magnetic resonance and plain radiographic imaging was randomized, blinded, and evaluated by two authors for a Pfirrmann grade, herniated disc, and/or pars fracture.
Results
A total of 114 patients met the inclusion criteria and were stratified into 66 athletes and 48 non-athletes. Athletes were more likely to have abnormal findings compared to non-athletes (67 vs. 40 %, respectively, p = 0.01). Specifically, the prevalence of a spondylolysis with or without a slip was higher in athletes vs. non-athletes (32 vs. 2 %, respectively, p = 0.0003); however, there was no difference in the average Pfirrmann grade (1.19 vs. 1.14, p = 0.41), percentage of patients with at least one degenerative disc (39 vs. 31 %, p = 0.41), or disc herniation (27 vs. 33 %, p = 0.43). Body mass index, smoking history, and pelvic incidence (51.5° vs. 48.7°, respectively, p = 0.41) were similar between the groups.
Conclusion
Adolescents with low back pain have a higher-than-expected prevalence of structural pathology regardless of athletic activity. Independent of pelvic incidence, adolescent athletes with low back pain had a higher prevalence of spondylolysis compared to adolescent non-athletes with back pain, but there was no difference in associated disc degenerative changes or herniation.
With the increasing aging population in developed countries, there has been an associated increased prevalence of osteoporotic vertebral fracture (OVF). Many previous reports have attempted to predict the risk of delayed union associated with OVF. However, the role of endplate failure and the degeneration of adjacent intervertebral discs, and their association with delayed union has received little attention. The aim of this study was to evaluate the endplate fracture and disc degeneration rank as risk factors for delayed union.
Materials and methods
Two hundred and eighteen consecutive patients with fresh OVF were enrolled in the study. MRI and X–ray were performed at the time of enrollment and at the 6 months follow-up. The MR images were used to assess the degeneration grade of adjacent intervertebral discs (using the modified Pfirrmann grading system), and endplate failure. Supine and weight-bearing radiographs were used to define angular motion and compression ratio of the anterior vertebral body wall.
Results
A total of 139 patients (112 female, 27 male) completed the 6 month follow-up (a 65.1% follow-up rate). The study revealed 27 cases of delayed union (19.4%). A healthier adjacent caudal disc with low grade degeneration was found to be associated with an increased risk of delayed union (P = 0.008). Bi-endplate injury and significant compression of the anterior vertebral body wall were significantly associated with delayed union (P = 0.019, and P = 0.001 respectively). Rapid progression of the adjacent cranial disc degeneration was observed at the end of the 6 month follow-up period (P = 0.001).
Conclusion
Modified Pfirrmann grading system revealed that a healthier adjacent intervertebral disc at the caudal level and bi-endplate fracture were significantly associated with an increased risk of delayed union. These findings may influence the management strategy for patients with OVF. 相似文献
Dialysis-related destructive spondyloarthropathy caused by beta-2 microglobulin (β2M) amyloid deposits in intervertebral discs is a major burden for patients undergoing long-term dialysis. This study aimed to quantify the presence of β2M amyloid deposits in the intervertebral disc tissue of such patients and analyze whether there was a significant correlation between β2M accumulation and the duration of dialysis.
Methods
Two groups of patients who had undergone surgery for degenerative spinal pathologies were selected: the dialysis group (n?=?29) with long-term dialysis and the control group (n?=?10) with no renal impairment. Tissue sections were prepared from specimens of intervertebral disc tissue obtained during spinal surgery and analyzed via histological staining, including immunohistochemistry (IHC) and Congo red.
Results
There was a statistically significant multifold increase of β2M expression in the disc tissue of long-term dialysis patients when compared to non-dialysis patients, as shown by both IHC (0.019?±?0.023 μm2 vs. 0.00020?±?0.00033 μm2, respectively; p?=?0.012) and Congo red staining (0.027?±?0.041 μm2 vs. 9.240?×?10?5?±?5.261?×?10?5 μm2, respectively; p?=?0.047). We also note a moderate strength positive correlation between the duration of dialysis and positive IHC (r?=?0.39; p?=?0.015) and Congo-red staining (r?=?0.42; p?=?0.007).
Conclusions
The problem of β2M amyloidosis in long-term dialysis patients remains unresolved even with predominant use of high-flux dialysis membranes. This highlights the insufficiency of current dialysis modalities to effectively filter β2M.
