Heterogeneous and convoluted morphological features of dendritic spines in the human amygdaloid complex.

This study comparatively analyzed the biomechanical performance of different vertebral level osteotomies in patients with severe kyphosis secondary to ankylosing spondylitis (ASK) using finite element analysis. The hilus pulmonis-hip axis (HP-HA) method was employed to determine osteotomy angles. Posterior vertebral column resection (PVCR) was simulated at four distinct vertebral levels (T12, L1, L2, and L3), followed by pedicle screw-rod fixation combined with interbody fusion cages. Total displacement, von Mises stress distribution in the pedicle screw-rod construct, titanium cage, and cage-vertebral interface were evaluated and compared across models. Four finite element models (A-D, corresponding to T12, L1, L2, and L3 osteotomies) were successfully established and validated. Total displacement decreased progressively from model A to model D, measuring 6.88mm, 5.44mm, 3.90mm, and 2.26mm, respectively. Peak von Mises stresses in the pedicle screw-rod systems were 115.58MPa, 139.53MPa, 191.35MPa, and 184.14MPa, respectively. Model D (L3 osteotomy) demonstrated the smallest displacement and well-dispersed stress distribution, while model A (T12 osteotomy) exhibited the largest displacement despite having the lowest screw-rod stress. All stresses remained below the yield strength of the internal fixation devices. This finite element study demonstrates that L3 osteotomy yields superior stability compared to T12 osteotomy, though the conclusion is based on a single-case model and requires further validation through multicase studies. These findings underscore the importance of considering segment-specific biomechanical factors in surgical planning for ASK patients.

Osteoporotic pincer-type fractures (OF4) represent a distinct and challenging fracture subtype, yet the absence of reproducible experimental models limits scientific opportunities for biomechanical research and the development of tailored treatments. This study describes and validates a standardized method to generate OF4 pincer fractures in human cadaveric spines. Twelve osteoporotic bisegmental thoracolumbar specimens underwent controlled fracture induction using a servo-hydraulic testing machine. Radiological assessment confirmed fracture morphology consistent with OF4 pincer-type fractures. OF4 fractures were successfully induced in eight specimens (mean age 73.5 ± 7.5 years; mean BMD 68.4 ± 7.2mg/cm³). Four specimens were excluded due to fracture patterns inconsistent with OF4 pincer-type morphology (instability, scoliosis, asymmetrical collapse, or comminution). Biomechanical testing revealed significant increases in range of motion post-fracture in flexion/extension (+ 9.6° ± 2.4°, p < 0.001), lateral bending (+ 16.2° ± 7.8°, p < 0.001), and axial rotation (+ 6.0° ± 4.3°, p = 0.01). Central vertebral body height loss reached 55% (p < 0.001), reflecting hallmark characteristics of clinical OF4 pincer fractures. This protocol offers a reproducible and biomechanically validated model of osteoporotic OF4 pincer fractures. It presents a model that can potentially be used for biomechanical evaluation of surgical interventions and the development of novel techniques.

