Search Results (51)

The traditional bilateral pedicle screw system has been used for the treatment of various lumbar spine conditions including advanced degenerative disc disease. However, there is an ongoing need to develop more effective and less invasive techniques. The purpose of this study was to compare the traditional bilateral pedicle screw system (BPSS) with the novel reverse transdiscal screw system (RTSS) for lumbar disc degenerative disease. A 3D solid lumbar L1–L5 spine model was developed and validated based on a human CT scan. Fusions were simulated at L3–L4. The first scenario comprised a transforaminal lumbar interbody cage in combination with the bilateral pedicle screw-rod system (BPSS-TLIF). In the second scenario, the same TLIF cage was combined with reverse L3–L4 transdiscal screws (RTSS-TLIF). Testing parameters included range of motion (ROM) in three orthogonal axes, hardware (cage and screw) stress, and shear load resistance. The ROM of the surgical model was reduced by approximately 90% compared to the intact model at the fused level. The RTSS model demonstrated less ROM compared to the BPSS model at the fused level for all loading conditions. Overall, the RTSS model exhibited lower stress on both screws and cage compared with the BPSS model in all biomechanical testing conditions. The RTSS model also exhibited higher anterior and posterior shear load resistance than the BPSS model. In conclusion, the RTSS model proved superior to the BPSS model in all respects. These findings indicate that the RTSS could serve as a feasible option for patients undergoing lumbar fusion, especially for adjacent segment disease, potentially enhancing surgical outcomes for disc degeneration. Full article

Objectives: To investigate whether preservation of the posterior elements protects the spine from degeneration and improves postoperative symptoms in lumbar spine laminoplasty. Methods: Eighty-five consecutive patients who underwent lumbar spine laminoplasty were retrospectively reviewed. They were non-randomly stratified into two groups, the posterior elements resection (R) group and the preservation (P) group, and they were followed for two years after surgery. We radiographically analyzed the conditions of the spine and intervertebral disc (IVD) two years after surgery. The Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) was used for symptom assessments. Logistic regression analysis was performed to determine whether the kissing spine was a significant factor for the outcomes in group R. Results: The 2-year D score increment and 2-year IVD height decrement was lower in group P. No difference was found in the flexion–extension angles or incidence of instability between groups. The JOABPEQ revealed higher scores in walking ability, social life function, and mental health in group P one year after surgery. Walking ability was the only score that remained higher two years after surgery. The visual analog scale of pain in the buttocks and lower limbs was lower in group P only one year after surgery. Finally, the kissing spine was not a significant factor in any outcome. Conclusions: The preserved posterior elements were considered to protect the IVD in lumbar spine laminoplasty. In addition, they positively affected postoperative health status from multiple aspects. Full article

The lumbar degenerative cascade is a pathological process that affects most of the aging adult population and has significant negative economic consequences. Lumbar fusion surgery remains a mainstay of treatment for refractory degenerative disease but carries significant long-term consequences. More recently, lumbar arthroplasty and motion-sparing technology has become an increasingly popular alternative surgical option in carefully indicated patients. Arthroplasty technology carries the theoretical benefits of spinal segment motion preservation and decreased degeneration of adjacent segments as compared to traditional fusion procedures. This article will review the lumbar degenerative cascade and its related anatomic considerations, current management strategies and the challenges surrounding lumbar spinal fusion, including adjacent segment disease. This article will also review the theoretical benefits of lumbar arthroplasty and motion preservation. Furthermore, this paper will highlight the current state of lumbar arthroplasty, including current concepts of implant design, limitations, outcomes and ongoing development. It will review the development and current state of artificial disk arthroplasty, total joint arthroplasty and posterior column motion-preserving implants, including flexible rods and facet joint replacement. Full article

