Comparing CT-Like Images Based on Ultra-Short Echo Time and Gradient Echo T1-Weighted MRI Sequences for the Assessment of Vertebral Disorders Using Histology and True CT as the Reference Standard.

BACKGROUND: Several magnetic resonance (MR) techniques have been suggested for radiation-free imaging of osseous structures. PURPOSE: To compare the diagnostic value of ultra-short echo time and gradient echo T1-weighted MRI for the assessment of vertebral pathologies using histology and computed tomography (CT) as the reference standard. STUDY TYPE: Prospective. SUBJECTS: Fifty-nine lumbar vertebral bodies harvested from 20 human cadavers (donor age 73 ± 13 years; 9 male). FIELD STRENGTH/SEQUENCE: Ultra-short echo time sequence optimized for both bone (UTEb) and cartilage (UTEc) imaging and 3D T1-weighted gradient-echo sequence (T1GRE) at 3 T; susceptibility-weighted imaging (SWI) gradient echo sequence at 1.5 T. CT was performed on a dual-layer dual-energy CT scanner using a routine clinical protocol. ASSESSMENT: Histopathology and conventional CT were acquired as standard of reference. Semi-quantitative and quantitative morphological features of degenerative changes of the spines were evaluated by four radiologists independently on CT and MR images independently and blinded to all other information. Features assessed were osteophytes, endplate sclerosis, visualization of cartilaginous endplate, facet joint degeneration, presence of Schmorl's nodes, and vertebral dimensions. Vertebral disorders were assessed by a pathologist on histology. STATISTICAL TESTS: Agreement between T1GRE, SWI, UTEc, and UTEb sequences and CT imaging and histology as standard of reference were assessed using Fleiss' κ and intra-class correlation coefficients, respectively. RESULTS: For the morphological assessment of osteophytes and endplate sclerosis, the overall agreement between SWI, T1GRE, UTEb, and UTEc with the reference standard (histology combined with CT) was moderate to almost perfect for all readers (osteophytes: SWI, κ range: 0.68-0.76; T1GRE: 0.92-1.00; UTEb: 0.92-1.00; UTEc: 0.77-0.85; sclerosis: SWI, κ range: 0.60-0.70; T1GRE: 0.77-0.82; UTEb: 0.81-0.92; UTEc: 0.61-0.71). For the visualization of the cartilaginous endplate, UTEc showed the overall best agreement with the reference standard (histology) for all readers (κ range: 0.85-0.93). DATA CONCLUSIONS: Morphological assessment of vertebral pathologies was feasible and accurate using the MR-based bone imaging sequences compared to CT and histopathology. T1GRE showed the overall best performance for osseous changes and UTEc for the visualization of the cartilaginous endplate. LEVEL OF EVIDENCE: 1 TECHNICAL EFFICACY: Stage 2.

Simulative investigation of the required level of geometrical individualization of the lumbar spines to predict fractures.

Injury mechanisms of the lumbar spine under dynamic loading are dependent on spine curvature and anatomical variation. Impact simulation with finite element (FE) models can assist the reconstruction and prediction of injuries. The objective of this study was to determine which level of individualization of a baseline FE lumbar spine model is necessary to replicate experimental responses and fracture locations in a dynamic experiment.Experimental X-rays from 26 dynamic drop tower tests were used to create three configurations of a lumbar spine model (T12 to L5): baseline, with aligned vertebrae (positioned), and with aligned and morphed vertebrae (morphed). Each model was simulated with the corresponding loading and boundary conditions from dynamic lumbar spine experiments. Force, moment, and kinematic responses were compared to the experimental data. Cosine similarity was computed to assess how well simulation responses match the experimental data. The pressure distribution within the vertebrae was used to compare fracture risk and fracture location between the different models.The positioned models replicated the injured spinal level and the fracture patterns quite well, though the morphed models provided slightly more accuracy. However, for impact reconstruction or injury prediction, the authors recommend pure positioning for whole-body models, as the gain in accuracy was relatively small, while the morphing modifications of the model require considerably higher efforts. These results improve the understanding of the application of human body models to investigate lumbar injury mechanisms with FE models.

Photon-Counting Detector CT Versus Energy-Integrating Detector CT of the Lumbar Spine: Comparison of Radiation Dose and Image Quality.

