Decompression with or without Fusion in Degenerative Lumbar Spondylolisthesis.

BACKGROUND: In patients with lumbar spinal stenosis and degenerative spondylolisthesis, it is uncertain whether decompression surgery alone is noninferior to decompression with instrumented fusion. METHODS: We conducted an open-label, multicenter, noninferiority trial involving patients with symptomatic lumbar stenosis that had not responded to conservative management and who had single-level spondylolisthesis of 3 mm or more. Patients were randomly assigned in a 1:1 ratio to undergo decompression surgery (decompression-alone group) or decompression surgery with instrumented fusion (fusion group). The primary outcome was a reduction of at least 30% in the score on the Oswestry Disability Index (ODI; range, 0 to 100, with higher scores indicating more impairment) during the 2 years after surgery, with a noninferiority margin of -15 percentage points. Secondary outcomes included the mean change in the ODI score as well as scores on the Zurich Claudication Questionnaire, leg and back pain, the duration of surgery and length of hospital stay, and reoperation within 2 years. RESULTS: The mean age of patients was approximately 66 years. Approximately 75% of the patients had leg pain for more than a year, and more than 80% had back pain for more than a year. The mean change from baseline to 2 years in the ODI score was -20.6 in the decompression-alone group and -21.3 in the fusion group (mean difference, 0.7; 95% confidence interval [CI], -2.8 to 4.3). In the modified intention-to-treat analysis, 95 of 133 patients (71.4%) in the decompression-alone group and 94 of 129 patients (72.9%) in the fusion group had a reduction of at least 30% in the ODI score (difference, -1.4 percentage points; 95% CI, -12.2 to 9.4), showing the noninferiority of decompression alone. In the per-protocol analysis, 80 of 106 patients (75.5%) and 83 of 110 patients (75.5%), respectively, had a reduction of at least 30% in the ODI score (difference, 0.0 percentage points; 95% CI, -11.4 to 11.4), showing noninferiority. The results for the secondary outcomes were generally in the same direction as those for the primary outcome. Successful fusion was achieved with certainty in 86 of 100 patients (86.0%) who had imaging available at 2 years. Reoperation was performed in 15 of 120 patients (12.5%) in the decompression-alone group and in 11 of 121 patients (9.1%) in the fusion group. CONCLUSIONS: In this trial involving patients who underwent surgery for degenerative lumbar spondylolisthesis, most of whom had symptoms for more than a year, decompression alone was noninferior to decompression with instrumented fusion over a period of 2 years. Reoperation occurred somewhat more often in the decompression-alone group than in the fusion group. (NORDSTEN-DS ClinicalTrials.gov number, NCT02051374.).

Dural Sac Cross-sectional area change from preoperatively and up to 2 years after decompressive surgery for central lumbar spinal stenosis: investigation of operated levels, data from the NORDSTEN study.

PURPOSE: The aim of the present study was to investigate how canal area size changed from before surgery and up to 2 years after decompressive lumbar surgery lumbar spinal stenosis. Further, to investigate if an area change postoperatively (between 3 months to 2 years) was associated with any preoperative demographic, clinical or MRI variables or surgical method used. METHODS: The present study is analysis of data from the NORDSTEN- SST trial where 437 patients were randomized to one of three mini-invasive surgical methods for lumbar spinal stenosis. The patients underwent MRI examination of the lumbar spine before surgery, and 3 and 24 months after surgery. For all operated segments the dural sac cross-sectional area (DSCA) was measured in mm2. Baseline factors collected included age, gender, BMI and smoking habits. Furthermore, surgical method, index level, number of levels operated, all levels operated on and baseline Schizas grade were also included in the analysis. RESULTS: 437 patients were enrolled in the NORDSTEN-SST trial, whereof 310 (71%) had MRI at 3 months and 2 years. Mean DSCA at index level was 52.0 mm2 (SD 21.2) at baseline, at 3 months it increased to 117.2 mm2 (SD 43.0) and after 2 years the area was 127.7 mm2 (SD 52.5). Surgical method, level operated on or Schizas did not influence change in DSCA from 3 to 24 months follow-up. CONCLUSION: The spinal canal area after lumbar decompressive surgery for lumbar spinal stenosis increased from baseline to 3 months after surgery and remained thereafter unchanged 2 years postoperatively.