Cell therapy would be favorably performed immediately after nucleotomy, to restore intervertebral disc functionality and to slow down disc degeneration. Promising results were reported from small animal models but remaining problems, especially in larger animals, include loss of vital cells due to annular damage at the injection site and detrimental intradiscal conditions. The aim of the present study was to optimize cell-based disc therapy using a new albumin–hyaluronan hydrogel together with bone marrow-derived mesenchymal stem cells in a large porcine disc model.
Methods
Luciferase cell labeling was evaluated to follow-up stem cells metabolically up to 7 days in 3D cell cultures mimicking the harsh disc environment with low oxygen and glucose concentrations. As a pilot in vivo study, the implant was injected into porcine discs after removal of ~10 % of nucleus volume and animals were killed immediately after surgery (n = 6) and 3 days later (n = 6). 24 discs were analyzed. Implant persistence and cell activity (luciferase + WST assay) were observed simultaneously.
Results
In vitro cell culture with reduction of glucose (20, 5, 0.5, 0 mM) and oxygen (21, 5, 2 %) significantly decreased metabolic cell activity and luciferase activity after 3 days, with no recovery and a further decrease after 7 days, establishing luciferase activity as a metabolic sensor. During 3 days of 3D culture with disc-like conditions, luciferase activity decreased to 8 %. In vivo, initial implant volume shrank to 61 % at day 3 with evidence for hydrogel compression. Luciferase activity in vivo at day 3 was 2 % without referencing but 23 % after referencing to in vitro cell adaptation, and 38 % after additional consideration of detected implant volume loss.
Conclusion
In vitro analysis up to 7 days established for the first time luciferase activity as a metabolic sensor for mesenchymal stem cells used in regenerative disc therapy. Under the present protocol, short-term in vivo analysis after 3 days suggests improved implant retainment inside the disc and persistence of metabolically active cells; however, further studies will have to prove long-term in vivo outcome. 相似文献
Epidemiological studies show that 5–40 % of type 2 diabetes (T2DM) patients have diabetic nephropathy, and oxidative stress is one of several underlying mechanisms. We investigated associations between oxidative stress markers and severity of diabetic nephropathy.
Methods
Fifty-nine T2DM patients from the endocrinology outpatient department were included, and their levels of oxidative stress markers were measured. Three groups were determined by their urine albumin-to-creatinine ratio (UACR): group A (UACR < 30 mg/g, n = 22); group B (30 ≤ UACR < 300 mg/g, n = 22); and group C (UACR ≥ 300 mg/g, n = 15).
Results
Vitamin C levels correlated negatively and moderately with serum creatinine (γ = ?0.459, p < 0.001), urine albumin (γs = ?0.458, p = 0.001) and UACR (γs = ?0.408, p = 0.001), but only weakly with hydroxy-2-deoxyguanosine (8-OHdG) and estimated glomerular filtration rate (eGFR). Vitamin C levels decreased as 8-OHdG, serum creatinine, albumin and UACR increased. T2DM patients with more severe diabetic nephropathy had lower vitamin C levels.
Conclusion
Our results identified several oxidative stress markers that may be clinically important in diabetic nephropathy. Studies with larger sample sizes should be undertaken to confirm these findings.
The study design included a multidisciplinary examination of the mineral phase of ovine intervertebral disc calcifications. The objective of the study was to investigate the mineral phase and its mechanisms of formation/association with degeneration in a naturally occurring animal model of disc calcification. The aetiology of dystrophic disc calcification in adult humans is unknown, but occurs as a well-described clinical disorder with hydroxyapatite as the single mineral phase. Comparable but age-related pathology in the sheep could serve as a model for the human disorder. Lumbar intervertebral discs (n = 134) of adult sheep of age 6 years (n = 4), 8 years (n = 12) and 11 years (n = 2) were evaluated using radiography, morphology, scanning and transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray powder diffraction, histology, immunohistology and proteoglycan analysis. Half of the 6-year, 84% of the 8-year and 86% of the 11-year-old discs had calcific deposits. These were not well delineated by plain radiography. They were either: (a) punctate deposits in the outer annulus, (b) diffuse deposits in the transitional zone or inner annulus fibrosus with occasional deposits in the nucleus, or (c) large deposits in the transitional zone extending variably into the nucleus. Their maximal incidence was in the lower lumbar discs (L4/5–L6/7) with no calcification seen in the lumbosacral or lower thoracic discs. All deposits were hydroxyapatite with large crystallite sizes (800–1,300 Å) compared to cortical bone (300–600 Å). No type X-collagen, osteopontin or osteonectin were detected in calcific deposits, although positive staining for bone sialoprotein was evident. Calcified discs had less proteoglycan of smaller hydrodynamic size than non-calcified discs. Disc calcification in ageing sheep is due to hydroxyapatite deposition. The variable, but large, crystal size and lack of protein markers indicate that this does not occur by an endochondral ossification-like process. The decrease in disc proteoglycan content and size suggests that calcification may precede or predispose to disc degeneration in ageing sheep. 相似文献
Grading inter-vertebral disc degeneration (IDD) is important in the evaluation of many degenerative conditions, including patients with low back pain. Magnetic resonance imaging (MRI) is considered the best imaging instrument to evaluate IDD. The Pfirrmann classification is commonly used to grade IDD; the authors describing this classification showed an adequate agreement using it; however, there has been a paucity of independent agreement studies using this grading system. The aim of this study was to perform an independent inter- and intra-observer agreement study using the Pfirrmann classification.