BACKGROUND. Photon-counting detector (PCD) CT could be useful to help address the typically high radiation doses of conventional energy-integrating detector (EID) CT of the lumbar spine. OBJECTIVE. The purpose of our study was to compare PCD CT and EID CT of the lumbar spine, both performed using tin filtration, in terms of radiation dose and image quality. METHODS. This study included a prospective sample of 39 patients (22 men, 17 women; mean age, 27.2 years) who underwent investigational PCD CT of the lumbar spine as part of a separate study and a retrospective sample of 39 patients (22 men, 17 women; mean age, 34.9 years) who underwent clinically indicated EID CT of the lumbar spine. In both groups, all examinations were performed using unenhanced technique with tin prefiltration between June 2022 and January 2023. Patients were matched between groups using age, sex, and BMI. A custom gaussian curve-fitting algorithm was used to automatically calculate image noise, SNR, and CNR for each examination, on the basis of all voxels within the image set. Three radiologists independently reviewed examinations to perform a subjective visual assessment of visualization of trabecular architecture, cortical bone, neuroforaminal content, paraspinal muscles, and intervertebral disk, as well as overall image quality, using a 4-point Likert scale (1 = poor, 4 = excellent). PCD CT and EID CT examinations were compared. RESULTS. Mean CTDIvol was 4.4 ± 1.0 (SD) mGy for PCD CT versus 11.1 ± 1.9 mGy for EID CT (p < .001). Mean size-specific dose estimate (SSDE) was 6.2 ± 1.0 (SD) mGy for PCD CT versus 14.2 ± 1.8 mGy for EID CT (p < .001). PCD CT and EID CT examinations were not significantly different in terms of image noise or SNR (both p > .05). PCD CT, in comparison with EID CT, showed significantly higher CNR (mean ± SD, 33.6 ± 3.3 vs 29.3 ± 4.1; p < .001). For all three readers, the median score for overall image quality was 4 (range, 3-4) for both PCD CT and EID CT. PCD CT and EID CT examinations showed no significant difference in terms of any qualitative measure for any reader (all p > .05). CONCLUSION. PCD CT, in comparison with EID CT, yielded significantly lower radiation dose with preserved image quality. CLINICAL IMPACT. The findings support expanded use of PCD CT for lumbar spine evaluation.

Lumbar foraminal stenosis was associated with back pain and leg pain: epidemiological evidence from a population-based cohort.

OBJECTIVES: To determine the characteristics of lumbar foraminal stenosis (LFS) on magnetic resonance (MR) images and their association with back pain and radiating leg pain in a population-based sample of Chinese subjects. METHODS: This study was an extension of the Hangzhou Lumbar Spine Study, a cross-sectional study focusing on back pain and lumbar spine MR imaging findings. Questionnaire data, including demographics, lifestyle, occupational exposures, back pain and radiating leg pain were included. On lumbar spine MR images, disc degeneration was assessed using Pfirrmann grade and Modic changes were evaluated. Using Lee's scale, the L3-S1 intervertebral foramina were evaluated, with grade 2-3 representing substantial LFS and grade 0-1 no LFS. Characteristics of LFS were noted, and associations of LFS with back pain and radiating leg pain were examined. RESULTS: Among the 644 study subjects, 141 (21.9%) had at least one LFS, and its occurrence was associated with greater age (OR = 1.93 for each 10 years, p < 0.001). Substantial LFS was associated with the presence of back pain (OR = 1.92, p = 0.001) and the intensity of the worst back pain (Coef = 8.30, p < 0.001) over the past 12 months, and disabling back pain during their lifetime (OR = 2.25, p < 0.001). Substantial LFS was also associated with leg pain (OR = 14.27, p < 0.001), with a sensitivity of 75.7% for the presence of radiating leg pain and a specificity of 81.4%. CONCLUSION: Substantial LFS on MR images was a common age-related degenerative phenotype in adults, and appears to be an independent risk factor for back pain and leg pain.

Development and validation of metrics for assessment of ultrasound-guided fascial block skills☆.