The association between lumbar lordosis preoperatively and changes in PROMs for lumbar spinal stenosis patients 2 years after spinal surgery: radiological and clinical results from the NORDSTEN-spinal stenosis trial.

BACKGROUND: Patients with lumbar spinal stenosis (LSS) sometimes have lower lumbar lordosis (LL), and the incidence of LSS correlates closely with the loss of LL. The few studies that have evaluated the association between LL and clinical outcomes after non-instrumented surgery for LSS show conflicting results. This study investigates the association between preoperative LL and changes in PROMs 2 years after decompressive surgery. METHOD: This prospective cohort study obtained preoperative and postoperative data for 401 patients from the multicenter randomized controlled spinal stenosis trial as part of the NORwegian degenerative spondylolisthesis and spinal STENosis (NORDSTEN) study. Before surgery, the radiological sagittal alignment parameter LL was measured using standing X-rays. The association between LL and 2-year postoperative changes was analyzed using the oswestry disability index (ODI), a numeric rating scale (NRS) for low back and leg pain, the Zurich claudication questionnaire (ZCQ), and the global perceived effect (GPE) score. The changes in PROMs 2 years after surgery for quintiles of lumbar lordosis were adjusted for the respective baseline PROMs: age, sex, smoking, and BMI. The Schizas index and the Pfirrmann index were used to analyze multiple regressions for changes in PROMs. RESULTS: There were no associations in the adjusted and unadjusted analyses between preoperative LL and changes in ODI, ZCQ, GPE, and NRS for back and leg pain 2 years after surgery. CONCLUSION: LL before surgery was not associated with changes in PROMs 2 years after surgery. Lumbar lordosis should not be a factor when considering decompressive surgery for LSS.

Preoperative fatty infiltration of paraspinal muscles assessed by MRI is associated with less improvement of leg pain 2 years after surgery for lumbar spinal stenosis.

PURPOSE: Fatty infiltration (FI) of the paraspinal muscles may associate with pain and surgical complications in patients with lumbar spinal stenosis (LSS). We evaluated the prognostic influence of MRI-assessed paraspinal muscles' FI on pain or disability 2 years after surgery for LSS. METHODS: A muscle fat index (MFI) was calculated (by dividing signal intensity of psoas to multifidus and erector spinae) on preoperative axial T2-weighted MRI of patients with LSS. Pain and disability 2 years after surgery were assessed using the Oswestry disability index, the Zurich claudication questionnaire and numeric rating scales for leg and back pain. Multivariate linear and logistic regression analyses (adjusted for preoperative outcome scores, age, body mass index, sex, smoking status, grade of spinal stenosis, disc degeneration and facet joint osteoarthritis) were used to assess the associations between MFI and patient-reported clinical outcomes. In the logistic regression models, odds ratios (OR) and 95% confidence intervals (CI) were calculated for associations between the MFI and ≥ 30% improvement of the outcomes (dichotomised into yes/no). RESULTS: A total of 243 patients were evaluated (mean age 66.6 ± 8.5 years), 49% females (119). Preoperative MFI and postoperative leg pain were significantly associated, both with leg pain as continuous (coefficient - 3.20, 95% CI - 5.61, - 0.80) and dichotomised (OR 1.51, 95% CI 1.17, 1.95) scores. Associations between the MFI and the other outcome measures were not statistically significant. CONCLUSION: Preoperative FI of the paraspinal muscles on MRI showed statistically significant association with postoperative NRS leg pain but not with ODI or ZCQ.

Evaluating a targeted person-centred pain management intervention programme in lumbar spine surgery - a controlled segment-specific before-and-after interventional design.

BACKGROUND: Postoperative pain management in lumbar spine surgery care remains a challenge. The aim of this study was to evaluate the impact of a person-centred postoperative pain management intervention programme on lumbar spine surgery patients on postoperative pain, shared decision-making, and satisfaction with postoperative pain management. METHODS: The study was performed with a controlled before-and-after interventional design in an orthopaedic unit at a university hospital. Person-centred pain management for patients undergoing spine surgery was developed in co-creation by a multi-professional team and implemented throughout the care pathway. The usual care group (pre-intervention) served as a comparison to the intervention group. Pain intensity, shared decision-making in pain management, and patient satisfaction with results of pain management, served as patient-reported measures, collected using the International Pain Outcomes questionnaire and analysed using descriptive statistics. RESULTS: The intervention showed no benefit for patients' pain and satisfaction, while shared decision-making in pain management was significant lower in the intervention group than in the conventional group. The per-protocol analysis showed no significant differences between groups. CONCLUSION: The initial assumption of the study, that the implementation of a co-created structured person-centred care pathway would improve patient-reported outcomes, was not confirmed. The periodically low fidelity to the intervention due to organizational constraints (due to sub-optimal organizational conditions and managerial support) may have affected the results.

