Artificial intelligence automatic measurement technology of lumbosacral radiographic parameters.

Background: Currently, manual measurement of lumbosacral radiological parameters is time-consuming and laborious, and inevitably produces considerable variability. This study aimed to develop and evaluate a deep learning-based model for automatically measuring lumbosacral radiographic parameters on lateral lumbar radiographs. Methods: We retrospectively collected 1,240 lateral lumbar radiographs to train the model. The included images were randomly divided into training, validation, and test sets in a ratio of approximately 8:1:1 for model training, fine-tuning, and performance evaluation, respectively. The parameters measured in this study were lumbar lordosis (LL), sacral horizontal angle (SHA), intervertebral space angle (ISA) at L4-L5 and L5-S1 segments, and the percentage of lumbar spondylolisthesis (PLS) at L4-L5 and L5-S1 segments. The model identified key points using image segmentation results and calculated measurements. The average results of key points annotated by the three spine surgeons were used as the reference standard. The model's performance was evaluated using the percentage of correct key points (PCK), intra-class correlation coefficient (ICC), Pearson correlation coefficient (r), mean absolute error (MAE), root mean square error (RMSE), and box plots. Results: The model's mean differences from the reference standard for LL, SHA, ISA (L4-L5), ISA (L5-S1), PLS (L4-L5), and PLS (L5-S1) were 1.69°, 1.36°, 1.55°, 1.90°, 1.60%, and 2.43%, respectively. When compared with the reference standard, the measurements of the model had better correlation and consistency (LL, SHA, and ISA: ICC = 0.91-0.97, r = 0.91-0.96, MAE = 1.89-2.47, RMSE = 2.32-3.12; PLS: ICC = 0.90-0.92, r = 0.90-0.91, MAE = 1.95-2.93, RMSE = 2.52-3.70), and the differences between them were not statistically significant (p > 0.05). Conclusion: The model developed in this study could correctly identify key vertebral points on lateral lumbar radiographs and automatically calculate lumbosacral radiographic parameters. The measurement results of the model had good consistency and reliability compared to manual measurements. With additional training and optimization, this technology holds promise for future measurements in clinical practice and analysis of large datasets.

Recompression after percutaneous transforaminal endoscopic decompression for degenerative lumbar spinal stenosis: risk factors and outcomes of two different reoperation procedures.

Purpose: To determine the risk factors for recompression after percutaneous transforaminal endoscopic decompression (PTED) for the treatment of degenerative lumbar spinal stenosis (DLSS) and compare the outcomes of PTED and posterior lumbar interbody fusion (PLIF) as revision surgery. Methods: We retrospectively evaluated 820 consecutive DLSS patients who underwent PTED at our institution. 26 patients developed postoperative recompression and underwent reoperation. In total, 208 patients with satisfactory clinical outcomes were enrolled in the control group. The demographic and imaging data of each patient were recorded. Univariate and multivariate analyses were performed to assess risk factors for recompression. Additionally, patients with recompression were divided into PTED and PLIF groups according to the reoperation procedure. The clinical outcomes of the two groups were compared using independent-sample t-tests. Results: The grade of surgical-level disc degeneration [odds ratio (OR): 2.551, p = 0.045] and the number of disc degeneration levels (OR: 11.985, p < 0.001) were independent risk factors for recompression after PTED. There was no significant difference in the visual analog score (VAS) and Oswestry disability index (ODI) two weeks postoperatively between the PTED and PLIF groups for surgical treatment. However, the mean VAS of back pain (14.1 vs. 20.5, p = 0.016) and ODI (16.0 vs. 21.8, p = 0.016) of patients in the PLIF group were smaller than those in the PTED group at the final follow-up. Conclusion: More severe degeneration and degenerated levels indicate a higher recompression rate after PTED. Although both PTED and PLIF could achieve immediate relief postoperatively in the treatment of recompression, the final follow-up results showed that the outcome of PLIF appeared better than that of PTED.

Development of a software system for surgical robots based on multimodal image fusion: study protocol.

