Intervertebral Disc Space Research Articles

Hybrid Bone Single Photon Emission Computed Tomography Imaging in Evaluation of Chronic Low Back Pain: Correlation with Modic Changes and Degenerative Disc Disease.

Multiple radiologic modalities are used in the evaluation of patients with low back pain (LBP). Only limited evidence currently exists to support the use of bone hydroxydiphosphonate single photon emission computed tomography (SPECT/CT) in patients with Modic changes (MCs) and degenerative disc disease. The aim of this study was to assess the value of the hybrid bone SPECT/CT imaging in patients with chronic LBP. We evaluate the correlation of hybrid bone SPECT/CT imaging patterns with MCs and disc abnormalities on magnetic resonance imaging (MRI). This was a prospective study. Ninety-nine consecutive patients with LBP from a single center. The degree of lumbar intervertebral disc and endplate degeneration on MRI and osteoblastic activity was shown on SPECT/CT. These 99 consecutive patients with LBP were prospectively evaluated. Patients with contemporary lumbosacral spine MRI and bone SPECT/CT were included. Patients with known or suspected malignancy, trauma, infectious processes, and previous surgery were excluded. The effect of LBP on the daily quality of life was assessed using Oswestry disability index. We analyzed the correlation between the degenerative changes at the intervertebral disc spaces and endplates on MRI and bone SPECT/CT findings using receiver operating characteristic curve analysis and Kappa statistics. The Pfirrmann grading system was used to score the severity of disc space degeneration on MRI scans. A total of 99 patients were included in the study (58 women, 41 men; mean age, 56.2 years). Mean Oswestry disability index score was 38.5% (range, 8%-72%). The L2-3 through to L5-S1 levels were studied. MCs were found in 54% of patients. Of the 396 levels examined 85 were found to have MCs (21.5%). The most affected levels were L4-5 (31.3%) and L5-S1 (40.9%). Pfirrmann grade 5 disc space (72.9%) was associated with MC (Pp<0.001). MC (70.6%) and Pfirrmann grade 5 disc spaces (73%) resulted in scintigraphically active endplate/disc space on SPECT/CT (P< 0.001). Bone SPECT/CT showed high metabolic activity in 96.1% of endplates with MC type I, 56% with MC type II, and 77.8% with MC type III. In this study we found a high agreement between MCs and increased metabolic activity on bone SPECT/CT imaging. MC type 1 and Pfirrmann grade 5 were the best binary predictors for positivity on bone SPECT/CT and had equivalent correlations. Lower vertebral levels in the lumbar spine were associated with higher degree of disc degeneration, high frequency of MCs, and positivity on bone SPECT/CT.

Extraforaminal Lumbar Interbody Fusion at the L5-S1 Level: Technical Considerations and Feasibility.

Background Extraforaminal lumbar interbody fusion (ELIF) surgery is a muscle-sparing approach that allows the treatment of various degenerative spinal diseases. It is technical challenging to perform the ELIF approach at the L5-S1 level because the sacral ala obstructs the view of the intervertebral disk space. Methods We reported earlier on the ELIF technique in which the intervertebral disk is targeted at an angle of 45 degrees relative to the midline. In this article we describe the technical process we developed to overcome the anatomic relation between the sacral ala and the intervertebral disk space L5-S1 that hinders the ELIF approach at this level. We then report in a retrospective analysis on the short-term clinical and radiologic outcome of 100 consecutive patients with degenerative L5-S1 pathologies who underwent ELIF surgery. Results The L5-S1 ELIF approach could be realized in all patients. The short-term clinical outcome was evaluated 5 months after surgery: 92% of the patients were satisfied with their postoperative result; 8% had a poor result. Overall, 17% of the patients presented light radicular or low back pain not influencing their daily activity, and 82% of the patients working before surgery returned to work 3 to 7 months after surgery. The radiologic outcome was documented by computed tomography at 5 months after surgery and showed fusion in 99% of the patients. Lumbar magnetic resonance imaging performed in 5 patients at 6 months after surgery revealed the integrity of the paraspinal muscles. Conclusions ELIF surgery at the L5-S1 level is technically feasible for various degenerative spinal diseases. Analysis of the clinical and radiologic data in a consecutive retrospective cohort of patients who underwent this surgical procedure showed a good short-term clinical outcome and fusion rate.