Detailed MRI evaluation of the spine: a 2-year follow-up study of young individuals reporting different training doses.

OBJECTIVE: To characterize the discs and vertebrae in detail over time in a group of adolescent individuals with varying training doses using magnetic resonance imaging (MRI). METHOD: Thirty-five students were recruited from regular high schools (n=13) as well as schools with athlete competitive skiing programmes (n = 22). The thoraco-lumbar spine of all individuals was examined at baseline and at 2-year follow-up using the same 1.5T scanner and imaging protocol. The individuals were grouped based on their reported training dose: low-to-normal training dose (≤5 h/week, n = 11, mean age 16.5 ± 0.5 years) and high training dose (>5 h/week, n = 24, mean age 17.2 ± 0.6 years.) RESULTS: At baseline, the signal intensity in the discs and vertebrae were significantly lower in individuals reporting high compared to low-to-normal training dose. The vertebral signal changed significantly over the 2-year period in both groups. However, only individuals reporting low-to-normal training dose displayed an overall disc signal change. Interestingly, the regional analysis displayed at baseline high annular signals in the more training-active individuals followed by a reduction over the two-year period. CONCLUSION: This study suggests that disc degeneration is manifested earlier in individuals reporting a higher training dose. Over a 2-year period, however, the degeneration process did not accelerate further. Also, a significant difference in the vertebral signal, at baseline and follow-up as well as over time, could be seen between groups of individuals reporting high versus low-to-normal training dose.

Clinical outcome and MRI appearance in a group of chronic low back pain patients more than 10 years after discography evaluation and consideration for surgery.

BACKGROUND: It is an ongoing debate whether fusion surgery is superior to non-operative treatment for non-specific low back pain (LBP) in terms of patient outcome. Further, the evidence for how signs of intervertebral disc (IVD) degeneration on magnetic resonance imaging (MRI) correlate with patient outcome is insufficient. Longitudinal studies of low back pain (LBP) patients are thus of interest for increased knowledge. The aim of this study was to investigate long-term MRI appearance in LBP patients 11-14 years after discography. METHODS: In 2021, 30 LBP patients who had same-day discography and MRI in 2007-2010 were asked to undergo MRI (Th12/L1-L5/S1), complete visual analog scale (VAS), Oswestry Disability Index (ODI) and EuroQol-5 Dimension (EQ5D) questionnaires. Patients who had fusion surgery before the follow-up were compared with those without such surgery. MRIs were evaluated on Pfirrmann grade, endplate classification score (EPS), and High Intensity Zones (HIZ). For each disk it was noted if injected at baseline or not. RESULTS: Of 17 participants (6 male;mean age 58.5 years, range 49-72), 10 (27 disks) had undergone fusion surgery before the follow-up. No differences in VAS, ODI, or EQ5D scores were found between patients with and without surgery (mean 51/32/0.54 vs. 50/37/0.40, respectively; 0.77 > p < 0.65). Other than more segments with EPS ≥ 4 in the surgery group (p < 0.05), no between-group differences were found in longitudinal change in MRI parameters. Of 75 non-fused disks, 30 were injected at baseline. Differences were found between injected and non-injected disks at both baseline and follow-up for Pfirrmann grade and HIZ, and at follow-up for EPS (0.04 > p < 0.001), but none for progression over time (0.09 > p < 0.82). CONCLUSIONS: Other than more endplate changes in the surgery group, no differences in longitudinal change of MRI parameters were established between LBP patients treated with or without fusion surgery in the studied cohort. The study also highlights the limited progress of degenerative changes, which may be seen over a decade, despite needle puncture and chronic LBP.

Is the presence of foraminal stenosis associated with outcome in lumbar spinal stenosis patients treated with posterior microsurgical decompression.

