Disc Height Research Articles

Analysis Re-Entrant honeycomb auxetic structure for lumbar vertebrae using finite element analysis

Lumbar spinal fusion is a frequent surgical solution among people who are experiencing severe persistent lower back pain. One treatment option is Lateral Lumbar Interbody Fusion (LLIF) surgery. In the medical field, finite element analysis (FEA) can be used to predict the best surgical plan. LLIF surgery involves implanting an interbody cage into the disc space, which may potentially move to regain the disk height while helping stabilize the vertebral bones. In this study, FEA was applied using Mechanical Finder software (MF) to develop a 3D spine model lumbar vertebrae of the fourth and fifth lumbar vertebrae (L4 - L5) with the interbody cage design. The cage was made of polyether ether ketone (PEEK) and designed using Solidworks software. Given the auxetic structure's outstanding energy absorption capabilities, a re-entrant auxetic structure core with a novel sandwich panel was implanted between the lumbar vertebrae L4 and L5, as determined by CT scans using MF software. The model was analyzed in MF to assess the strength and fracture risk analysis of the interbody cage, with the results compared to mechanical properties values obtained by applying compression load (1000 N) to simulate spinal movements. Stress and strain distribution rates were exhibited when applying a force of 1000 N. The findings underscore the relevance of cage design, namely the surface endplate, in mitigating undesirable occurrences associated with cage sinking. To attain enough strength under typical conditions, a lumbar cage with a re-entrant auxetic construction has been proposed.

Comparing OLIF Combined with Lateral Screw Fixation versus Minimally Invasive TLIF for Treating Single-Level Degenerative Lumbar Spondylolisthesis: A Retrospective Cohort Study.

The present study aimed to compare the clinical and radiologic outcomes of oblique lumbar interbody fusion (OLIF) combined with lateral screw fixation and minimally invasive transforaminal lumbar interbody fusion (Mis-TLIF) for the treatment of single-level degenerative lumbar spondylolisthesis (DLS). Data regarding clinical and radiologic outcomes for single-level DLS treated using OLIF combined with lateral screw fixation or Mis-TLIF between November 2017 and June 2020 were retrospectively analyzed. Seventy-five patients with single-level DLS (≥2 years' follow-up) were included and divided into two groups according to the surgical method used: OLIF (n = 33) and Mis-TLIF (n = 42). Operative time, intraoperative blood loss, and length of hospital stay were significantly lower in the OLIF group than that in the Mis-TLIF group. There were no significant differences in preoperative low back pain (LBP), leg pain (LP), visual analog scale (VAS) scores, and Oswestry Disability Index (ODI) between the two groups, although the OLIF group had significantly lower LBP VAS scores at 1, 3, and 6 months postoperatively. Additionally, the LP VAS score was significantly lower in the Mis-TLIF group than that in the OLIF group at 1 month postoperatively, and the ODI of the OLIF group at 3 months postoperatively was significantly lower than that of the Mis-TLIF group. There was no significant difference in the preoperative and postoperative lumbar lordosis angles between the two groups, whereas the postoperative surgical segmental lordosis angle and disk height (at 1, 6, 12, and 24 months) in the OLIF group were significantly higher than those in the Mis-TLIF group. Additionally, there was no significant difference in complication rates between the two groups (18.2% in the OLIF group vs. 11.9% in the Mis-TLIF group; p = 0.520). OLIF combined with lateral screw fixation yielded better clinical and radiologic outcomes than Mis-TLIF in patients with single-level DLS.

Titanium-Coated Polyetheretherketone Cages Vs Full Titanium Cages for Stand-Alone 1- or 2-Level Anterior Cervical Discectomy and Fusion: A Comparative Study.

Anterior cervical discectomy and fusion (ACDF) for the surgical treatment of cervical degenerative disease often includes an intervertebral cage, which restores disc height and lordosis while promoting fusion . Cage materials include titanium (TTN) or polyetheretherketone (PEEK). Controversy in material selection stems from higher fusion rates with TNN, despite a higher subsidence rate, while PEEK cages demonstrate superior preservation of interspace height. Combining the advantages of both materials, TTN-coated PEEK (TCPEEK) cages were developed, featuring a PEEK core with similar stiffness to the bone, enveloped with a TTN coat, improving osteointegration. However, the potential superiority of TCPEEK over TTN cages has not been investigated. This study aimed to compare clinical and radiographic outcomes following single- or double-level ACDF using either TTN or TCPEEK cages. This retrospective single-center study included patients undergoing single- or double-level ACDF between 2017 and 2019. Clinical outcomes included the Neck Disability Index and revision surgery incidence. Radiographic parameters included cervical and segmental lordosis, C2 to C7 sagittal vertical axis, fusion, subsidence, and adjacent segment degeneration at a minimum 12-month follow-up. A total of 45 patients (16 TTN; 29 TCPEEK) and 58 cervical levels (21 TTN; 37 TCPEEK) were included. Both cages significantly improved Neck Disability Index scores (TTN -10.0; TCPEEK -14.1) without significant differences. Two single-level TCPEEK patients required revision surgery due to non-union. In the radiological assessments, no significant difference was found for subsidence rates (TTN 52.4%; TCPEEK 56.8%), adjacent segment degeneration, cervical and segmental lordosis, and changes in C2 to C7 sagittal vertical axis. Though not statistically significant, fusion rates trended slightly higher with TTN (90.5%) vs TCPEEK cages (86.5%). TTN and TCPEEK cages achieve satisfactory clinical and radiological outcomes in single- or double-level ACDF. This finding suggests that the choice between them can be based on other factors, such as surgeon preference or availability, rather than specific material properties. This study found that the selection of ACDF cage material did not affect clinical outcomes.