Background: Surgical robots are gaining increasing popularity because of their capability to improve the precision of pedicle screw placement. However, current surgical robots rely on unimodal computed tomography (CT) images as baseline images, limiting their visualization to vertebral bone structures and excluding soft tissue structures such as intervertebral discs and nerves. This inherent limitation significantly restricts the applicability of surgical robots. To address this issue and further enhance the safety and accuracy of robot-assisted pedicle screw placement, this study will develop a software system for surgical robots based on multimodal image fusion. Such a system can extend the application range of surgical robots, such as surgical channel establishment, nerve decompression, and other related operations. Methods: Initially, imaging data of the patients included in the study are collected. Professional workstations are employed to establish, train, validate, and optimize algorithms for vertebral bone segmentation in CT and magnetic resonance (MR) images, intervertebral disc segmentation in MR images, nerve segmentation in MR images, and registration fusion of CT and MR images. Subsequently, a spine application model containing independent modules for vertebrae, intervertebral discs, and nerves is constructed, and a software system for surgical robots based on multimodal image fusion is designed. Finally, the software system is clinically validated. Discussion: We will develop a software system based on multimodal image fusion for surgical robots, which can be applied to surgical access establishment, nerve decompression, and other operations not only for robot-assisted nail placement. The development of this software system is important. First, it can improve the accuracy of pedicle screw placement, percutaneous vertebroplasty, percutaneous kyphoplasty, and other surgeries. Second, it can reduce the number of fluoroscopies, shorten the operation time, and reduce surgical complications. In addition, it would be helpful to expand the application range of surgical robots by providing key imaging data for surgical robots to realize surgical channel establishment, nerve decompression, and other operations.

Simulation and parameter determination of the net sorption of phenanthrene by sediment particles.

The distribution of polycyclic aromatic hydrocarbons (PAHs) in the ocean is affected by the sorption-desorption process of sediment particles. This process is determined by the concentration of PAHs in seawater, water temperature, and organic matter content of sediment particles. Quantitative relationships between the net sorption rates (=the difference of sorption and desorption rates) and these factors have not been established yet and used in PAH transport models. In this study, phenanthrene was chosen as the representative of PAHs. Three groups of experimental data were collected to address the dependence of the net sorption processes on the initial concentration, water temperature, and organic carbon content representing organic matter content. One-site and two-compartment mass-transfer models were tested to represent the experimental data using various parameters. The results showed that the two-compartment mass-transfer model performed better than the one-site mass-transfer model. The parameters of the two-compartment mass-transfer model include the sorption rate coefficients kafand kas (L g-1 min-1), and the desorption rate coefficients kdf and kds (min-1). The parameters at different temperatures and organic carbon contents were obtained by numerical simulations. Linear relationships were obtained between the parameters and water temperature, as well as organic carbon content. kaf, kas and kdf decreased linearly, while kds increased linearly with temperature. kaf, kas and kdf increased linearly, while kds decreased linearly with organic carbon content. The r2 values between the simulation results based on the relationships and the experimental results reached 0.96-0.99, which supports the application of the model to simulate sorption-desorption processes at different water temperatures and organic carbon contents in a realistic ocean.

Effect of hydrodynamic and ecosystem conditions on persistent organic pollutant temporal-spatial variations in the Yellow Sea.

Coastal seas are important pools of persistent organic pollutants (POPs) discharged from land. Considering the complex conditions in coastal seas and various biochemical features of POPs, special temporal-spatial variations in POPs have been reported. To understand these variations, we developed a three-dimensional hydrodynamic-ecosystem-POP coupled model and applied it to the Yellow Sea. We selected two POP species (polychlorinated biphenyl congener 153 (PCB-153) and decabromodiphenyl ether (BDE-209)), which have different biochemical properties, as target materials. The dissolved PCB-153 simulated concentration was high in late spring and low in autumn, whereas that of BDE-209 was high in summer and low in winter. Both PCB-153 and BDE-209 showed high particle-bound concentrations in early spring. In summer, dissolved PCB-153 accumulated at the sea bottom, whereas dissolved BDE-209 accumulated at the sea surface. Seasonal and spatial variation differences in the two POPs are likely caused by greater Henry's Law Constant (H') and bioconcentration factor (BCF) of PCB-153 than that of BDE-209, which leads to higher volatilization and stronger absorption by the particles for PCB-153 than BDE-209. As a component of such differences, the "biological pump" of PCB-153 in the central Yellow Sea is more apparent than that of BDE-209.