BACKGROUND: We aim to investigate associations between preoperative radiological findings of lumbar foraminal stenosis with clinical outcomes after posterior microsurgical decompression in patients with predominantly central lumbar spinal stenosis (LSS). METHODS: The study was an additional analysis in the NORDSTEN Spinal Stenosis Trial. In total, 230 men and 207 women (mean age 66.8 (SD 8.3)) were included. All patients underwent an MRI including T1- and T2-weighted sequences. Grade of foraminal stenosis was dichotomized into none to moderate (0-1) and severe (2-3) category using Lee's classification system. The Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ), and numeric rating scale (NRS) for back and leg pain were collected at baseline and at 2-year follow-up. Primary outcome was a reduction of 30% or more on the ODI score. Secondary outcomes included the mean improvement on the ODI, ZCQ, and NRS scores. We performed multivariable regression analyses with the radiological variates foraminal stenosis, Pfirrmann grade, Schizas score, dural sac cross-sectional area, and the possible plausible confounders: patients' gender, age, smoking status, and BMI. RESULTS: The cohort of 437 patients presented a high degree of degenerative changes at baseline. Of 414 patients with adequate imaging of potential foraminal stenosis, 402 were labeled in the none to moderate category and 12 in the severe category. Of the patients with none to moderate foraminal stenosis, 71% achieved at least 30% improvement in ODI. Among the patients with severe foraminal stenosis, 36% achieved at least 30% improvement in ODI. A significant association between severe foraminal stenosis and less chance of reaching the target of 30% improvement in the ODI score after surgery was detected: OR 0.22 (95% CI 0.06, 0.83), p=0.03. When investigating outcome as continuous variables, a similar association between severe foraminal stenosis and less improved ODI with a mean difference of 9.28 points (95%CI 0.47, 18.09; p=0.04) was found. Significant association between severe foraminal stenosis and less improved NRS pain in the lumbar region was also detected with a mean difference of 1.89 (95% CI 0.30, 3.49; p=0.02). No significant association was suggested between severe foraminal stenosis and ZCQ or NRS leg pain. CONCLUSION: In patients operated with posterior microsurgical decompression for LSS, a preoperative severe lumbar foraminal stenosis was associated with higher proportion of patients with less than 30% improvement in ODI. TRIAL REGISTRATION: The study is registered at ClinicalTrials.gov (22.11.2013) under the identifier NCT02007083.

Transmission-Based Vertebrae Strength Probe Development: Far Field Probe Property Extraction and Integrated Machine Vision Distance Validation Experiments.

We are developing a transmission-based probe for point-of-care assessment of vertebrae strength needed for fabricating the instrumentation used in supporting the spinal column during spinal fusion surgery. The device is based on a transmission probe whereby thin coaxial probes are inserted into the small canals through the pedicles and into the vertebrae, and a broad band signal is transmitted from one probe to the other across the bone tissue. Simultaneously, a machine vision scheme has been developed to measure the separation distance between the probe tips while they are inserted into the vertebrae. The latter technique includes a small camera mounted to the handle of one probe and associated fiducials printed on the other. Machine vision techniques make it possible to track the location of the fiducial-based probe tip and compare it to the fixed coordinate location of the camera-based probe tip. The combination of the two methods allows for straightforward calculation of tissue characteristics by exploiting the antenna far field approximation. Validation tests of the two concepts are presented as a precursor to clinical prototype development.

Interpretation of Morphological Details of Nondegenerated Lumbar Intervertebral Discs on Magnetic Resonance Imaging: Insights From a Comparison Between Computed Tomography Discograms and Magnetic Resonance Imaging.