BACKGROUND: As few anaesthetists provide lumbar erector spinae block for disc surgery, there is a need to provide training to enable a randomised controlled trial investigating analgesia after painful spinal surgery (NIHR153170). The primary objective of the study was to develop and measure the construct validity of a checklist for assessment of skills in performing lumbar and thoracic erector spinae fascial plane injection using soft-embalmed Thiel cadavers. METHODS: Twenty-four UK consultant regional anaesthetists completed two iterations of a Delphi questionnaire. The final checklist consisted of 11 steps conducive to best practice. Thereafter, we validated the checklist by comparing the performance of 12 experts with 12 novices, each performing lumbar and thoracic erector spinae plane injections or fascia iliaca, serrato-pectoral (PEC II) and serratus injections, randomly allocated to the left and right sides of six soft-embalmed Thiel cadavers. Six expert, trained raters blinded to operator and site of block examined 120 videos each. RESULTS: The mean (95% confidence interval) internal consistency of the 11-item checklist for erector spinae plane injection was 0.72 (0.63-0.79) and interclass correlation was 0.88 (0.82-0.93). The checklist showed construct validity for lumbar and thoracic erector spinae injection, experts vs novices {median (interquartile range [range]) 8.0 (7.0-10.0 [1-11]) vs 7.0 (5.0-9.0 [4-11]), difference 1.5 (1.0-2.5), P<0.001}. Global rating scales showed construct validity for lumbar and thoracic erector spinae injection, 28.0 (24.0-31.0 [7-35]) vs 21.0 (17.0-24.0 [7-35]), difference 7.5 (6.0-8.5), P<0.001. The most difficult items to perform were identifying the needle tip before advancing and always visualising the needle tip. Instrument handling and flow of procedure were the areas of greatest difficulty on the global rating scale (GRS). Checklists and GRS scores correlated. There was homogeneity of regression slopes controlling for status, type of injection, and rater. Generalisability analysis showed a high reliability using the checklist and GRS for all fascial plane blocks (Rho [ρ2] 0.93-0.96: Phi [ϕ] 0.84-0.87). CONCLUSIONS: An 11-point checklist developed through a modified Delphi process to provide best practice guidance for fascial plane injection showed construct validity in performing lumbar and thoracic erector spinae fascial plane injection in soft-embalmed Thiel cadavers.

Characterizing utilization patterns and reoperation risk factors of interspinous process devices: analysis of a national claims database.

INTRODUCTION: Interspinous process devices (IPDs) were developed as minimally invasive alternatives to open decompression surgery for spinal stenosis. However, given high treatment failure and reoperation rates, there has been minimal adoption by spine surgeons. This study leveraged a national claims database to characterize national IPD usage patterns and postoperative outcomes after IPD implantation. METHOD: Using the PearlDiver database, we identified all patients who underwent 1- or 2-level IPD implantation between 2010 and 2018. Univariate and multivariable logistic regression was performed to identify predictors of the number of IPD levels implanted and reoperation up to 3 years after the index surgery. Right-censored Kaplan-Meier curves were plotted for duration of reoperation-free survival and compared with log-rank tests. RESULTS: Patients (n = 4865) received 1-level (n = 3246) or 2-level (n = 1619) IPDs. Patients who were older (adjusted odds ratio [aOR] 1.02, 95% confidence interval [CI] 1.01-1.03, P < .001), male (aOR 1.31, 95% CI 116-1.50, P < .001), and obese (aOR 1.19, 95% CI 1.05-1.36, P < .01) were significantly more likely to receive a 2-level IPD than to receive a 1-level IPD. The 3-year reoperation rate was 9.3% of patients when mortality was accounted for during the follow-up period. Older age decreased (aOR 0.97, 95% CI 0.97-0.99, P = .0039) likelihood of reoperation, whereas 1-level IPD (aOR 1.37, 95% CI 1.01-1.89, P = .048), Charlson Comorbidity Index (aOR 1.07, 95% CI 1.01-1.14, P = .018), and performing concomitant open decompression increased the likelihood of reoperation (aOR 1.68, 95% CI 1.35-2.09, P = .0014). CONCLUSION: Compared with 1-level IPDs, 2-level IPDs were implanted more frequently in older, male, and obese patients. The 3-year reoperation rate was 9.3%. Concomitant open decompression with IPD placement was identified as a significant risk factor for subsequent reoperation and warrants future investigation.

Diagnosing (severe) osteoporosis by Hologic vs. Lunar measurements: A single-center retrospective study.

INTRODUCTION: Although different dual-energy X-ray absorptiometry (DXA) scanners provide different bone mineral density (BMD) values, there is not a gold standard DXA scanner. T-score is used to facilitate the interpretation of BMD, and osteoporosis (OP) is diagnosed based on T-scores. In this retrospective study, we aimed to evaluate the BMD and T-score differences between Lunar Prodigy and Hologic Horizon DXA scanners. METHODOLOGY: Data were collected for patients with previous BMD measurement on Lunar Prodigy and Hologic Horizon DXA scanners within one year in the same medical center. RESULTS: In a total of 55 patients, BMD values of femoral neck/total, and lumbar vertebrae were all lower at Hologic than Lunar (all p < 0.01). The mean T-score difference at the lumbar spine was 0.74 ±â€¯0.42 (p < 0.001). Of the 49 patients diagnosed as OP (T-score ≤-2.5) with the Hologic, the diagnoses were changed for 25 individuals (51.0 %) with Lunar (p < 0.001). Herewith, although the diagnoses of OP did not change by the repeat technique in other 24 patients (49 %), 13 of them (26.5 %) were categorized as having "high fracture risk" instead of "very high fracture risk" group (i.e., T-score <-3.0). We observed moderate-to-good reliabilities (with an intraclass correlation coefficient [ICC] of 0.633-0.878 and 0.733-0.842 for BMD and T-scores, respectively) between measurements with the Lunar and Hologic scanners. Except for one measurement in L3, L4, L1-4 vertebrae, the Bland-Altman plot did not reveal any consistent bias between the measurements of the Lunar and Hologic scanners. CONCLUSIONS: The consistency between different DXA scanners (especially for Hologic vs. Lunar) is important for proper management, especially in patients with low T-scores and OP.