Novel rat tail discitis model using bioluminescent Staphylococcus aureus.

Management of spondylodiscitis is a challenging clinical problem requiring medical and surgical treatment strategies. The purpose of this study was to establish a rat model of spondylodiscitis that utilizes bioluminescent Staphylococcus aureus (S. aureus), thus permitting in vivo surveillance of infection intensity. Inocula of the bioluminescent S. aureus strain XEN36 were created in concentrations of 102 CFU/0.1 ml, 104 CFU/0.1 ml, and 106 CFU/0.1 ml. Three groups of rats were injected with the bacteria in the most proximal intervertebral tail segment. The third most proximal tail segment was injected with saline as a control. Bioluminescence was measured at baseline, 3 days, and weekly for a total of 6 weeks. Detected bioluminescence for each group peaked at day 3 and returned to baseline in 21 days. The average intensity was highest for the experimental group injected with the most concentrated bacterial solution (106 CFU/0.1 ml). Radiographic analysis revealed loss of intervertebral disc space and evidence of osseous bridging. Saline-injected spaces exhibited no decrease in intervertebral spacing as compared to distal sites. Histologic analysis revealed neutrophilic infiltrates, destruction of the annulus fibrosus and nucleus pulposus, destruction of vertebral endplates, and osseous bridging. Saline-injected discs exhibited preserved annulus fibrosus and nucleus pulposus on histology. This study demonstrates that injection of bioluminescent S. aureus into the intervertebral disc of a rat tail is a viable animal model for spondylodiscitis research. This model allows for real-time, in vivo quantification of infection intensity, which may decrease the number of animals required for infection studies of the intervertebral disc. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2075-2081, 2017.

Tumor Necrosis Factor Alpha Overexpression Induces Mainly Osteoclastogenesis at the Vertebral Site.

Syndesmophyte occurrence and axial bone loss were investigated in the heterozygous Tg187 tumor necrosis factor (TNF) transgenic mouse model (Tg-huTNF) of arthritis. Female and male Tg-huTNF mice were compared to wild-type mice (WT) at 2, 4, 6, 8, and 10weeks. Syndesmophytes, intervertebral disc space, osteoclasts, osteoid surface, and vertebra microarchitecture were assessed by histomorphometry and microcomputed tomography. No spontaneous syndesmophyte formation was detected in Tg-huTNF compared to WT mice. However, increased porosity was observed mainly in peridiscal lumbar vertebra. Accordingly, bone microarchitecture parameters were altered in Tg-huTNF mice, with decrease in bone volume fraction, and trabecular number and thickness after 6 weeks compared to WT (p < 0.05). Osteoclast count and surface were increased (p < 0.01). Moreover, the non-mineralized (osteoid) surface was also increased in Tg-huTNF after 6weeks (p < 0.01). Despite increased osteoclast and osteoid surfaces, an imbalance between both was observed in favour of osteoid surface at the early phase and then to osteoclast surface. These results demonstrated an axial bone loss in the Tg-huTNF model, additional to the common limb arthritis, related to overexpression of TNF. However, the absence of syndesmophyte and the increase of osteoid surface suggested that chronic inflammation might block bone mineralisation. Finally, the relative increased osteoid surface was not enough to compensate the high osteoclast activity.

Whole-spine Computed Tomography Findings in SAPHO Syndrome.