OBJECTIVE: To gain better insight into the magnetic resonance imaging (MRI) appearance of morphological intervertebral disc (IVD) details, such as annular and nucleus pulposus dimensions, by comparing contemporaneously obtained MRI and postdiscogram computed tomography (CT) scans of nondegenerated IVDs. METHODS: Axial T2-weighted images and same-day postdiscography CTs, acquired after the MRI, of 26 normal-appearing lumbar IVDs (control IVDs at discography) were compared. The location and extent of central hyperintense zone on MRI and the extent of contrast distribution on CT relative to the IVD width (in anteroposterior [AP] and lateral planes) were assessed, with difference in measures between the modalities used to provide apparent inner annulus thickness and to estimate dimensions of also the outer annulus and location of nucleus pulposus. RESULTS: The mean (SD) extent of contrast distribution on CT discograms (53.1% [6.6%] and 58.1% [8.7%] of AP and lateral IVD width) was smaller than (P < 0.001 for both), and correlated weakly (r = 0.31 and 0.32 for AP and lateral planes) with corresponding measurements (58.4% [5.3%] and 65.7% [5.9%], respectively) for central hyperintense zone at MRI. The center of contrast opacification on CT discograms was located posterior to that of central T2 hyperintense zone on MRI in AP (P < 0.01), without any difference in lateral direction (P = 0.60). CONCLUSIONS: Normal-appearing lumbar IVDs are supported by outer annulus of larger relative thickness anteriorly, seen on both modalities. The shown discrepancy between the central T2 hyperintense zone and contrast distribution on CT discogram might reflect the inner annulus or structural changes within the borderzone nucleus and annulus. The exact nucleus size and inner annulus thickness could not be established due to a variable permeation of contrast across the central hyperintense zone on T2-weighted images.

The effect of gender on intramuscular pressure in patients with chronic exertional compartment syndrome of the lower leg.

This study aimed to compare intramuscular pressure (IMP) in all four compartments of the lower leg between men and women in patients with suspected chronic exertional compartment syndrome (CECS), and to assess possible effects of gender in relation to covariation factors. A consecutive series of patients with exertional leg pain (n = 962, median age 27 years, 56.2% women) underwent IMP measurements between 2009 and 2019. The CECS diagnosis was confirmed (n = 491, 48% women) or ruled out (n = 471, 65% women) based on the patient's history, clinical examination, and IMP measurements. IMP values of the compartments were compared between genders. A multiple linear regression analysis was performed for IMP in the anterior and lateral compartments, where the number of patients was large enough to investigate the possible impact of other factors such as height, age, and duration of pain. Among those with a confirmed CECS diagnosis, one-minute post-exercise IMP was significantly lower in women than in men for all four muscle compartments: anterior (median [range] mmHg 44 [24-120] vs. 50 [24-130]), lateral (35 [20-89] vs. 40 [26-106]), deep posterior (31 [25-36] vs. 34 [24-53]), and superficial posterior (32 [27-39] vs. 37 [22-54]). In the multiple regression analysis, gender differences remained significant in the anterior compartment but not the lateral compartment, where only height remained a significant predictor of IMP. Gender should be considered when using cut-off values for IMP in diagnosing CECS, especially for the anterior compartment.

A systematic review of validated classification systems for cervical and lumbar spinal foraminal stenosis based on magnetic resonance imaging.

PURPOSE: Foraminal stenosis is commonly investigated with radiological methods in patients with radiating pain in extremities. However, there is a lack of consensus regarding the methodology to assess compression of the nerve roots. This systematic review was performed to identify validated classification systems for foraminal stenosis in the lumbar and cervical spine based on magnetic resonance imaging (MRI). METHODS: A systematic search was conducted according to the PRISMA guidelines. The search included Cochrane, Embase, Medline and PubMed databases going back 30 years and up to September 2021. Three categories of words were used in different variations; foraminal stenosis, MRI and scoring. For inclusion, at least one word from each category had to be present. Articles suggesting classification systems or reporting on their validation were selected for inclusion. RESULTS: A total of 823 articles were identified and all abstracts were reviewed. Subsequently, a full-text review of 64 articles was performed and finally 14 articles were included. A total of three validated classification systems were found for the cervical and lumbar spine. The remaining 11 articles reported on validation or suggested modifications of the classification systems. CONCLUSION: The three classification systems demonstrated moderate to good reliability and have all been shown feasible in the clinical setting. There is however a need for further studies testing the validity of these classifications in relation to both clinical findings and to surgical outcome data.

Identification of potentially painful disc fissures in magnetic resonance images using machine-learning modelling.