Background: Osteoporotic vertebral fractures (OVFs) often lead to poor global sagittal alignment (GSA) and reduced quality of life (QOL). While pseudarthrosis and kyphotic deformities are well-known predictors of conservative treatment failure, the impact of vertebral collapse, paraspinal muscle degeneration, sarcopenia, and nutritional status on GSA remains unclear. This study investigated the relationship between these factors and GSA in patients with conservatively treated OVFs. Methods: This post hoc analysis of a multicenter prospective observational study included 70 patients (single OVF; age ≥ 60 years; 12-month follow-up). Radiographic parameters, paraspinal muscle degeneration, and nutritional status were assessed. GSA was categorized based on the sagittal vertical axis (SVA [mm]): normal (SVA ≤ 40), moderate (40 ≤ SVA ≤ 95), and severe (SVA > 95). Clinical outcomes were assessed using the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ), Oswestry Disability Index (ODI), and visual analog scale (VAS). Results: At 12 months, 22.9% of patients had severe GSA and showed significantly lower JOABPEQ gait dysfunction scores (p = 0.01), higher ODI scores (p < 0.01), and reduced lower lumbar lordosis (p = 0.01). A higher prevalence of lower lumbar OVFs, including prior fractures, was observed in the severe group. No significant correlations were found between GSA and paraspinal muscle degeneration or nutritional status. Conclusions: OVFs in the lower lumbar spine significantly contributed to GSA deterioration. This indicates their critical role in sagittal alignment. Although paraspinal muscle degeneration and malnutrition are common in OVFs, their direct impact on GSA is limited. These findings highlight the need for targeted strategies to manage lumbar OVFs and prevent sagittal malalignment. Full article

Degenerative changes are characterized by the formation of vertebral osteophytes, the hypertrophy of facet joints, and narrowing of the intervertebral space. This study aimed to investigate the concentrations of trace elements (Al, As, Se, Zn, Fe, Mo, Cu) in spinal tissues (intervertebral discs, muscle, and bone) of patients with degenerative lumbar spine disease (DLSD) and their potential associations with the disease. The research involved 13 patients undergoing surgery for symptomatic degenerative spine disease. The trace element concentrations were analyzed using chemical and radiographic assessments, with a statistical analysis performed through a Mann–Whitney U-test, Spearman’s rank correlation test, principal component analysis (PCA), and canonical discriminant analysis (CDA). The results showed significant variations and correlations among the trace elements across different spinal tissues, suggesting their roles in metabolic and oxidative processes and the pathology of spinal degeneration. Full article

This study presents a novel approach for predicting the location and fatigue life of degenerative intervertebral discs (IVDs) under cyclic loading conditions, aiming to improve the understanding of disc degeneration mechanisms. Based on mechanical theories linking IVD degeneration to stress imbalance and water loss, a finite element (FE) model of the L4–L5 lumbar spine was developed, combining probability-weighted anatomical structures, inverse dynamics, and cumulative fatigue mechanics. By quantifying stress variations and calculating cumulative damage across disc regions, stress-concentration areas prone to degeneration were identified, and validation via a case study of a retired weightlifter diagnosed with intervertebral disc disease (IVDD) demonstrated that the predicted degeneration location correlated well with affected areas observed in CT scan images. These findings suggest that prolonged, abnormal stress imbalances within the disc may contribute significantly to degeneration, offering potential clinical applications in preventive assessment and targeted treatment for spine health. Full article

A novel total joint replacement (TJR) that treats lumbar spine degeneration was previously assessed under Mode I and Mode IV conditions. In this study, we relied on these previous wear tests to establish a relationship between finite element model (FEM)-based bearing stresses and in vitro wear penetration maps. Our modeling effort addressed the following question of interest: Under reasonably worst-case misaligned conditions, do the lumbar total joint replacement (L-TJR) polyethylene stresses and strains remain below values associated with Mode IV impingement wear tests? The FEM was first formally verified and validated using the risk-informed credibility assessment framework established by ASME V&V 40 and FDA guidance. Then, based on criteria for unreasonable misuse outlined in the surgical technique guide, a parametric analysis of reasonably worst-case misalignment using the validated L-TJR FEM was performed. Reasonable misalignment was created by altering device positioning from the baseline condition in three scenarios: Axial Plane Convergence (20–40°), Axial Plane A-P Offset (0–4 mm), and Coronal Plane Tilt (±20°). We found that, for the scenarios considered, the contact pressures, von Mises stresses, and effective strains of the L-TJR-bearing surfaces remained consistent with Mode I (clean) conditions. Specifically, the mechanical response values fell below those determined under Mode IV (worst-case) boundary conditions, which provided the upper-bound benchmarks for the study (peak contact pressure 83.3 MPa, peak von Mises stress 32.2 MPa, and peak effective strain 42%). The L-TJR was judged to be insensitive to axial and coronal misalignment under the in vitro boundary conditions imposed by the study. Full article

