MRI-based Pedicle Bone Quality score: Correlation to Quantitative Computed Tomography Bone Mineral Density and its Role in Quantitative Assessment of Osteoporosis.

BACKGROUND CONTEXT: Bone quality in the pedicle region generally determines screw pullout strength, insertion torque, and vertebral body loading characteristics. Dual-energy X-ray absorptiometry (DEXA), as the gold standard for evaluating bone mineral density (BMD), cannot measure the BMD of specific parts, such as pedicle, and DEXA is limited in many ways. Recent studies have shown a correlation between the magnetic resonance imaging (MRI)-based vertebral bone quality (VBQ) score and BMD measured using DEXA or quantitative computed tomography (QCT). However, no studies have been reported on the MRI-based pedicle bone quality (PBQ) score. Moreover, few studies have investigated the relationship between MRI-based PBQ and osteoporosis. PURPOSE: To create a new site-specific MRI-based PBQ assessment method and assess its diagnostic capacity in patients with normal BMD and osteopenia/osteoporosis. STUDY DESIGN/SETTING: A retrospective study. PATIENT SAMPLE: A total of 156 patients underwent lumbar fusion surgery for chronic low back pain at our hospital between 2021 and 2022, with lumbar QCT and T1-weighted MRI performed before surgery. OUTCOME MEASURES: Correlation of the PBQ score with QCT BMD, and the association between the PBQ score and presence of osteopenia/osteoporosis. METHODS: BMD of the lumbar was calculated as the mean BMD of the L1 and L2 vertebral bodies on the basis of asynchronous QCT measurements. The PBQ score, which is the average of the bone quality values of both pedicles on the basis of site-specific T1-weighted sagittal MRI images, was calculated by dividing the median signal intensity of the L1-L4 pedicles by the signal intensity of the cerebrospinal fluid at the L3 level. The interobserver reliability of the PBQ score was assessed using the intraclass correlation coefficient (ICC). A receiver operating characteristic curve was drawn, and the area under the curve (AUC) was calculated to assess the predictive performance of PBQ for osteoporosis. The PBQ score was compared with QCT BMD, as the gold standard, using Pearson correlation analysis. RESULTS: In total, 156 patients participated in this study, including 51 in the Normal BMD group and 105 in the osteopenia/osteoporosis group. The PBQ score in the osteopenia/osteoporosis group was significantly higher than that in the normal BMD group (3.19 ± 0.55 vs. 2.84 ± 0.51, p < 0.001). The VBQ and PBQ scores were calculated by two authors and were in good agreement (intraclass correlation coefficient = 0.949 and 0.929, respectively). Pearson's test showed a significant negative correlation between PBQ and QCT BMD (r = -0.4887, p < 0.001). The optimal cutoff PBQ score to differentiate patients with osteopenia/osteoporosis from those with normal BMD was 3.160, with a sensitivity of 66.7%, specificity of 72.5%, and AUC of 0.776. The PBQ score correlated more strongly with QCT BMD (r = -0.4887) than VBQ (r = -0.4078). CONCLUSIONS: In this study, we propose a novel, MRI-based pedicle-specific bone quality score. This is the first study to investigate the relationship between the PBQ score and QCT BMD. The PBQ score showed diagnostic utility, differentiating between patients with osteopenia/osteoporosis and those with normal BMD (AUC = 0.776), and the PBQ score correlated more strongly with QCT BMD than VBQ.

Surgical Treatment Outcomes of Anterior-Only Correction and Reconstruction for Severe Cervical Kyphotic Deformity with Neurofibromatosis-1: A Retrospective Study with a 5-Year Follow-Up.

OBJECTIVES: Currently, anterior-only (AO), posterior-only, and combined anterior-posterior spinal fusions are common strategies for treating cervical kyphosis in patients with neurofibromatosis-1 NF-1. Nevertheless, the choice of surgical strategy remains a topic of controversy. The aim of our study is to evaluate the safety and effectiveness of anterior decompression and spinal reconstruction for the treatment of cervical kyphosis in patients with NF-1. METHODS: Twelve patients with NF-1-associated cervical kyphotic deformity were reviewed retrospectively between January 2010 and April 2020. All patients underwent AO correction and reconstruction. The X-ray was followed up in all these patients to assess the preoperative and postoperative local kyphosis angle (LKA), the global kyphosis angle (GKA), the sagittal vertical axis, and the T1 slope. The visual analog scale score, Japanese Orthopedic Association (JOA) score, and neck disability index (NDI) score were used to evaluate the improvement inclinical symptoms. The results of the difference in improvement from preoperatively to the final follow-up assessment were assessed using a paired t-test or Mann-Whitney U-test. RESULTS: The LKA and GKA decreased from the preoperative average of 64.42 (range, 38-86) and 35.50 (range, 10-81) to an average of 16.83 (range, -2 to 46) and 4.25 (range, -22 to 39) postoperatively, respectively. The average correction rates of the LKA and GKA were 76.11% and 111.97%, respectively. All patients had achieved satisfactory relief of neurological symptoms (p < 0.01). JOA scores were improved from 10.42 (range, 8-16) preoperatively to 15.25 (range, 11-18) at final follow-up (p < 0.01). NDI scores were decreased from an average of 23.25 (range, 16-34) preoperatively to an average of 7.08 (range, 3-15) at the final follow-up (p < 0.01). CONCLUSION: Anterior-only correction and reconstruction is a safe and effective method for correcting cervical kyphosis in NF-1 patients. In fixed cervical kyphosis cases, preoperative skull traction should also be considered.

