Vertebral Research Articles

Large L5-S1 Lordosis is an Independent Risk Factor for recurrENCE AFTER BOne Union of Pediatric Lumbar Spondylolysis at L5: A Retrospective Case-control Study.

Retrospective case-control study. To determine risk factors for recurrence of pediatric lumbar spondylolysis at L5 after return to sport in patients who achieved bone union with conservative treatment. Pediatric lumbar spondylolysis is a stress fracture commonly observed in adolescent athletes, particularly at the L5 vertebra. Because some patients experience a recurrence of spondylolysis after bone fusion with conservative treatment, identifying risk factors for recurrence may help athletes continue sports activities, maintain performance levels, and preserve mental health. Of the 375 pediatric patients (<18 years of age) who received conservative treatment for lumbar spondylolysis at L5 between 2015 and 2021, 296 patients who achieved bone fusion and returned to their original sports activities were analyzed. Recurrence rate, sports, pathological stage of spondylolysis at initial examination, presence of spina bifida occulta (SBO), duration of conservative treatment for initial spondylolysis, and radiological parameters including lumber lordosis, L5-S1 lordosis, and sacral slope were examined. Recurrence and non-recurrence groups were compared using univariate and multivariate analyses to investigate risk factors for recurrence. A receiver operating characteristic (ROC) curve was drawn to determine cut-off values of the parameters to predict spondylolysis recurrence. Recurrence was observed in 52 out of 296 patients (17.6%). Multivariate logistic regression analysis revealed that a large L5-S1 lordosis was a significant independent risk factor for recurrence. ROC analysis demonstrated a cut-off value of 24.5° for L5-S1 lordosis. Age, sex, SBO, and duration of conservative treatment for initial spondylolysis were not significant predictors of recurrence. We identified large L5-S1 lordosis as an independent risk factor for recurrence of pediatric lumbar spondylolysis at L5 following conservative treatment. Intensive athletic rehabilitation to prevent recurrence and follow-up measures to monitor and detect recurrence are recommended for patients with large L5-S1 lordosis.

Oblique lateral interbody fusion using angle-adjustable cage.

Orthogonal cage rotation is an essential technique in oblique lateral interbody fusion (OLIF). However, during OLIF at L4-5, this is often limited due to iliac crest. Angle-adjustable cages are designed to insert cages without interference from iliac crest, but there are few studies on whether they are useful. We aimed to compare the radiological outcomes between the conventional cage and angle-adjustable cage inOLIF at L4-5. This study involved 90 consecutive patients with degenerative lumbar disease who underwent OLIF at L4-5 with a minimum one-year follow-up. The previous 41 patients used conventional cage (group I), and then 49 patients used angleadjustable cage (group II). Radiological outcomes including cage obliquity, cage position, foraminal height, fusion rate, and cage subsidence were compared between the two groups. There were no differences in the mean iliac crest height between the two groups. The cage obliquity was greater in the group I than group II (12.1 ± 7.4° vs. 8.3 ± 7.0°, P = 0.015), and so were the mean cage position from the anterior margin of the L5 vertebra (6.3 ± 3.9mm vs. 4.7 ± 3.6mm, P = 0.043). Other than that, there was no significant difference in radiological outcomes between the two groups. Our study demonstrated that using an angle-adjustable cage at L4-5 OLIF is more advantageous for orthogonal cage rotation and anterior cage positioning. In L4-5 OLIF, an angle-adjustable cage system is a particularly good option for patients with a high iliac crest.

In Vivo Bone Mineral Density Assessment With Spectral Localizer Radiographs From Photon-Counting Detector CT

Purpose The aim of this study was to determine in a prospective patient study the accuracy of areal bone mineral density (aBMD) measurements with spectral localizer radiographs obtained with a clinical photon-counting detector computed tomography (PCD-CT) scanner in comparison with dual-energy x-ray absorptiometry (DXA). Methods In this institutional review board–approved, prospective study, 41 patients (15 females, 26 males; mean age 61.3 years, age range 35–78 years) underwent PCD-CT of the abdomen with a spectral localizer radiograph (tube voltage 140 kVp, tube current 30 mA) and DXA within a median of 45 days. aBMD values were derived for lumbar vertebrae L1–L4 from both methods and were compared with linear regression, Pearson correlation, intraclass correlation coefficients (ICCs), and Bland-Altman plots. T-scores were calculated on a patient level and were compared between methods. Results DXA and spectral localizer radiographs showed strong correlation in aBMD measurements (R = 0.97, P &lt; 0.001) and patient level T-scores (R = 0.99, P &lt; 0.001). There was a strong agreement between aBMD from both methods (ICC, 0.96; 95% CI, 0.94–0.97). Bland-Altman analysis revealed a very small mean difference in aBMD between methods (mean absolute error 0.019 g/cm2) with narrow limits of agreement (−0.083 g/cm2 to 0.121 g/cm2). Similarly, there were small differences in regard to the T-score (mean absolute error 0.156) with narrow limits of agreement (−0.422 to 0.734) between methods. ICCs indicated an excellent agreement between T-scores from DXA and spectral localizer radiographs (ICC, 0.98; 95% confidence interval, 0.95–0.99). Conclusions Our prospective patient study indicates that spectral localizer radiographs obtained with a clinical PCD-CT system enable accurate quantification of the lumbar bone areal mineral density. This opens up the opportunity for opportunistic screening of osteoporosis in patients who undergo CT for other indications.