Background: Chronic low back pain (LBP) has been associated with intervertebral disc (IVD) degeneration, but its association with abnormal morphology at the discovertebral junction (DVJ) is unclear. The goal of this study was to evaluate the DVJ morphology in asymptomatic (Asx) and symptomatic (Sx) subjects for LBP using ultrashort echo time (UTE) MRI. Methods: We recruited 42 subjects (12 Asx and 32 Sx). Lumbar IVD degeneration was assessed using Pfirrmann grading (1 to 5), while the abnormality of DVJ (0 = normal; 1 = focal; 2 = broad abnormality) was assessed using UTE MRI. The effects of LBP and level on the mean IVD and DVJ grades, the correlation between IVD and DVJ grade, and the effect of LBP and age on the number of abnormal DVJs within a subject were determined. Results: IVD grade was higher in Sx subjects (p = 0.013), varying with disc level (p = 0.033), adjusted for age (p < 0.01). Similarly, DVJ grade was also significantly higher in Sx subjects (p = 0.001), but it did not vary with DVJ level (p = 0.7), adjusted for age (p = 0.5). There was a weak positive (rho = 0.344; p < 0.001) correlation between DVJ and IVD grade. The total number of abnormal DVJs within a subject was higher in Sx subjects (p < 0.001), but not with respect to age (p = 0.6) due to a large spread throughout the age range. Conclusions: These results demonstrate the feasibility of using in vivo UTE MRI of the lumbar spine to evaluate the DVJ and the correlation of DVJ with LBP. This study highlights the need for a better understanding of DVJ pathology and the inclusion of DVJ assessment in routine lumbar MRI. Full article

Background/Objectives: Three-dimensional accelerometry data from the lower trunk during running is associated with intervertebral disc degeneration. The kinematic function known as the lumbo–pelvic–hip complex involves movements in the sagittal plane during running. If pelvic movement and acceleration in the anteroposterior direction are correlated, improving running mechanics may reduce the load on the intervertebral disc. This study investigated the relationship between the anteroposterior acceleration of the lower lumbar spine and pelvic tilt movements during running. Methods: Sixteen healthy male college students were enrolled and asked to run on a treadmill for 1 min at 16 km/h, and the acceleration data for their lower lumbar region and running motion in the sagittal plane were recorded. The pelvic tilt angle during running was calculated through two-dimensional motion analysis. Subsequently, a simple linear regression analysis was employed to clarify the relationship between the acceleration data of the lower lumbar region and the pelvic tilt angle during running. Results: The simple linear regression analysis indicated that the root mean squares of the anteroposterior acceleration of the lower lumbar spine were associated with the maximum pelvic tilt angle (r  =  0.32, p  =  0.003, adjusted R² = 0.09) and its range (r  =  0.42, p  =  0.0001, adjusted R² = 0.16). Conclusions: However, the adjusted R² value was low, indicating that although the pelvic tilt angle during running may be related to acceleration in the anteroposterior direction, the effect is small. Full article

Background: The gold standard treatment for adolescent idiopathic scoliosis (AIS) is posterior spinal fusion (PSF). However, long-term consequences of PSF can include reduced spinal flexibility, back pain, and intervertebral disc degeneration. Vertebral body tethering (VBT) is a non-fusion alternative that preserves motion. We investigated the outcomes of VBT for the treatment of thoracolumbar (TL) major AIS in the largest single-surgeon series with a minimum 2-year follow-up (FU). Methods: We performed a retrospective single-center review. Inclusion criteria were AIS, Lenke 5/6 curvature, and skeletally immature Variables were compared using Student’s t-tests, Wilcoxon rank sum tests, Chi-square, and Fisher’s exact tests. Results: A total of 37 consecutive patients, age 14.1 ± 1.6 years, 86.5% F, 35.9 ± 11.5-month FU, were examined. Overall, 27 patients (73%) had Lenke 5 and 10 (27%) had Lenke 6 curvatures. Instrumentation of the TL curve alone was performed in 59.5%, and thoracic (T) and TL in 40.5% of patients. Overall, 45.9% of patients had two tethers placed in the TL spine; no patients had double tethers placed at the main thoracic curves. The TL (51 ± 8° to 20 ± 11°; p < 0.0001) and T (37 ± 13° to 17 ± 10°; p < 0.0001) curvatures improved from baseline to the latest FU. Overall, 89% of patients achieved major Cobb < 35°; the three patients who did not experienced at least one cord breakage or required PSF. T5-T12 kyphosis increased (p = 0.0401) and lumbar lordosis was maintained (p = 0.9236). Both the TL inclinometer (16 ± 4º to 4 ± 2°; p < 0.0001) and T (6 ± 4° to 4 ± 3°; p = 0.0036) measurements improved. There was a 49% tether breakage rate as follows: 60% for single-cord TL constructs and 35% for double cords (p = 0.0991). There was an 8.1% re-operation rate as follows: one conversion to T PSF and revision of the TL tether; one release of the T tether and revision of the TL tether; one screw revision for radiculopathy. One patient was re-admitted for poor pain control. Conclusions: Patients with TL major curvature treated with VBT experienced a high rate of clinically successful outcomes with maintenance of lumbar lordosis and relatively low complication rates at the latest FU. Full article