S1 vertebral bone quality score independently predicts pedicle screw loosening following surgery in patients with adult degenerative scoliosis.

BACKGROUND CONTEXT: MRI-based vertebral bone quality (VBQ) score is an effective predictor of pedicle screw loosening after lumbar fusion surgery and has been recognized as a valuable tool for assessing preoperative bone quality. Due to the lateral curvature of lumbar spine of degenerative scoliosis, accurate measurement of VBQ score by conventional measurement methods that capture MRI signal intensity at L1-4 may be limited under certain conditions. To this end, a new simplified S1 VBQ score method has been proposed, which is comparable to the previous L1-4 VBQ score or S1 Hounsfield unit (HU) value, and has high accuracy and reliability. PURPOSE: To evaluate the predictive value of MRI-based S1 VBQ score for pedicle screw loosening following surgery for adult degenerative scoliosis (ADS). STUDY DESIGN/SETTING: Retrospective single-center cohort. PATIENT SAMPLE: We reviewed 92 patients who underwent posterior lumbar interbody fusion (PLIF) with pedicle screw fixation for ADS between January 2017 and January 2020. OUTCOME MEASURES: Association between S1 VBQ score and pedicle screw loosening following surgery for ADS. METHODS: We retrospectively reviewed the records of all patients who performed PLIF between January 2017 and January 2020. The clear zone around pedicle screws≥1 mm can be identified as screw loosening. The S1 VBQ score is calculated from the S1 central-based non-contrast T1-weighted magnetic resonance imaging (MRI). The signal intensity (SI) of the cerebrospinal fluid (CSF) was then measured using ROI placed at the L3 level to normalize the results. Multivariate logistic regression analysis was performed to identify independent risk factors for screw loosening. Then, constructed a receiver operating characteristic (ROC) curve and determined the threshold (cut-off) of VBQ score with high sensitivity and specificity based on Youden Index. RESULTS: A total of 92 patients were included, including 34 males and 58 females. The mean age of the patients was 61.23±1.23 years old. At 1-year follow-up, the screw loosening rate was 56.5% (52/92). The age and levels of fixation were higher in the loosening group than in the non-loosening group (p=.036, p=.025). Patients in the loosening group had a greater VBQ score compared to patients in the non-loosening group (3.31±0.41 vs 3.01±0.28, p=.001). Multivariate logistic regression analysis showed that advanced age (OR, 1.090; 95% CI 1.005-1.183; p=.039) and higher VBQ score (OR, 5.778; 95% CI 2.889-16.177; p=.001) were independent risk factors for screw loosening. In addition, the ROC curve were created to assess the role of VBQ score as predictors of screw loosening with a diagnostic accuracy of 74.6% (95% CI 64.2%-85.1%).The most suitable threshold for the VBQ score as determined by the Youden Index was 3.175 (sensitivity: 76.0%, specificity: 83.3%). CONCLUSIONS: Higher S1 VBQ score was significantly associated with pedicle screw loosening following surgery for ADS. The S1 VBQ score can be used as an effective preoperative predictor, which has the potential clinical application.

Percutaneous vertebroplasty versus percutaneous kyphoplasty for osteoporotic vertebral compression fractures: an umbrella review protocol of systematic reviews and meta-analyses.

INTRODUCTION: Several systematic reviews and meta-analyses have confirmed that percutaneous vertebroplasty and percutaneous kyphoplasty showed safety and beneficial efficacy in patients with osteoporotic vertebral compression fractures. Whereas, there is wide variation among results, which are not conducive to the evaluation and use of clinicians. This study will investigate the efficacy and safety of percutaneous vertebroplasty and percutaneous kyphoplasty for the treatment of osteoporotic vertebral compression fractures, aiming to provide a more reliable evidence base for clinical practice in treating osteoporotic vertebral compression fractures. METHODS AND ANALYSIS: We will retrieve the relevant articles using the five databases(PubMed, Scopus, EMBASE, Cochrane Library and Web of Science) from inception to March 2023 for systematic review and meta-analysis comparing the overall safety and efficacy of percutaneous vertebroplasty and percutaneous kyphoplasty in patients with osteoporotic vertebral compression fractures. Three reviewers will screen citation titles, abstracts and evaluate the full text of each relevant citation based on prespecified eligibility criteria. Any discrepancies in decisions between reviewers will be resolved through discussion. We will assess the methodological quality of the included studies according to A MeaSurement Tool to Assess systematic Reviews 2 checklist. ETHICS AND DISSEMINATION: This umbrella review will inform clinical and policy decisions regarding the benefits and harms of percutaneous vertebroplasty versus percutaneous kyphoplasty for osteoporotic vertebral compression fractures. Neither primary data nor individual patient information will be collected, thus ethics approval is not required. Findings will be reported through a peer-reviewed publication, conference presentations and the popular press. PROSPERO REGISTRATION NUMBER: CRD42021268141.