We evaluated the whole-spine computed tomography (CT) findings in patients with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome to improve our understanding of this rare disease. Whole-spine CT images obtained in 69 patients with SAPHO were reviewed. For each individual, a total of 25 vertebrae were evaluated for the distribution of affected vertebrae, CT manifestations of vertebral lesions, symmetry and location of distribution of the lesions on vertebrae, involvement pattern, and narrowing of adjacent intervertebral disc space. Paravertebral ligamentous ossifications, apophyseal joint disorders, and costovertebral joint disorders were also evaluated. All the 69 patients with SAPHO exhibited abnormalities on whole-spine CT. Sixty-four had vertebral lesions, 52 had paravertebral ossifications, and 47 had both. The vertebral lesions were observed in 441 vertebrae, with a predilection for thoracic spine. The lesions exhibited a mixture of cortical erosion, reactive osteosclerosis of surrounding cancellous bone, and syndesmophyte. They may be confined to the vertebral corner (65.1%) or be extensive, involving the endplate (34.9%). Corner lesions could start in any part of the epiphyseal ring. The lesions were asymmetrically distributed. The affected vertebrae were more consecutively involved in a "kissing" appearance (78.2%). Intervertebral disc spaces were usually normal or mildly narrowed. There were 320 foci of paravertebral ossifications observed, with a predilection for the supraspinous ligament. Paravertebral ossifications were delicate and segmental. Ossifications throughout annulus fibrosis and apophyseal joint were not observed. Our investigation of the distributional, morphological features and the involvement pattern of spinal lesions in patients with SAPHO demonstrated distinct CT characteristics.

Retrieval of a retained broken scalpel blade from lumbar intervertebral disc space - a case report

Abstract Lumbar diskectomy is a common procedure in neurosurgery, besides the common complications broken scalpel blade during disc removal is a rare event. Usually retrieval of such sharp retained fragments in same sitting is difficult and to prevent further complications another session is warranted [1]. We report a case of broken scalpel blade during L1-L2 lumbar intervertebral disc removal and successful surgical retrieval of that tip of knife with the help of operative microscope under fluoroscopic guidance during same sitting before any hazardous complications develop.

Chronic low back pain and its association with lumbar vertebrae and intervertebral disc changes in adults. A case control study.

This study was done to determine the association between chronic low back pain and vertebral fractures, intervertebral disc space (IDS) narrowing, vertebral osteophytes and spondylolisthesis among adults. This case control study was done in Sri Lanka. Cases were patients with low back pain and controls were without low back pain. Postero-anterior and lateral radiographs of lumbar sacral spine of both groups were studied. To detect vertebral fractures in fourth and fifth lumbar vertebrae, anterior and posterior heights of vertebrae were measured using a Vernier caliper and antero-posterior ratio (A/P) was calculated. Having an A/P ratio value of < 0.89 was considered as a vertebral fracture. Presence of disc space narrowing, vertebral osteophytes and spondylolisthesis was assessed by two radiologists working independently. Bivariate and logistic regression analysis was done to find associations. There were 140 cases and 140 controls. Mean (SD) age for cases was 51.6 (17) years. Mean (SD) age for controls was 50 (15) years. Females made up 62% of cases and controls. Fifth lumbar vertebral fracture (odds ratio [OR] = 10.2; P = 0.001), fourth lumbar vertebral fracture (OR = 2.5; P = 0.017) and IDS narrowing (OR = 4.15, P = 0.009) had a significant association with low back pain and vertebral osteophytes and spondylolisthesis did not have a significant association with low back pain. Only vertebral fractures and IDS narrowing had a significant association with chronic low back pain.

Unilaterally posterior lumbar interbody fusion with double expandable peek cages without pedicle screw support for lumbar disc herniation

ObjectivesPosterior lumbar interbody fusion (PLIF) is usually bilateral procedure, and it is combined with posterior by bilateral pedicle screw support or with fixation. The purpose of this retrospective study was to compare the surgical outcomes of simple discectomy and PLIF without pedicle screw support in patients with lumbar disc herniation (LDH). Patients and methods60 patients with single segment LDH were operated between February 2010 and June 2013. 40 patients were treated with simple discectomy (Group 1) and 20 patients were treated with PLIF using double expandable polyetheretherketone (PEEK) cages without instrumentation (Group 2) unilaterally. Pain and function were evaluated by the visual analog scale (VAS) and Oswestry disability index (ODI) before and 18 months after surgery. Besides, PLIF patients were evaluated with computerized tomography (CT) scan of lumbar vertebra for the evaluation of the height of the disc, instability and fusion. ResultsBoth leg and low back pain VAS scores were significantly improved 18 months after surgery in both of the groups (p<0.001). Significant decrease in VAS low back pain scores was seen in group 2 when compared to group 1 (p<0.001). Height of the intervertebral disc space was preserved and no instability was detected in group 2. No recurrence and 80% fusion rate was achieved in group 2. ConclusionThis study showed that unilateral PLIF intervention with double expandable PEEK cages without pedicle screw support would be sufficient in the management of single segment lumbar disc herniation in patients whom are thought to have lumbar stabilization.