Methods
T2-weighted sagittal images of 79 patients consecutively studied with lumbar spine MRI were classified using the Pfirrmann grading system by six evaluators (three spine surgeons and three radiologists). After a 6-week interval, the 79 cases were presented to the same evaluators in a random sequence for repeat evaluation. The intra-class correlation coefficient (ICC) and the weighted kappa (wκ) were used to determine the inter- and intra-observer agreement.
Results
The inter-observer agreement was excellent, with an ICC = 0.94 (0.93–0.95) and wκ = 0.83 (0.74–0.91). There were no differences between spine surgeons and radiologists. Likewise, there were no differences in agreement evaluating the different lumbar discs. Most differences among observers were only of one grade. Intra-observer agreement was also excellent with ICC = 0.86 (0.83–0.89) and wκ = 0.89 (0.85–0.93).
Conclusions
In this independent study, the Pfirrmann classification demonstrated an adequate agreement among different observers and by the same observer on separate occasions. Furthermore, it allows communication between radiologists and spine surgeons.
To investigate if instrumentation (unilateral vs. bilateral fixation) has an effect on the rate of fusion cage migration.
Methods
This clinical study of transforaminal lumbar interbody fusion involved a prospective group of 116 patients who were randomly assigned to either unilateral (n = 57) or bilateral (n = 59) fixation. Fourteen were lost to follow-up (11 from the unilateral group and 3 from the bilateral group).
Results
The unilateral fixation group consisted of 20 male and 26 female patients. In the unilateral group, the mean age was 53.5 years (range, 18–77), and the preoperative diagnosis consisted of degenerative disc disease, with or without herniated disc (n = 44), and degenerative spondylolisthesis with spinal stenosis (n = 2). The bilateral fixation group consisted of 20 male and 36 female patients. In the bilateral group, the mean age was 55.7 years (range, 26–82), and the preoperative diagnosis consisted of degenerative disc disease, with or without herniated disc (n = 40), and degenerative spondylolisthesis with spinal stenosis (n = 16). A total of 17 cases of cage migration were found; of these, 11 were from the unilateral group and 6 from the bilateral group, resulting in rates of cage migration of 23 and 11 % (p = 0.03), respectively. In regard to migration cases, 5 were male and 12 were female. Ages ranged from 27 to 79 years (mean age, 55 years).
Conclusion
We conclude that unilateral fixation is not stable enough to prevent fusion cage migration in some patients who undergo TLIF. 相似文献
An increasing body of evidence suggests gender differences in the presentation and prognosis of bladder cancer. We aimed to assess the impact of gender on outcomes in patients with primary T1 high-grade (HG) urothelial carcinoma of the bladder (UCB).
Methods
We retrospectively analysed the data from 916 patients with primary T1HG UCB from 7 tertiary care centres. Patients were treated with transurethral resection of the bladder with or without intravesical instillation therapy (IVT). Univariable and multivariable Cox regression analyses assessed the effect of gender on outcomes.