Clinical outcome of percutaneous endoscopic lumbar decompression in treatment of elderly patients with lumbar spinal stenosis: a matched retrospective study.

PURPOSE: This retrospective cohort study aimed to evaluate the efficacy and safety of percutaneous endoscopic lumbar decompression (PELD) in elderly patients with lumbar spinal stenosis (LSS). STUDY DESIGN: A matched retrospective study. SETTING: The research was conducted in Beijing Chaoyang Hospital, Capital Medical University, China. METHODS: This study included patients treated with PELD for LSS from September 2016 to September 2020. Patients with LSS aged ≥ 80 years were screened according to the inclusion and exclusion criteria as the study group, and then the same number of patients with LSS aged 50-80 years were matched according to gender, stenosis type, and surgical segment as the control group. Preoperative patient status was assessed using the Charlson comorbidity index (CCI) and the American Society of Anesthesiologists (ASA) physical status classification score. Clinical outcomes were assessed using the visual analog scale (VAS), Oswestry Disability Index (ODI) scores, modified Macnab criteria, radiological parameters and complication rates. RESULTS: A total of 624 LSS patients met the screening criteria between September 2016 and September 2020, with 47 LSS patients ≥ 80 years old serving as the study group. Forty-seven LSS patients aged 50-80 years were matched to the study group according to gender, stenosis type, and stenosis segment. The CCI score (1.77 ± 1.67) and ASA classification (2.62 ± 0.74) of the study group were significantly higher than the CCI score (0.66 ± 0.96) and ASA classification (1.28 ± 0.54) of the control group, and the difference was statistically significant. Compared with preoperative data, postoperative ODI, leg pain VAS scores and back pain VAS scores were significantly improved in both groups (p < 0.05). However, no significant difference was found between two groups in preoperative and postoperative ODI, leg pain VAS scores and back pain VAS scores (p > 0.05). The operation time and postoperative hospital stay in control group were significantly lower than those in study (p < 0.05), but there was no significant difference in blood loss between the two groups (p > 0.05). Besides, overall radiological parameters were comparable in elder and younger patients (p > 0.05), and disc height (DH), lumbar lordosis and segmental lordosis decreased after two year follow-up in both groups (p < 0.05). In addition, complication rates were similar between the two groups (p > 0.05), and no serious complications and deaths were found. LIMITATIONS: Single-centre retrospective design, non-randomized sample, small sample size. CONCLUSION: Although elderly LSS patients (≥ 80 years old) are less fit and have more comorbidities, satisfactory outcomes can be achieved with PELD, comparable to those of LSS patients < 80 years old, and without increased complications.

Unprecedented phytoplankton blooms in autumn/winter in the southern Bohai Sea (China) due to high Yellow River discharge: Implications of extreme rainfall events.

The occurrence of abnormal phytoplankton blooms is one of the significant changes in coastal ecosystems due to climate change. However, the underlying mechanism of such blooms remains poorly understood due to the complexity of the system. In this study, the data from numerous observations was used to elucidate the unprecedented phytoplankton blooms in the autumn and winter of 2021 in Laizhou Bay, a typical aquaculture bay in the southern Bohai Sea of China. The abundance of phytoplankton cells increased by more than tenfold in the southern waters compared to that in the same period from 2019 to 2020. The phytoplankton bloom was first observed in winter in the Bohai Sea, with the cell abundance in the southern bay exceeding 108 cells L-1 in December 2021. The diversity and evenness of phytoplankton communities decreased in the southern area. Cerataulina pelagica was the dominant algae, comprising 69 % of the total phytoplankton in October and 99 % in December. In autumn 2021, the largest flood of the Yellow River in recent decades occurred. This was attributed to extreme rainfall events within the river basin. The input of substantial riverine nutrients played a significant role in promoting phytoplankton blooms. Correlation analysis indicated the important cumulative impact of the Yellow River on phytoplankton blooms rather than a direct short-term effect. Numerical modeling results indicated that exceptionally high Yellow River discharge in autumn could significantly affect the entire bay from autumn to the following spring. This study may contribute to understanding the abnormal phytoplankton blooms in coastal waters and provide valuable insights for environmental management in river basins and coastal waters.