The Association between High Preoperative MRI-based Vertebral Bone Quality (VBQ) Score and Titanium Mesh Cage Subsidence after Anterior Cervical Corpectomy and Fusion.

OBJECTIVE: Recently, the MRI-based vertebral bone quality (VBQ) score has been shown to correlate with Hounsfeld units (HU) value, dual-energy X-ray absorptiometry (DEXA) T-score and predict osteoporotic fractures. Preoperative cervical HU value is an independent correlative factor for early titanium mesh cage (TMC) subsidence after anterior cervical corpectomy and fusion (ACCF). However, to date the direct association between cervical VBQ score and TMC subsidence has not been studied. This study aims to investigate the predictive effect of cervical VBQ score derived from sagittal non-contrast-enhanced T1-weighted MRI on the early TMC subsidence after ACCF. METHODS: Patients who underwent one-level ACCF from January 2016 to January 2020 were included. We retrospectively collected baseline data on age, sex, body mass index (BMI), disease type, level of surgery and radiology parameters. The cervical VBQ score was measured using preoperative non-contrast-enhanced T1-weighted MRI. Univariate and multivariate logistic regression analysis were performed to screen the independent risk factors of TMC subsidence. The receiver operating characteristic (ROC) curve and area under curve (AUC) were performed to assess the predictive ability of TMC subsidence based on the cervical VBQ score. Spearman correlation analysis was used to determine the correlations between the cervical VBQ score and TMC subsidence. RESULTS: A total of 134 patients who underwent one-level ACCF were included in this study, and 46 (34.33%) patients had TMC subsidence. Univariable analyses demonstrated that the age, TMC placement depth and VBQ score were associated with subsidence. The cervical VBQ score in the subsidence group was significantly higher than that in the no subsidence group (3.75 ± 0.45 vs. 3.20 ± 0.42, p < 0.001). The multivariate logistic regression analysis proved that the higher VBQ score (odds ratio[OR] = 13.563, 95% confidence interval [CI] 4.968 - 37.031, p < 0.001) was the only variable that significantly predicted subsidence. Using a VBQ score cutoff value of 3.445, the cervical VBQ score yielded a sensitivity of 69.6% and a specificity of 85.2% with an AUC of 0.810 to differentiate patients with subsidence and with no subsidence. CONCLUSION: Preoperative higher cervical VBQ score is an independent risk factor for TMC subsidence after ACCF. The cervical VBQ score may be a valuable tool for assisting in distinguishing the presence of TMC subsidence.

Comparison of Long-term Follow-Up of n-HA PA66 Cage and PEEK Cage of Lumbar Interbody Fusion in Multi-level Degenerative Lumbar Diseases: A Stepwise Propensity Score Matching Analysis.

OBJECTIVE: Previous studies have confirmed that the nanohydroxyapatite/polyamide-66 (n-HA/PA66) cage is an ideal alternative material for degenerative lumbar disease (DLD) comparable to the polyether ether ketone (PEEK) cage due to its similar radiographic fusion, subsidence rate, and clinical results. However, these studies were restricted to one-level surgery. The aim of this study was to analyze the long-term clinical and radiologic outcomes between n-HA PA66 cage and PEEK cage for patients with multi-level degenerative lumbar diseases (DLDs). METHODS: We retrospectively reviewed all patients who underwent multi-level transforaminal lumbar interbody fusion (TLIF) from June 2010 to December 2016 with a minimum 6-year follow-up. Matched-pair analysis was performed using a 1-to-1 closest neighbor approach to match patients who received an n-HA PA66 cage with those who received a PEEK cage. Clinical outcomes and radiographic evaluations were compared between the two groups. The independent student's t-test and χ2 -test were applied to compare the differences between groups. RESULTS: At the end of the propensity score matching (PSM) analysis, 48 patients from n-HA/PA66 group were matched to 48 patients in the PEEK group. No significant difference was observed in cage subsidence and bony fusion except for adjacent segment degeneration (ASD). The occurrence of ASD was 14.58% (7/48) in the n-HA/PA 66 group, which was significantly less than that in the PEEK group (33.33% [16/48]) (p = 0.031). Although the intervertebral space height (IH), segmental angle (SA) and lumbar lordosis (LL) significantly increased after surgery in both groups, there was no significant difference at any time point after surgery (p > 0.05). The visual analogue scale (VAS) and Oswestry disability index (ODI) scores significantly improved in both groups at 3m postoperative, 1y postoperative and at final follow-up. However, there were no significant differences in the VAS and ODI score at any time point (p > 0.05). The total complications and re-admission rate were not different between the two groups. CONCLUSION: Overall, our data suggest that the outcomes of n-HA/PA66 cage group are comparable to those of the PEEK cage group, with a similar high fusion rate and low cage subsidence rate as PEEK cages, except its lower rate of ASD occurrence.