Spontaneous subdural haematoma secondary to undiagnosed metastatic gastric adenocarcinoma

A man in his 80s presented with 3 weeks of lower back pain, generalised weakness, poor appetite and intermittent melena, without genitourinary symptoms or recent trauma. CT showed an old L1 compression fracture and new sclerotic lesions in the L3 and L4 vertebrae, as well as mildly enlarged abdominal lymph nodes. 3 days later, he returned to the emergency department with worsening symptoms, including new left hemiparesis. A head CT revealed a right subdural haematoma (SDH) with a midline shift. Despite treatment for disseminated intravascular coagulation, the patient’s condition deteriorated, leading to a suspicion of spontaneous intracranial hypotension. An autopsy revealed disseminated metastatic adenocarcinoma with dura and leptomeningeal metastases, ultimately causing spontaneous SDH and subsequent transtentorial herniation. This case highlights the impact of anchoring bias in clinical decision-making and the importance of early recognition of underlying malignancy as the aetiology of spontaneous SDH in patients presenting with signs and symptoms of metastatic cancer.

Textural and geometric measures derived from digital tomosynthesis discriminate women with and without vertebral fracture.

Vertebral fractures are a common and debilitating consequence of osteoporosis. Bone mineral density (BMD), measured by dual energy x-ray absorptiometry (DXA), is the clinical standard for assessing overall bone quantity but falls short in accurately predicting vertebral fracture. Fracture risk prediction may be improved by incorporating metrics of microstructural organization from an appropriate imaging modality. Digital tomosynthesis (DTS)-derived textural and microstructural parameters have been previously correlated to vertebral bone strength in vitro, but the in vivo utility has not been explored. Therefore, the current study sought to establish the extent to which DTS-derived measurements of vertebral microstructure and size discriminate patients with and without vertebral fracture. In a cohort of 93 postmenopausal women with or without history of vertebral fracture, DTS-derived microstructural parameters and vertebral width were calculated for T12 and L1 vertebrae, as well as lumbar spine BMD and trabecular bone score (TBS) from DXA images. Fracture patients had lower BMD and TBS, while DTS-derived degree of anisotropy and vertebral width were higher, compared to nonfracture (p<0.02 to p<0.003) patients. The addition of DTS-derived parameters (fractal dimension, lacunarity, degree of anisotropy and vertebral width) improved discriminative capability for models of fracture status (AUC=0.79) compared to BMD alone (AUC=0.67). For twelve additional participants who were imaged twice, in vivo repeatability errors for DTS parameters were low (0.2% - 7.3%). The current results support the complementary use of DTS imaging for assessing bone quality and improving the accuracy of fracture risk assessment beyond that achievable by DXA alone.

Comparative analysis of morphologival parameters in isolated and fused L5 spondylolysis patients on the basis of CT features