IL-1ra loaded chondroitin sulfate-functionalized microspheres for minimally invasive treatment of intervertebral disc degeneration

Presently, the clinical treatment of intervertebral disc degeneration (IVDD) remains challenging, but the strategy of simultaneously overcoming the overactive inflammation and restoring the anabolic/catabolic balance of the extracellular matrix (ECM) in the nucleus pulposus (NP) has become an effective way to alleviate IVDD. IL-1ra, a natural antagonist against IL-1β, can mitigate inflammation and promote regeneration in IVDD. Chondroitin sulfate (CS), an important component of the NP, can promote ECM synthesis and delay IVDD. Thus, these were chosen and integrated into functionalized microspheres to achieve their synergistic effects. First, CS-functionalized microspheres (GelMA-CS) with porous microstructure, good monodispersion, and about 200 µm diameter were efficiently and productively fabricated using microfluidic technology. After lyophilization, the microspheres with good local injection and tissue retention served as the loading platform for IL-1ra and achieved sustained release. In in vitro experiments, the IL-1ra-loaded microspheres exhibited good cytocompatibility and efficacy in inhibiting the inflammatory response of NP cells induced by lipopolysaccharide (LPS) and promoting the secretion of ECM. In in vivo experiments, the microspheres showed good histocompatibility, and local, minimally invasive injection of the IL-1ra-loaded microspheres could reduce inflammation, maintain the height of the intervertebral disc (IVD) and the water content of NP close to about 70 % in the sham group, and retain the integrated IVD structure. In summary, the GelMA-CS microspheres served as an effective loading platform for IL-1ra, eliminated inflammation through the controlled release of IL-1ra, and promoted ECM synthesis via CS to delay IVDD, thereby providing a promising intervention strategy for IVDD. Statement of significanceThe strategy of simultaneously overcoming the overactive inflammation and restoring the anabolic/catabolic balance of the extracellular matrix (ECM) in nucleus pulposus (NP) has shown great potential prospects for alleviating intervertebral disc degeneration (IVDD). From the perspective of clinical translation, this study developed chondroitin sulfate functionalized microspheres to act as the effective delivery platform of IL-1ra, a natural antagonist of interleukin-1β. The IL-1ra loading microspheres (GelMA-CS-IL-1ra) showed good biocompatibility, good injection with tissue retention, and synergistic effects of inhibiting the inflammatory response induced by lipopolysaccharide and promoting the secretion of ECM in NPCs. In vivo, they also showed the beneficial effect of reducing the inflammatory response, maintaining the height of the intervertebral disc and the water content of the NP, and preserving the integrity of the intervertebral disc structure after only one injection. All demonstrated that the GelMA-CS-IL-1ra microspheres would have great promise for the minimally invasive treatment of IVDD.

Transforaminal lumbar interbody fusion subsidence: computed tomography analysis of incidence, associated risk factors, and impact on outcomes.

The aims of this study were to 1) define the incidence of transforaminal lumbar interbody fusion (TLIF) interbody subsidence; 2) determine the relative importance of preoperative and intraoperative patient- and instrumentation-specific risk factors predictive of postoperative subsidence using CT-based assessment; and 3) determine the impact of TLIF subsidence on postoperative complications and fusion rates. All adult patients who underwent one- or two-level TLIF for lumbar degenerative conditions at a multi-institutional academic center between 2017 and 2019 were retrospectively identified. Patients with traumatic injury, infection, malignancy, previous fusion at the index level, combined anterior-posterior procedures, surgery with greater than two TLIF levels, or incomplete follow-up were excluded. Interbody subsidence at the superior and inferior endplates of each TLIF level was directly measured on the endplate-facing surface of both coronal and sagittal CT scans obtained greater than 6 months postoperatively. Patients were grouped based on the maximum subsidence at each operative level classified as mild, moderate, or severe based on previously documented < 2-mm, 2- to 4-mm, and ≥ 4-mm thresholds, respectively. Univariate and regression analyses compared patient demographics, medical comorbidities, preoperative bone quality, surgical factors including interbody cage parameters, and fusion and complication rates across subsidence groups. A total of 67 patients with 85 unique fusion levels met the inclusion and exclusion criteria. Overall, 28% of levels exhibited moderate subsidence and 35% showed severe subsidence after TLIF with no significant difference in the superior and inferior endplate subsidence. Moderate (≥ 2-mm) and severe (≥ 4-mm) subsidence were significantly associated with decreases in cage surface area and Taillard index as well as interbody cages with polyetheretherketone (PEEK) material and sawtooth surface geometry. Severe subsidence was also significantly associated with taller preoperative disc spaces, decreased vertebral Hounsfield units (HU), the absence of bone morphogenetic protein (BMP) use, and smooth cage surfaces. Regression analysis revealed decreases in Taillard index, cage surface area, and HU, and the absence of BMP use predicted subsidence. Severe subsidence was found to be a predictor of pseudarthrosis but was not significantly associated with revision surgery. Patient-level risk factors for TLIF subsidence included decreased HU and increased preoperative disc height. Intraoperative risk factors for TLIF subsidence were decreased cage surface area, PEEK cage material, bullet cages, posterior cage positioning, smooth cage surfaces, and sawtooth surface designs. Severe subsidence predicted TLIF pseudarthrosis; however, the causality of this relationship remains unclear.