PURPOSE: It is suggested that non-specific low back pain (LBP) can be related to nerve ingrowth along granulation tissue in disc fissures, extending into the outer layers of the annulus fibrosus. Present study aimed to investigate if machine-learning modelling of magnetic resonance imaging (MRI) data can classify such fissures as well as pain, provoked by discography, with plausible accuracy and precision. METHODS: The study was based on previously collected data from 30 LBP patients (age = 26-64 years, 11 males). Pressure-controlled discography was performed in 86 discs with pain-positive discograms, categorized as concordant pain-response at a pressure ≤ 50 psi and for each patient one negative control disc. The CT-discograms were used for categorization of fissures. MRI values and standard deviations were extracted from the midsagittal part and from 5 different sub-regions of the discs. Machine-learning algorithms were trained on the extracted MRI markers to classify discs with fissures extending into the outer annulus or not, as well as to classify discs as painful or non-painful. RESULTS: Discs with outer annular fissures were classified in MRI with very high precision (mean of 10 repeated testings: 99%) and accuracy (mean: 97%) using machine-learning modelling, but the pain model only demonstrated moderate diagnostic accuracy (mean accuracy: 69%; precision: 71%). CONCLUSION: The present study showed that machine-learning modelling based on MRI can classify outer annular fissures with very high diagnostic accuracy and, hence, enable individualized diagnostics. However, the model only demonstrated moderate diagnostic accuracy regarding pain that could be assigned to either a non-sufficient model or the used pain reference.

Clinical and MRI findings in lumbar spinal stenosis: baseline data from the NORDSTEN study.

PURPOSE: The aim was to describe magnetic resonance imaging findings in patients planned for lumbar spinal stenosis surgery. Further, to describe possible associations between MRI findings and patient characteristics with patient reported disability or pain. METHODS: The NORDSTEN spinal stenosis trial included 437 patients planned for surgical decompression of LSS. The following MRI findings were evaluated before surgery: morphological (Schizas) and quantitative (cross-sectional area) grade of stenosis, disk degeneration (Pfirrmann), facet joint tropism and fatty infiltration of the multifidus muscle. Patients were dichotomized into a moderate or severe category for each radiological parameter classification. A multivariable linear regression analysis was performed to investigate the association between MRI findings and preoperative scores for Oswestry Disability Index, Zurich Claudication Questionnaire and Numeric rating scale for back and leg pain. The following patient characteristics were included in the analysis: gender, age, smoking and weight. RESULTS: The percentage of patients with severe scores was as follows: Schizas (C + D) 71.3%, cross-sectional area (< 75 mm2) 86.8%, Pfirrmann (4 + 5) 58.1%, tropism (≥ 15°) 11.9%, degeneration of multifidus muscle (2-4) 83.7%. Regression coefficients indicated minimal changes in severity of symptoms when comparing the groups with moderate and severe MRI findings. Only gender had a significant and clinically relevant association with ODI score. CONCLUSION: In this cross-sectional study, the majority of the patients had MRI findings classified as severe LSS changes, but the findings had no clinically relevant association with patient reported disability and pain at baseline. Patient characteristics have a larger impact on disability and pain than radiological findings. TRIAL REGISTRATION: www. CLINICALTRIALS: gov identifier: NCT02007083, registered December 2013.

The association between preoperative MRI findings and clinical improvement in patients included in the NORDSTEN spinal stenosis trial.

PURPOSE: To investigate potential associations between preoperative MRI findings and patient reported outcome measures (PROMs) after surgery for lumbar spinal stenosis (LSS). METHODS: The NORDSTEN trial included 437 patients. We investigated the association between preoperative MRI findings such as morphological grade of stenosis (Schizas grade), quantitative grade of stenosis (dural sac cross-sectional area), disc degeneration (Pfirrmann score), facet joint tropism and fatty infiltration of the multifidus muscle, and improvement in patient reported outcome measures (PROMs) 2 years after surgery. We dichotomized each radiological parameter into a moderate or severe category. PROMs i.e., Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ) and Numeric rating scale (NRS) for back and leg pain were collected before surgery and at 2 year follow-up. In the primary analysis, we investigated the association between MRI findings and ODI score (dichotomized to ≥ 30% improvement or not). In the secondary analysis, we investigated the association between MRI findings and the mean improvement on the ODI-, ZCQ- and NRS scores. We used multivariable regression models adjusted for patients' gender, age, smoking status and BMI. RESULTS: The primary analysis showed that severe disc degeneration (Pfirrmann score 4-5) was significantly associated with less chance of achieving a 30% improvement on the ODI score (OR 0.54, 95% CI 0.34, 0.88). In the secondary analysis, we detected no clinical relevant associations. CONCLUSION: Severe disc degeneration preoperatively suggest lesser chance of achieving 30% improvement in ODI score after surgery for LSS. Other preoperative MRI findings were not associated with patient reported outcome.