Background and objectiveThe classification of lumbar spondylolysis varies, and there is currently no clear consensus on a standardized system. This study examines the morphological characteristics and parameter differences of the L5 vertebra in patients with isolated versus fused spondylolysis using CT measurements. It also proposes a preliminary classification system based on the separation distance at the fracture site and explores its clinical significance.MethodsA total of 117 young male patients with L5 spondylolysis related to high-intensity physical activity were enrolled. Patients with a pars interarticularis separation distance ≥ 2 mm were classified into the isolated group (Group A, 66 patients), while those with a separation distance < 1 mm were classified into the fused group (Group B, 51 patients).Additionally, 117 patients without spondylolysis but experiencing lower back pain were included as the control group (group C). Multislice spiral computed tomography (MSCT) was used to measure the morphological parameters of the L5 vertebra in all three groups, including the sagittal pedicle height (SPH), transverse pedicle width (TPW), transverse pedicle vertical length (TPVL), pedicle screw trajectory length (PSTL), pedicle angle of attack (PAA), frontal vertebral body height (FVH), posterior vertebral body height (PVH), sagittal midline intervertebral space height (SMISH), horizontal vertebral body angle (HVA), and vertical vertebral body angle (VVA). Differences in the morphological imaging parameters of the L5 vertebrae and pedicles among the three groups were compared.ResultsThere were no significant differences in age, height, weight, body mass index (BMI), or Pfirrmann grade among the three groups. No significant differences were observed in any of the pedicle parameters between the left and right sides within the groups. Group A showed significantly greater TPVL and PSTL values compared to Group B, while TPW and PAA were significantly lower. No significant difference in SPH was observed between Group A and Group B. When compared to Group C, Group A exhibited significant differences in SPH, TPW, TPVL, and PSTL, but not in PAA. Group B, compared to Group C, demonstrated significant differences in SPH and PAA, but no significant differences were observed in TPW, TPVL, or PSTL. Significant differences were also found in FVH, HVA, and VVA between Group A and Group B, with Group A showing a smaller PVH. No significant difference in SMISH was observed between the two groups. Compared to Group C, Group A showed significant differences in PVH, HVA, and VVA, but no significant differences were found in FVH or SMISH. In Group B, significant differences were noted in FVH and HVA compared to Group C, but no differences were observed in PVH, SMISH, or VVA.ConclusionDifferences in the sagittal morphological parameters of the pedicles and vertebral bodies can be observed between the two types of spondylolysis patients. In the isolated spondylolysis pattern, the pedicles exhibit a "thin, long, and contracted" morphology, while the vertebral bodies present a "stuffed bun" shape, both anteriorly, posteriorly, and superiorly. In contrast, the fused type is characterized by "short, thick, and expanded" pedicles, with the vertebral bodies showing a "less pronounced stuffed bun" shape in the anterior–posterior direction. These morphological differences indicate that spondylolysis separation may involve adaptive stress-induced bone remodeling. Surgeons must pay special attention when choosing surgical techniques, as isolated spondylolysis may present a tendency toward slippage. Caution is advised in performing isolated pars repair surgeries, especially during the placement of pedicle screws, where special attention must be given to the length and direction of the screws to avoid additional damage.

CompositIA: an open-source automated quantification tool for body composition scores from thoraco-abdominal CT scans

BackgroundBody composition scores allow for quantifying the volume and physical properties of specific tissues. However, their manual calculation is time-consuming and prone to human error. This study aims to develop and validate CompositIA, an automated, open-source pipeline for quantifying body composition scores from thoraco-abdominal computed tomography (CT) scans.MethodsA retrospective dataset of 205 contrast-enhanced thoraco-abdominal CT examinations was used for training, while 54 scans from a publicly available dataset were used for independent testing. Two radiology residents performed manual segmentation, identifying the centers of the L1 and L3 vertebrae and segmenting the corresponding axial slices. MultiResUNet was used to identify CT slices intersecting the L1 and L3 vertebrae, and its performance was evaluated using the mean absolute error (MAE). Two U-nets were used to segment the axial slices, with performance evaluated through the volumetric Dice similarity coefficient (vDSC). CompositIA’s performance in quantifying body composition indices was assessed using mean percentage relative error (PRE), regression, and Bland–Altman analyses.ResultsOn the independent dataset, CompositIA achieved a MAE of about 5 mm in detecting slices intersecting the L1 and L3 vertebrae, with a MAE < 10 mm in at least 85% of cases and a vDSC greater than 0.85 in segmenting axial slices. Regression and Bland–Altman analyses demonstrated a strong linear relationship and good agreement between automated and manual scores (p values < 0.001 for all indices), with mean PREs ranging from 5.13% to 15.18%.ConclusionCompositIA facilitated the automated quantification of body composition scores, achieving high precision in independent testing.Relevance statementCompositIA is an automated, open-source pipeline for quantifying body composition indices from CT scans, simplifying clinical assessments, and expanding their applicability.Key PointsManual body composition assessment from CTs is time-consuming and prone to errors.CompositIA was trained on 205 CT scans and tested on 54 scans.CompositIA demonstrated mean percentage relative errors under 15% compared to manual indices.CompositIA simplifies body composition assessment through an artificial intelligence-driven and open-source pipeline.Graphical

A data-driven framework for developing a unified density-modulus relationship for the human lumbar vertebral body.