Lumbar spinal stenosis (LSS) is a degenerative spinal condition characterized by the narrowing of the spinal canal, resulting in low back pain (LBP) and limited leg mobility. Twin and family studies have suggested that genetics contributes to disease progression. However, the genetic causes of familial LSS remain unclear. We performed whole-exome and direct sequencing on seven female patients from a Han Chinese family with LBP, among whom four developed LSS. Based on our genetic findings, we performed gene knockdown studies in human chondrocytes to study possible pathological mechanisms underlying LSS. We found a novel nonsense mutation, c.417C > G (NM_002183, p.Y139X), in IL3RA, shared by all the LBP/LSS cases. Knockdown of IL3RA led to a reduction in the total collagen content of 81.6% in female chondrocytes and 21% in male chondrocytes. The expression of MMP-1, -3, and/or -10 significantly increased, with a more pronounced effect observed in females than in males. Furthermore, EsRb expression significantly decreased following IL3RA knockdown. Moreover, the knockdown of EsRb resulted in increased MMP-1 and -10 expression in chondrocytes from females. We speculate that IL3RA deficiency could lead to a reduction in collagen content and intervertebral disk (IVD) strength, particularly in females, thereby accelerating IVD degeneration and promoting LSS occurrence. Our results illustrate, for the first time, the association between IL3RA and estrogen receptor beta, highlighting their importance and impact on MMPs and collagen in degenerative spines in women. Full article

Introduction: The disco-vertebral junction (DVJ) of the lumbar spine contains thin structures with short T2 values, including the cartilaginous endplate (CEP) sandwiched between the bony vertebral endplate (VEP) and the nucleus pulposus (NP). We previously demonstrated that ultrashort-echo-time (UTE) MRI, compared to conventional MRI, is able to depict the tissues at the DVJ with improved contrast. In this study, we sought to further optimize UTE MRI by characterizing the contrast-to-noise ratio (CNR) of these tissues when either single echo or echo subtraction images are used and with varying echo times (TEs). Methods: In four cadaveric lumbar spines, we acquired 3D Cones (a UTE sequence) images at varying TEs from 0.032 ms to 16 ms. Additionally, spin echo T1- and T2-weighted images were acquired. The CNRs of CEP-NP and CEP-VEP were measured in all source images and 3D Cones echo subtraction images. Results: In the spin echo images, it was challenging to distinguish the CEP from the VEP, as both had low signal intensity. However, the 3D Cones source images at the shortest TE of 0.032 ms provided an excellent contrast between the CEP and the VEP. As the TE increased, the contrast decreased in the source images. In contrast, the 3D Cones echo subtraction images showed increasing CNR values as the second TE increased, reaching statistical significance when the second TE was above 10 ms (p < 0.05). Conclusions: Our study highlights the feasibility of incorporating UTE MRI for the evaluation of the DVJ and its advantages over conventional spin echo sequences for improving the contrast between the CEP and adjacent tissues. Additionally, modulation of the contrast for the target tissues can be achieved using either source images or subtraction images, as well as by varying the echo times. Full article