The Safety of CT-Guided Epidural Steroid Injections in an Older Patient Cohort

Background: Epidural steroid injections (ESIs) are a common method for treating lower back pain, which is one of the most prevalent health-related complaints in the adult U.S. population. Although the safety of CT-guided ESIs has been extensively studied in adults, there is limited data concerning the procedure’s safety profile in an older patient population. Objective: This retrospective study analyzed safety data among a single-center cohort of patients &gt; 65 years-old who received one or more CT-guided interlaminar ESIs from 2012 to 2015. Study Design: An Institutional Review Board (IRB)-approved retrospective chart review. Setting: University hospital center. Methods: A total of 688 CT-guided ESI procedures were evaluated and a linear regression analysis was conducted to examine the relationship between dose length product (DLP), body mass index (BMI), procedure duration, and kVp/mA settings. Further analysis was performed on a sample of long procedure time, average-DLP and high-DLP procedures. Results: Average age was 75.77 years, with 44% having a BMI &gt; 30. The mean DLP was 55.58 mGy x cm and the mean procedure duration was 5.94 minutes. All procedures were technically successful and no complications were observed during or after any of the procedures, including at one-month follow-up office visits. The kVp and mA settings were the strongest predictors of DLP, followed by procedure time. The high-DLP cases had a greater number of needle placement series, more intervertebral disc spaces included in each planning series and higher machine settings (kVp 120; mA 87.5) than the average-DLP cases (kVp 100; mA 49.9). Limitations: This study is limited by its retrospective design. Conclusion: CT-guided interlaminar ESIs can be performed safely, with low procedure times, relatively low DLP’s and without complications in an older patient population. Key words: Epidural steroid injection, interlaminar approach, CT-guidance, older adults, back pain, lumbar spine, thoracic spine, cervical spine, dose length product, radiation exposure

IVC Filter Perforation: A Rare Cause of Abdominal Pain

Abdominal pain is one of the most common complaints of patients seeking medical care. Devices such as inferior vena cava (IVC) filters are frequently placed in patients with deep vein thrombosis and contraindications to anticoagulation. Symptomatic perforation of the filter into the adjacent tissue or vessels is a rare, but challenging, complication. A 65-year-old woman with a history of asthma and anxiety presented to clinic with abdominal pain. Seven weeks prior, she had been hospitalized for a diverticular bleed and focal diverticulitis. During her stay, venous sonography demonstrated a right femoral vein thrombosis and anticoagulation was initiated with heparin. She developed significant rectal bleeding leading to anticoagulation discontinuation and placement of a retrievable IVC filter. On presentation to the clinic, she reported lower back pain radiating to the right flank and buttock, nausea, and cramping post prandial abdominal pain. She had previously presented to a local emergency department with these symptoms and was prescribed an anti-spasmodic agent after clinical and laboratory evaluation was unrevealing. Now, seven weeks later, she reported persistence of symptoms. On evaluation, she was afebrile, hemodynamically stable, and physical examination was without abnormalities. CT scan of the abdomen and pelvis revealed caudal migration of the IVC filter with the primary legs perforating the IVC and splaying into the L3/L4 intervertebral disc space and aorta (Figures 1,2). She was admitted for endovascular retrieval of the IVC filter. A post-retrieval vena cavagram and CT angiogram with 3D vessel reconstruction demonstrated no complications such as peri-caval hematoma. Her symptoms resolved and she was discharged home the following day. Perforation of the IVC by a primary leg of the device is a rare, but important complication. Symptomatic perforation usually presents in the days to weeks following placement; however, symptoms may not manifest for years later. It is wise to have a high index of suspicion in patients with recent filter placement with only vague abdominal complaints that cannot be otherwise explained. Retrievable filters should be removed as soon as they are no longer needed. We recommend prompt removal of the device via endovascular or surgical approach for symptomatic perforations and asymptomatic perforations involving vital tissues such as the aorta, small bowel, and bone.Figure 1Figure 2