Despite the broad agreement that bone stiffness is heavily dependent on the underlying bone density, there is no consensus on a unified relationship that applies to both cancellous and cortical compartments. Bone from the two compartments is generally assessed separately, and few mechanical test data are available for samples from the transitional regions between them. In this study, we present a data-driven framework integrating experimental testing and numerical modeling of the human lumbar vertebra through an energy balance criterion, to develop a unified density-modulus relationship across the entire vertebral body, without the necessity of differentiation between trabecular and cortical regions. A dataset of 25 spinal segments harvested from fresh-frozen human spines consisting of L1 vertebrae with adjacent intervertebral disks and neighboring T12 and L2 endplates was examined through a systematic process. Each specimen was subjected to axial compression using a custom-designed radiolucent device, and the deformation at multiple points during the ramp was quantified using digital volume correlation applied to the time-lapse series of microcomputed tomography images acquired during loading. A finite element model of each specimen was constructed from quantitative computed tomography images, with the experimental displacement fields imposed to replicate the observed deformation. The optimal density-modulus relationship, both in exponential and polynomial forms, was then determined by using data-driven techniques to match the numerical strain energy with the experimental external work. The resulting relationships effectively recovered bone tissue modulus at the microscale. Subsequently, the unified relationships were applied to investigate the vertebral structure-property correlations at the macroscale: as expected, compressive stiffness exhibited a moderate correlation with bone mineral density, whereas bending stiffness was revealed to correlate strongly with bone mineral content. These findings support the accuracy of the developed density-modulus relationships for the vertebral body and indicate the potential of the proposed framework to extend to other properties of interest such as vertebral strength and toughness.

Evaluation of lumbar vertebral bone quality using T1-weighted MRI: Can it differentiate normal, osteopenia, and osteoporosis?

Osteoporosis, a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration, poses a significant public health challenge globally. While the gold standard for diagnosing osteoporosis is dual-energy X-ray absorptiometry (DXA), its use is limited by factors like spinal deformities and artifacts. This study aims to explore the potential of routine T1-weighted MRI sequences in predicting osteopenia and osteoporosis through the vertebral bone signal (VB) to cerebrospinal fluid signal (CSF) ratio. We conducted a retrospective study of patients who underwent both DXA and lumbar MRI within a six-month interval between 2020 and 2023. Excluding patients with known vertebral fractures, bone tumors, heterogeneous bone marrow, or endplate signal changes due to degenerative alterations, we divided the patients into normal, osteopenic, and osteoporotic groups based on their DXA T-scores. The T1-weighted sagittal MRI sequences were analyzed, and the T1 VB/CSF ratios were calculated for each vertebra (L1-L4). The study included 376 patients, with an average age of 60.8 ± 9.1 years. Statistically significant differences were found in the T1 VB/CSF ratios across the normal, osteopenic, and osteoporotic groups (p < 0.05). The L1 vertebra demonstrated the highest diagnostic performance for predicting osteoporosis, with an AUC of 0.75, a sensitivity of 88.1 %, and a specificity of 84.5 %. For differentiating osteopenia from normal, the L1 vertebra achieved an AUC of 0.68, with a sensitivity of 78.2 % and a specificity of 76.4 %. The optimal cut-off values were determined as 3.62 for osteopenia and 3.80 for osteoporosis. The T1 VB/CSF ratio derived from routine lumbar MRI sequences provides a promising, radiation-free tool for opportunistic screening of osteoporosis and osteopenia. Given the frequent use of lumbar MRI for patients with spinal complaints, this method could facilitate early diagnosis and intervention, guiding high-risk patients towards further DXA evaluation and management.

Asymmetry in the Onset of Paraspinal Muscles Activity Differs in Adolescents With Idiopathic Scoliosis Compared With Those With a Symmetrical Spine.