Anterior cervical discectomy and fusion (ACDF) is a well-established treatment for cervical degenerative disease (CDD). Nevertheless, its anterior approach carries inherent risks to critical neck structures, prompting the exploration of posterior fusion alternatives for selected patients. Traditional anterior cervical discectomy and fusion (ACDF) for cervical degenerative disease involves navigating complex anterior neck anatomy with potential risks to critical neurovascular structures, motivating the development of safer posterior fusion alternatives. Twenty-four fresh C5-C6 segments from adult goats were randomly assigned to the intact, ACDF, and CILC groups (n = 8 per group). After confirming the anatomical similarity between goat and human cervical spines via three-dimensional reconstruction, corresponding surgical procedures were performed at the C5-C6 level. Range of motions (ROMs) in flexion-extension, lateral bending, and axial rotation were measured under a pure moment of 1.5N·m using a material testing machine. A finite element model of C3-C7 was developed based on computed tomography data from healthy adults. ACDF and CILC procedures were simulated, with a 1N·m moment and 73.6N pre-load applied to analyse the stress distribution in adjacent segment discs, facet cartilage, and implants. Anatomical measurements confirmed a high similarity between goat and human C5-C6 segments (P > 0.05), validating its use as an experimental model. In biomechanical tests, both CILC and ACDF significantly reduced segmental motion (P < 0.001). Compared with ACDF, CILC demonstrated greater ROM in flexion (3.31° vs. 1.52°, P < 0.05), but superior stability in extension (1.86° vs. 3.86°) and axial rotation (left: 5.89° vs. 8.19°; right: 6.11° vs. 8.89°) (P < 0.05). Finite element analysis confirmed model reliability, demonstrating close alignment between predicted and reported ROM values. CILC generated lower or comparable stress in C3/4 and C4/5 discs compared with ACDF, but higher stress at C5/6. Moreover, CILC resulted in higher facet joint contact forces and implant stress than ACDF, particularly during flexion and extension. Although CILC demonstrates biomechanical performance comparable to ACDF with specific advantages in controlling extension and axial rotation without significant advantages, its posterior minimally invasive approach effectively avoids neurovascular risks associated with anterior surgery. The device provides a safer alternative for cervical fusion, particularly in cases with complex anterior anatomy or those requiring revision surgery. However, the observed higher facet and implant stresses underscore the need for careful patient selection, particularly regarding pre-existing facet joint condition and bone quality.

Hybrid III lumbar spinal column injury risk curves from vertical impact.

ABSTRACTBackgroundSeveral techniques have been developed to facilitate safe and accurate thoracic pedicle screw placement. However, their impact on screw anchorage has not been systematically evaluated. This study compared thoracic pedicle screw anchorage following placement using the Modified Slide, Slide, Funnel, and Conventional techniques under cyclic loading.Study DesignCadaveric biomechanical study.MethodsForty‐five fresh‐frozen human thoracic vertebrae (T4–T11) were allocated to three experimental groups (n = 15 each). For standardized paired comparisons, one randomly selected pedicle of each vertebra was instrumented using the Modified Slide technique, developed by the authors as a refinement of the original Slide technique, and the contralateral pedicle with one of three established techniques. Screws were subjected to cyclic craniocaudal loading until loosening or a maximum load level of 750 N.ResultsScrews placed using the Modified Slide technique withstood 1.9‐fold and 1.5‐fold more load cycles until loosening than those placed with the Slide and Funnel techniques, respectively (both p < 0.001), but only 0.9‐fold that of screws inserted with the Conventional technique (p = 0.008).ConclusionsThe Modified Slide technique preserves the advantage of the Funnel and original Slide techniques by allowing direct visualization of the pedicle entry point for accurate screw placement, yet substantially enhances thoracic pedicle screw anchorage compared with those techniques. Although anchorage was lower than that of the Conventional technique, screws placed using the Modified Slide technique still withstood loads substantially exceeding those reported to occur during daily activities.

Spinal Column Shortening for Adult Tethered Cord Syndrome in the Absence of Low-Lying Conus Medullaris: A 2-Dimensional Operative Video.

Vertebropexy (VPX) is a purely tendon-based fixation technique of the lumbar spine. It stabilizes the segment in flexion, without immobilizing it in other directions, and therefore might biomechanically address some shortcomings of both spinal fusion and decompression-only surgery. This newly developed cyclic testing setup evaluates the ability of VPX to maintain flexion restriction under long-term biomechanical loading. Five spinal segments of three cadaveric human lumbar spines were selected for testing. VPX was performed using a human peroneus longus tendon allograft, looped twice around the spinous processes and secured with a Prusik knot. Each segment underwent load-controlled flexion-extension (FE) testing in five conditions: native (intact), after decompression (deco-pre, bilateral laminorecessotomy), after VPX (VPX-pre), after long-term cyclic simulation (VPX-post), and after removal of VPX (deco-post). Long-term behavior was simulated using the Dynamic Spine Simulator (DSS), applying 46,800 cycles in the three principal motion directions (FE, lateral bending (LB), axial rotation (AR)). Compared to the paired decompressed state (deco-pre), median flexion immediately after VPX decreased to 0.5% [25th-75th percentile: - 26.3% to 12.9%]. Following the controlled cyclic durability simulation, VPX limited median flexion to 40.0% [4.2%-54.0%] relative to its decompressed state (deco post). This cadaveric proof-of-concept study demonstrates that VPX maintains stabilizing function following cyclic loading. Immediately after decompression, pre-tensioning effectively restricts flexion. Following controlled cyclic durability simulation, this restriction partially attenuates while preserving a net stabilizing effect relative to the decompressed state. These findings support VPX as a biomechanically reasonable dynamic ligamentous restraint that warrants further investigation in larger cadaveric samples and ultimately in vivo validation.