Reliability of preoperative MRI findings in patients with lumbar spinal stenosis.

BACKGROUND: Magnetic Resonance Imaging (MRI) is an important tool in preoperative evaluation of patients with lumbar spinal stenosis (LSS). Reported reliability of various MRI findings in LSS varies from fair to excellent. There are inconsistencies in the evaluated parameters and the methodology of the studies. The purpose of this study was to evaluate the reliability of the preoperative MRI findings in patients with LSS between musculoskeletal radiologists and orthopaedic spine surgeons, using established evaluation methods and imaging data from a prospective trial. METHODS: Consecutive lumbar MRI examinations of candidates for surgical treatment of LSS from the Norwegian Spinal Stenosis and Degenerative Spondylolisthesis (NORDSTEN) study were independently evaluated by two musculoskeletal radiologists and two orthopaedic spine surgeons. The observers had a range of experience between six and 13 years and rated five categorical parameters (foraminal and central canal stenosis, facet joint osteoarthritis, redundant nerve roots and intraspinal synovial cysts) and one continuous parameter (dural sac cross-sectional area). All parameters were re-rated after 6 weeks by all the observers. Inter- and intraobserver agreement was assessed by Gwet's agreement coefficient (AC1) for categorical parameters and Intraclass Correlation Coefficient (ICC) for the dural sac cross-sectional area. RESULTS: MRI examinations of 102 patients (mean age 66 ± 8 years, 53 men) were evaluated. The overall interobserver agreement was substantial or almost perfect for all categorical parameters (AC1 range 0.67 to 0.98), except for facet joint osteoarthritis, where the agreement was moderate (AC1 0.39). For the dural sac cross-sectional area, the overall interobserver agreement was good or excellent (ICC range 0.86 to 0.96). The intraobserver agreement was substantial or almost perfect/ excellent for all parameters (AC1 range 0.63 to 1.0 and ICC range 0.93 to 1.0). CONCLUSIONS: There is high inter- and intraobserver agreement between radiologists and spine surgeons for preoperative MRI findings of LSS. However, the interobserver agreement is not optimal for evaluation of facet joint osteoarthritis. TRIAL REGISTRATION: www.ClinicalTrials.gov identifier: NCT02007083 , registered December 2013.

Cervical spine and muscle adaptation after spaceflight and relationship to herniation risk: protocol from 'Cervical in Space' trial.

BACKGROUND: Astronauts have a higher risk of cervical intervertebral disc herniation. Several mechanisms have been attributed as causative factors for this increased risk. However, most of the previous studies have examined potential causal factors for lumbar intervertebral disc herniation only. Hence, we aim to conduct a study to identify the various changes in the cervical spine that lead to an increased risk of cervical disc herniation after spaceflight. METHODS: A cohort study with astronauts will be conducted. The data collection will involve four main components: a) Magnetic resonance imaging (MRI); b) cervical 3D kinematics; c) an Integrated Protocol consisting of maximal and submaximal voluntary contractions of the neck muscles, endurance testing of the neck muscles, neck muscle fatigue testing and questionnaires; and d) dual energy X-ray absorptiometry (DXA) examination. Measurements will be conducted at several time points before and after astronauts visit the International Space Station. The main outcomes of interest are adaptations in the cervical discs, muscles and bones. DISCUSSION: Astronauts are at higher risk of cervical disc herniation, but contributing factors remain unclear. The results of this study will inform future preventive measures for astronauts and will also contribute to the understanding of intervertebral disc herniation risk in the cervical spine for people on Earth. In addition, we anticipate deeper insight into the aetiology of neck pain with this research project. TRIAL REGISTRATION: German Clinical Trials Register, DRKS00026777. Registered on 08 October 2021.

Terminal complement complex formation is associated with intervertebral disc degeneration.