Adolescent idiopathic scoliosis (AIS) is characterized by an asymmetrical formation of the spine and ribcage. Recent work provides evidence of asymmetrical (right versus left side) paraspinal muscle size, composition, and activation amplitude in adolescents with AIS. Each of these factors influences muscle force generation. The timing of paraspinal muscle activation may also contribute to an asymmetry in the timing of forces applied to the spine. The main objectives were to determine (1) whether the timing and asymmetry of erector spinae muscle activation during a rapid bilateral arm raise task differs between adolescents with AIS and those without AIS and (2) whether the magnitude of erector spinae activation asymmetry in AIS is associated with scoliosis curve severity (Cobb angle) or skeletal development level (Risser stage). Finally, (3) we investigated potential kinematic confounders to determine whether symmetry of bilateral rapid arm movements differed between those with and without AIS, and whether any asymmetry in arm movement was associated with erector spinae activation asymmetry. All patients were made aware of the project through flyers at one outpatient spine clinic and a scoliosis rehabilitation clinic in Brisbane, Australia. They were invited between August 2022 and September 2023 to contribute if they met the selection criteria. This cross-sectional study included females with AIS who agreed to participate (n = 24, mean ± SD age of 14 ± 2 years). They all had a primary right-thoracic curve, diagnosed by an orthopaedic specialist. Twenty age- and sex-matched controls (age 13 ± 2 years) who did not have AIS were recruited from the local community. Volunteers (from either group) were excluded if they had any history of spinal surgery, neurological disorders, or musculoskeletal disorders (other than AIS). The experimental task required participants to perform a bilateral rapid arm flexion in response to a visual cue. Muscle activation was recorded using surface electrodes, placed bilaterally on the anterior deltoid and erector spinae adjacent to the C7, T9 (the curve apex for AIS), T12, and L5 vertebrae. Muscle activation onsets were determined from 6 of 10 trials with the quickest deltoid onset for each participant. A linear mixed model (with fixed factors) was used to determine whether activation asymmetry (left-right onset difference) differed between groups (AIS, control) and vertebral level (C7, T9/apex, T12, and L5). Where a group difference in onset asymmetry was identified, the relation of the Cobb angle and Risser stage with the magnitude of asymmetry was evaluated in the AIS cohort using a linear mixed model. Task kinematics, including peak angular arm movement velocity and deltoid onset relative to the light signal, were analyzed using a linear mixed model with group and side as fixed factors. Erector spinae activation timing asymmetry differed between groups at the T9/apex (mean difference 14 ± 23 ms; p < 0.01). In the AIS group, muscle activation was 6 ± 17 ms earlier on the right (convex) relative to the left side of the spine, whereas in controls, activation was 8 ± 19 ms earlier on the left relative to the right side. This difference in activation timing asymmetry between groups was explained by later activation of the T9 level erector spinae muscles on the left (concave) side of the spine in AIS compared with controls (mean group difference of left T9/apex erector spinae onset 13 ± 26 ms; p = 0.01). There were no between-group differences at other vertebral levels. Within the AIS group, no association was observed between the magnitude of the erector spinae activation asymmetry measured at T9/apex and Cobb angle or Risser stage. There were no differences between groups in either the bilateral deltoid onset relative to light or arm peak velocity. Erector spinae muscle activation is asymmetrical at the T9/apex vertebral level during a rapid bilateral arm raise task. This asymmetry was opposite between the AIS and control cohorts, with left-side activation delayed in AIS. It is well established in conditions such as cerebral palsy that muscles forces can influence bone development in children. In children with AIS, there is growing evidence of asymmetrical paraspinal muscle size, composition, and activation amplitude. Each of these factors contribute to paraspinal muscle force generation. Our findings add to what we know by identifying an asymmetry in the timing of erector spinae activation during a well-controlled, bilateral movement task. Combined with previous research, these results support further investigation into whether asymmetrical paraspinal muscle forces might contribute to the curve progression and asymmetrical bony development in AIS. This is important as muscle forces are modifiable through targeted rehabilitation.

Hounsfield unit values are a better predictor than DXA T-score for adjacent vertebral fracture following balloon kyphoplasty.

Hounsfield unit values (HU) are known to correlate with dual-energy X-ray absorptiometry (DXA), and they are gaining attention as a new method for assessing Bone mineral density (BMD) that is not affected by the limitations of DXA, such as degeneration, scoliosis, and vascular calcification. The purpose of this study was to compare the efficacy of HU and DXA T-scores in predicting adjacent vertebral fractures (AVF) following balloon kyphoplasty (BKP) using the same computed tomography and DXA at one institution. The study included 84 cases (20 males, 64 females, mean age 79.3±6.9) who underwent BKP for osteoporotic vertebral fractures. Cases were divided into two groups based on the presence or absence of AVF within 2 months postoperatively. BMD assessment included DXA T-scores (lumbar spine, hip, the lowest), HU of the fractured adjacent vertebra (adjacent-HU) and HU of the L1 vertebra (L1-HU). Logistic regression analysis was performed to identify risk factors for AVF, and the accuracy of AVF prediction was evaluated using the area under the receiver operating characteristics curve (AUC). AVF occurred in 23 of the 84 cases (27.4%) within 2 months postoperatively. In the logistic regression analysis, T-score was not identified as an independent risk factor, but L1-HU was identified as an independent risk factor for AVF (odds ratio: 0.982, P=0.044∗). The AUC for predicting AVF was 0.515, 0.568, and 0.510 for T-score (lumbar spine, hip, the lowest), and 0.551 for adjacent-HU. The highest AUC was observed for L1-HU at 0.629 (95% confidence interval 0.495-0.764). In the risk assessment of AVF, L1-HU was a better evaluation method than DXA T-score.

Sarcopenia as a Predictor of Mortality in a Cohort of Elderly Patients Undergoing Endoscopic Retrograde Cholangiopancreatography.

Despite technical advances, endoscopic retrograde cholangiopancreatography (ERCP) is associated with complications and potentially lethal outcomes. Sarcopenia, a complex syndrome mainly associated with aging, has been recognized as a predictor of poor surgical outcomes. Thus far, the impact of sarcopenia on ERCP remains unknown. The present study evaluates the role of sarcopenia as a predictor of ERCP-related outcomes in a cohort of elderly patients. Patients who underwent ERCP between June 2019 and January 2023 were retrospectively included. Demographic and procedure-associated data were collected. Sarcopenia was assessed using the skeletal muscle index (SMI) measured from a single axial slice through the L3 vertebra on a CT scan. ERCP-related outcomes were recorded. Univariate and multivariate analyses were used to assess the correlation between sarcopenia and procedural outcomes. In total, 256 patients were enrolled, of whom 30 (11.7%) were sarcopenic. Cardiopulmonary complications of ERCP occurred in 3.5%. Sarcopenia was associated with higher 30-day and 12-month post-ERCP mortality (OR 3.45, p = 0.03; OR 3.87, p = 0.004) and longer hospitalization time (7 vs. 11 days, p = 0.003). SMI is an easy and objective index of sarcopenia that could be used to predict ERCP outcomes. Indeed, sarcopenia was independently associated with prolonged hospitalization and increased mortality in a retrospective cohort of elderly patients.