Anterior Cervical Discectomy and Fusion Surgery: Results with Zero - Profile Spacer/Cage

OBJECTIVES This study aimed to evaluate the clinical outcomes of Anterior Cervical Discectomy and Fusion (ACDF) treatments for cervical disc degenerative disease (CDDD) using a Zero Profile cage. METHODOLOGY A retrospective study of 26 patients with cervical disc disease treated with a zero-profile cage was designed and followed up for an average of 12 months in descriptive research. For arm and neck pain, the Neck Disability Index (NDI) and Visual Analogue Scale (VAS) scores were used to assess function. Nurick’s myelopathy classification scheme based on gait impairments was also documented. RESULTSThe average age of the 26 patients was 48.96 13.13 years (mean SD), with 44 percent falling into the 40-60-year age bracket. The male/female gender distribution was 21 (84%) and 04 (16%) male/female. Radiculomyelopathic symptoms were detected in 11 (28%) of the patients, with radicular pain occurring bilaterally in seven (28%) of the patients and on the left side in four (16%). A radiological examination of fusion was performed at six months and one year. The fusion had a success rate of 95 percent at six months (19 patients) and 100 percent at one year. CONCLUSION A zero-profile device provides biomechanical stability and fusion rates with excellent outcomes for one- and two-level ACDFs. Advantages include low rates of dysphagia, decreased operative time, restoration of cervical lordosis and disc height, and lack of cage subsidence or screw back out.

Magnetorotational dynamo can generate large-scale vertical magnetic fields in 3D GRMHD simulations of accreting black holes

ABSTRACT Jetted astrophysical phenomena with black hole engines, including binary mergers, jetted tidal disruption events, and X-ray binaries, require a large-scale vertical magnetic field for efficient jet formation. However, a dynamo mechanism that could generate these crucial large-scale magnetic fields has not been identified and characterized. We have employed three-dimensional global general relativistic magnetohydrodynamical simulations of accretion discs to quantify, for the first time, a dynamo mechanism that generates large-scale magnetic fields. This dynamo mechanism primarily arises from the non-linear evolution of the magnetorotational instability (MRI). In this mechanism, large non-axisymmetric MRI-amplified shearing wave modes, mediated by the axisymmetric azimuthal magnetic field, generate and sustain the large-scale vertical magnetic field through their non-linear interactions. We identify the advection of magnetic loops as a crucial feature, transporting the large-scale vertical magnetic field from the outer regions to the inner regions of the accretion disc. This leads to a larger characteristic size of the, now advected, magnetic field when compared to the local disc height. We characterize the complete dynamo mechanism with two time-scales: one for the local magnetic field generation, $t_{\rm gen}$, and one for the large-scale scale advection, $t_{\rm adv}$. Whereas the dynamo we describe is non-linear, we explore the potential of linear mean field models to replicate its core features. Our findings indicate that traditional $\alpha$-dynamo models, often computed in stratified shearing box simulations, are inadequate and that the effective large-scale dynamics is better described by the shear current effects or stochastic $\alpha$-dynamos.

Comparison of the effects between oblique lateral interbody fusion (OLIF) and minimally invasive transforaminal interbody fusion (MIS-TLIF) in the treatment of adult degenerative lumbar scoliosis

BackgroundManaging adult degenerative lumbar scoliosis (ADLS) presents a complex challenge, requiring advanced, minimally invasive surgical techniques. ObjectiveThis study aims to evaluate and compare the efficacy and outcomes of oblique lateral interbody fusion (OLIF) and minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in treating ADLS, with an emphasis on surgical methods, recovery times, and spinal correction results. MethodsWe reviewed 42 patients with ADLS who did not respond to conservative treatments. These patients underwent either OLIF or MIS-TLIF procedures. Key factors analyzed included surgical duration, blood loss, complications, and changes in preoperative and postoperative lumbar lordosis (LL), anterior and posterior disc height (ADH, PDH), and Cobb angles. Statistical analysis was conducted using SPSS software, with significance determined at p < 0.05. ResultsThe OLIF technique showed notable benefits in multi-segment spinal corrections, particularly in enhancing intervertebral disc height and correcting Cobb angles. While both surgical methods effectively addressed spinal deformities, OLIF was less invasive, resulting in reduced blood loss, shorter surgery times, and fewer complications. No significant differences were found between the two techniques for single-segment corrections. ConclusionFor multi-segment spinal corrections in ADLS, OLIF is a superior choice due to its minimal invasiveness and favorable recovery profile. However, for patients with primarily radicular symptoms and no significant postural alterations, MIS-TLIF may be more appropriate.