Thoracolumbar burst fractures with morphological characteristics in human cadaveric specimens are essential for surgical training and biomechanical research. This study aimed to develop a technique for simulating thoracolumbar burst fractures and to evaluate their consistency of fracture patterns. Six fresh-frozen human thoracolumbar spine segments (Th12-L5) were fractured using a custom-made drop-test bench. Specimens were potted at the cranial and caudal endplates, leaving a central vertebral body exposed to a standardized combined axial-flexion loading applied via a 10° wedge block. Pre- and post-fracture radiographs and computed tomography scans were obtained. Bone quality was assessed using Hounsfield units. In two specimens, fracture initiation and propagation were recorded using high-speed video imaging at 5400 frames per second. Fractures were classified according to the AO Spine Thoracolumbar Injury Classification System. Thoracolumbar burst fractures were successfully generated in all specimens. Two incomplete burst fractures (AO Type A3) and four complete burst fractures (AO Type A4) were produced. Retropulsion of bony fragments into the spinal canal occurred in four specimens. High-speed video analysis demonstrated a consistent two-step mechanism, consisting of initial anterior collapse followed by posterior wall failure. Interobserver agreement for fracture classification was excellent (κ = 1.0). A high-energy combined axial-flexion loading induces consistent thoracolumbar burst fracture patterns in human cadaveric specimens. This experimental model provides a robust platform for biomechanical testing and advanced surgical training. III.

Tethered spinal cord syndrome (TSCS) is a neurological disorder characterized by tissue attachments limiting spinal cord movement, which can result in the conus medullaris terminating at a level lower than the typical L1. This abnormality can cause significant complications during spinal anesthesia due to the risk of injury at the traditional puncture sites of L4‐L5. This case report discusses the anesthetic management of a 65‐year‐old female patient diagnosed with TSCS with her spinal cord extending to L5‐S1. She presented for a right total knee replacement. The patient had a history of successful spinal anesthesia for her previous left knee replacement but was apprehensive about repeating the procedure due to her spinal anatomy and the associated risks. A thorough preoperative assessment was conducted with this patient. This included a detailed MRI review by a radiologist and a neurosurgeon, which highlighted the risks associated with spinal anesthesia. Given the minimal cerebrospinal fluid around critical levels of the spinal cord, the risk of injury during spinal anesthesia was significant. After discussion with the patient about the risks and benefits of each anesthetic option, the care team and patient jointly decided that general anesthesia would offer the safest approach. General anesthesia was administered successfully with standard intraoperative monitoring and airway management. A preoperative adductor nerve block was also performed to manage postoperative knee pain. The patient emerged from anesthesia without complications, with stable vital signs and good neurovascular function. The interdisciplinary approach and careful preoperative planning were crucial to achieve a positive outcome in this case. This case highlights the importance of individualized anesthetic planning for patients with TSCS. It underscores the need for thorough preoperative assessment and patient‐centered care to determine the safest anesthetic approach. This report also reviews the mechanisms of spinal cord injury during neuraxial anesthesia in TSCS, discusses epidural anesthesia as an alternative, and synthesizes evidence‐based recommendations for preoperative assessment in the absence of formal guidelines. Further research and the development of formal guidelines for anesthetic management in TSCS are warranted to improve patient safety and outcomes.