Fracture Risk Associated with Different Numbers and Combinations of Lumbar Vertebrae: The Manitoba BMD Registry.

Bone mineral density (BMD) is widely used for assessment of fracture risk. For the lumbar spine, BMD is typically measured from L1-L4 as it provides the largest area for assessment with the best measurement precision. Structural artifact often confounds spine BMD in clinical practice, and the International Society for Clinical Densitometry (ISCD) recommends removing vertebrae with artifact when reporting spine BMD. In its most recent position statements, the ISCD recommended against the use of a single vertebra when reporting spine BMD but stated that further studies should be done. The current analysis was performed to compare the performance of BMD from different numbers and combination of vertebral levels on fracture prediction in a large clinical registry of DXA tests for the Province of Manitoba, Canada. The study population comprised 39,727 individuals aged 40 years and older (mean age 62.7 years, 91.0 % female) with baseline DXA after excluding those with evidence of structural artifact. Mean follow-up for ascertaining fracture outcomes was 8.7 years. Area under the curve (AUC) for incident fracture risk stratification was statistically significant regardless of the BMD measurement site or fracture outcome. AUC differences with the various numbers and combinations of vertebral levels including a single vertebral body were small (less than or equal to 0.01). More substantial AUC differences were seen for femoral neck and total hip BMD versus L1-L4 BMD, approaching 0.1 for hip fracture stratification. In summary, we found that using combinations of fewer than 4 vertebrae including individual lumbar vertebrae predicted incident fractures. Importantly, differences between these different combinations were small when compared with L1-L4. Spine BMD was a better predictor of incident spine fracture compared to the hip, whereas the hip was better for hip fracture and overall fracture prediction.

The Components of Lumbar Motor Control Are Not Inter-related.

OBJECTIVES: To verify the relationship between the indicators of components of lumbar motor control and determine the factors related to the indicators to each of these components. METHODS: Twenty-five healthy university students were included in the study. The lumbar spine and hip kinematic parameters of posterior/anterior pelvic tilt (mobility and smoothness), ball catching (reactivity), and forward/backward rocking (adaptive stability) were measured as indicators of lumbar motor control. Lumbar proprioception, trunk muscle strength, and lower trunk muscle thickness were also measured. Kinematic parameters of the lumbar spine and hip were measured using a small accelerometer. The data verified the relevance of indicators of lumbar motor control and the relationship with relevant factors. RESULTS: No significant correlations were found for most lumbar motor control indicators. Lumbar proprioception and rectus abdominis muscle thickness were identified as relevant indicators of lumbar motor control. CONCLUSIONS: Each component of lumbar motor control is independent and must be evaluated for the component whose function is required. Additionally, some components of lumbar motor control are associated with lumbar proprioception and rectus abdominis muscle thickness; thus, evaluation of these components is necessary when evaluating lumbar motor control.

Radiomic nomogram based on lumbar spine magnetic resonance images to diagnose osteoporosis.

BACKGROUND: We aimed to establish a novel model using a radiomics analysis of magnetic resonance (MR) images for predicting osteoporosis. PURPOSE: To investigate the effectiveness of a radiomics approach utilizing magnetic resonance imaging (MRI) of the lumbar spine in identifying osteoporosis. MATERIAL AND METHODS: In this retrospective study, a total of 291 patients who underwent MRI were analyzed. Radiomics features were extracted from the MRI scans of all 1455 lumbar vertebrae, and build the radiomics model based on T2-weighted (T2W), T1-weighted (T1W), and T2W + T1W imaging. The performance of the combined model was assessed using metrics such as the area under the receiver operating characteristic curve (AUC), sensitivity, specificity, and accuracy. The AUCs of these models were compared using the DeLong test. Their clinical usefulness was assessed using a decision curve analysis. RESULTS: T2W, T1W, and T1W + T2W imaging retained 27, 27, and 17 non-zero coefficients, respectively. The AUCS about radiomics scores based on T2W, T1W, and T1W + T2W imaging were 0.894, 0.934, and 0.945, respectively, which all performed better than the clinical model significantly. The rad-signatures based on T1W + T2W imaging, which exhibited a stronger predictive power, were included in the creation of the nomogram for osteoporosis diagnosis, and the AUC was 0.965 (95% confidence interval (CI)=0.944-0.986) in the training cohort and 0.917 (95% CI=0.738-1.000) in the test cohort. The calibration curve indicated that the radiomics nomogram had considerable clinical usefulness in prediction, observation, and decision curve analysis. CONCLUSION: A reliable and powerful tool for identifying osteoporosis can be provided by the nomogram that combines the T1W and T2W imaging radiomics score with clinical risk factors.