Hysterectomy—a possible risk factor for operative intervention in female patients for degenerative lumbar spine conditions: a case control and cohort study

Researchers have recently linked hysterectomy, which alters sex hormone levels, to diseases like osteoporosis, lumbar spondylolisthesis, hypertension and diabetes etc. However, the association between hysterectomy and lumbar disc herniation (LDH)/lumbar spinal stenosis (LSS) remains unclarified. To determine whether there is a correlation between hysterectomy and surgical intervention for LDH/LSS in women, further substantiated through imaging and clinical research. A case control and cohort study. The study group comprised 1202 female patients aged 45 and older who had undergone operative treatment due to LDH/LSS (825 for LDH and 377 for LSS), and the comparison group comprised 1168 females without lumbar diseases who visited health examination clinic during the same period. One hundred and 2 hysterectomized patients were further selected (Hysterectomy cohort) and matched approximately with the control cohort at a 1:2 ratio from the study group with a minimum follow-up of 2 years. Odds Ratios (ORs) and 95% Confidence Intervals (CIs) were calculated to assess the association between hysterectomy and surgical intervention for LDH/LSS in women after adjusted by confounding factors. Patients from both the hysterectomy and control cohorts underwent a comprehensive assessment. This assessment included the evaluation of several parameters: the functional cross-sectional area, fat infiltration rate, relative functional cross-sectional area of the lumbar paravertebral muscles, facet joint degeneration grade, cartilage endplate damage, Modic changes for the L3/4-L5/S1 segments, Pfirrmann grade of lumbar disc degeneration, and disc height index for the L1/2-L5/S1 segments. Additionally, the Visual Analog Scale (VAS) and Japanese Orthopaedic Association (JOA) scores were recorded preoperatively and at the last follow-up. Associations between hysterectomy and patients treated surgically for LDH or LSS were analyzed using multivariate binomial logistic regression analysis. Lumbar X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) were used to evaluate the imaging variables. Imaging and clinical variables were compared. Hysterectomized women were associated with requiring surgery due to LDH/LSS, with ORs of 2.613 (p<.001) and 2.084 (p=.006), respectively. The imaging evaluation further revealed that the hysterectomy cohort had more severe degeneration of the paraspinal muscles, facet joints, endplates, and intervertebral discs, Modic changes at L3/4-L5/S1 segments, and intervertebral height reduction at L1/2-L5/S1 segments when compared to the control cohort (p<.01). Compared to the control cohort, the hysterectomy cohort exhibited higher preoperative and last follow-up VAS scores for low back pain, and last follow-up JOA scores (p<.01). Based on the findings of this study, it seems that women who have had a hysterectomy are correlated with requiring surgical intervention due to LDH/LSS. Imaging and clinical studies also indicate that hysterectomized patients exhibited more severe lumbar degeneration and back pain.

The postoperative clinical effects of utilizing 3D printed (Ti6Al4V) interbody fusion cages in posterior lumbar fusion: A retrospective cohort study.

The research focused on the postoperative effect of using interbody fusion cage in lumbar posterior lamina decompression and interbody fusion with pedicle screw by comparing the postoperative effect of using 3D printing (Ti6Al4V) and PEEK material interbody fusion cage. Ninety-one patients with lumbar degenerative diseases from the Department of Spine Surgery of Tianjin Hospital were included in the study cohort. They were divided into 3D group (n = 39) and PEEK group (n = 52) according to the use of interbody fusion cage. The imaging data of the patients were collected and the postoperative data of the 2 groups were compared to evaluate patients' health status and the recovery of lumbar structure and function after operation. Combined with the degree of fusion, the clinical effect of 3D printing titanium alloy interbody fusion cage was comprehensively judged. At the last follow-up, the JOA score, ODI index, VAS, prolo function score, and SF-36 scale of the 2 groups showed that the clinical symptoms were better than those before operation (P < .05). The height of intervertebral disc, the area of intervertebral foramen and the physiological curvature of lumbar vertebrae increased in varying degrees after operation (P < .05). At the last follow-up, the vertebral cage fusion rates were as high as 89.13% and 90.91% in the 3D and PEEK groups, with collapse rates of 6.5% and 4.5%, respectively. There were 10 cases of cage displacement in 3D group and 7 cases of cage displacement in PEEK group. There was no significant difference between the 2 groups (P > .05). In conclusion, 3D printed (Ti6Al4V) interbody fusion cage can obtain good clinical effect in the surgical treatment of lumbar degenerative diseases. Posterior lumbar lamina decompression, bilateral pedicle screw fixation combined with 3D printed cage interbody fusion is excellent in rebuilding the stability of lumbar vertebrae. 3D printed interbody fusion cage can be an ideal substitute material for intervertebral bone grafting. The stable fusion time of interbody fusion cage after lumbar fusion is mostly from 3 months to half a year after operation.