Within Normal Limits

Figure: A lateral radiograph of the thoracic spine, left, shows bulky bridging osteophytes (arrowheads) along the anterior thoracic spine involving greater than 4 contiguous vertebral bodies compatible with DISH. A fracture along the inferior endplate of the T8 vertebral body is barely perceptible (arrow). A sagittal CT scan, center, of the thoracic spine shows an acute, minimally displaced fracture of the middle to inferior half of the T8 vertebral body which extends into and widens the disc space (arrow). Note the extent of DISH at levels above and below the fracture. A sagittal CT scan of the thoracic spine, right, further shows the extent of the fracture and intact bulky osteophytes above and below the fracture site (arrow).FigureFigureFigureA 66-year-old man was brought to the emergency department after being in a motor vehicle crash in which he was rear-ended with very low impact. He complained of point tenderness in the lower thoracic spine, and a trauma workup was performed according to routine protocol. Thoracic radiographs showed evidence of bulky bridging osteophytes consistent with DISH (diffuse idiopathic skeletal hyperostosis) but no evidence of a fracture at the site of pain. Further evaluation with CT showed a displaced fracture of the T8 vertebral body, which extended through the disc space. The patient was placed in a brace and managed for non-life-threatening injuries, and was then discharged home. DISH most commonly occurs in the thoracic spine, typically involving T7-T11 levels. Most patients with DISH are discovered incidentally on imaging because they are often asymptomatic. Occasionally, patients can present with pain, postural instability, neurological symptoms, or dysphagia. A DISH diagnosis is typically made on radiography, followed by cross-sectional imaging, namely CT or MRI. It is characterized by the presence of ‘‘flowing’’ bulky ossifications along the anterolateral margin of at least four contiguous vertebral bodies, preservation of the intervertebral disk height without any degenerative-related findings and absence of apophyseal joint ankyloses, or fusion at the costovertebral or sacroiliac joints. Imaging features are characteristic, but the differential diagnosis for DISH include seronegative spondyloarthropathies such as ankylosing spondylitis, reactive arthritis and psoriatic arthritis. Unlike ankylosing spondylitis, fusion of the sacroiliac, facet, and uncovertebral joints do not occur in DISH. Similarly, reactive arthritis has asymmetric sacroiliac joint involvement and psoriatic arthritis has a predilection for the cervical and lower lumbar spine, while DISH occurs most commonly in the thoracic spine. The fused spine in DISH or any preexisting fusion-type condition is more prone to fracture than a normal spine, and these fractures can involve multiple vertebral columns and can occur after even minor trauma. Patients with moderate to severe disease are more prone to fractures. The thoracic and cervical spine are most commonly involved. Hyperextension is the most common mechanism of injury resulting in DISH-related spinal fractures. Acute spinal fractures are not common, but can lead to neurological injury, nonunion, deformity, or death. DISH produces broad bridging osteophytes that encompass the anterior longitudinal ligament, annulus fibrosis, and paraspinal connective tissues. The bridging osteophytes are most robust at the intervertebral disk space, extending to the adjacent vertebral body. The proximal and distal thirds of a vertebral body, therefore, are typically covered by ossifications, leaving the mid-vertebral body above and below the site of attachment of the ossifications most vulnerable to fractures. Alternatively, fractures may occur at the end of a fused segment, involving the vertebral body at the junction of fused and unfused spine. Radiographs of the spine may be initially obtained if fractures are suspected following minor trauma. Fractures may not be easily detected with radiographs in the patients with DISH or any other spinal fusion because of overlapping bone and soft tissues and the presence of productive bone formation. It is therefore reasonable to conclude from this case that a low threshold must be used to order a CT scan of the spine if patients with spinal fusion sustain minor trauma. This will not only assist in making an early and accurate diagnosis but ensure appropriate and timely treatment for patients. Share this article on Twitter and Facebook. Access the links in EMN by reading this on our website or in our free iPad app, both available at www.EM-News.com. Comments? Write to us at [email protected].

Motor control exercise for symptomatic lumbar disc herniation: protocol for a systematic review and meta-analysis.