Results
Within a median follow-up of 42.8 months, 365 (39.8 %) patients experienced disease recurrence, 104 (11.4 %) progression, 59 (6.4 %) cancer-specific mortality and 190 (20.7 %) mortality of any cause. Overall, 634 (69.2 %) patients received IVT of which 234 (25.5 %) received BCG therapy. Female gender (n = 190, 20.7 %) was associated with higher risk of disease recurrence (HR:1.359;1.071–1.724, p = 0.012) in all patients and in a subgroup of patients treated with BCG therapy (HR:1.717;1.101–2.677, p = 0.017). There was no difference between genders with regard to disease progression, cancer-specific mortality and any-cause mortality. In multivariable analyses that adjusted for the effects of concomitant carcinoma in situ (CIS), tumour size, number of tumours, and IVT, gender remained an independent predictor for disease recurrence (p = 0.026) when analysed in all patients, but not in the subgroup of BCG treated patients (p = 0.093).
Conclusions
In patients with T1HG UCB, female gender is associated with higher risk of disease recurrence, but not with disease progression. This gender disparity may be due to differences in care and/or biology of UCB. 相似文献
Fluorescence-based enhanced reality (FLER) is a technique to evaluate intestinal perfusion based on the elaboration of the Indocyanine Green fluorescence signal. The aim of the study was to assess FLER’s performances in evaluating perfusion in an animal model of long-lasting intestinal ischemia.
Materials and methods
An ischemic segment was created in 18 small bowel loops in 6 pigs. After 2 h (n = 6), 4 h (n = 6), and 6 h (n = 6), loops were evaluated clinically and by FLER to delineate five regions of interest (ROIs): ischemic zone (ROI 1), presumed viable margins (ROI 2a–2b), and vascularized areas (3a–3b). Capillary lactates were measured to compare clinical vs. FLER assessment. Basal (V0) and maximal (Vmax) mitochondrial respiration rates were determined according to FLER.
Results
Lactates (mmol/L) at clinically identified resection lines were significantly higher when compared to those identified by FLER (2.43 ± 0.95 vs. 1.55 ± 0.33 p = 0.02) after 4 h of ischemia. Lactates at 2 h at ROI 1 were 5.45 ± 2.44 vs. 1.9 ± 0.6 (2a–2b; p < 0.0001) vs. 1.2 ± 0.3 (3a–3b; p < 0.0001). At 4 h, lactates were 4.36 ± 1.32 (ROI 1) vs. 1.83 ± 0.81 (2a–2b; p < 0.0001) vs. 1.35 ± 0.67 (3a–3b; p < 0.0001). At 6 h, lactates were 4.16 ± 2.55 vs. 1.8 ± 1.2 vs. 1.45 ± 0.83 at ROI 1 vs. 2a–-2b (p = 0.013) vs. 3a–3b (p = 0.0035). Mean V0 and Vmax (pmolO2/second/mg of tissue) were significantly impaired after 4 and 6 h at ROI 1 (V04h = 34.83 ± 10.39; Vmax4h = 76.6 ± 29.09; V06h = 44.1 ± 12.37 and Vmax6h = 116.1 ± 40.1) when compared to 2a-–2b (V04h = 67.1 ± 17.47 p = 0.00039; Vmax4h = 146.8 ± 55.47 p = 0.0054; V06h = 63.9 ± 28.99 p = 0.03; Vmax6h = 167.2 ± 56.96 p = 0.01). V0 and Vmax were significantly higher at 3a–3b.
Conclusions
FLER may identify the future anastomotic site even after repetitive assessments and long-standing bowel ischemia. 相似文献
Evolution and progression of disc and endplate bone marrow degeneration of the lumbar spine are thought to be multifactorial, yet, their influence and interactions are not understood. The aim of this study was to find association of potential predictors of evolution of degeneration of the lumbar spine.
Methods
Patients (n = 90) who underwent two lumbar magnetic resonance imaging (MRI) exams with an interval of at least 4 years and without any spinal surgery were included into the longitudinal cohort study with nested case–control analysis. Disc degeneration (DD) was scored according to the Pfirrmann classification and endplate bone marrow changes (EC) according to Modic in 450 levels on both MRIs. Potential variables for degeneration such as age, gender, BMI, scoliosis and sagittal parameters were compared between patients with and without evolution or progression of degenerative changes in their lumbar spine. A multivariate analysis aimed to identify the most important variables for progression of disc and endplate degeneration, respectively.
Results
While neither age, gender, BMI, sacral slope or the presence of scoliosis could be identified as progression factor for DD, a higher lordosis was observed in subjects with no progression (49° ± 11° vs 43° ± 12°; p = 0.017). Progression or evolution of EC was only associated with a slightly higher degree of scoliosis (10° ± 10° vs 6° ± 9°; p = 0.04) and not to any of the other variables.