Zero-profile implant system versus novel plate systems after ACDF for comparison of sagittal balance parameters and clinical efficacy analysis

BackgroundThe zero-profile implant system (Zero-P) and conventional plates have been widely used in anterior cervical discectomy and fusion (ACDF) to treat cervical spondylosis. The purpose of this study was to compare the effects of the application of Zero-P and new conventional plates (ZEVO, Skyline) in ACDF on the sagittal imaging parameters of cervical spondylosis patients and to analyze their clinical efficacy.MethodsWe conducted a retrospective study on 119 cervical spondylosis patients from January 2018 to December 2021, comparing outcomes between those receiving the Zero-P device (n = 63) and those receiving a novel conventional plate (n = 56, including 46 ZEVO and 10 Skyline plates) through ACDF. Cervical sagittal alignment was assessed pre- and postoperatively via lateral radiographs. The Japanese Orthopedic Association (JOA), Neck Disability Index (NDI), and visual analog scale (VAS) scores were recorded at baseline, after surgery, and at the 2-year follow-up to evaluate patient recovery and intervention success.ResultsThere were significant differences in the postoperative C0-C2 Cobb angle and postoperative sagittal segmental angle (SSA) between patients in the novel conventional plate group and those in the Zero-P group (P < 0.05). Postoperatively, there were significant changes in the C2‒C7 Cobb angle, C0‒C2 Cobb angle, SSA, and average surgical disc height (ASDH) compared to the preoperative values in both patient groups (P < 0.05). Dysphagia in the immediate postoperative period was lower in the Zero-P group than in the new conventional plate group (0% in the Zero-P group, 7.14% in the novel conventional plate group, P = 0.046), and the symptoms disappeared within 2 years in both groups. There was no statistically significant difference between the two groups in terms of complications of adjacent spondylolisthesis (ASD) at 2 years postoperatively (3.17% in the Zero-P group, 8.93% in the novel conventional plate group; P = 0.252). According to the subgroup analysis, there were significant differences in the postoperative C2‒C7 Cobb angle, C0‒C2 Cobb angle, T1 slope, and ASDH between the ZEVO group and the Skyline group (P < 0.05). Compared with the preoperative scores, the JOA, NDI, and VAS scores of all groups significantly improved at the 2-year follow-up (P < 0.01). According to the subgroup analysis, the immediate postoperative NDI and VAS scores of the ZEVO group were significantly better than those of the Skyline group (P < 0.05).ConclusionIn ACDF, both novel conventional plates and Zero-P can improve sagittal parameters and related scale scores. Compared to the Zero-P plate, the novel conventional plate has a greater advantage in correcting the curvature of the surgical segment, but the Zero-P plate is less likely to produce postoperative dysphagia.

Cost-Effectiveness and Clinical Outcomes of Lateral Lumbar Interbody Fusion With Tricalcium Phosphate and Iliac Bone Graft Compared With Posterior Lumbar Interbody Fusion With Local Bone Graft in Single-Level Lumbar Spinal Fusion Surgery in Thailand.

Nowadays, minimally invasive lateral lumbar interbody fusion (LLIF) is used to treat degenerative lumbar spine disease. Many studies have proven that LLIF results in less soft tissue destruction and rapid recovery compared with open posterior lumbar interbody fusion (PLIF). Our recent cost-utility study demonstrated that LLIF was not cost-effective according to the Thai willingness-to-pay threshold, primarily due to the utilization of an expensive bone substitute: bone morphogenetic protein 2. Therefore, this study was designed to use less expensive tricalcium phosphate combined with iliac bone graft (TCP + IBG) as a bone substitute and compare cost-utility analysis and clinical outcomes of PLIF in Thailand. All clinical and radiographic outcomes of patients who underwent single-level LLIF using TCP + IBG and PLIF were retrospectively collected. Preoperative and 2-year follow-up quality of life from EuroQol-5 Dimensions-5 Levels and health care cost were reviewed. A cost-utility analysis was conducted using a Markov model with a lifetime horizon and a societal perspective. All enrolled patients were categorized into an LLIF group (n = 30) and a PLIF group (n = 50). All radiographic results (lumbar lordosis, foraminal height, and disc height) were improved at 2 years of follow-up in both groups (P < 0.001); however, the LLIF group had a dramatic significant improvement in all radiographic parameters compared with the PLIF group (P < 0.05). The fusion rate for LLIF (83.3%) and PLIF (84%) was similar and had no statistical significance. All health-related quality of life (Oswestry Disability Index, utility, and EuroQol Visual Analog Scale) significantly improved compared with preoperative scores (P < 0.001), but there were no significant differences between the LLIF and PLIF groups (P > 0.05). The total lifetime cost of LLIF was less than that of PLIF (15,355 vs 16,500 USD). Compared with PLIF, LLIF was cost-effective according to the Thai willingness-to-pay threshold, with a net monetary benefit of 539.76 USD. LLIF with TCP + IBG demonstrated excellent radiographic and comparable clinical health-related outcomes compared with PLIF. In economic evaluation, the total lifetime cost was lower in LLIF with TCP + IBG than in PLIF. Furthermore, LLIF with TCP + IBG was cost-effective compared with PLIF according to the context of Thailand. LLIF with less expensive TCP + IBG as bone graft results in better clinical and radiographic outcomes, less lifetime cost, and cost-effectiveness compared with PLIF. This suggests that LLIF with TCP + IBG could be utilized in lower- and middle-income countries for treating patients with degenerative disc disease.