Fetiform teratoma (FT) and fetus-in-fetu (FIF) represent a spectrum of rare retroperitoneal masses containing organoid structures. While FIF is classically defined by the presence of a vertebral axis, FT lacks this organized skeletal development. Distinguishing between these entities is critical given the malignant potential associated with FT, estimated at approximately 10%. We report a case of a 5-month-old male presenting with a large (12 cm) retroperitoneal mass and elevated alpha-fetoprotein (AFP 56.8 IU/mL; age-matched reference <7 IU/mL). Macroscopically, the resected tumor featured a distinct rudimentary digitiform projection with a nail bed. Histopathology demonstrated extensive organoid differentiation, including gastrointestinal loops with muscular layers, respiratory epithelium, and well-formed pancreatic parenchyma and adrenal cortex. Despite the complex organogenesis and limb-like morphology, the absence of a vertebral column or ossified long bones supported a diagnosis of mature cystic teratoma with fetiform features (FT) over FIF. This report highlights the diagnostic ambiguity within the "gray zone" of these lesions and emphasizes the role of axial skeletal organization and serum AFP levels as complementary tools for classification and oncologic surveillance.

Posterior vertebral column resection (PVCR) for severe post-traumatic thoracic angular kyphosis is effective but carries high morbidity. This study compares unilateral PVCR (UPVCR) with traditional bilateral PVCR (BPVCR), hypothesizing that UPVCR is non-inferior to BPVCR in deformity correction while offering improved perioperative outcomes in appropriately selected patients with an intact contralateral osseo-ligamentous tension band. A retrospective cohort study of patients who underwent PVCR for post-traumatic thoracic angular kyphosis (January 2019 - June 2023) at a tertiary academic center was conducted. Of 58 screened patients, propensity-score matching (1:1) on age, preoperative kyphotic angle, vertebral level, BMI, and preoperative neurological status yielded 40 patients (UPVCR: n = 19; BPVCR: n = 21) with a minimum 24-month follow-up. The primary outcome was correction of the local kyphotic angle. A pre-specified non-inferiority margin of 10° was defined for kyphotic angle correction. Secondary outcomes included operative time, estimated blood loss (EBL), complications, hospital stay, additional radiographic parameters, and patient-reported outcomes (VAS, ODI). All secondary outcome analyses are exploratory and unadjusted for multiplicity. UPVCR was applied exclusively for patients with an intact contralateral tension band and without severe rotational deformity (axial Cobb < 15°); a selection criterion that inherently limits direct comparability and is addressed in detail in the Limitations section. UPVCR met the pre-specified non-inferiority threshold for kyphotic angle correction (mean difference - 1.9°; 95% CI - 4.3° to + 2.1°; upper bound < 10° margin). UPVCR was associated with significantly shorter operative time (179.7 ± 12.5 vs. 269.3 ± 13.8min, p < 0.001), lower EBL (740.5 ± 96.4 vs. 1378.6 ± 348.8 mL, p < 0.001), and a shorter hospital stay (5.6 ± 1.2 vs. 9.2 ± 1.6 days, p < 0.001). Complication rates were 10.5% for UPVCR and 19.0% for BPVCR; this numerical difference did not reach statistical significance (Fisher's exact test, p = 0.67), and the study was not powered to detect differences in complication rates. Both techniques achieved comparable correction in sagittal vertical axis (SVA) and pelvic incidence-lumbar lordosis (PI-LL) mismatch, with no differences in correction loss or cage subsidence. Clinical outcomes (VAS, ODI) improved significantly and similarly in both groups. In appropriately selected patients, specifically those with focal angular post-traumatic kyphosis, an intact contralateral tension band, and no severe rotational component, UPVCR demonstrates radiographic and clinical outcomes that are non-inferior to BPVCR for kyphotic angle correction, while showing statistically significant reductions in operative time, blood loss, and hospital stay. Complication rates, while numerically lower, did not differ significantly between groups, and this study was underpowered to evaluate complications. Confirmation in larger, prospective, adequately powered studies is required before practice recommendations can be made.