Individuals with Heterogenous Trabecular Bone Texture by Clinical MRI have Lower Bone Strength and Stiffness by QCT Based Finite Element Analysis.

Opportunistic screening is essential to improve the identification of individuals with osteoporosis. Our group has utilized image texture features to assess bone quality using clinical MRIs. We have previously demonstrated that greater heterogeneity of MRI texture related to history of fragility fractures, lower bone density, and worse microarchitecture. The present study investigated relationships between MRI-based texture features and biomechanical properties of bone using CT-based finite element analyses (FEA). We hypothesized that individuals with greater texture heterogeneity would have lower stiffness and failure load. Thirty individuals included in this prospective study had CT and MRI of L1 and L2 vertebrae. Using T1-weighted MR images, a gray-level co-occurrence matrix was generated to characterize the distribution and spatial organization of voxelar signal intensities to derive the following texture features: contrast (variability), entropy (disorder), angular second moment (ASM; uniformity), and inverse difference moment (IDM; homogeneity). Features were calculated in five directions relative to the image plane. Whole-bone stiffness and failure load were calculated from phantom-calibrated lumbar QCT. Mean age of subjects was 59 ± 11years (57% female). Individuals with lower vertebral stiffness had greater texture heterogeneity; specifically, higher contrast (r = -0.54, P<.01), higher entropy (r = -0.52, P<.01), lower IDM (r = 0.54, P<.01) and lower ASM (r = 0.51, P<.01). Lower vertebral failure load and lower vBMD were similarly associated with greater texture heterogeneity. Relationships were unchanged when using the average of texture in all directions or the vertical direction in isolation. In summary, individuals with more heterogeneous MRI-based trabecular texture had lower stiffness and failure load by FEA, and lower vBMD by central quantitative CT. These results-the first relating MRI-based texture features and biomechanical properties of bone-provide further support that MRI-based texture measurements can be used to opportunistically detect skeletal fragility.

Effect of excluding fractured or abnormal vertebrae on the trabecular bone score measurement

SummaryBrief rationale: The use of L1–L4 vertebrae, without exclusions, has been recommended for trabecular bone score (TBS) measurements.Main result: Excluding abnormal and fractured vertebrae affected the TBS.Significance of the paper: Fracture or degenerative abnormality may not affect TBS. The preferred action may involve including all levels without exclusions.PurposeThe use of L1–L4 vertebrae, without exclusions, has been recommended for trabecular bone score (TBS) measurements. We aimed to investigate the effect of excluding fractured or abnormal vertebrae from TBS.MethodsDual-energy X-ray absorptiometry images of 2767 participants, including 1080 without excluded vertebrae, 556 with fractured vertebrae, and 1131 with abnormal vertebrae showing a 1.0 T-score difference compared to the adjacent vertebrae, were retrospectively reviewed. Differences between TBS measurements with and without fractured or abnormal vertebrae were evaluated.ResultsAmong 1080 participants without excluded vertebrae, TBS was 1.234 at L1, 1.296 at L2, 1.308 at L3, and 1.301 at L4. A significantly higher mean TBS was seen after excluding L1, whereas a significantly lower mean TBS was seen after excluding L2–L4. In the 556 participants with fractured vertebrae, excluding the involved level from the TBS calculation led to a significant difference in the total sample, women, ≥ 70 years old, and overweight subgroups. A significantly higher mean TBS was seen after excluding the fractured L1, whereas a significantly lower mean TBS was seen after excluding fractures at L2–L4. Among the 1131 participants with abnormal vertebrae, excluding the involved level from the TBS led to a significant difference in age, sex, and body mass index subgroups. Excluding abnormal L1 and L4 vertebrae led to a significantly higher and lower mean TBS, respectively.ConclusionExcluding fractured or abnormal vertebrae led to differences in TBS across various subgroups. Regarding the effect of vertebral level exclusion, the observed differences may be attributed to the systematic intervertebral variation, which is unrelated to any effect from fractures or degenerative abnormalities.