Disc Height and Angle Changes on Radiographs and Magnetic Resonance Imaging after Anterior or Posterior Percutaneous Endoscopic Cervical Discectomy.

Objectives: Cervical disc herniation (CDH) leads to pain, numbness, and potential disability. Percutaneous endoscopic cervical discectomy (PECD) offers an anterior or posterior approach. This study aims to compare postoperative disc height and angle changes one year after PECD, considering both approaches. Methods: We retrospectively reviewed the data from patients with CDH who underwent PECD from October 2017 to July 2022. Cervical disc height was measured using the preoperative and one-year postoperative magnetic resonance imaging (MRI) examinations. Lordotic angle (LA), global alignment angle (GAA), segmental alignment angle (SAA), and slippage distance (SD) at the surgical level were measured on radiographs in the neutral, flexion, and extension positions. Results: Thirty-eight patients who underwent posterior PECD (PPECD) and five patients who underwent anterior PECD (APECD) were included in the evaluation. The mean age of the patients was 47.4 years (range: 29-69 years). There was a significant difference in the preoperative and one-year postoperative GAA and SAA in extension in the PPECD group (p = 0.003 and 0.031, respectively). The mean decreased disc height one-year postoperative was 1.30 mm in the APECD group and 0.3 mm in the PPECD group by MRI. A significant disc height decrease was observed in the APECD group (p < 0.001). Conclusions: Treating CDH with PPECD or APECD is feasible, as it can relieve symptoms and reduce disability. Stability remained unaffected during the first year after surgery, even though there was an increase in angulation during extension. Despite a significant decrease in disc space following APECD, patients reported significant symptom improvement and no new symptoms.

Does Baseline Facet Arthropathy Influence Early Clinical and Radiographic Outcomes After Cervical Disc Replacement?

Severe facet arthropathy is generally a contraindication to undergoing cervical disc replacement (CDR) due to associated instability and potentially limited improvement in neck pain caused by arthropathy. This study evaluates the influence of facet arthropathy on radiographic/early clinical outcomes after CDR. One/two-level CDR patients from a single surgeon's prospectively maintained database created 2 cohorts based on facet arthropathy: grade 0-1 or 2-3 (milder/moderate arthropathy). Patient-reported outcome measures for neck disability, neck/arm pain, depressive burden, mental/physical health/function were obtained preoperatively and through final follow-up (average follow-up: 8.5 ± 6.5 months). Preoperative/postoperative radiographs measured segmental lordosis and C2-C7/segmental range of motion (ROM) and determined facet grade for each operative level. Demographic differences, perioperative variables, baseline patient-reported outcomes, and intercohort differences/changes for postoperative patient-reported/radiographic outcomes were determined. Of 161 patients, 100 were in the milder arthropathy group. There were no differences in baseline patient-reported outcomes. Patients with moderate arthropathy reported superior 6-week 12-Item Veterans Rand Mental/Physical Composite Scores (P ≤ .047, all). By final follow-up, moderate patients reported better 12-Item Veterans Rand Mental/Physical Composite Scores/Patient-Reported Outcome Measurement Information System-Physical Function/Patient-Health Questionnaire-9 (P ≤ .049, all). Cohorts reported similar improvements in all patient-reported outcomes by 6 weeks/final follow-up. Those with more severe facet arthropathy had significantly shorter preoperative disc heights (P < .001). Accounting for baseline disc height differences, by final follow-up, moderate patients had lower segmental ROM (P = .036). There were no significant differences in radiographic measurement changes (P ≥ .264, all). Postoperatively, patients with moderate facet arthropathy reported lower depressive burden, better mental health/physical function, and lower segmental ROM. However, this did not translate to inferior short-term clinical outcomes. Further study should be conducted on the relationship between clinical/radiographic outcomes in CDR patients with facet arthropathy.

Can zoledronic acid reduce the risk of cage subsidence after oblique lumbar interbody fusion combined with bilateral pedicle screw fixation in the elderly population? A retrospective study

