Proton Density Fat Fraction Spine MRI for Differentiation of Erosive Vertebral Endplate Degeneration and Infectious Spondylitis

Vertebral Modic type 1 (MT1) degeneration may mimic infectious disease on conventional spine magnetic resonance imaging (MRI), potentially leading to additional costly and invasive investigations. This study evaluated the diagnostic performance of the proton density fat fraction (PDFF) for distinguishing MT1 degenerative endplate changes from infectious spondylitis. A total of 31 and 22 patients with equivocal diagnosis of MT1 degeneration and infectious spondylitis, respectively, were retrospectively enrolled in this IRB-approved retrospective study and examined with a chemical-shift encoding (CSE)-based water-fat 3D six-echo modified Dixon sequence in addition to routine clinical spine MRI. Diagnostic reference standard was established according to histopathology or clinical and imaging follow-up. Intravertebral PDFF [%] and PDFFratio (i.e., vertebral endplate PDFF/normal vertebrae PDFF) were calculated voxel-wise within the single most prominent edematous bone marrow lesion per patient and examined for differences between MT1 degeneration and infectious spondylitis. Mean PDFF and PDFFratio of infectious spondylitis were significantly lower compared to MT1 degenerative changes (mean PDFF, 4.28 ± 3.12% vs. 35.29 ± 17.15% [p < 0.001]; PDFFratio, 0.09 ± 0.06 vs. 0.67 ± 0.37 [p < 0.001]). The areas under the curve (AUC) and diagnostic accuracies were 0.977 (p < 0.001) and 98.1% (cut-off at 12.9%) for PDFF and 0.971 (p < 0.001) and 98.1% (cut-off at 0.27) for PDFFratio. Our data suggest that quantitative evaluation of vertebral PDFF can provide a high diagnostic accuracy for differentiating erosive MT1 endplate changes from infectious spondylitis.

Incidence and clinical impact of vertebral endplate changes after limited lumbar microdiscectomy and implantation of a bone-anchored annular closure device

Background An annular closure device (ACD) could potentially prevent recurrent herniation by blocking larger annular defects after limited microdiscectomy (LMD). The purpose of this study was to analyze the incidence of endplate changes (EPC) and outcome after LMD with additional implantation of an ACD to prevent reherniation. Methods This analysis includes data from a) RCT study-arm of patients undergoing LMD with ACD implantation and b) additional patients undergoing ACD implantation at our institution. Clinical findings (VAS, ODI), radiological outcome (reherniation, implant integrity, volume of EPC) and risk factors for EPC were assessed. Results Seventy-two patients (37 men, 47 ± 11.63yo) underwent LMD and ACD implantation between 2013–2016. A total of 71 (99%) patients presented with some degree of EPC during the follow-up period (14.67 ± 4.77 months). In the multivariate regression analysis, localization of the anchor was the only significant predictor of EPC (p = 0.038). The largest EPC measured 4.2 cm3. Reherniation was documented in 17 (24%) patients (symptomatic: n = 10; asymptomatic: n = 7). Six (8.3%) patients with symptomatic reherniation underwent rediscectomy. Implant failure was documented in 19 (26.4%) patients including anchor head breakage (n = 1, 1.3%), dislocation of the whole device (n = 5, 6.9%), and mesh dislocation into the spinal canal (n = 13, 18%). Mesh subsidence within the EPC was documented in 15 (20.8%) patients. Seven (9.7%) patients underwent explantation of the entire, or parts of the device. Conclusion Clinical improvement after LMD and ACD implantation was proven in our study. High incidence and volume of EPC did not correlate with clinical outcome. The ACD might prevent disc reherniation despite implant failure rates. Mechanical friction of the polymer mesh with the endplate is most likely the cause of EPC after ACD.

Incidence and Clinical Impact of Vertebral Endplate Changes after Limited Lumbar Microdiscectomy and Implantation of a Bone-anchored Annular Closure Device