A novel endoscope-port unit for lumbar microendoscopic surgery: a single-center case series review.

Minimally invasive spinal surgery has shown benefits not only from a clinical standpoint but also in some cost-effectiveness metrics. Microendoscopic procedures combine optical advantages of endoscopy with the preservation of bimanual surgical maneuvers that are not feasible with full percutaneous endoscopic procedures. TELIGEN is a new endoscopic platform designed to optimize these operations. Our aim was to present a retrospective review of surgical data from the first consecutive cases applying this device in our institution and describe some of its technical details. 25 patients have underwent procedures using this device at our institution to the date, with a mean follow-up of 341.7 ± 45.1 days. 17 decompression-only procedures, including microendoscopic discectomies (MED) and decompression of stenosis (MEDS), with or without foraminotomies (± MEF) and 8 microendoscopic transforaminal lumbar interbody fusions (ME-TLIF) were performed. Mean age and body mass index (BMI) were respectively 58.8 ± 17.4 years and 27.6 ± 5.3 kg/m2. Estimated blood loss (13 ± 4.8, 12.8 ± 6.98 and 76.3 ± 35.02 mL), postoperative length of hospital stay (11.2 ± 21.74, 22.1 ± 26.85 and 80.7 ± 44.60 h), operative time (130.3 ± 58.53, 121 ± 33.90 and 241.5 ± 45.27 min) and cumulative intraprocedural radiation dose (14.2 ± 6.36, 15.4 ± 12.17 and 72.8 ± 12.26 mGy) are reported in this paper for MED ± MEF, MEDS ± MEF and ME-TLIF, respectively. TELIGEN affords an expanded surgical field of view with unique engineered benefits that provide a promissing platform to enhance minimally invasive spine surgery.

A new classification of lumbar Basstrup's disease based on radiographic and clinical symptoms.

OBJECTIVE: To propose a new classification method for lumbar Basstrup's disease based on radiographic and clinical symptoms, and to test its credibility and reproducibility. METHODS: A retrospective analysis of 116 patients with complete data of lumbar Basstrup's disease in our hospital from January 2019 to January 2022, radiological imaging including X-ray, CT and MRI, were divided into two main types according to the number of segments: type I (single segment) and type II (multiple segments), each type was divided into a total of eight subtypes according to the degree of degeneration: Ia, Ib, Ic, Id, IIa, IIb, IIc, IId; it was further divided into 16 subtypes according to the presence or absence of clinical symptoms (i.e. low back pain or/and lower limb neurological symptoms: no 0, yes 1): Ia0, Ia1, Ib0, Ib1, Ic0, Ic1, Id0, Id1; IIa0, IIa1, IIb0, IIb1, IIc0, IIc1, IId0, IId1.The 116 patients with Basstrup's disease were successively typed twice (1 month interval) by five physicians according to the new classification method, and the reliability and reproducibility of the new classification were assessed using the Kappa consistency test. RESULTS: Among 116 patients with lumbar Basstrup's disease: there were 60 cases of type I (single segment), accounting for 51.72%, including Ia 19 cases, Ib 16 cases, Ic 10 cases, and Id 15 cases; there were 56 cases of type II (multiple segments), accounting for 48.28%, including IIa 10 cases, IIb 20 cases, IIc 14 cases, and IId 12 cases. Of the 116 patients, 47 cases had no clinical symptoms (Ia0 16 cases, Ib0 3 cases, Ic0 6 cases, Id0 1 case, IIa0 8 cases, IIb0 2 cases, IIc0 10 cases, IId0 1 case), accounting for 40.52%; 69 cases were accompanied by low back pain or/and lower extremity nerve symptoms (Ia1 3 cases, Ib1 13 cases, Ic1 4 cases, Id1 14 cases, IIa1 2 cases, IIb1 18 cases, IIc1 4 cases, IId1 11 cases), accounting for 59.48%.Five physicians completed two rounds of a total of 1160 typings, with inter-assessor typing agreement of 82.47% (80.17-85.34%) and a mean Kappa value of 0.723 (0.771-0.831); intra-assessor typing agreement of 82.76% (77.59-86.21%) and a mean Kappa value of 0.801 (0.742-0.841). CONCLUSION: The new classification method for lumbar Basstrup's disease based on radiographic and clinical symptoms is simple, practical, with good credibility and reproducibility, and provides some guidance for clinical treatment.