BackgroundThe objective of this study was to evaluate the potential of zoledronic acid for reducing the incidence of cage subsidence and enhancing interbody fusion rates following oblique lumbar interbody fusion (OLIF) surgery, particularly as the first reported evidence of the role of zoledronic acid combined with OLIF.MethodsA retrospective analysis was conducted on data from 108 elderly patients treated for degenerative lumbar diseases using OLIF combined with bilateral pedicle screw fixation from January 2018 to December 2021. Patients were divided into the zoledronic acid (ZOL) group (43 patients, 67 surgical segments) and the control group (65 patients, 86 surgical segments). A comparative analysis of the radiographic and clinical outcomes between the groups was performed, employing univariate and multivariate regression analyses to explore the relationships between cage subsidence and the independent variables.ResultsRadiographic outcomes, including anterior height, posterior height, disc height, coronal disc angle, foraminal height, and lumbar lordosis, were not significantly different between the two groups. Similarly, no statistically significant differences were noted in the back visual analog scale (VAS) scores and Oswestry Disability Index (ODI) scores between the groups. However, at the 1-year follow-up, the leg VAS score was lower in the ZOL group than in the control group (P = 0.028). The ZOL group demonstrated a notably lower cage subsidence rate (20.9%) than did the control group (43.0%) (P < 0.001). There was no significant difference in the interbody fusion rate between the ZOL group (93.0%) and the control group (90.8%). Non-use of zoledronic acid emerged as an independent risk factor for cage subsidence (OR = 6.047, P = 0.003), along with lower bone mineral density, lower postoperative anterior height, and concave endplate morphology. The model exhibited robust discriminative performance, with an area under the curve (AUC) of 0.872.ConclusionThe administration of zoledronic acid mitigates the risk of cage subsidence following OLIF combined with bilateral pedicle screw fixation in elderly patients; however, it does not improve the interbody fusion rate.

Clinical Outcomes of the Transforaminal Lumbar Interbody Fusion Technique Among Patients With Low Back Pain Showing Type 1 Modic Changes on MRI.

Introduction The unilateral transforaminal lumbar interbody fusion (TLIF) signifies a different surgical method, circumventing both the anterior method and the method via the spinal canal. Due to the shortage of literature available for clinical outcomes and consequences post-TLIF, we undertook the current study to assess the TLIF technique's clinical outcomes among patients with low back pain showing type 1 Modic changes on MRI. Material and methods A cross-sectional study was conducted between January 2019 and March 2021. All patients included in the study had Modic type 1 change and disabling lowback pain as the main complaint and/or leg pain. Data were collected on age, body mass index (BMI), gender, and other risk factors like diabetes mellitus, steroid use, and smoking. Pain intensity was evaluated using a visual analog scale (VAS) before and after surgery. A radiographic evaluation was also performed. Preand post-operative pain scores and differences in disc height were assessed using the Wilcoxon rank sum test. A p-value of less than 0.05 was considered significant. Results The mean length of stay in the hospital was 4.3±1.61. The mean pre-operative lower back pain score was 8.78±0.79. The mean post-operative score was substantially lowered to 0.83±0.7. There was a significant difference between pre- and post-operative lumbar pain (p-value < 0.001). There was a significant increase in mean disc height from pre-operative (7.14 mm) to post-operative (11.02 mm) and also at one year (10.21 mm) with a p-value of <0.001. Of the patients,82.14% did not have any complications, and 3.57% each had either delayed wound healing without any infection or transient post-operative radiculopathy that improved in six weeks. Conclusion TLIF procedure can be considered safeto provide anterior and posterior column support by adopting a unilateral posterior approach. The outcomes were favorable in terms of no prolonged length of stay, less blood loss, no mortality, reduction in the severity of pain, and improvement in disc height. However, the appropriate selection of patients for this technique is pivotal for the success of the procedure.

Growth modulation response in vertebral body tethering depends primarily on magnitude of concave vertebral body growth

PurposeThere is variability in clinical outcomes with vertebral body tethering (VBT) partly due to a limited understanding of the growth modulation (GM) response. We used the largest sample of patients with 3D spine reconstructions to characterize the vertebra and disc morphologic changes that accompany growth modulation during the first two years following VBT.MethodsA multicenter registry was used to identify idiopathic scoliosis patients who underwent VBT with 2 years of follow-up. Calibrated biplanar X-rays obtained at longitudinal timepoints underwent 3D reconstruction to obtain precision morphological measurements. GM was defined as change in instrumented coronal angulation from post-op to 2-years.ResultsFifty patients (mean age: 12.5 ± 1.3yrs) were analyzed over a mean of 27.7 months. GM was positively correlated with concave vertebra height growth (r = 0.57, p < 0.001), 3D spine length growth (r = 0.36, p = 0.008), and decreased convex disc height (r = − 0.42, p = 0.002). High modulators (patients experiencing GM > 10°) experienced an additional 1.6 mm (229% increase) of mean concave vertebra growth during study period compared to the Poor Modulators (GM < − 10°) group, (2.3 vs. 0.7 mm, p = 0.039), while convex vertebra height growth was similar (1.3 vs. 1.4 mm, p = 0.91).ConclusionWhen successful, VBT enables asymmetric vertebra body growth, leading to continued postoperative coronal angulation correction (GM). A strong GM response is correlated with concave vertebral body height growth and overall instrumented spine growth. A poor GM response is associated with an increase in convex disc height (suspected tether rupture). Future studies will investigate the patient and technique-specific factors that influence increased growth remodeling.

The Effect of Intraoperative Overdistraction on Subsidence Following Anterior Cervical Discectomy and Fusion.