Characteristics of paraspinal muscle fat infiltration in asymptomatic Chinese adults: a cross-sectional study.

Background: Paraspinal muscle fat infiltration is closely related to the occurrence and development of lumbar spine disorders and postoperative complications. This study aimed to explore the effects of age, sex, muscle, and level on paraspinal muscle fat infiltration among Chinese adults to identify the best single level of assessing whole-level paraspinal muscle fat infiltration and to define the standardized identification thresholds for paraspinal muscle fat infiltration by means of magnetic resonance imaging. Methods: This was a single-center, cross-sectional study conducted on 336 asymptomatic Chinese volunteers aged 20 to 69 years recruited from Beijing and surrounding communities through designed advertisements from May 2022 to October 2022. The fat signal fraction of multifidus (FSFMF), erector spinae (FSFES), psoas major (FSFPM), and the sum of multifidus, erector spinae, and psoas major (FSFTotal) at lumbar levels L1-L5 were measured with magnetic resonance imaging. The Student t-test and Mann-Whitney test were performed, and Pearson correlations and intraclass correlation coefficients were determined. Subgroups were compared using analysis of variance followed by a post hoc Bonferroni test or Kruskal-Wallis test. Results: FSFTotal (14.02%±4.71% vs. 10.34±4.08%; P<0.001), FSFMF (21.14%±6.77% vs. 16.21%±6.26%; P<0.001), and FSFES (15.97%±5.56% vs. 12.37%±4.80%; P<0.001) were higher in females than in males and increased with age and lumbar level, whereas FSFPM did not significantly differ by age (all P values >0.05) or sex (P=0.12) and showed a decreasing trend from L1 to L5. The FSFTotal at L4 showed both the strongest correlation (Pearson correlation coefficient =0.95; P<0.001) and agreement (intraclass correlation coefficient =0.92; P<0.001) with the whole-level FSFTotal. Pathological paraspinal muscle fat infiltration identification thresholds of FSFTotal, FSFMF, FSFES, and FSFPM were 10.0-33.9%, 19.2-47.4%, 16.2-43.6%, and 4.8%, respectively, in each age (range, 20-69 years) and sex group. Conclusions: In asymptomatic Chinese adults, paraspinal muscle fat infiltration can be influenced by age, sex, muscle type, and location. The L4 level can serve as an optimal substitution in whole-level fat infiltration measurement. We present the first data concerning the identification thresholds of pathological paraspinal muscle fat infiltration, which will provide a valuable resource for researchers in the field.

Correlation Between Postoperative Imaging Parameters and Clinical Outcomes of Percutaneous Endoscopic Transforaminal Decompression for Lumbar Spinal Foraminal and Lateral Recess Stenosis.

Objective: To investigate the correlation between postoperative imaging parameters and clinical outcomes in patients with foraminal stenosis (FS) and lateral recess stenosis (LRS) who underwent percutaneous endoscopic transforaminal decompression (PETD). Methods: The study included 104 eligible patients who underwent PETD, and the mean follow-up time was 2.4 years (range 2.2-3.6 years). Visual Analog Scale (VAS) scores, Oswestry Disability Index (ODI) scores, and the modified MacNab criteria were used to evaluate the clinical outcomes. The related parameters of the FS and LRS based on computed tomography and magnetic resonance imaging were measured before and after surgery. Correlations between the imaging parameters and clinical outcomes were investigated. Results: The proportion of excellent and good results following MacNab evaluation was 82.6%. In the treatment of LRS, VAS-back, VAS-leg, and ODI at the 2-year follow-up were negatively correlated with postoperative facet joint length based on computed tomography. In the treatment of FS, the above clinical results were positively correlated with the variation of foraminal width and nerve root-facet distance before and after surgery based on magnetic resonance imaging. Conclusion: PETD can achieve good clinical outcomes in the treatment of patients with LRS or FS. Postoperative facet joint length was negatively correlated with clinical outcomes of LRS patients. In FS patients, the variation in foraminal width and nerve root-facet distance before and after surgery were positively correlated with their clinical outcomes. These findings may help surgeons optimize treatment strategies and selection of surgical candidates.