Conclusion
While a coronal deformity of the lumbar spine seems associated with evolution or progression of EC, a higher lumbar lordosis is protective for radiographic progression of DD. This implies that scoliotic deformity and lesser lumbar lordosis are associated with higher overall degeneration of the lumbar spine. 相似文献
Spinopelvic parameters can be useful in identifying risk factors for lumbar degenerative disc disease, but few studies assess patients with single-level disc herniation and most do not evaluate symptoms. This comparative retrospective study was aimed to analyse spinopelvic parameters, symptoms and MRI changes in patients with single-level lumbar disc herniation undergoing conservative or surgical treatment.
Methods
Patients with clinical and radiological assessment (Japanese Orthopaedic Association Score) and an MRI evaluation of the lumbar spine were identified and divided into two groups: surgically treated (group A) and not requiring surgery (group B). Spinopelvic parameters were determined on standing profile radiographs of the lumbar spine and pelvis, and mean values were compared to those reported in the literature for normal subjects. MRI findings were graded according to the system described by Pfirrmann et al.
Results
The study included 71 patients with single-level lumbar disc herniation: 26 in group A (39.4 ± 12.1 years) and 45 in group B (51.4 ± 17.2 years). The notable differences in spinopelvic parameter means between the two groups did not reach statistical significance. A positive correlations of age with pelvic tilt and Pfirrmann changes with pelvic incidence was only found in group A, while both groups showed highly significant positive correlations of pelvic incidence with the spine’s conformational type (p = 0.001).
Conclusions
Characteristic changes in spinopelvic parameters identified in patients with lumbar degenerative disc disease were a reduction in pelvic incidence, sacral slope and lumbar lordosis, with an increased pelvic tilt. These were found to correlate with MRI changes in surgically treated patients.
We tested the hypothesis that whiplash trauma leads to changes of the signal intensity of cervical discs in T2-weighted images.
Methods and materials
50 whiplash patients (18–65 years) were examined within 48 h after motor vehicle accident, and again after 3 and 6 months and compared to 50 age- and sex-matched controls. Signal intensity in ROI's of the discs at the levels C2/3 to C7/T1 and the adjacent vertebral bodies were measured on sagittal T2 weighted MR images and normalized using the average of ROI's in fat tissue. The contrast between discs and both adjacent vertebrae was calculated and disc degeneration was graded by the Pfirrmann-grading system.
Results
Whiplash trauma did not have a significant effect on the normalized signals from discs and vertebrae, on the contrast between discs and adjacent vertebrae, or on the Pfirrmann grading. However, the contrast between discs and adjacent vertebrae and the Pfirrmann grading showed a strong correlation. In healthy volunteers, the contrast between discs and adjacent vertebrae and Pfirrmann grading increased with age and was dependent on the disc level.
Conclusion
We could not find any trauma related changes of cervical disc signal intensities. Normalized signals of discs and Pfirrmann grading changed with age and varied between disc levels with the used MR sequence. 相似文献
Lumbar laminectomy affects spinal stability in shear loading. However, the effects of laminectomy on torsion biomechanics are unknown. The purpose of this study was to investigate the effect of laminectomy on torsion stiffness and torsion strength of lumbar spinal segments following laminectomy and whether these biomechanical parameters are affected by disc degeneration and bone mineral density (BMD).
Methods
Ten human cadaveric lumbar spines were obtained (age 75.5, range 59–88). Disc degeneration (MRI) and BMD (DXA) were assessed. Disc degeneration was classified according to Pfirrmann and dichotomized in mild or severe. BMD was defined as high BMD (≥median BMD) or low BMD (<median BMD). Laminectomy was performed either on L2 (5×) or L4 (5×). Twenty motion segments (L2–L3 and L4–L5) were isolated. The effects of laminectomy, disc degeneration and BMD on torsion stiffness (TS) and torsion moments to failure (TMF) were studied.
Results
Load–displacement curves showed a typical bi-phasic pattern with an early torsion stiffness (ETS), late torsion stiffness (LTS) and a TMF. Following laminectomy, ETS decreased 34.1 % (p < 0.001), LTS decreased 30.1 % (p = 0.027) and TMF decreased 17.6 % (p = 0.041). Disc degeneration (p < 0.001) and its interaction with laminectomy (p < 0.031) did significantly affect ETS. In the mildly degenerated group, ETS decreased 19.7 % from 7.6 Nm/degree (6.4–8.4) to 6.1 Nm/degree (1.5–10.3) following laminectomy. In the severely degenerated group, ETS decreased 22.3 % from 12.1 Nm/degree (4.6–21.9) to 9.4 Nm/degree (5.6–14.3) following laminectomy. In segments with low BMD, TMF was 40.7 % (p < 0.001) lower than segments with high BMD [34.9 Nm (range 23.7–51.2) versus 58.9 Nm (range 43.8–79.2)].