Retrospective cohort. The purpose of this study was to evaluate the effect of overdistraction on interbody cage subsidence. Vertebral overdistraction due to the use of large intervertebral cage sizes may increase the risk of postoperative subsidence. Patients who underwent anterior cervical discectomy and fusion between 2016 and 2021 were included. All measurements were performed using lateral cervical radiographs at 3 time points - preoperative, immediate postoperative, and final follow-up >6 months postoperatively. Anterior and posterior distraction were calculated by subtracting the preoperative disc height from the immediate postoperative disc height. Cage subsidence was calculated by subtracting the final follow-up postoperative disc height from the immediate postoperative disc height. Associations between anterior and posterior subsidence and distraction were determined using multivariable linear regression models. The analyses controlled for cage type, cervical level, sex, age, smoking status, and osteopenia. Sixty-eight patients and 125 fused levels were included in the study. Of the 68 fusions, 22 were single-level fusions, 35 were 2-level, and 11 were 3-level. The median final follow-up interval was 368 days (range: 181-1257d). Anterior disc space subsidence was positively associated with anterior distraction (beta = 0.23; 95% CI: 0.08, 0.38; P = 0.004), and posterior disc space subsidence was positively associated with posterior distraction (beta = 0.29; 95% CI: 0.13, 0.45; P < 0.001). No significant associations between anterior distraction and posterior subsidence (beta = 0.07; 95% CI: -0.06, 0.20; P = 0.270) or posterior distraction and anterior subsidence (beta = 0.06; 95% CI: -0.14, 0.27; P = 0.541) were observed. We found that overdistraction of the disc space was associated with increased postoperative subsidence after anterior cervical discectomy and fusion. Surgeons should consider choosing a smaller cage size to avoid overdistraction and minimize postoperative subsidence.

A multipurpose, adolescent idiopathic scoliosis-specific, short MRI protocol: A feasibility study in volunteers

IntroductionVisualization of scoliosis typically requires ionizing radiation (radiography and CT) to visualize bony anatomy. MRI is often additionally performed to screen for neural axis abnormalities. We propose a 14-minutes radiation-free scoliosis-specific MRI protocol, which combines MRI and MRI-based synthetic CT images to visualize soft and osseous structures in one examination. We assess the ability of the protocol to visualize landmarks needed to detect 3D patho-anatomical changes, screen for neural axis abnormalities, and perform surgical planning and navigation. Methods18 adult volunteers were scanned on 1.5 T MR-scanner using 3D T2-weighted and synthetic CT sequences. A predefined checklist of relevant landmarks was used for the parameter assessment by three readers. Parameters included Cobb angles, rotation, torsion, segmental height, area and centroids of Nucleus Pulposus and Intervertebral Disc. Precision, reliability and agreement between the readers measurements were evaluated. Results91 % of Likert-based questions scored ≥ 4, indicating moderate to high confidence. Precision of 3D dot positioning was 1.0 mm. Precision of angle measurement was 0.6° (ICC 0.98). Precision of vertebral and IVD height measurements was 0.4 mm (ICC 0.99). Precision of area measurement for NP was 8 mm2 (ICC 0.55) and for IVD 18 mm2 (ICC 0.62) for IVD. Precision of centroid measurement for NP was 1.3 mm (ICC 0.88–0.92) and for IVD 1.1 mm (ICC 0.88–91). ConclusionsThe proposed MRI protocol with synthetic CT reconstructions, has high precision, reliability and agreement between the readers for multiple scoliosis-specific measurements. It can be used to study scoliosis etiopathogenesis and to assess 3D spinal morphology.

New evidence on the controversy over the correlation between vertebral osteoporosis and intervertebral disc degeneration: a systematic review of relevant animal studies.

The effect of vertebral osteoporosis on disc degeneration remains controversial. The aim of this study was to conduct a systematic review and meta-analysis of relevant animal studies to shed more light on the effects and mechanisms of vertebral osteoporosis on disc degeneration and to promote the resolution of the controversy. The PubMed, Cochrane Library, and Embase databases were searched for studies that met the inclusion criteria. Basic information and data were extracted from the included studies and data were analyzed using STATA 15.1 software. This study was registered on INPLASY with the registration number INPLASY202370099 and https://doi.org/10.37766/inplasy2023.7.0099 . A total of 13 studies were included in our study. Both animals, rats and mice, were covered. Meta-analysis results showed in disc height index (DHI) (P < 0.001), histological score (P < 0.001), number of osteoblasts in the endplate (P = 0.043), number of osteoclasts in the endplate (P < 0.001), type I collagen (P < 0.001), type II collagen (P < 0.001), aggrecan (P < 0.001), recombinant a disintegrin and metalloproteinase with thrombospondin-4 (ADAMTS-4) (P < 0.001), matrix metalloproteinase-1 (MMP-1) (P < 0.001), MMP-3 (P < 0.001), MMP-13 (P < 0.001), the difference between the osteoporosis group and the control group was statistically significant. In terms of disc volume, the difference between the osteoporosis group and the control group was not statistically significant (P = 0.459). Our study shows that vertebral osteoporosis may exacerbate disc degeneration. Abnormal bone remodeling caused by vertebral osteoporosis disrupts the structural integrity of the endplate, leading to impaired nutrient supply to the disc, increased expression of catabolic factors, and decreased levels of type II collagen and aggrecan may be one of the potential mechanisms.