Background: An annular closure device (ACD) could potentially prevent recurrent herniation by blocking larger annular defects after limited microdiscectomy (LMD). The purpose of this study was to analyze the incidence of endplate changes (EPC) and outcome after LMD with additional implantation of an ACD to prevent reherniation. Methods: This analysis includes data from a) RCT study-arm of patients undergoing LMD with ACD implantation and b) additional patients undergoing ACD implantation at our institution. Clinical findings (VAS,ODI), radiological outcome (reherniation, implant integrity, volume of (EPC) and risk factors for EPC were assessed. Results: Seventy-two patients (37men, 47±11.63yo) underwent LMD and ACD implantation between 2013-2016. A total of 71 (99%) patients presented with some degree of EPC during the follow-up period (14.67±4.77months). In the multivariate regression analysis, localization of the anchor was the only significant predictor of EPC (p=0.038). The largest EPC measured 4.2 cm3. Reherniation was documented in 17 (24%) patients (symptomatic: n=10; asymptomatic: n=7). Six (8.3%) patients with symptomatic reherniation underwent rediscectomy. Implant failure was documented in 19 (26.4%) patients including anchor head breakage (n=1, 1.3%), dislocation of the whole device (n=5, 6.9%), and mesh dislocation into the spinal canal (n=13, 18%). Mesh subsidence within the EPC was documented in 15 (20.8%) patients. Seven (9.7%) patients underwent explantation of the entire, or parts of the device.Conclusion: Clinical improvement after LMD and ACD implantation was proven in our study. High incidence and volume of EPC did not correlate with clinical outcome. The ACD might prevent disc reherniation despite implant failure rates. Mechanical friction of the polymer mesh with the endplate is most likely the cause of EPC after ACD.

Incidence and clinical impact of vertebral endplate changes after limited lumbar microdiscectomy and implantation of a bone-anchored annular closure device

Background: An annular closure device (ACD) could potentially prevent recurrent herniation by blocking larger annular defects after limited microdiscectomy (LMD). The purpose of this study was to analyze the incidence of endplate changes (EPC) and outcome after LMD with additional implantation of an ACD to prevent reherniation. Methods: This analysis includes data from a) RCT study-arm of patients undergoing LMD with ACD implantation and b) additional patients undergoing ACD implantation at our institution. Clinical findings (VAS,ODI), radiological outcome (reherniation, implant integrity, volume of (EPC) and risk factors for EPC were assessed. Results: Seventy-two patients (37men, 47±11.63yo) underwent LMD and ACD implantation between 2013-2016. A total of 71 (99%) patients presented with some degree of EPC during the follow-up period (14.67±4.77months). In the multivariate regression analysis, localization of the anchor was the only significant predictor of EPC (p=0.038). The largest EPC measured 4.2 cm3. Reherniation was documented in 17 (24%) patients (symptomatic: n=10; asymptomatic: n=7). Six (8.3%) patients with symptomatic reherniation underwent rediscectomy. Implant failure was documented in 19 (26.4%) patients including anchor head breakage (n=1, 1.3%), dislocation of the whole device (n=5, 6.9%), and mesh dislocation into the spinal canal (n=13, 18%). Mesh subsidence within the EPC was documented in 15 (20.8%) patients. Seven (9.7%) patients underwent explantation of the entire, or parts of the device.Conclusion: Clinical improvement after LMD and ACD implantation was proven in our study. High incidence and volume of EPC did not correlate with clinical outcome. Mechanical friction of the polymer mesh with the endplate is most likely the cause of EPC after ACD.

Endplate Changes with Polyetheretherketone Cages in Posterior Lumbar Interbody Fusion

Study Design: A retrospective radiographic analysis.Purpose: The aim of the current study is to assess endplate changes after the use of polyetheretherketone (PEEK) cages in posterior lumbar interbody fusion (PLIF).Overview of Literature: A few recent reports had revealed endplate abnormalities due to PEEK cages, which may lead to nonunions.Methods: A retrospective computed tomography (CT)-based analysis of the endplate cavities and fusion status following PLIFs with PEEK cages was conducted by two independent observers. The term “cavity” was used to describe the endplate changes. The vertebral endplate cavities were assessed according to the size, multiplicity, location, and presence or absence of sclerosis.Results: There were 86 fixed levels in 65 consecutive patients, with a mean age of 35.44±19.60 years. The mean follow-up was 16.5±10.1 months (range, 6–57 months). Definite fusion was seen in 56 levels (65.12%) by observer 1 versus 44 levels (51.16) by observer 2. The strength of agreement was moderate. Endplate cavities were observed in 42 levels (48.84%) by observer 1 versus 47 levels (54.65%) by observer 2, with fair agreement. The strengths of agreement for the locations, multiplicity, and size were moderate, fair, and poor, respectively. Neither age, sex, etiology, levels, nor follow-up period was significantly associated with the presence of cavities. With regard to fusions, the nonunions detected by observer 1 were significantly associated with the presence of cavities (p<0.0001). However, those detected by observer 2 were nearly significant (p=0.05).Conclusions: There was a high rate of unfavorable radiographic findings in the form of endplate cavities in PLIF cases with PEEK cages. A more comprehensive classification for the assessment of fusions and endplate cavities should be formulated. We strongly recommend further CT-based studies with larger sample size and longer follow-up periods.

