Quantitative MRI to Characterize the Nucleus Pulposus Morphological and Biomechanical Variation According to Sagittal Bending Load and Radial Fissure, an ex vivo Ovine Specimen Proof-of-Concept Study.

Background and context: Low back pain is a dramatic burden worldwide. Discography studies have shown that 39% of chronic low back pain patients suffer from discogenic pain due to a radial fissure of intervertebral disc. This can have major implications in clinical therapeutic choices. The use of discography is restricted because of its invasiveness and interest in it remains low as it represents a static condition of the disc morphology. Magnetic Resonance Imaging (MRI) appears to be less invasive but does not describe the biomechanical dynamic behavior of the fissure. Purpose: We aimed to seek a quantitative MRI protocol combined with ex vivo sagittal loading to analyze the morphological and biomechanical changes of the intervertebral disc structure and stress distribution. Study design: Proof of concept. Methods: We designed a proof-of-concept ovine study including 3 different 3.0 T-MRI sequences (T2-weighted, T1 and T2 mapping). We analyzed 3 different mechanical states (neutral, flexion and extension) on a fresh ovine spine specimen to characterize an intervertebral disc before and after puncturing the anterior part of the annulus fibrosus. We used a mark tracking method to calculate the bending angles and the axial displacements of the discal structures. In parallel, we created a finite element model to calculate the variation of the axial stress and the maximal intensity shear stress, extrapolated from our experimental boundary conditions. Results: Thanks to an original combination of specific nuclear relaxation time quantifications (T1, T2) of the discal tissue, we characterized the nucleus movement/deformation into the fissure according to the synchronous mechanical load. This revealed a link between disc abnormality and spine segment range of motion capability. Our finite element model highlighted significant variations within the stress distribution between intact and damaged disc. Conclusion: Quantitative MRI appears to provide a new opportunity to characterize intra-discal structural morphology, lesions and stress changes under the influence of mechanical load. This preliminary work could have substantial implications for non-invasive disc exploration and could help to validate novel therapies for disc treatment.

Clinical guidelines and care pathway for management of low back pain with or without radicular pain.

OBJECTIVE: To develop guidelines for low back pain management according to previous international guidelines and the updated literature. METHODS: A report was compiled from a review of systematic reviews of guidelines published between 2013 and 2018 and meta-analysis of the management of low back pain published between 2015 and 2018. This report summarized the state-of-the-art scientific knowledge for each predefined area of the guidelines from a critical review of selected literature. A multidisciplinary panel of experts including 17 health professionals involved in low back pain management and 2 patient representatives formulated preliminary guidelines based on the compilation report and a care pathway. The compilation report and preliminary guidelines were submitted to 25 academic institutions and stakeholders for the consultation phase. From responses of academic institutions and stakeholders, the final guidelines were developed. For each area of the guidelines, agreement between experts was assessed by the RAND/UCLA method. RESULTS: The expert panel drafted 32 preliminary recommendations including a care pathway, which was amended after academic institution and stakeholder consultation. The consensus of the multidisciplinary expert panel was assessed for each final guideline: 32 recommendations were assessed as appropriate; none was assessed as uncertain or inappropriate. Strong approval was obtained for 27 recommendations and weak for 5. CONCLUSION: These new guidelines introduce several concepts, including the need to early identify low back pain at risk of chronicity to provide quicker intensive and multidisciplinary management if necessary.

Optimizing the Management and Outcomes of Failed Back Surgery Syndrome: A Proposal of a Standardized Multidisciplinary Team Care Pathway.

Failed back surgery syndrome (FBSS) is a major, worldwide health problem that generates considerable expense for healthcare systems. A number of controversial issues concerning the management of FBSS are regularly debated, but no clear consensus has been reached. This pitfall is the result of lack of a standardized care pathway due to insufficient characterization of underlying pathophysiological mechanisms, which are essential to identify in order to offer appropriate treatment, and the paucity of evidence of treatment outcomes. In an attempt to address the challenges and barriers in the clinical management of FBSS, an international panel of physicians with a special interest in FBSS established the Chronic Back and Leg Pain (CBLP) Network with the primary intention to provide recommendations through consensus on how to optimize outcomes. In the first of a series of two papers, a definition of FBSS was delineated with specification of criteria for patient assessment and identification of appropriate evaluation tools in order to choose the right treatment options. In this second paper, we present a proposal of a standardized care pathway aiming to guide clinicians in their decision-making on how to optimize their management of FBSS patients. The utilization of a multidisciplinary approach is emphasized to ensure that care is provided in a uniform manner to reduce variation in practice and improve patient outcomes.

Optimizing the Management and Outcomes of Failed Back Surgery Syndrome: A Consensus Statement on Definition and Outlines for Patient Assessment.

Failed back surgery syndrome (FBSS) is a controversial term for identifying patients affected by new, recurrent, or persistent pain in the low back and/or legs following spinal surgery. The lack of a comprehensive standardized care pathway compromises the appropriate management of FBSS patients, which is associated with a heavy financial burden. An international panel of spine surgeons, neurosurgeons, and pain specialists with a particular interest in FBSS established the chronic back and leg pain (CBLP) network with the aim of addressing the challenges and barriers in the clinical management of FBSS patients by building a common transdisciplinary vision. Based on literature reviews, additional input from clinical expertise of multiple professional disciplines, and consensus among its members, the network attempted to provide recommendations on the management of patients with FBSS utilizing a multidisciplinary team (MDT) approach. The presentation of this work has been divided in two separate parts to enhance its clarity. This first paper, in favour of selecting appropriate validated tools to improve the FBSS patient assessment, focuses on FBSS taxonomy and its clinical implications for evaluation. Concise recommendations for assessment, treatment, and outcome evaluation using a MDT approach would be an important resource for specialists and nonspecialist clinicians who manage patients with FBSS, to improve decision-making, reduce variation in practice, and optimize treatment outcomes in this difficult-to-treat population.