Relating preoperative MCS-12 to microdiscectomy outcomes.

PURPOSE: To determine the impact of poor mental health on patient-reported and surgical outcomes after microdiscectomy. METHODS: Patients ≥ 18 years who underwent a single-level lumbar microdiscectomy from 2014 to 2021 at a single academic institution were retrospectively identified. Patient-reported outcomes (PROMs) were collected at preoperative, three-month, and one-year postoperative time points. PROMs included the Oswestry Disability Index (ODI), Visual Analog Scale Back and Leg (VAS Back and VAS Leg, respectively), and the mental and physical component of the short form-12 survey (MCS and PCS). The minimum clinically important differences (MCID) were employed to compare scores for each PROM. Patients were categorized as having worse mental health or better mental health based on a MCS threshold of 50. RESULTS: Of 210 patients identified, 128 (61%) patients had a preoperative MCS score ≤ 50. There was no difference in 90-day surgical readmissions or spine reoperations within one year. At 3- and 12-month time points, both groups demonstrated improvements in all PROMs (p < 0.05). At three months postoperatively, patients with worse mental health had significantly lower PCS (42.1 vs. 46.4, p = 0.004) and higher ODI (20.5 vs. 13.3, p = 0.006) scores. Lower mental health scores were associated with lower 12-month PCS scores (43.3 vs. 48.8, p < 0.001), but greater improvements in 12-month ODI (- 28.36 vs. - 18.55, p = 0.040). CONCLUSION: While worse preoperative mental health was associated with lower baseline and postoperative PROMs, patients in both groups experienced similar improvements in PROMs. Rates of surgical readmissions and reoperations were similar among patients with varying preoperative mental health status.

Passive intervertebral restraint is different in patients with treatment-resistant chronic nonspecific low back pain: a retrospective cohort study and control comparison.

PURPOSE: In vivo studies of continuous lumbar sagittal plane motion have found passive intervertebral motion to be more uneven in patients with chronic nonspecific low back pain (CNSLBP) than healthy controls, but the mechanisms are unclear. This study aimed to compare patients with CNSLBP with a matched group of pain-free controls for intervertebral restraint during passive recumbent bending. METHODS: Seventeen patients with CNSLBP and minimal disc degeneration who had quantitative fluoroscopy investigations were matched to 17 healthy controls from a database acquired using the same imaging protocol. The entire database (n = 136) was examined for clustering of peaking times, magnitudes and ROM of the first derivatives of the intervertebral angle/motion curves (PTFD, PMFD and ROM) during flexion and return that might introduce confounding. The groups were then compared for differences in these variables. RESULTS: There were significant segmental ROM differences among clusters in the database when PMFD and ROM were used as clustering variables, indicating heterogeneity. However, in the patient-control study, it was PTFD (velocity) that differentiated the groups. At L5-S1, this was at 10.82% of the motion path compared with 25.06% in the controls (p = 0.0002). For L4-5, PTFD was at 23.42% of the motion path in patients and 16.33% in controls (p = 0.0694) suggesting a reduced initial bending moment there. There were no significant differences for PMFD or ROM. CONCLUSION: Peaking time of passive intervertebral velocity occurs early at L5-S1 in patients with CNSLBP; however, these findings should be treated with caution pending their replication. Future studies should explore relationships with altered disc pressures and biochemistry. Usefulness for monitoring regenerative disc therapies should be considered.

Lower preoperative Hounsfield unit values as a risk factor for poor 5-year clinical outcomes after lumbar spine surgery.