Posterior concave reconstruction with cage in the surgical treatment of complex lumbar deformity caused by lumbosacral hemivertebrae.

PURPOSE: To identify the clinical and radiological outcomes in the coronal and sagittal planes after treatment of congenital complex lumbosacral hemivertebrae (LSHV) with or without posterior concave reconstruction. METHODS: We retrospectively reviewed a consecutive series of patients with congenital LSHV deformities treated by posterior-only hemivertebra resection. The minimum follow-up was 2 years. The patients were divided into a concave-cage group and a non-cage group. The radiographic and clinical results were compared between the two groups. RESULTS: Forty patients were categorized into the cage group (n = 14) and non-cage group (n = 26). At the end of the propensity score matching analysis, 14 patients from the cage group were matched to 14 patients in the non-cage group. The lumbosacral curve and thoracolumbar/lumbar curve improved significantly in both groups at the final postoperative follow-up (P < 0.001), and the lumbosacral curve at the final follow-up was remarkably lower in the cage than non-cage group. The correction rates of the lumbosacral curve and thoracolumbar/lumbar curve were significantly higher in the cage than non-cage group. The lower lumbar lordosis improved significantly in both groups at the final postoperative follow-up (P < 0.05), and the lower lumbar lordosis at the final follow-up and its correction were remarkably higher in the cage than non-cage group (both P < 0.05). CONCLUSIONS: Posterior column reconstruction with insertion of a concave cage may achieve a higher correction rate of large lower lumbar lordosis and lumbosacral coronal deformity, attain better sagittal balance, and have fewer complications related to implant failure than posterior-only hemivertebra resection in patients with congenital LSHV.

A Comparison of Corpectomy ACDF Hybrid Procedures with Nano-Hydroxyapatite/Polyamide 66 Cage and Titanium Mesh Cage for Multi-level Degenerative Cervical Myelopathy: A Stepwise Propensity Score Matching Analysis.

OBJECTIVE: Previous studies have found satisfactory clinical results with the nano-hydroxyapatite/polyamide 66 (n-HA/PA66) cage to reconstruct the stability of anterior cervical column. However, studies evaluating the long-term outcomes of the n-HA/PA66 cage in multi-level degenerative cervical myelopathy (MDCM) have not been reported. This study aims to compare the outcomes of corpectomy anterior cervical discectomy and fusion (ACDF) hybrid procedures between the n-HA/PA66 cage and titanium mesh cage (TMC) to treat MDCM. METHODS: After the screening for eligibility, this retrospective study involved 90 patients who underwent corpectomy ACDF hybrid (CACDFH) procedure from June 2013 to June 2018. The CACDFH procedure is the combination of ACDF and anterior cervical corpectomy and fusion (ACCF). According to the cage utilized, we categorized patients into a n-HA/PA66 cage group and a TMC group. Then, stepwise propensity score matching (PSM) was performed to maintain comparable clinical data between groups. All the patients were followed up ≥4 years and the longest follow-up time was 65.43 (±11.49) months. Cage subsidence, adjacent segment degeneration (ASD), segmental height (SH), segmental angle (SA), cervical lordosis (CL), and clinical data (visual analogue scale [VAS] and Japanese Orthopaedic Association [JOA] score) was evaluated preoperatively, at 1 week, and at the final surgery follow-up. The independent student's t test and chi-square test were applied to compare the differences between groups. RESULTS: Through PSM analysis, 25 patients from the n-HA/PA66 group were matched to 25 patients in the TMC group. The occurrence of ASD was 16.0% (4/25) in the n-HA/PA 66 group, which was significantly less than in the TMC group at 44.0% (11/25) (p = 0.031). Moreover, the cage subsidence rate was significantly higher in the TMC group as compared to the n-HA/PA 66 group (40.0% vs. 12.0%, p = 0.024). But there was no significant difference in SH, SA, and CL at any time after surgery as determined through follow-up. The VAS and JOA scores significantly improved in both groups at 3 months postoperative and at final follow-up. However, there were no significant differences in the VAS and JOA score at any time between the two groups in preoperative (p > 0.05). CONCLUSION: The n-HA/PA66 cage is associated with lower rate of cage subsidence and ASD than the TMC in the treatment of MDCM. The n-HA/PA66 cage could be superior to the TMC in corpectomy ACDF hybrid procedures.

Lumbar Disc Herniation with Contralateral Symptoms: A Case-Series of 11 Patients and Literature Review.