Vertebral Bone Marrow and Endplate Assessment on MR Imaging for the Differentiation of Modic Type 1 Endplate Changes and Infectious Spondylodiscitis

On magnetic resonance (MR) imaging, Modic type 1 (MT1) endplate changes and infectious spondylodiscitis share similar findings. Therefore, this study investigated vertebral bone marrow and endplate changes to enable their differentiation. The lumbar spine MR examinations of 91 adult patients were retrospectively included: 39 with MT1; 19 with early spondylodiscitis without abscess; and 33 with advanced spondylodiscitis with abscess. The assessment included percentage of bone marrow edema on sagittal short tau inversion recovery images, and the signal ratio of edema to unaffected bone and endplate contour (normal; irregular, yet intact; blurred; destructive) on sagittal unenhanced T1-weighted images. Differences were tested for statistical significance by Chi-square test and mixed model analysis of variance. The MR diagnostic accuracy in differentiating MT1 and spondylodiscitis was assessed by cross-tabulation and receiver-operating characteristic analysis. The endplate contours, edema extents, and T1-signal ratios of MT1 (extent, 31.96%; ratio, 0.83) were significantly different (p < 0.001) from early spondylodiscitis (56.42%; 0.60), and advanced spondylodiscitis (91.84%; 0.61). The highest diagnostic accuracy (sensitivity, 94.87%; specificity, 94.23%; accuracy, 94.51%) in identifying MT1 was provided by an irregular, yet intact endplate contour. This may be a useful MR feature for the differentiation between MT1 and spondylodiscitis, particularly in its early stage.

Associations between high intensity zones, Modic and endplate changes in lumbar spine of low back pain patients

Background High intensity zones (HIZ), Modic and endplate changes have all been pointed out as potential markers of low back pain (LBP). If an association between these morphological features exist, it may not only deepen the understanding of the underlying patho-physiological mechanism of LBP but may also improve the diagnostics by enabling stratification between individuals with non-specific LBP as well as within individuals having multi-segmental changes. The aim was to investigate if HIZ, Modic and endplate changes are associated and if endplate and vertebral T2-values reflect functional tissue characteristics related to these morphological features.Methods 150 IVDs with corresponding endplates and vertebrae in 26 chronic LBP-patients (25-69y, mean 38y, 11 males) were examined with T1- and T2-weighted MRI, and T2-mapping. Associations between morphological features and between morphological features and functional T2-values were determined. Results HIZ (62% of patients, 1-2/patient) was associated with endplate changes (100% of patients, 1-7/patient) (p=0.0003 and 0.0004 for upper and lower endplates), with an occurrence of 91% for upper and 71% for lower endplates adjacent to discs with HIZ. Modic changes (81% of patients, 1-3/patient) was associated with endplate changes (p<0.0001) with an occurrence of 87% for endplates adjacent to vertebrae with Modic changes. The occurrence of both HIZ and Modic changes was 43% (p=0.0001) for upper and 29% (p=0.003) for lower vertebrae. Significantly higher T2-values (p<0.004) were found in the vertebral tissue with associated Modic changes and HIZ. Conclusions This study of LBP-patients suggests that HIZ is associated with simultaneous presence of both Modic and endplate changes in the same motion segment. If these three simultaneous morphological features are linked to an active inflammatory process, reflected as a clinical specific pain profile remains to be investigated.

MRI signal changes and their association with intervertebral disc disease in canine vertebral endplates

Background This study was undertaken to determine the relationship between intervertebral endplate changes and intervertebral disc disease. This study was designed as a cross-sectional, observational study. Two hundred thirteen canine MRI scans performed between 2007 and 2014 were retrieved from a digital image archive. Scans which included any sagittal sections of the vertebral column from C1 to S1 were assessed for morphological changes to the vertebral endplate. Results There was found to be a significant association between vertebral endplate changes and intervertebral disc disease of the adjacent disc (P = 0.021). There was not found to be any significant association between dogs having vertebral endplate changes and having intervertebral disc disease (P = 0.38). There was found to be a highly significant association between discs with vertebral endplate changes on both associated vertebrae (bilateral) and having intervertebral disc disease (P = < 0.0001). Conclusions The presence of endplate changes should alert the observer to closely examine the disc, as intervertebral disc disease is mildly more likely to occur adjacent to these changes.