IntroductionLumbar disc herniation (LDH) is a common condition in adults and can impose a heavy burden on both the individual and society. It is defined as displacement of disc components beyond the intervertebral disc space. Various conservative treatments have been recommended for the treatment of LDH and physical therapy plays a major role in the management of patients. Therapeutic exercise is effective for relieving pain and improving function in individuals with symptomatic LDH. The aim of this systematic review is to evaluate the effectiveness of motor control exercise (MCE) for symptomatic LDH.Methods and analysisWe will include all clinical trial studies with a concurrent control group which evaluated the effect of MCEs in patients with symptomatic LDH. We will search PubMed, SCOPUS, PEDro, SPORTDiscus, CINAHL, CENTRAL and EMBASE with no restriction of language. Primary outcomes of this systematic review are pain intensity and functional disability and secondary outcomes are functional tests, muscle thickness, quality of life, return to work, muscle endurance and adverse events. Study selection and data extraction will be performed by two independent reviewers. The assessment of risk of bias will be implemented using the PEDro scale. Publication bias will be assessed by funnel plots, Begg's and Egger's tests. Heterogeneity will be evaluated using the I2 statistic and the χ2 test. In addition, subgroup analyses will be conducted for population and the secondary outcomes. All meta-analyses will be performed using Stata V.12 software.Ethics and disseminationNo ethical concerns are predicted. The systematic review findings will be published in a peer-reviewed journal and will also be presented at national/international academic and clinical conferences.Trial registration numberCRD42016038166.

Detection of compressive hydrated nucleus pulposus extrusion in dogs with multislice computed tomography

Compressive hydrated nucleus pulposus extrusion (HNPE) in dogs is defined as acute extradural compression by hydrated nucleus pulposus material at the level of the associated intervertebral disc. Magnetic resonance imaging (MRI) is the imaging modality of choice for diagnosis of HNPE. The aims of this study were to determine the usefulness of unenhanced computed tomography (CT) and contrast enhanced CT (CE-CT), and the sensitivity and specificity of CE-CT, for detection of compressive HNPE. Using CE-CT, HNPE was visualised as a hypodense extradural compressive lesion with rim enhancement immediately dorsal to the intervertebral disc space, with a sensitivity of 91% and a specificity of 100%. CE-CT is a useful technique to detect compressive HNPE in dogs. However, if no clear lesion is identified with CE-CT, or if additional information about intramedullary changes is required, MRI still needs to be performed.

Clinical Outcomes of the Dynamic Lumbar Pedicle Screw-rod Stabilization

This study included 67 patients who underwent dynamic stabilization of the lumbar spine with the polyetheretherketone (PEEK) and Ti-alloy-cable composite. Patient participation was based on the presence of degenerative spondylolisthesis (grade I), lateral or central spinal stenosis, and their physician’s recommendation that the patient required decompression and instrumented fusion for 1 or 2 contiguous spinal levels between L1 and S1. Participants were evaluated preoperatively and postoperatively at 3, 6, 12, and 24 months. The ratio of intervertebral disk space to vertebral body height (IVS) and segmental and lumbar lordosis were evaluated preoperatively and postoperatively. Pain scores were evaluated by Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) preoperatively and postoperatively. The mean pain and function scores improved significantly from the baseline to 24-month follow-up evaluation, as follows: ODI score from 53.4% to 27.3% and back pain VAS from 63.2 to 31.9. The ODI and VAS scores decreased significantly from preoperative to postoperative. The IVS ratio remained unchanged between preoperative and postoperative conditions. The lumbar and segmental lordotic angles increased insignificantly from preoperative levels in the months following surgery. In conclusions, the early clinical outcomes of treatment with the dynamic rod composed of PEEK and Ti-alloy cable are promising in terms of maintenance of segmental lordosis and intervertebral space ratio, and improvement in pain and disability. Future clinical studies would be needed to examine and provide information regarding the impact of this dynamic pedicle screw system on the incidence of adjacent-level disease.

Epidural Fibrosis Seen from a Different Angle: Extraforaminal Lumbar Interbody Fusion.