OBJECTIVE: Lumbar disc herniation (LDH) is a common pathology that typically causes unilateral radiculopathy on the same side as herniation, while patients may occasionally present with contralateral symptoms. Owing to the rare incidence of LDH with contralateral symptoms, the pathological mechanism remains unclear and the optimal surgical strategy is a subject of debate. This study aimed to provide new insights into the pathological mechanism of contralateral symptoms and assess the efficacy of ipsilateral hemilaminectomy and discectomy surgery in this population. METHODS: This study was a retrospective, single-center, clinical case series, including 11 LDH cases with exclusive contralateral symptoms. We searched for LDH cases that were presented at our institution between January 2011 and December 2020. Adult LDH Patients with contralateral radicular pains were included, while those with ipsilateral radiculopathy, lumbar stenosis, foraminal stenosis on the symptomatic side, multilevel disc herniations, scoliosis, and lumbar operation history were excluded. Visual Analog Scale (VAS), clinical features, radiographic images, and other data were collected from the study cohort of 11 cases for further analysis. We also reviewed LDH cases in English literature from 1978 to 2023 to analyze their clinical characteristics and treatment. RESULTS: The incidence rate of LDH with contralateral symptoms in single-level LDH cases was 0.32%. The average age of our 11 cases was 49.3 years old, and five of them were female (45.5%). All individuals had single-level lateral LDH, with six cases (54.5%) located at L4-5 and five cases (45.5%) located at L5-S1. Upon admission, patients presented with lower back pain (seven cases, 63.6%), radicular pain (seven cases, 63.6%), hypoesthesia (seven cases, 63.6%), and muscle weakness (one case, 9.1%) on the contralateral side alone. Each case experienced ipsilateral hemilaminectomy and discectomy, and no lateral recess stenosis, hypertrophy of facets or ligaments, and sequestrated discs were found during surgery. All of them have good pain relief with two cases reporting no pain and nine cases reporting only mild pain at the last follow-up. CONCLUSIONS: Based on the surgical findings of our 11 LDH cases with contralateral symptoms, we hypothesized that the contralateral symptoms might be produced when the nerve root on the contralateral symptomatic side was tightly pulled by the herniated disc via the dural mater. Ipsilateral hemilaminectomy and discectomy surgery effectively and efficiently relieve the symptoms without postoperative complications for these patients.

Tranexamic acid can reduce blood loss in adolescent scoliosis surgery: a systematic review and meta-analysis.

BACKGROUND: Tranexamic acid (TXA) has been widely used in orthopedic surgery, but its efficacy in adolescent scoliosis (AS) surgery remains unclear in the literature. The purpose of this systematic review and meta-analysis is to evaluate the safety and efficacy of TXA compared to placebo treatment during or after AS surgery, by gathering data from randomized both controlled trials (RCTs) and non-RCTs. METHODS: English and Chinese electronic databases including PubMed, Web of Science, Embase, Cochrane, CNKI, and Wan Fang database were searched to identify the relevant literature up until August 2022. The primary outcomes were intraoperative blood loss and total blood loss. The secondary outcomes included the need for transfusion, postoperative hemoglobin (Hb) level, and change in Hb level. Stata 17 was used for data analysis and the risk of bias was assessed. We followed the PRISMA checklist to ensure the quality of this article. RESULTS: Twelve studies (795 participants) were included in the meta-analysis for intraoperative blood loss during surgery. The results suggest that TXA can reduce the intraoperative blood loss of the patients (MD = -306.40ml, 95%CI = -404.04ml to -208.77ml, p < 0.001). Six studies (2027 patients) were included in the meta-analysis for total blood loss. The pooled result shows that the total blood loss of the TXA group was significantly lower than that of the control group (MD = -779.24ml, 95% CI = -1157.10ml to -410.39ml, p < 0.001). Five studies (419 patients) were included in the meta-analysis for postoperative Hb level and shows a non-significant outcome (MD = 5.09 g/l, 95%CI = 2.92 g/l to 7.25 g/l, p = 0.611). Three studies (268 patients) were included in the meta-analysis for the postoperative Hb level. There is a non-significant decrease in the TXA group (MD = -0.23 g/l, 95%CI = -0.48 g/l to 0.01 g/l, p = 0.319). Eight studies (670 patients) reported data on the need for transfusion after surgery. The overall relative risks (RR) showed a significant difference between the TXA and control group, with a lower risk of transfusion in the TXA group (RR = 0.547, 95%CI = 0.308 to 0.972, p = 0.04). CONCLUSIONS: The meta-analysis of the data reveals that TXA usage is associated with a significant reduction in intraoperative and total blood loss, a lower risk of transfusion, and a non-significant change in postoperative Hb levels in AS surgery However, it should be noted that the surgical operation situations varied across different studies. Therefore, further research is required to investigate the effects of TXA on specific subgroups of gender, operation time, and blood transfusion indicators. Overall, our study provides valuable evidence for the clinical management of AS surgery and may inform the development of practice guidelines and protocols for the use of TXA in this setting.