OBJECTIVE: Hounsfield Unit (HU) value has been associated with future osteoporotic fractures and postoperative complications. However, no studies on the impact of low HU values on mid-term clinical outcomes following lumbar spine surgery have been reported. We aimed to evaluate the usefulness of preoperative HU values for 5-year clinical outcomes following lumbar spine surgery. METHODS: We enrolled 200 patients who underwent lumbar surgery (≤ 3-disc levels) for lumbar spinal stenosis. HU values were assessed using preoperative lumbar computed tomography as part of routine preoperative planning for lumbar surgery. Patients were divided into two groups based on the cutoff value of the HU values obtained from the receiver operating characteristic curve for the incidence of vertebral fractures within five years postoperatively. Clinical scores preoperatively and 1, 2, and 5 years postoperatively, including Japanese Orthopedic Association Back Pain Evaluation Questionnaire (JOABPEQ) and Short Form-36 (SF-36), were compared using a mixed-effects model. RESULTS: Comparative analysis indicated that all domains of JOABPEQ, except for lumbar function, and the physical component summary of the SF-36 were significantly worse in the low HU group than in the high HU group. Using multiple regression analysis, low HU values were significantly correlated with worse 5-year postoperative scores in all domains of JOABPEQ and SF-36. CONCLUSION: Low preoperative HU values are a risk factor for poor 5-year clinical outcomes after lumbar spine surgery. HU values are not only a valuable tool for analyzing bone mineral density but also may be a valuable poor prognostic factor of postoperative clinical outcomes.

Reconsidering high intensity zones: its role in intervertebral disk degeneration and low back pain.

PURPOSE: High intensity zones (HIZ) in the lumbar intervertebral disk (IVD) can be associated with degenerative changes which may ultimately manifest as low back pain (LBP). However, the relationship between the prevalence of HIZ and lumbar degenerative parameters is still unclear. The purpose of this study was to determine the prevalence of HIZ in the lumbar spine, analyze the independent relationship between HIZ and lumbar degenerative parameters measured on MRI and X-ray and determine the association between HIZ and the presence of LBP. METHODS: A retrospective review of MRI data, X-ray data, and radiology reports for 136 consecutively recruited patients, above 18-years-age and with both lumbar MRI and X-ray scans was conducted. 57 patients with HIZ were identified. Patients without HIZ (n = 79) made up the control group. RESULTS: HIZ was prevalent in 41.9% of patients and in 11.0% of all lumbar IVDs. The odds of developing HIZ were 6.4 (Exp(B) 6.4, 95%CI [3.157-12.988]) and 3.0 (Exp(B) 3.0, 95%CI [1.603, 5.674]) times higher in IVDs with disk bulge/protrusion and nucleus degeneration, respectively. Odds of HIZ was also increased in disks with larger IVD angle (Exp(B) 1.1, 95%CI [1.034, 1.169]). The odds of patients presenting to imaging with LBP was 3.0 (OR 3.0, 95%CI [1.478-6.338]) times higher in the HIZ compared to the control group. CONCLUSIONS: HIZ was prevalent in 41.9% of participants that were recruited in this study. Nucleus degeneration, disk bulge/protrusion and increased IVD angle were found to be independently associated with HIZ and since there is an increased likelihood of LBP, we posit that HIZ is likely a symptomatic and clinically meaningful diagnostic tool in the assessment of LBP.

Deep-learning reconstructed lumbar spine 3D MRI for surgical planning: pedicle screw placement and geometric measurements compared to CT.

PURPOSE: To test equivalency of deep-learning 3D lumbar spine MRI with "CT-like" contrast to CT for virtual pedicle screw planning and geometric measurements in robotic-navigated spinal surgery. METHODS: Between December 2021 and June 2022, 16 patients referred for spinal fusion and decompression surgery with pre-operative CT and 3D MRI were retrospectively assessed. Pedicle screws were virtually placed on lumbar (L1-L5) and sacral (S1) vertebrae by three spine surgeons, and metrics (lateral deviation, axial/sagittal angles) were collected. Vertebral body length/width (VL/VW) and pedicle height/width (PH/PW) were measured at L1-L5 by three radiologists. Analysis included equivalency testing using the 95% confidence interval (CI), a margin of ± 1 mm (± 2.08° for angles), and intra-class correlation coefficients (ICCs). RESULTS: Across all vertebral levels, both combined and separately, equivalency between CT and MRI was proven for all pedicle screw metrics and geometric measurements, except for VL at L1 (mean difference: - 0.64 mm; [95%CI - 1.05, - 0.24]), L2 (- 0.65 mm; [95%CI - 1.11, - 0.20]), and L4 (- 0.78 mm; [95%CI - 1.11, - 0.46]). Inter- and intra-rater ICC for screw metrics across all vertebral levels combined ranged from 0.68 to 0.91 and 0.89-0.98 for CT, and from 0.62 to 0.92 and 0.81-0.97 for MRI, respectively. Inter- and intra-rater ICC for geometric measurements ranged from 0.60 to 0.95 and 0.84-0.97 for CT, and 0.61-0.95 and 0.93-0.98 for MRI, respectively. CONCLUSION: Deep-learning 3D MRI facilitates equivalent virtual pedicle screw placements and geometric assessments for most lumbar vertebrae, with the exception of vertebral body length at L1, L2, and L4, compared to CT for pre-operative planning in patients considered for robotic-navigated spine surgery.