BackgroundIn the emergency department (ED), decisions regarding radiological imaging for older patients who have experienced low-energy falls (LEF) are frequently complicated by inconsistencies between the reported mechanism of injury, the patients’ symptoms, and the findings on physical examination. Our study aimed to investigate the coherence between physician-documented complaints, the implementation of radiological imaging and the diagnosis of fractures of the vertebral column, rib cage and pelvic ring.MethodsThis is a secondary analysis of a retrospective consecutive sample of 2882 patients presenting with LEF to two urban Level I trauma centers between 1 January 2016 and 31 December 2016, who underwent radiological imaging to diagnose their fractures. Physician-documented complaints were abstracted from electronic health records.ResultsA total of 2882 patients were included. Mild signs of concussion (e.g. headache) (22.0%), extremity pain (18.0%) and pain of the pelvic ring (14.2%) occurred most frequently. Physician-documented complaints were significantly associated with radiological imaging in the respective regions. True prevalence of fractures ranged from 0.14 (95%CI: 0.09, 0.20) in the cervical spine to 0.36 (95%CI: 0.30, 0.41) in the pelvic ring. The sensitivity of documented pain for fractures ranged from 0.78 (95%CI: 0.56, 0.93) in the thoracic spine to 0.98 in the rib cage (95%CI: 0.88, 1.00) and the pelvic ring (95%CI: 0.94, 1.00). Specificity was poor to moderate in all regions of interest. Positive likelihood ratios (LR+) were of poor value, ranging from 1.48 (95%CI: 1.09, 2.02) in the thoracic spine to 1.08 (95%CI: 1.03, 1.13) in the pelvic ring. Negative likelihood ratios (LR-) were of moderate to good value, ranging from 0.07 in the rib cage (95%CI: 0.01, 0.50) to 0.46 in the thoracic spine (95%CI: 0.20, 1.04). Area under the curve (AUC) values ranged from 0.51 (95%CI: 0.48–0.54) for the lumbar spine to 0.62 (95%CI: 0.59–0.65) for the rib cage.ConclusionThe presence of physician-documented complaints pertaining to the trunk skeleton have a relevant probability of triggering imaging studies in older persons with LEF in the ED. Nevertheless, these complaints do not safely enable discrimination between individuals with and without fractures and are of limited value modifying the subsequent diagnostic imaging process.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12873-026-01644-2.

The aim of the research is to develop a method of registering spinopelvic balance parameters employing shadow moiré topography (SMT) and to use this diagnostic method while clinical observation of adolescents with functional and spine disorders. The subject of the study was a group of adolescents aged 12-17 (n = 50) with the symptoms of mild or moderate scoliosis (according to Cobb). SMT was employed as a clinical diagnostic method. The obtained values were compared with the values provided by the analysis of the standard thoracic and lumbar spine radiographs. The Mann-Whitney U-test was used to evaluate the differences between the values provided by radiography and SMT (due to a small number of subjects). The differences were considered significant at the criterion level α = 0,05, α = 0,01. The data were processed using built-in functions and small self-documenting codes for the Microsoft Office Excel 2013 program. Follow-up data analysis showed no significant differences with the probability of 95% (α = 0,05) in thoracolumbar kyphosis, pelvic incidence, and sagittal vertical axis values, whereas the differences are significant with the probability of 99% (α = 0,01) in the Cobb angle, Lumbar lordosis (LL1), and sacral slope values and with the probability of 95% (α = 0,05) in thoracic kyphosis values. The research found that SMT employed as a diagnostic method in vertebrogenic pathology is reliable and valid and can be employed as a screening, diagnostic, and monitoring tool in the vertebral column state while medical rehabilitation of adolescents with scoliosis.