Clinical Outcomes of Isobar TTL System with Isthmic Bone Grafting and Pedicle Screw-Vertebral Plate Hook with Direct Repair of Defect for Lumbar Spondylolysis: A Matched-Pair Case Control Study.

OBJECTIVE: Although direct isthmic repair, such as PSVPH, did not affect the mobility of the fixed segment and adjacent segment, it has a relatively low rate of isthmic fusion compared with conventional fusion. The Isobar TTL dynamic internal fixation system has been widely used in clinical practice and has achieved satisfactory clinical results. However, the use of the Isobar TTL system in combination with direct isthmic repair for lumbar spondylolysis has rarely been reported. The aim of this study was to compare the clinical and radiologic outcomes between patients who underwent Isobar TTL system and PSVPH with direct repair of defect for lumbar spondylolysis. METHODS: Stepwise propensity score matching (PSM) for age and sex were performed to keep comparable clinical data between groups in this retrospective and matched-pair case control study. A total of 50 patients diagnosed with lumbar spondylolysis underwent surgical implantation of the Isobar TTL group (n = 25) or PSVPH group (n = 25) from June 2009 to June 2016. Clinical outcomes were assessed using the Oswestry disability index (ODI), and visual analog score (VAS). Radiographic evaluations included range of motion (ROM) and the disc heights of stabilized segment and adjacent segment, adjacent segment degeneration (ASD) and bony fusion. Three-dimensional reconstruction of lumbar CT scan was obtained to evaluate bone fusion of the isthmic at final follow-up. The independent Student's t test and chi-square test were applied to compare the differences between groups. RESULTS: A total of 25 patients from TTL group were matched to 25 patients in PSVPH group for age, sex, body mass index (BMI), defect side, spondylolisthesis meyerding, and follow-up duration. The intervertebral space height (IH) of stabilized segment at postoperative 1 week and final follow-up in the TTL group was higher than those in the PSVPH group, respectively (P = 0.030; P = 0.013). The ROM of stabilized segment at final follow-up in the TTL group was significantly lower than that in the PSVPH group (P < 0.001). The bony fusion rate at the final follow-up was 88.0% (22/25 cages) in the TTL group and 80.0% (20/25 cages) in the PSVPH group. The ODI score at final follow-up in the TTL group was significantly lower than that in the PSVPH group (P = 0.007). CONCLUSION: Overall, our data suggest that the Isobar TTL system outcomes are comparable to those in the PSVPH, with a similar high bony fusion rate as PSVPH, especially its wider indications as a new surgery.

[Nomographic Model for Predicting Severe Foot Pain in Nurses from Tertiary Hospitals in China].

Objective: To investigate the prevalence and common sites of severe foot pain among nurses, to define the risk factors of severe foot pain in nurses in tertiary hospital in China, and to construct a nomograph model for predicting individuals' risks for severe foot pain. Methods: Between August 2019 and December 2019, a stratified global sampling method was used to select 10691 nurses from 351 tertiary hospitals in China to investigate the incidence of severe foot pain among them. The variables that may affect the occurrence of severe foot pain were analyzed by single factor analysis to identify the influencing factors of severe foot pain in nurses. Furthermore, the independent risk factors of severe foot pain were analyzed by stepwise logistic regression analysis. The statistically significant factors identified in the multivariate regression analysis were incorporated into the nomograph prediction model. The predictive performance of the nomograph was measured by the consistency index (C-index) and calibrated with 1000 Bootstrap samples. Results: A total of 3419 nurses out of the 10691 had foot pain, resulting in an incidence of 31.98%. The incidence of severe pain (VAS score 7-10) was 2.27% (243 of 10691). The locations of severe pain were more commonly found in the soles and heels of both feet. Six factors, including age, education, the material of the work shoes, comfortableness of the work shoes, number of complications, and foot injure history, were incorporated in the nomograph predicting model. The C-index value was 0.706 and the standard curve fitted well with the calibrated prediction curve. Conclusion: The risk prediction model constructed in this study showed sound performance in predicting the risk of severe foot pain in nurses, and all the indicators involved are simple and the relevant data are easily obtained. The model can provide reference for preventing severe foot pain in nurses.

Comparison of Long-Term Clinical and Radiographical Outcomes between the Anterior and Combined Anterior and Posterior Approaches for Treating Lumbosacral Tuberculosis.