Background Postoperative epidural fibrosis (PEF) localized around the exposed dura and nerve roots is a known radiologic entity seen after lumbar surgery. Although excessive PEF is associated with residual and new lumbar pain and radiculopathy, its role as the generator of the pain is still discussed. Various materials acting as an adhesion barrier have been tested. There is no undebated class I evidence that any one of them is suitable to reduce or avoid PEF and provide a better clinical outcome. In revision surgery, the dissection of epidural scar tissue is time consuming and related to an elevated risk of dural tear and nerve damage. To avoid the formation of posterior PEF, we propose a surgical approach whose working corridor is situated lateral to the dural sac and the nerve roots: the extraforaminal lumbar interbody fusion (ELIF) technique. Methods Description of ELIF surgical technique. Conclusions The ELIF technique is a muscle-sparing approach to the intervertebral disk space and the spinal canal that avoids the formation of posterior PEF. It represents an option to treat various degenerative lumbar spinal diseases as well as offering another approach for revision surgery in patients who have developed PEF.

Presumptive acute non-compressive nucleus pulposus extrusion in 11 cats: clinical features, diagnostic imaging findings, treatment and outcome.

Objectives The aim of the study was to describe the clinical features, diagnostic imaging findings, treatment and outcome in cats diagnosed with presumptive acute non-compressive nucleus pulposus extrusion. Methods Medical records and imaging studies of cats diagnosed with presumptive acute non-compressive nucleus pulposus extrusion were retrospectively reviewed. Information on long-term outcome was acquired from patient records and from either owners or referring veterinary surgeons via a telephone questionnaire. Results Eleven cats met the inclusion criteria. All cats had a peracute onset of clinical signs, with eight cats experiencing witnessed (n = 6) or suspected (n = 2) external trauma based on imaging findings. Neuroanatomical localisation included C1-C5 (n = 1), T3-L3 (n = 7) and L4-S3 (n = 3) spinal cord segments. MRI revealed acute non-compressive nucleus pulposus extrusions located at C3-C4 (n = 1), T12-T13 (n = 1), T13-L1 (n = 1), L1-L2 (n = 1), L3-L4 (n = 3), L4-L5 (n = 1) and L5-L6 intervertebral disc spaces (n = 3). Treatment included supportive care and 10 cats were discharged with a median hospitalisation time of 10 days (range 3-26 days). One cat was euthanased during hospitalisation owing to complications unrelated to neurological disease. All cats that presented as non-ambulatory regained an ambulatory status with the median time to ambulation of 17 days (range 6-21 days). Overall, the outcome for cats diagnosed with acute non-compressive nucleus pulposus extrusion was successful, with almost 90% returning to ambulation with urinary and faecal continence. Conclusions and relevance The majority of cats diagnosed with acute non-compressive nucleus pulposus extrusion had good outcomes. Acute non-compressive nucleus pulposus extrusion should be considered as a differential diagnosis for cats presenting with peracute onset of spinal cord dysfunction, particularly if there is a clinical history or evidence of trauma.

EVALUATION OF MAGNETIC RESONANCE IMAGING GUIDELINES FOR DIFFERENTIATION BETWEEN THORACOLUMBAR INTERVERTEBRAL DISK EXTRUSIONS AND INTERVERTEBRAL DISK PROTRUSIONS IN DOGS.

Four MRI variables have recently been suggested to be independently associated with a diagnosis of thoracolumbar intervertebral disk extrusion or protrusion. Midline intervertebral disk herniation, and partial intervertebral disk degeneration were associated with intervertebral disk protrusion, while presence of a single intervertebral disk herniation and disk material dispersed beyond the boundaries of the intervertebral disk space were associated with intervertebral disk extrusion. The aim of this retrospective, cross-sectional study was to determine whether using these MRI variables improves differentiation between thoracolumbar intervertebral disk extrusions and protrusions. Eighty large breed dogs with surgically confirmed thoracolumbar intervertebral disk extrusions or protrusions were included. Randomized MRI studies were presented on two occasions to six blinded observers, which were divided into three experience categories. During the first assessment, observers made a presumptive diagnosis of thoracolumbar intervertebral disk extrusion or protrusion without guidelines. During the second assessment they were asked to make a presumptive diagnosis with the aid of guidelines. Agreement was evaluated by Kappa-statistics. Diagnostic accuracy significantly improved from 70.8 to 79.6% and interobserver agreement for making a diagnosis of intervertebral disk extrusion or intervertebral disk protrusion improved from fair (κ = 0.27) to moderate (κ = 0.41) after using the proposed guidelines. Diagnostic accuracy was significantly influenced by degree of observer experience. Intraobserver agreement for the assessed variables ranged from fair to excellent and interobserver agreement ranged from fair to moderate. The results of this study suggest that the proposed imaging guidelines can aid in differentiating thoracolumbar intervertebral disk extrusions from protrusions.