Abdominal aortic calcification is an independent predictor of perioperative blood loss in posterior spinal fusion surgery.

OBJECTIVE: Abdominal aortic calcification (AAC), often found incidentally on lateral lumbar radiographs, is increasingly recognized for its association with adverse outcomes in spine surgery. As a marker of advanced atherosclerosis affecting cardiovascular dynamics, this study evaluates AAC's impact on perioperative blood loss in posterior spinal fusion (PSF). METHODS: Patients undergoing PSF from March 2016 to July 2023 were included. Estimated blood loss (EBL) and total blood volume (TBV) were calculated. AAC was assessed on lateral lumbar radiographs according to the Kauppila classification. Predictors of the EBL-to-TBV ratio (%EBL/TBV) were examined via univariable and multivariable regression analyses, which adjusted for parameters such as hypertension and aspirin use. RESULTS: A total of 199 patients (47.2% female) were analyzed. AAC was present in 106 patients (53.3%). AAC independently predicted %EBL/TBV, accounting for an increase in blood loss of 4.46% of TBV (95% CI 1.17-7.74, p = 0.008). CONCLUSIONS: This is the first study to identify AAC as an independent predictor of perioperative blood loss in PSF. In addition to its link to degenerative spinal conditions and adverse postoperative outcomes, the relationship between AAC and increased blood loss warrants attention in patients undergoing PSF.

Poor lumbar spine coordination in acute low back pain predicts persistent long-term pain and disability.

PURPOSE: Sitting balance on an unstable surface requires coordinated out-of-phase lumbar spine and provides sufficient challenge to expose quality of spine control. We investigated whether the quality of spine coordination to maintain balance in acute low back pain (LBP) predicts recovery at 6 months. METHODS: Participants in an acute LBP episode (n = 94) underwent assessment of sitting balance on an unstable surface. Seat, hip and spine (lower lumbar, lumbar, upper lumbar, thoracic) angular motion and force plate data were recorded. Coordination between the seat and hip/spine segments to maintain balance was quantified in the frequency domain to evaluate coordination (coherence) and relative timing (phase angle: in-phase [segments move together]; out-of-phase [segments move opposite]). Center of pressure (CoP) and upper thorax motion assessed overall balance performance. Hip and spine coordination with the seat were compared between those who did not recover (increased/unchanged pain/disability), partially recovered (reduced pain/disability) or recovered (no pain and disability) at 6 months. RESULTS: In both planes, coherence between the seat and lower lumbar spine was lower (and in-phase-unhelpful for balance) at baseline in those who did not recover than those who recovered. Coherence between the seat and hip was higher in partially recovered in both planes, suggesting compensation by the hip. LBP groups had equal overall balance performance (CoP, upper thorax motion), but non-recovery groups used a less optimal strategy that might have consequences for long-term spine health. CONCLUSION: These longitudinal data revealed that individuals with compromised contribution of the lumbar spine to the balance during unstable sitting during acute LBP are less likely to recover.

The attainment of a patient acceptable symptom state in patients undergoing revision spine fusion.

INTRODUCTION: Revision lumbar fusion is most commonly due to nonunion, adjacent segment disease (ASD), or recurrent stenosis, but it is unclear if diagnosis affects patient outcomes. The primary aim of this study was to assess whether patients achieved the patient acceptable symptom state (PASS) or minimal clinically important difference (MCID) after revision lumbar fusion and assess whether this was influenced by the indication for revision. METHODS: We retrospectively identified all 1-3 level revision lumbar fusions at a single institution. Oswestry Disability Index (ODI) was collected at preoperative, three-month postoperative, and one-year postoperative time points. The MCID was calculated using a distribution-based method at each postoperative time point. PASS was set at the threshold of ≤ 22. RESULTS: We identified 197 patients: 56% with ASD, 28% with recurrent stenosis, and 15% with pseudarthrosis. The MCID for ODI was 10.05 and 10.23 at three months and one year, respectively. In total, 61% of patients with ASD, 52% of patients with nonunion, and 65% of patients with recurrent stenosis achieved our cohort-specific MCID at one year postoperatively with ASD (p = 0.78). At one year postoperatively, 33.8% of ASD patients, 47.8% of nonunion patients, and 37% of patients with recurrent stenosis achieved PASS without any difference between indication (p = 0.47). CONCLUSIONS: The majority of patients undergoing revision spine fusion experience significant postoperative improvements regardless of the indication for revision. However, a large proportion of these patients do not achieve the patient acceptable symptom state. While revision spine surgery may offer substantial benefits, these results underscore the need to manage patient expectations.