Biomechanical changes in lumbar intervertebral discs after percutaneous endoscopic transforaminal discectomy surgery at different Body Mass Index (BMI) categories

ObjectivePercutaneous Endoscopic Transforaminal Discectomy (PETD) is recognized as the leading surgical intervention for lumbar disc herniation (LDH). Moreover, Body Mass Index (BMI) has been established as an independent risk factor for disc reherniation post-PETD. Furthermore, there is a lack of studies investigating the biomechanical changes in the disc post-PETD in relation to diverse BMI levels.MethodsA three-dimensional nonlinear finite element model was developed to simulate the L3-S1 lumbar spine, and a surgical model of the lumbar 4/5 right PETD was also constructed. Forces of 392 N (BMI 20.76 kg/m2), 457 N (24.22 kg/m2), 523 N (27.68 kg/m2), 588 N (31.14 kg/m2) and 653 N (34.6 kg/m2) were applied from the superior edge of the L3 vertebrae. The equivalent von Mises stresses and maximum deformation of the L4/5 nucleus pulposus were observed in normal group and PETD surgery group.ResultsWe established normal and PETD surgery model with different BMIs, contributes to understand the equivalent von Mises stresses and maximum deformation of the L4/5 nucleus pulposus with different BMI. The results indicated that the rise in BMI correlates with heightened equivalent von Mises stresses and maximum deformation within the L4/5 nucleus pulposus in both in normal group and PETD surgery group. Besides, the von Mises stress and maximum deformation of the NP in flexion loading are significantly higher than in other loading conditions under the same BMI condition. These values, alongside the occurrence of high-stress areas, display fluctuations across distinct postures, under the influence of BMI. Furthermore, a discernible accumulation of stress was noted within the compromised regions of the nucleus pulposus.ConclusionThe study suggested that patients who undergone PETD surgery should refrain from engaging in strenuous activities especially flexion during early rehabilitation through finite element analysis. For patients with a high BMI, it is advisable to scientifically reduce weight before and after the surgery in order to maintain appropriate stress on the intervertebral disc.

Effect of Instrumented Hospital Bed on Physical Loads at a Disc Between L5 and S1 Vertebrae During Patient Repositioning

Effect of Instrumented Hospital Bed on Physical Loads at a Disc Between L5 and S1 Vertebrae During Patient Repositioning

Surgical Management of Vertebral Body Fractures in Proximal Junctional Kyphosis: A Case Series Utilizing Intravertebral Reduction Devices and Hardware Extension

Vertebral body fracture is the most common manifestation of proximal junctional failure (PJF), a frequent complication following adult spinal deformity surgery and a leading cause of reoperation(1). In the absence of established consensus regarding optimal revision techniques for PJF, this case report presents two patients with non-traumatic vertebral fractures secondary to PJF, successfully managed with intravertebral reduction device (SpineJack®) and bone cement augmentation, combined with the extension of previous instrumentation. While the etiology of PJF in these two cases remains undetermined, this report aims to contribute to the evolving literature on surgical revision strategies for PJF, particularly in the context of vertebral fractures. The first case involves a 62-year-old female with degenerative scoliosis, flat back deformity, adult idiopathic scoliosis, coronal malalignment, and degenerative disc disease with lateral listhesis underwent lateral lumbar interbody fusion (LLIF) at L2-3, L3-4, and L4-5 with titanium interbody devices and posterior L1 to pelvis instrumentation and fusion. Following L1 compression fracture at the proximal end of the instrumentation, the patient underwent surgical revision at 6 weeks postoperative. The pedicle screws at L1 were explanted, and the pedicle tracks were utilized for open placement of SpineJack® implants under fluoroscopic guidance to reduce and elevate the compressed L1 vertebra, restoring anterior vertebral height. The postoperative course was unremarkable, and the patient exhibited significant clinical improvement. The second case involves a 60-year-old female patient with a history of painful thoracolumbar scoliosis who underwent a T8-Pelvis posterior spinal fusion (PSF) with multiple Smith-Petersen osteotomies (SPOs) and L4-S1 transforaminal lumbar interbody fusion (TLIF) with right-sided instrumentation. Following discovery of a T8 vertebral compression fracture at 8 weeks postoperative, existing hardware at the fracture level was removed, and SpineJack® implants were inserted bilaterally into T8, under fluoroscopic direction. The patient’s postoperative course was unremarkable with significant clinical improvement in pain and neurological function. This report aims to contribute to the literature on surgical strategies for managing vertebral fractures associated with PJF. The use of SpineJack® with cement augmentation appears effective in restoring vertebral body height and spinal alignment while offering a less invasive alternative to more extensive procedures like vertebral column resection (VCR). This technique may offer promising results for spine surgeons addressing vertebral fractures in the context of PJF. While the limitations inherent to case reports preclude establishment of intravertebral reduction devices with cement augmentation as a standard clinical practice guideline for vertebral fractures in the setting of proximal junctional kyphosis and/or failure (PJK/PJF), the successful treatment of two patients with this combined approach aims to contribute to the existing literature by presenting the safety and efficacy of such a technique. It suggests its potential utility for spine surgeons encountering this PJF vertebral fractures moving forward.