Metastatic hormone-sensitive prostate cancer (mHSPC) with limited metastatic burden presents a therapeutic challenge, with residual PSMA-avid disease post-androgen receptor pathway inhibitor (ARPI) treatment poorly characterized in prospective studies. The CHAMPION trial (NCT05717582) was a multicenter, single-arm, phase II study designed to evaluate the efficacy and safety of a response-adapted treatment strategy incorporating consolidative therapy (TCT) for PSMA-avid residual resistant clones following ARPI in newly diagnosed mHSPC patients with ≤ 10 conventional imaging (CI)-defined distant metastases from March 2023 to August 2024. PSMA PET/CT scans were performed at baseline and after three cycles of apalutamide plus castration. Patients with > 10 PSMA-positive distant metastases continued apalutamide therapy, while those with ≤ 10 metastases underwent radical prostatectomy or radiotherapy, with stereotactic body radiotherapy targeting all remaining PSMA-positive lesions, if present. The primary endpoint was the proportion of patients achieving an undetectable PSA level (≤ 0.2 ng/mL) after 6 cycles of apalutamide. A total of 48 patients with a median baseline PSA level of 56.8 ng/mL were enrolled. Baseline CI revealed 1-3 distant metastases in 31 patients (64.6%) and 4-10 in 17 patients (35.4%). Baseline PSMA PET/CT showed 1-3 distant metastases in 17 patients (35.4%), 4-5 in 8 patients (16.7%), and > 5 in 23 patients (47.9%); the most common PSMA-positive sites were bone (47/48, 97.9%), regional lymph nodes (28/48, 58.3%), and distant lymph nodes (15/48, 31.3%). After 3-cycle of apalutamide, two patients with > 10 PSMA-positive metastases continued apalutamide, while the remaining 46 with ≤ 10 metastases received TCT. After six cycles, the overall undetectable PSA rate was 95.8% (46/48; 95% CI: 86.0%-98.8%), a 29.1% increase from the 66.7% (32/48) observed after three cycles. Only two patients (4.2%) experienced grade ≥ 3 rash. Post-treatment, distant lymph node metastases showed the highest response rate at 93.3% (140/150), followed by vertebral column and pelvis bone metastases at 78.5% (255/325), and other bone metastases at 50.0% (58/116), with significant differences between each metastatic site pair (p < 0.0001). This novel treatment paradigm, integrating PSMA PET/CT-guided TCT for residual lesions with intensified systemic therapy, was associated with a high PSA response rate and manageable adverse event profile in newly diagnosed mHSPC patients with ≤ 10 distant metastases. NCT05717582. Registered: 8 February 2023.

Heightened sympathetic outflow is a major contributor to the development of hypertension. The hypothalamic paraventricular nucleus (PVN) and the rostral ventrolateral medulla (RVLM) are critical regions for generating and regulating sympathetic activity associated with hypertension. Although presympathetic neural circuitry in the healthy brain is well characterized, it remains unclear whether these pathways undergo alterations in hypertension. Here, we determined presympathetic neural circuits by injecting pseudorabies virus (PRV), a transsynaptic retrograde tracer, into the adrenal gland of spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). Adult SHR exhibited a significantly greater number of PRV-labeled neurons in the PVN and RVLM, but not in the spinal intermediolateral column, compared with WKY. In contrast, the numbers of PRV-labeled neurons in the PVN and RVLM were comparable between young, prehypertensive SHR and age-matched WKY. Remarkably, long-term treatment with losartan—a brain-penetrant angiotensin II AT1 receptor antagonist— initiated in young, prehypertensive SHR blunted the age-dependent hypertension development and reversed the increase in neuronal labeling in both the PVN and RVLM. However, losartan treatment had no effects in WKY. Additionally, electrophysiological recordings showed an elevated frequency of miniature excitatory postsynaptic currents in PVN presympathetic neurons of SHR, which was also normalized by long-term losartan treatment. These findings reveal an age-dependent expansion of presympathetic neuronal connectivity from the hypothalamus and brainstem to the adrenal gland during hypertension development in SHR. Enhanced AT1 receptor activity contributes to hypertension by increasing active glutamatergic synaptic input and promoting the recruitment of additional presympathetic neurons in the hypothalamus and brainstem.Key Points1. The numbers of neurons labeled by PRV injected into the adrenal gland are increased in the PVN and RVLM, but not in the spinal cord IML, in adult SHR compared to normotensive WKY. 2. The numbers of neurons in the PVN, RVLM, and spinal cord labeled by PRV injected into the adrenal gland are comparable in young, prehypertensive SHR and age-matched WKY. 3. Losartan treatment, initiated at a young age, blunts the hypertension development and reverses the increased numbers of PRV-labeled neurons in the PVN and RVLM of adult SHR but has no such effects in WKY. 4. The active glutamatergic synapses in PVN presympathetic neurons are elevated in adult SHR, and this elevation is reversed by long-term losartan treatment.