PURPOSE: The complement system is a crucial part of innate immunity. Recent work demonstrated an unexpected contribution to tissue homeostasis and degeneration. This study investigated for the first time, in human disc tissues, the deposition profile of the complement activation product terminal complement complex (TCC), an inflammatory trigger and inducer of cell lysis, and its inhibitor CD59, and their correlation with the degree of disc degeneration (DD). METHODS: Disc biopsies were collected from patients diagnosed with DD (n = 39, age 63 ± 12) and adolescent idiopathic scoliosis (AIS, n = 10, age 17 ± 4) and compared with discs from healthy Young (n = 11, age 7 ± 7) and Elder (n = 10, age 65 ± 15) donors. Immunohistochemical detection of TCC and CD59 in nucleus pulposus (NP), annulus fibrosus (AF) and endplate (EP) was correlated with age, Pfirrmann grade and Modic changes. RESULTS: Higher percentage of TCC+ cells was detected in the NP and EP of DD compared to Elder (P < 0.05), and in the EP of Young versus Elder (P < 0.001). In DD, TCC deposition was positively correlated with Pfirrmann grade, but not with Modic changes, whereas for Young donors, a negative correlation was found with age, indicating TCC's involvement not only in DD, but also in early stages of skeletal development. Higher CD59 positivity was found in AIS and DD groups compared to Young (P < 0.05), and it was negatively correlated with the age of the patients. CONCLUSION: TCC deposition positively correlated with the degree of disc degeneration. A functional relevance of TCC may exist in DD, representing a potential target for new therapeutics.

The impact of implementing a person-centred pain management intervention on resistance to change and organizational culture.

BACKGROUND: Resistance to change and organizational culture are essential factors to consider in change management in health care settings. Implementation of structural change remains a challenge. There is a lack of studies providing information on the impact of implementation processes on the organization. The aim of this study was to describe the impact of implementing a systematic change process concerning postoperative person-centred pain management on resistance to change and organizational culture in an orthopaedic spine surgery unit. METHODS: The study was set in an orthopaedic spine surgery unit at a university hospital. Person-centred bundles of care for postoperative pain management of spine surgery patients were developed in co-creation by a multi-professional expert group and implemented throughout the care pathway. The intervention was underpinned by theories on organizational culture and inspired by principles of person-centred care. Quantitative data were collected using the Resistance to Change Scale and the Organizational Culture Assessment Instrument and analysed using descriptive statistics. RESULTS: The findings showed a low resistance to change decreasing during the study. The organizational culture shifted from a result-oriented to a formalized and structured culture after the implementation. The culture preferred by the staff was team-oriented and participation-focused throughout the study. The discrepancy between the current and preferred cultures remained extensive over time. CONCLUSION: It is challenging to describe the influence of the development and implementation of a postoperative pain management program on organizational culture as well as in terms of resistance to change, in a complex health care setting. In the current study the unit was under organizational strain during the implementation. Albeit, the important discrepancy between the current and preferred organizational culture could imply that structural changes aren't enough when implementing person-centred pain management structures and needs to be combined with relational aspects of change.

Significantly lower intramuscular pressure in the posterior and lateral compartments compared with the anterior compartment suggests alterations of the diagnostic criteria for chronic exertional compartment syndrome in the lower leg.

PURPOSE: To investigate distributions and identify possible differences in intramuscular pressure (IMP) values at 1 min post-exercise between the four muscle compartments of the lower leg, in patients with exertional leg pain with or without chronic exertional compartment syndrome (CECS). METHODS: A consecutive series of patients seeking orthopaedic consultation for exertional leg pain underwent IMP measurements between 2009 and 2018. The diagnosis of CECS was confirmed (n = 442) or ruled out (n = 422), based on the patient's history, clinical examination, and IMP measurements. RESULTS: The median (range) 1 min post-exercise IMP values in affected compartments in the patients diagnosed with CECS were 33 (25-53) mmHg (deep posterior), 35 (27-54) mmHg (superficial posterior), 40 (26-106) mmHg (lateral), and 47 (24-120) mmHg (anterior). In patients with no CECS, the median (range) 1 min post-exercise IMP values in the compartments were 12 (2-28) mmHg (deep posterior), 12 (2-27) mmHg (superficial posterior), 14 (2-26) mmHg (lateral), and 18 (4-34) mmHg (anterior). The IMP was significantly lower in the lateral and both posterior compartments than in the anterior compartment in both patients diagnosed with CECS and patients without CECS. CONCLUSION: The study demonstrates significantly lower IMP values in the posterior and lateral compartments compared to the anterior compartments. These findings suggest a lowering of the IMP 1 min post-exercise cut-off value for diagnosing CECS in the lateral and both posterior compartments, which may lead to improved treatment of patients with suspected CECS in the lower leg. LEVEL OF EVIDENCE: Level II.