Efficacy of Repeat Percutaneous Endoscopic Lumbar Decompression for Reoperation of Lumbar Spinal Stenosis: A Retrospective Study.

Purpose: To evaluate the efficacy of repeat percutaneous endoscopic lumbar decompression (PELD) in lumbar spinal stenosis (LSS) reoperation. Patients and Methods: This study included patients with LSS who relapsed following treatment with PELD therapy between March 2017 and March 2020. Visual analog scale (VAS) scores and Oswestry Disability Index (ODI) were analyzed preoperatively, postoperatively at 3, 6, 12, and 24 months, and at final follow-up. The modified MacNab criteria were used to assess clinical effects. All complications were recorded. Results: At a mean follow-up of 3 years, 24 patients with LSS who underwent repeat PELD were identified. The patients' mean operative time was 122.3±29.2 min, blood loss was 12.5±5.3 mL, and mean hospital stay was 7.0±1.9 days. VAS leg-pain score improved from 6.1±1.0 to 2.0±1.2 (P<0.001), VAS back-pain score improved from 6.2±0.8 to 2.1±1.1 (P<0.001), and ODI improved from 68.9±6.0 to 20.9±5.6 (P <0.001). According to the modified MacNab criteria, the good-to-excellent rate was 83.3%. Postoperative complications, including hematoma, nerve root injury, and dural injury, developed in four patients. Conclusion: Repeat PELD for reoperation in patients with LSS has a good clinical effect, and is recommended in routine clinical practice. Careful intraoperative manipulation is recommended to prevent complications.

Reoperations After Percutaneous Endoscopic Transforaminal Decompression for Treating Lumbar Spinal Stenosis: Incidence and Predictors.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: The main purpose of the present study was to report the incidence and identify predictors of reoperation in patients with lumbar spinal stenosis (LSS) treated with percutaneous endoscopic transforaminal decompression (PETD). METHODS: This study retrospectively reviewed consecutive patients with LSS who underwent PETD at our center between January 2016 and July 2020. The incidence of reoperations was calculated. We then designed a surgical period-matched case-control study to identify predictors among demographic data, clinical baseline data, and imaging parameters. RESULTS: This study identified 496 eligible patients. 33 (6.7%) patients underwent reoperation with a mean follow-up of 3 years, consisting 22 (4.4%) at the index level and 11 (2.2%) at the adjacent levels. There were significant differences in age and age-adjusted Charlson comorbidity index (AACCI) between the two groups, with younger age (P = .004) and lower AACCI (P = .019) in reoperation group. Age was identified as the sole independent predictor (P = .006). The duration of symptoms ≥12 months (P = .034) and the presence of heart problems (P = .012) were recognized as specific predictors among patients younger than 65 years. CONCLUSIONS: In a mean follow-up of 3 years, the incidence of reoperation in LSS treated with PETD was 6.7%. A younger age was the independent predictor for reoperation. Younger patients with the duration of symptoms ≥12 months or without heart problems were more likely to undergo a second operation. Prospective randomized controlled trials are required to confirm these findings.

Comparative efficacy and complications of single and dual growing rods for early-onset scoliosis: an updated meta-analysis.

PURPOSE: This updated meta-analysis aimed to compare single and dual growing rods, including both traditional growing rod and magnetically controlled growing rod (MCGR) used in the treatment of early-onset scoliosis (EOS) with regard to deformity correction, spinal growth, and complications. METHODS: This meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using articles extracted from PubMed, EMBASE databases, and Cochrane Library databases. Only articles reporting the complications and the imaging parameters before and after growing rods in the patients diagnosed with EOS were included. We extracted and statistically analyzed the data deemed relevant for this study, and used the Newcastle-Ottawa Scale to assess the risk of bias in each study. Data synthesis and statistical analyses were performed using R software. RESULTS: Fifteen eligible articles containing 409 participants (n = 185, single growing rods; n = 224, dual growing rods) were identified. The meta-analysis found no significant differences in the preoperative and postoperative major Cobb angle, T1-S1 distance, thoracic kyphosis, and coronal balance between single and dual rods groups. The final follow-up major Cobb angle (P = 0.01; standardized mean difference, - 0.42 [95% confidence interval (CI), - 0.74 to - 0.10]; I2 = 23%) was significantly smaller in dual rods group than single-rod group. However, no significant differences in the correction rate of angle (major Cobb angle and kyphosis angle) and changes in the T1-S1 distance between the two groups were observed. Moreover, there were no significant differences in the metalwork failure, infection, or proximal junctional kyphosis between single and dual rods groups. However, total complications (P = 0.03; risk ratio (RR), 0.79 [95% CI, 0.63-0.98]; I2 = 29%) and distraction failure in MCGR (P = 0.04; RR, 0.38 [95% CI, 0.14-0.98]; I2 = 11%) were significantly lower in dual rods group than single-rod group. CONCLUSION: This updated meta-analysis found that patients with dual growing rods had fewer complications, especially distraction failure in MCGR, than those with single growing rod. However, none of deformity correction, spinal growth, or other complications differed between single and dual growing rods. Therefore, we believe that dual growing rods do not provide strong advantages over single growing rod in the treatment of EOS.