The urinary bladder is innervated by two anatomically distinct populations of sensory neurons originating from dorsal root ganglia (DRG): one from the thoracolumbar (TL) and another from the lumbosacral (LS) spinal region. While we previously characterized the morphology and distribution of sensory endings arising from LS DRG, the terminals of TL afferents remain undefined. In this study, we employed anterograde neuronal tracing to map these endings in mice. Following bilateral injection of dextran biotin into T12-L3 DRG and a 7-9-day recovery, whole bladders were processed to visualize spinal afferent axons and their calcitonin gene-related peptide (CGRP) immunoreactivity. We identified four morphological types of sensory endings, similar to those described for LS DRG: simple and complex types in both the sub/urothelium and the detrusor muscle. However, their distribution was fundamentally different. Most TL afferents (79%) terminated within the sub/urothelium, with a minor proportion (21%) in the detrusor. This pattern is the inverse of LS innervation, which predominantly targets the detrusor (81%). Furthermore, nearly all TL endings (96%) were peptidergic (CGRP +). This stark anatomical and neurochemical segregation suggests that TL and LS spinal afferent populations are functionally specialized. We propose that the dense TL innervation of the sub/urothelium may constitute a protective surveillance system sensitive to chemical irritation and inflammation, whereas the predominant LS innervation of the detrusor is likely specialized for detecting mechanical stretch during bladder filling.

Biomechanical evaluation of transition rods and sublaminar hooks for proximal junctional kyphosis prevention: A finite element study.

Prediction of compressive strength of vertebral body with metastatic lesions based on quantitative computed tomography-based subject-specific finite element models.

BACKGROUND Vertebral fractures result from degenerative, osteoporotic, or traumatic spinal loading. Treatment options include conservative management, segmental fusion, and percutaneous vertebroplasty/kyphoplasty (PVP/BKP) performed using unilateral or bilateral pedicular approaches. This study compared vertebral height restoration, pain and disability outcomes, and complication rates between unilateral and bilateral PVP/BKP techniques. MATERIAL AND METHODS This retrospective analysis encompassed 150 patients (99 women, 51 men) who underwent PVP/BKP between January 2021 and January 2024. Patient comorbidities and fracture characteristics, including number and type (crush, biconcave, wedge), were recorded. Preoperative and postoperative computed tomography images were evaluated to measure anterior, middle, and posterior vertebral column heights in the sagittal plane. Pain and functional status were assessed using the visual analog scale (VAS) and Oswestry Disability Index (ODI) preoperatively, on postoperative day 1, and at 1 month postoperatively. RESULTS No significant differences (P>0.05) were observed between unilateral and bilateral groups regarding age, sex distribution, comorbidity rates, fracture number or type, anterior or posterior column height gain, total vertebral height gain, complication rates, or VAS and ODI scores. The bilateral group demonstrated a greater increase in middle column height (P<0.05). Both groups showed significant reductions (P<0.05) in VAS and ODI scores at 1 day and 1 month postoperatively. CONCLUSIONS Unilateral and bilateral PVP/BKP techniques provide significant pain relief and functional improvement with comparable clinical outcomes. Considering factors such as high comorbidity burden, cement-related risks, shorter procedure and anesthesia duration, and lower cost, the unilateral approach may be preferable in selected patients.