Opportunistic Screening for Osteoporosis by CT as Compared with DXA.

Osteoporosis is commonly evaluated using dual-energy X-ray absorptiometry (DXA) for bone mineral density (BMD). Non-contrast computed tomography (CT) scans provide an alternative for opportunistic osteoporosis assessment. This study aimed to evaluate screening thresholds for osteoporosis based on CT attenuation values in Hounsfield units (HU) of L1-L4 vertebrae from CT scans of the abdominal region, compared to DXA assessments of the lumbar spine and hips. Conducted retrospectively over approximately two years, the analysis included 109 patients who had both CT and DXA scans within 12 months, excluding those with metal artifacts affecting the vertebrae. CT attenuation values in the trabecular region of the vertebrae were measured and compared among three groups based on the lowest T-score from DXA. In a predominantly female cohort (mean age 66.3 years), the lowest CT attenuation values for L1-L4 vertebrae showed a moderate correlation with the lowest T-score, with a Pearson correlation coefficient of 0.542 (95% CI: 0.388, 0.667). A HU threshold of ≤142 at the L1 vertebra showed 91.9% sensitivity and 48.4% specificity, while a threshold of ≤160 HU showed 97.3% sensitivity and 31.3% specificity for screening osteoporosis. This study supports the use of non-contrast CT with these HU thresholds as an opportunistic tool for osteoporosis assessment.

Surgical treatment of double-level spondylolysis of the L4 and L5 vertebrae using custom-made implant

Background: Spondylolysis is a frequent cause of pain in the lumbar spine in adolescents and young adults, especially those who practice sports. Spondylolysis most commonly occurs at the L5 vertebrae, and less commonly at the L4 vertebrae. Multilevel spondylolysis is extremely rare. The low frequency of occurrence and, as a consequence, difficulties in diagnosing multilevel spondylolysis are the reason for the lack of a unified approach to the treatment of this pathology. In most cases, conservative measures are sufficient, but if they are ineffective, surgical intervention is indicated. Options of surgical treatment are mainly characterised by the focus on restoring the integrity of the arch and, if possible, preserving motion in the vertebral-motor segment. This article describes the experience of using custom-made implants for surgical treatment of double-level spondylolysis and a brief review of the literature. Clinical case description: A clinical case of a 16-year-old patient with bilateral spondylolysis of the L4 and L5 vertebrae is presented. The anamnesis, clinical manifestations, and diagnostic features, including radiological methods of examination, are described. The peculiarities of preoperative planning and modelling of individual implants, surgery and immediate results are presented. A brief literature review describes the main options for surgical treatment of multilevel spondylolysis and demonstrates the validity of the use of individual implants in the surgical treatment of this pathology. Conclusion: Surgical treatment of double-level bilateral spondylolysis with indirect restoration of the integrity of the vertebral arch with preservation of movements in the vertebral-motor segments can be successfully performed using custom-made implants manufactured using additive technologies. A number of advantages of such implants, such as the ability to design the position and shape of implants considering the individual anatomy of patients, as well as the prevention of contact between the elements of the metal structure during movement, make it possible to improve the results of surgical treatment of double-level spondylolysis.

Prognostic significance of osteosarcopenia in patients with stage IV gastric cancer undergoing conversion surgery

PurposeRecently, several investigators have focused on the clinical significance of osteosarcopenia in malignancies; however, its prognostic impact on patients with gastric cancer after conversion surgery (CS) remains unclear. Therefore, we aimed to investigate sarcopenia, osteopenia, and osteosarcopenia in this patient population.MethodsWe retrospectively analyzed 24 patients with gastric cancer who underwent CS. Before CS, the skeletal muscle index at the L3 vertebra and bone mineral density at the Th11 vertebra were measured to investigate sarcopenia and osteopenia, respectively. Osteosarcopenia was defined as the coexistence of sarcopenia and osteopenia. The relationship between perioperative osteosarcopenia and patient prognosis, including clinicopathological factors, was assessed.ResultsAmong the 24 patients, 10 (42%) had osteosarcopenia. Osteosarcopenia was significantly correlated with body mass index, depth of tumor invasion, and tumor stage (all p < 0.05). The median overall survival and disease-free survival after CS in patients with osteosarcopenia were significantly shorter than those in patients without osteosarcopenia (all p < 0.05). In the multivariate analysis, osteosarcopenia was identified as an independent factor related to overall survival alone (p = 0.04).ConclusionAssessment of osteosarcopenia has clinical utility in predicting the prognosis after CS in patients with stage IV gastric cancer after chemotherapy.