OBJECTIVE: Both anterior and combined anterior and posterior approaches have been used to treat lumbosacral tuberculosis. However, long-term follow-up studies of each approach have not been conducted. We aimed to compare the long-term clinical and radiographical outcomes between the two approaches. METHODS: In this retrospective cohort study, we included 49 patients with a minimum 6-year follow-up between January 2008 and March 2012. Twenty-four patients underwent the anterior approach (anterior group), and 25 underwent the combined anterior and posterior approach (anterior-posterior group). Student's t test, Mann-Whitney U test, and Pearson's chi-square test were used to compare the two groups regarding clinical data, such as visual analogue scale scores, Oswestry disability index scores and neurological status, and radiographical data, such as lumbosacral angle, lumbar lordosis, and L5-S1 height. Furthermore, operative time, length of stay, and intraoperative and postoperative blood loss (IBL, PBL) were recorded. RESULTS: Both groups had satisfactory clinical and radiographical outcomes until the final follow-up. All patients achieved bony fusion, and no group differences were found in any of the clinical indices. Both groups corrected and maintained the lumbosacral angle, lumbar lordosis, and L5-S1 height. However, the operative time, length of stay, maximum Hb drop, IBL, and PBL of the anterior group (140.63 ± 24.73 min, 12.58 ± 2.45 days, 28.33 ± 9.70 g/L, 257.08 ± 110.47 ml, and 430.60 ± 158.27 ml, respectively) were significantly lower than those of the anterior-posterior group (423.60 ± 82.81 min, P < 0.001; 21.32 ± 3.40 days, P < 0.001; 38.48 ± 8.03 g/L, P < 0.001; 571.60 ± 111.04 ml, P < 0.001; and 907.01 ± 231.99 ml, P < 0.001). CONCLUSION: This retrospective study demonstrated long-term efficacy of the anterior approach with a single screw fixation, which was as effective as that of the combined anterior and posterior approach, with the advantage of less trauma.

Incidence and Risk Factors for Postoperative Ileus after Posterior Surgery in Adolescent Idiopathic Scoliosis.

OBJECTIVE: Postoperative ileus (POI) is a relatively common complication after spinal fusion surgery, which can lead to delayed recovery, prolonged length of stay and increased medical costs. However, little is known about the incidence and risk factors of POI after corrective surgery for patients with adolescent idiopathic scoliosis (AIS). This study was performed to report the incidence of POI and identify the independent risk factors for POI after postoperative corrective surgery. METHODS: In this retrospective cohort study, A total of 318 patients with AIS who underwent corrective surgery from April 2015 to February 2021 were enrolled and divided into two groups: those with POI and those without POI. The Student's t test, Mann-Whitney U test, and Pearson's chi-square test were used to compare the two groups regarding patient demographics and preoperative characteristics (age, sex and the major curve type), intraoperative and postoperative parameters (lowest instrumented vertebra [LIV], number of screws, and length of stay), radiographic parameters (T5-12 thoracic kyphosis [TK], T10-L2 thoracolumbar kyphosis and height [TLK and T10-L2 height], L1-S1 lumbar lordosis [LL], and L1-5 height). Then, a multivariate logistic regression analysis was used to identify independent risk factors for POI, and a receiver operating characteristic (ROC) curve was performed to assess the predictive values of these risk factors. RESULTS: Forty-two (13.2%) of 318 patients who developed POI following corrective surgery were identified. The group with POI had a significantly longer length of stay, more lumbar screws, higher proportions of a major lumbar curve and lumbar anterior screw breech, and a lower LIV. Among radiographic parameters, the mean lumbar Cobb angle at baseline, the changes in the lumbar Cobb angle, and T10-L2 and L1-5 height from before to after surgery were significantly larger in the group with POI than in the group without POI. Multivariate logistic regression analysis showed that large changes in T10-L2 (odds ratio [OR] =2.846, P = 0.007) and L1-5 height (OR = 31.294, p = 0.000) and lumbar anterior screw breech (OR = 5.561, P = 0.006) were independent risk factors for POI. The cutoff values for the changes in T10-L2 and L1-5 height were 1.885 cm and 1.195 cm, respectively. CONCLUSION: In this study, we identified that large changes in T10-L2 and L1-5 height and lumbar anterior screw breech were independent risk factors for POI after corrective surgery. Improving the accuracy of pedicle screw placement might reduce the incidence of POI, and greater attention should be given to patients who are likely to have large changes in T10-L2 and L1-5 height after corrective surgery.

Comparison of Long-Term Outcomes between the n-HA/PA66 Cage and the PEEK Cage Used in Transforaminal Lumbar Interbody Fusion for Lumbar Degenerative Disease: A Matched-Pair Case Control Study.