Percutaneous Treatment of Herniated Lumbar Discs with Ozone: Investigation of the Mechanisms of Action

PurposeTo elucidate the mechanism of action of intradiscal oxygen-ozone therapy for herniated intervertebral disc therapy. MethodsOzone’s mechanism of action was investigated using 3 approaches: mathematical models of intervertebral disc space to explore the relationship between disc pressure and volume; ozonolysis experiments using glycosaminoglycans (GAGs) from a Chinese hamster ovary cell line that were similar in composition to GAGs found in human nucleus pulposus; and experiments in which live Yucatan miniature pigs received various concentrations of percutaneous, image-guided intradiscal oxygen-ozone treatment and were examined (after sacrifice) with histology and semiquantitative analysis of disc cytokine concentrations. ResultsEngineering calculations support observations that a small (6%) disc volume reduction can result in considerable (9.84%) intradiscal pressure reduction. Porcine disc histology and Chinese hamster ovary GAG ozonolysis results showed that administered ozone reacted with and fragmented disc proteoglycans, reducing disc volume through disc dehydration. Cytokine analysis of porcine discs found that each of 4 cytokines measured (interleukin [IL]-1β, IL-6, IL-8, and tumor necrosis factor α) increased in concentration after 2 wt% ozone treatment. ConclusionsOxygen-ozone therapy breaks down proteoglycan GAGs that maintain disc osmotic pressure, dehydrating the nucleus pulposus and reducing intervertebral disc volume. This is likely a primary mechanism by which ozone relieves nerve root compression and alleviates herniated disc–related pain. Additionally, 2 wt% ozone appears to interact with intradiscal cytokines, generating an antiinflammatory response that may contribute to symptom improvement.

Menopause as a potential cause for higher prevalence of low back pain in women than in age-matched men

SummaryFemale sex hormones play an important role in the aetiology and pathophysiology of a variety of musculoskeletal degenerative diseases. Postmenopausal women show accelerated disc degeneration due to relative oestrogen deficiency, resulting in narrower intervertebral disc space in women than age-matched men, increased prevalence of spondylolisthesis, and increased prevalence of facet joint osteoarthritis. Postmenopausal women also show higher osteoporosis related spine fracture rate, particularly at the thoracic–lumbar junction site. I propose the concept that low back pain (LBP) is more prevalent in postmenopausal women than age-matched men and is associated with the physiological changes caused by the relatively lower level of sex hormones after menopause in women. Considering hormone replacement treatment (HRT)'s consistent efficacy reported with menopause-associated osteoarthritis, an in-depth understanding of the role of the gonadal hormones in LBP modulation warrants further study. HRT initiated at early postmenopausal phase may be protective for recurring LBP. If this is the case, further cost–benefit analysis should be performed for optimal HRT regimen in cases of women with high risk of recurring severe LBP.

Excessive Activation of TGFβ by Spinal Instability Causes Vertebral Endplate Sclerosis.

Narrowed intervertebral disc (IVD) space is a characteristic of IVD degeneration. EP sclerosis is associated with IVD, however the pathogenesis of EP hypertrophy is poorly understood. Here, we employed two spine instability mouse models to investigate temporal and spatial EP changes associated with IVD volume, considering them as a functional unit. We found that aberrant mechanical loading leads to accelerated ossification and hypertrophy of EP, decreased IVD volume and increased activation of TGFβ. Overexpression of active TGFβ in CED mice showed a similar phenotype of spine instability model. Administration of TGFβ Receptor I inhibitor attenuates pathologic changes of EP and prevents IVD narrowing. The aberrant activation of TGFβ resulting in EPs hypertrophy-induced IVD space narrowing provides a pharmacologic target that could have therapeutic potential to delay DDD.