Conclusions
Laminectomy affects both torsion stiffness and torsion load to failure. In addition, torsional strength is strongly affected by BMD whereas disc degeneration affects torsional stiffness. Assessment of disc degeneration and BMD pre-operatively improves the understanding of the biomechanical effects of a lumbar laminectomy. 相似文献
To audit the cost of laser versus pneumatic semirigid ureteroscopic lithotripsy and to analyze their relative initial outcomes and cost.
Methods
Hundred and eighty-seven patients who underwent semirigid ureteroscopic lithotripsy were analyzed retrospectively in terms of age and sex of the patients; location and size of the stones; the type of probe and ancillary equipment such as guide wire, basket catheter, JJ stent requirements; irrigation amount; operation time; the cost of the anesthesia and further treatments such as a JJ stent removal operation and shock wave lithotripsy requirements and their costs. Two groups were formed based on this type of lithotripters, pneumatic and laser lithotripsy.
Results
Operation times (min.) in terms of the stone size, for stones <100 and >100 mm2 were 20.75 ± 10.78 and 25.82 ± 14.23, respectively (p = 0.007). Operation times for the pneumatic and laser groups were 33.05 ± 11.36 and 15.25 ± 6.14, respectively (p < 0.05).The stone-free rates for pneumatic and laser groups were 89.6 % (n = 69) and 98.2 % (n = 108), respectively (p = 0.01). The mean cost of the operations for each of the study groups was 261.5 ± 66.13 and 311.7 ± 51.97 US$, respectively (p = 0.001). The mean cost in terms of the stone size, for stones <100 and >100 mm2, was 272.86 ± 53.05 and 323.71 ± 66.88 US$, respectively (p = 0.01).
Conclusions
It seems that usage of laser lithotripsy (LL) in patients with ureteral stones is more effective than pneumatic lithotripsy (PL) in terms of operation time and SF rate. On the other hand, the mean cost of LL seems to be more expensive than PL. Urologists should think these parameters before the choice of these two treatment modalities. The higher the effectiveness, the greater the cost. 相似文献
Background contextDiurnal changes in T2 values, indicative for changes in water content, have been reported in the lumbar intervertebral discs. However, data concerning short-term T2 changes are missing.PurposeThe purpose of this study was to investigate the short-term effects of unloading on T2 values in lumbar intervertebral discs in vivo.Study designExperimental study with repeated measurements of lumbar discs T2 relaxation time during a period of 38 minutes of supine posture.Patient sampleForty-one patients with acute or chronic low back pain (visual analog scale ≥3).Outcome measuresT2 relaxation time in the intervertebral disc, lumbar lordosis angle, and intervertebral disc height.MethodsForty-one patients (mean age, 41.6 years) were investigated in the supine position using a 3-tesla magnetic resonance system. Sagittal T2 mapping was performed immediately after unloading and after a mean delay of 38 minutes. No patient movement was allowed between the measurements. One region of interest (ROI) was manually placed in both the anterior and the posterior annulus fibrosus (AF) and three ROIs in the nucleus pulposus (NP).ResultsThere was a statistically significant decrease in the anterior NP (?2.7 ms; p<.05) and an increase in T2 values in the posterior AF (+3.5 ms; p<.001). Discs with initially low T2 values in the NP showed minor increase in the posterior AF (+1.6 ms; p<.05), whereas a major increase in the posterior AF was found in discs with initially high T2 values in the NP (+6.8 ms; p=.001). Patients examined in the morning showed no differences, but those investigated in the afternoon showed a decrease in the anterior NP (?5.3 ms; p<.05) and an increase in the posterior AF (+7.8 ms; p=.002). No significant differences were observed in other regions. Correlation analysis showed moderate correlations between the time of investigation and T2 changes in the posterior AF (r=0.46; p=.002).ConclusionsA shift of water from the anterior to the posterior disc regions seems to occur after unloading the lumbar spine in the supine position. The clinical relevance of these changes needs to be investigated. 相似文献