Early Readmission and Reoperation After Percutaneous Transforaminal Endoscopic Decompression for Degenerative Lumbar Spinal Stenosis: Incidence and Risk Factors.

Purpose: To identify the incidence rates and risk factors for early readmission and reoperation after percutaneous transforaminal endoscopic decompression (PTED) for degenerative lumbar spinal stenosis (DLSS). Patients and Methods: A total of 1011 DLSS patients who underwent PTED were retrospectively evaluated. Of them, 58 were readmitted, and 31 underwent reoperation. The patients were matched with 174 control patients to perform case-control analyses. The clinical and preoperative imaging data of each patient were recorded. Univariate analyses were performed using independent sample t-tests and Fisher's exact tests. Furthermore, the risk factors for early readmission and reoperation were analyzed using multivariate logistic regression analyses. Results: The incidence rates of readmission and reoperation within 90 days after PTED were 5.7% and 3.1%, respectively. Age (odds ratio [OR]=1.054, p=0.001), BMI (OR=1.104, p=0.041), a history of lumbar surgery (OR=3.260, p=0.014), and the number of levels with radiological lumbar foraminal stenosis (LFS, OR=2.533, p<0.001) were independent risk factors for early readmission. The number of levels with radiological LFS (OR=5.049, p<0.001), the grade of surgical-level facet joint degeneration (OR=2.010, p=0.023), and a history of lumbar surgery (OR=10.091, p<0.001) were independent risk factors for early reoperation. Conclusion: This study confirmed that aging, a higher BMI, a history of lumbar surgery, and more levels with radiological LFS were associated with a higher risk of early readmission. More levels with radiological LFS, a higher grade of surgical-level facet joint degeneration, and a history of lumbar surgery were predictors of early reoperation. These results are helpful in patient counseling and perioperative evaluation of PTED.

Biomedical evidence engineering for data-driven discovery.

MOTIVATION: With the rapid development of precision medicine, a large amount of health data (such as electronic health records, gene sequencing, medical images, etc.) has been produced. It encourages more and more interest in data-driven insight discovery from these data. A reasonable way to verify the derived insights is by checking evidence from biomedical literature. However, manual verification is inefficient and not scalable. Therefore, an intelligent technique is necessary to solve this problem. RESULTS: This article introduces a framework for biomedical evidence engineering, addressing this problem more effectively. The framework consists of a biomedical literature retrieval module and an evidence extraction module. The retrieval module ensembles several methods and achieves state-of-the-art performance in biomedical literature retrieval. A BERT-based evidence extraction model is proposed to extract evidence from literature in response to queries. Moreover, we create a dataset with 1 million examples of biomedical evidence, 10 000 of which are manually annotated. AVAILABILITY AND IMPLEMENTATION: Datasets are available at https://github.com/SendongZhao.

Posterior Apophyseal Ring Fracture in Adult Lumbar Disc Herniation: An 8-Year Experience in Minimally Invasive Surgical Management of 48 Cases.