Various nutritional supplements are available over the counter, yet few have been investigated in randomized controlled trials. The rationale for using the specific mix of nutritional substances including collagen type II, hyaluronic acid, n-acetyl-glucosamine, bamboo extract, L-lysine, and vitamin C is the assumption that combining naturally occurring ingredients of the intervertebral disc would maintain spine function. This double-blinded, placebo-controlled randomized trial aimed to evaluate the efficacy of a nutraceutical supplement mix in the management of lumbar osteochondrosis. Fifty patients were randomly assigned to either the supplement or placebo group in a 1:1 ratio. Patient-Reported Outcome Measures (PROMs) included the Oswestry Disability Index (ODI), the visual analogue scale for pain (pVAS), short form-12 (SF-12) physical and mental component summary subscale scores (PCS and MCS, respectively), and global physical activity questionnaire (GPAQ). Magnetic resonance imaging (MRI) was used to evaluate degenerative changes of intervertebral discs (IVD) including Pfirrmann grades as well as three-dimensional (3D) volume measurements. Data were collected at baseline and after the 3-month intervention. None of the PROMs were significantly different between the supplement and placebo groups. Disc degeneration according to Pfirrmann classifications remained stable during the 3-month intervention in both groups. Despite no significance regarding the distribution of Pfirrmann grade changes (improvement, no change, worsening; p = 0.259), in the supplement group, one patient achieved a three-grade improvement, and worsening of Pfirrmann grades were only detected in the placebo group (9.1%). Furthermore, in-depth evaluations of MRIs showed significantly higher 3D-measured volume changes (increase) in the supplement (+740.3 ± 796.1 mm³) compared to lower 3D-measured volume changes (decrease) in the placebo group (−417.2 ± 875.0 mm³; p < 0.001). In conclusion, this multi-nutrient supplement might not only stabilize the progression of lumbar osteochondrosis, but it might also potentially even increase IVD volumes as detected on MRIs. Full article

Background: Physiological curvature changes of the lumbar spine and disc herniation can cause abnormal biomechanical responses of the lumbar spine. Finite element (FE) studies on special weightlifter models are limited, yet understanding stress in damaged lumbar spines is crucial for preventing and rehabilitating lumbar diseases. This study analyzes the biomechanical responses of a weightlifter with lumbar straightening and L4-L5 disc herniation during symmetric bending and lifting to optimize training and rehabilitation. Methods: Based on the weightlifter’s computed tomography (CT) data, an FE lumbar spine model (L1-L5) was established. The model included normal intervertebral discs (IVDs), vertebral endplates, ligaments, and a degenerated L4-L5 disc. The bending angle was set to 45°, and weights of 15 kg, 20 kg, and 25 kg were used. The flexion moment for lifting these weights was theoretically calculated. The model was tilted at 45° in Abaqus 2021 (Dassault Systèmes Simulia Corp., Johnston, RI, USA), with L5 constrained in all six degrees of freedom. A vertical load equivalent to the weightlifter’s body mass and the calculated flexion moments were applied to L1 to simulate the weightlifter’s bending and lifting behavior. Biomechanical responses within the lumbar spine were then analyzed. Results: The displacement and range of motion (ROM) of the lumbar spine were similar under all three loading conditions. The flexion degree increased with the load, while extension remained unchanged. Right-side movement and bending showed minimal change, with slightly more right rotation. Stress distribution trends were similar across loads, primarily concentrated in the vertebral body, increasing with load. Maximum stress occurred at the anterior inferior margin of L5, with significant stress at the posterior joints, ligaments, and spinous processes. The posterior L5 and margins of L1 and L5 experienced high stress. The degenerated L4-L5 IVD showed stress concentration on its edges, with significant stress also on L3-L4 IVD. Stress distribution in the lumbar spine was uneven. Conclusions: Our findings highlight the impact on spinal biomechanics and suggest reducing anisotropic loading and being cautious of loaded flexion positions affecting posterior joints, IVDs, and vertebrae. This study offers valuable insights for the rehabilitation and treatment of similar patients. Full article

An evaluation of the impact of osteoporosis on loss of spinal stability, with or without intervertebral disc degeneration, using computational analysis is presented. The research also investigates the correlation between osteoporosis and intervertebral disc degeneration. Three-dimensional finite element models of human lumbar spine segments were used to assess the influence of osteoporosis on spinal stability. Five different models of age-related degeneration were created using various material properties for trabecular bone and intervertebral discs. Calculation results indicate that in a spine with osteoporosis, the deformation of the intervertebral discs can increase by more than 30% when compared to a healthy spine. Thus, intervertebral disc deformation depends not only on the degree of degeneration of the discs themselves, but their deformation is also influenced by the degree of osteoporosis of the vertebrae. Additionally, the load-bearing capacity of the spine can decrease by up to 30% with osteoporosis, regardless of the degree of intervertebral disc deformation. In conclusion, osteoporosis can contribute to intervertebral disc degeneration. Full article