OBJECTIVE: Posterior apophyseal ring fracture (PARF) is an uncommon disorder that is usually accompanied by lumbar disc herniation (LDH). The aim of this study to describe the 8-year experience of performing minimally invasive treatment of PARF, giving particular attention to surgical technique and clinical outcome. METHODS: We reviewed 1,324 consecutive patients with LDH seen in our department between 2013 and 2020. Forty-eight patients (3.63%) were enrolled who were diagnosed with PARF associated with LDH and underwent transforminal endoscopic lumbar discectomy (TELD). Mean duration of the final postoperative follow-up was 5.1 years. The control group was comprised of 50 patients diagnosed with LDH without PARF at the same facility. Data on clinical outcomes were analyzed. RESULTS: The mean operation time in the PARF group was 105.4 minutes, which was longer than the mean operation time of the control group (83.9 minutes) (p = 0.001). Surgical complications, including dural tears (6.3%) and surgical instrument rupture (4.2%) were more common in the PARF group (p = 0.025). However, there was no significant difference in the proportion of excellent and good results and recurrence rates between the LDH patients with and those without PARF, respectively. CONCLUSION: TELD is a safe and effective minimally invasive approach for the treatment of PARF. However, minimally invasive techniques may require longer operation time and steeper learning curve for inexperienced surgeons. The separation and removal of bone fragments, a key step in the procedure, requires patience and care to prevent rupture, residual surgical instruments, and leakage of cerebrospinal fluid.

A predictive nomogram for intradiscal cement leakage in percutaneous kyphoplasty for osteoporotic vertebral compression fractures combined with intravertebral cleft.

Background: For patients with osteoporotic vertebral compression fractures (OVCFs) treated with percutaneous kyphoplasty (PKP), the occurrence and risk factors of intradiscal cement leakage should be characteristic of the presence of intravertebral cleft (IVC). This study aimed to identify risk factors for intradiscal leakage in individuals with OVCFs combined with IVC treated with PKP and build a powered and well-calibrated predictive nomogram. Methods: This study retrospectively reviewed consecutive patients who underwent PKP at our center between January 2016 and May 2021. Patients diagnosed with OVCFs combined with IVC were identified, and the incidence of different types of bone cement leakage was recorded. Risk factors for intradiscal leakage among the demographic, perioperative baseline, and radiologic data were identified, following which a nomogram was developed and verified. Results: A total of 109 eligible patients were included, and the intradiscal leakage rate was 32.1%. Compression rate (odds ratio [OR] 0.025; 95% confidence interval [CI] 0.002-0.264; P = 0.002) and cemented vertebral body fraction (OR 44.122; 95% CI 2.790-697.740; P = 0.007) were identified as independent risk factors. A predictive nomogram with good predictive power (C-statistic = 0.786) and fitness of data (Hosmer-Lemeshow goodness-of-fit test, P = 0.092) was established to build a quantitative relationship between the risk factors and intradiscal leakage. Conclusion: The incidence rate of intradiscal leakage in PKP for OVCFs combined with IVC was 32.1%. Compression rate and cemented vertebral body fraction were identified as independent risk factors. A powered and well-calibrated nomogram was established to accurately predict the probability of intradiscal leakage. Further prospective and multicenter studies are required to verify and calibrate our findings.

Paraspinal Muscle Degeneration: A Potential Risk Factor for New Vertebral Compression Fractures After Percutaneous Kyphoplasty.

Background: The paraspinal muscle is essential for maintaining normal spine function and structure, which degeneration is closely related to various spinal diseases. The main objective of this study was to identify the potential role of paraspinal muscle degeneration in the occurrence of new vertebral compression fractures (NVCF) and develop a clinically applicable nomogram for prospective NVCF risk prediction. Methods: A total of 202 patients with single-level osteoporotic vertebral compression fractures (OVCF) who underwent percutaneous kyphoplasty treatment between January 2016 and March 2019 were included in this study. Demographic, clinical, radiological, and treatment data were collected and analyzed. The paraspinal muscle cross-sectional area (CSA) and fat signal fraction (FSF) were measured to quantify the extent of muscle degeneration. Multivariate binary logistic regression analysis was performed to select risk factors to build a nomogram that predicted the occurrence of NVCF. The concordance index (C-index) and calibration curve were used to evaluate the discriminative capacity and predictive accuracy of the nomogram. Results: NVCF occurred in 54 of 202 patients (26.7%). The erector spinae FSF (OR = 1.064; P = 0.001), psoas major FSF (OR = 1.326; P < 0.001), and the difference index of the muscle CSA between multifidus and psoas major (OR = 1.048; P < 0.001) were independent risk factors for the occurrence of NVCF. The nomogram performance was good after evaluation using the calibration curves and C-index (95% confidence interval, 0.854-0.943). Conclusion: Paraspinal muscle degeneration is a potential risk factor for NVCF occurrence. A nomogram was designed to precisely predict the risk of NVCF. This predictive nomogram may help clinicians to make better clinical decisions and provide more accurate functional exercise protocol for OVCF patients.

Quantitative Radiological Characteristics of the Facet Joints in Patients with Lumbar Foraminal Stenosis.

Purpose: This study aimed to evaluate the degeneration patterns of the facet joints (FJs) in patients with lumbar foraminal stenosis (LFS) and investigate the correlation between quantitative parameters and FJ osteoarthritis (FJ OA). Patients and Methods: A total of 171 patients with LFS at the L4/5 level and 146 control patients were enrolled in this study. The severity of FJ OA was graded according to the Weishaupt classification. The FJ orientation, FJ tropism, superior articular process cross-sectional area (SAPA), and FJ area were measured at the L3/4, L4/5, and L5/S1 spinal levels. Associations among the parameters were assessed using Pearson's correlation coefficients. Independent sample t-tests and Pearson's chi-square tests were used for univariate analyses. The association between LFS and the quantitative parameters was also analyzed using multivariate logistic regression models adjusted for age, gender, and body mass index. Results: Patients with LFS had more sagittal FJ orientation (37.9 vs 45.0, p < 0.001), more FJ tropism (5.6 vs 3.8, p < 0.001), larger SAPA (129.0 vs 97.8, p < 0.001), and less FJ area (21.7 vs 23.3, p = 0.016). Logistic regression analysis showed that LFS was significantly associated with FJ tropism (odds ratio [OR]: 1.153; p = 0.003) and SAPA (OR: 1.113; p < 0.001). The SAPA showed the largest area under the curve (0.908, 95% confidence interval: 0.875-0.942) for the diagnosis of LFS. The optimal cutoff value was 114.75 mm2 with 85.4% sensitivity and 87.0% specificity. Additionally, a significant correlation was observed between FJ OA and SAPA and FJ area at each studied spinal level. Conclusion: This study confirmed that LFS is significantly associated with FJ hypertrophy and tropism. FJ hypertrophy and joint space narrowing correlated with the severity of FJ OA. These results are helpful in understanding the morphology and pathology of FJs.

Radiographic adjacent segment degeneration and risk factors for osteoporotic vertebral compression fractures treated with percutaneous kyphoplasty.

PURPOSE: In this study, we aimed to clarify whether osteoporotic vertebral compression fracture (OVCF) following percutaneous kyphoplasty (PKP) was associated with a high risk for radiographic adjacent segment degeneration (ASD) and to identify the risk factors for radiographic ASD in these individuals. METHODS: We retrospectively reviewed consecutive patients with OVCFs who underwent PKP at our institution between November 2015 and January 2021. The incidence of radiographic ASD was calculated and specific subgroups of ASD were identified. Univariate and multivariate analyses of demographic, clinical baseline, and radiologic data were performed to identify risk factors associated with radiographic ASD. RESULTS: With a mean follow-up time of 27.3 months, a total of 95 eligible patients were enrolled. The incidence of radiographic ASD distinguished from natural degeneration was 52.6%. Patients with OVCFs who underwent PKP had a high risk of developing radiographic ASD, particularly disc degeneration. Intradiscal cement leakage (odds ratio [OR], 5.706; 95% confidence interval [CI], 2.039-15.970; P = 0.001) and preoperative disc height (OR, 0.681; 95% CI, 0.518-0.895; P = 0.006) were identified as independent risk factors. CONCLUSION: Patients with OVCFs who underwent PKP were more likely to develop radiographic ASD, and their progression was distinguished from natural degeneration. Disc degeneration was the most common type of degeneration. Intradiscal cement leakage and preoperative disc height were identified as independent risk factors for developing radiographic ASD in these patients. Further validation through prospective multicenter studies is required.