OBJECTIVE: The nanohydroxyapatite/polyamide-66 (n-HA/PA66) cage is a novel bioactive nonmetal cage that is now used in some medical centers, while the polyetheretherketone (PEEK) cage is a typical device that has been widely used for decades with excellent clinical outcomes. This study was performed to compare the long-term radiographic and clinical outcomes of these two different cages used in transforaminal lumbar interbody fusion (TLIF). METHODS: In this retrospective and matched-pair case control study, we included 200 patients who underwent TLIF from January 2010 to December 2014 with a minimum 7-year follow-up. One hundred patients who used n-HA/PA66 cages were matched with 100 patients who used PEEK cages for age, sex, diagnosis, and fusion level. The independent student's t-test and Pearson's chi-square test were used to compare the two groups regarding radiographic (fusion status, cage subsidence rate, segmental angle [SA], and interbody space height [IH]) and clinical (Oswestry Disability Index [ODI], and Visual Analog Scale [VAS] for back and leg) parameters preoperatively, postoperatively, and at the final follow-up. RESULTS: The n-HA/PA66 and PEEK groups had similar fusion rates of bone inside and outside the cage at the final follow-up (95.3% vs 91.8%, p = 0.181, 92.4% vs 90.1%, p = 0.435). The cage union ratios exposed to the upper and lower endplates of the n-HA/PA66 group were significantly larger than those of the PEEK group (p < 0.05). The respective cage subsidence rates in the n-HA/PA66 and PEEK groups were 10.5% and 17.5% (p = 0.059). There were no significant differences between the two groups in the SA, IH, ODI scores, or VAS scores at any time point. The n-HA/PA66 group showed high fusion and low subsidence rates during long-term follow-up. CONCLUSION: Both n-HA/PA66 and PEEK cages can achieve satisfactory long-term clinical and radiographic outcomes in TLIF. However, the n-HA/PA66 group showed significantly larger cage union ratios than the PEEK group. Therefore, the results indicated that the n-HA/PA66 cage is an ideal alternative material comparable to the PEEK cage in TLIF.

Tent5a modulates muscle fiber formation in adolescent idiopathic scoliosis via maintenance of myogenin expression.

OBJECTIVE: Paravertebral muscle asymmetry may be involved in the pathogenesis of adolescent idiopathic scoliosis (AIS), and the Tent5a protein was recently identified as a novel active noncanonical poly(A) polymerase. We, therefore, explored the function of the AIS susceptibility gene Tent5a in myoblasts. MATERIALS AND METHODS: RNA-seq of AIS paravertebral muscle was performed, and the molecular differences in paravertebral muscle were investigated. Twenty-four AIS susceptibility genes were screened, and differential expression of Tent5a in paravertebral muscles was confirmed with qPCR and Western blot. After the knockdown of Tent5a, the functional effects of Tent5a on C2C12 cell proliferation, migration, and apoptosis were detected by Cell Counting Kit-8 assay, wound-healing assay, and TUNEL assay, respectively. Myogenic differentiation markers were tested with immunofluorescence and qPCR in vitro, and muscle fiber formation was compared in vivo. RESULTS: The AIS susceptibility gene Tent5a was differentially expressed in AIS paravertebral muscles. Tent5a knockdown inhibited the proliferation and migration of C2C12 cells and inhibited the maturation of type I muscle fibers in vitro and in vivo. Mechanistically, the expression of myogenin was decreased along with the suppression of Tent5a. CONCLUSIONS: Tent5a plays an important role in the proliferation and migration of myoblasts, and it regulates muscle fiber maturation by maintaining the stability of myogenin. Tent5a may be involved in the pathogenesis of AIS by regulating the formation of muscle fiber type I.

Protein tyrosine phosphatases in skeletal development and diseases.

Skeletal development and homeostasis in mammals are modulated by finely coordinated processes of migration, proliferation, differentiation, and death of skeletogenic cells originating from the mesoderm and neural crest. Numerous molecular mechanisms are involved in these regulatory processes, one of which is protein posttranslational modifications, particularly protein tyrosine phosphorylation (PYP). PYP occurs mainly through the action of protein tyrosine kinases (PTKs), modifying protein enzymatic activity, changing its cellular localization, and aiding in the assembly or disassembly of protein signaling complexes. Under physiological conditions, PYP is balanced by the coordinated action of PTKs and protein tyrosine phosphatases (PTPs). Dysregulation of PYP can cause genetic, metabolic, developmental, and oncogenic skeletal diseases. Although PYP is a reversible biochemical process, in contrast to PTKs, little is known about how this equilibrium is modulated by PTPs in the skeletal system. Whole-genome sequencing has revealed a large and diverse superfamily of PTP genes (over 100 members) in humans, which can be further divided into cysteine (Cys)-, aspartic acid (Asp)-, and histidine (His)-based PTPs. Here, we review current knowledge about the functions and regulatory mechanisms of 28 PTPs involved in skeletal development and diseases; 27 of them belong to class I and II Cys-based PTPs, and the other is an Asp-based PTP. Recent progress in analyzing animal models that harbor various mutations in these PTPs and future research directions are also discussed. Our literature review indicates that PTPs are as crucial as PTKs in supporting skeletal development and homeostasis.

Nomogram for predicting the distal adding-on phenomenon in severe and rigid scoliosis.

Background: The distal adding-on phenomenon has attracted extensive discussion in the field of spine surgery due to the continual occurrence after scoliosis correction. Previous work has mainly focused on adolescent idiopathic scoliosis (AIS), and a relatively high number of theories for the mechanism of the distal adding-on phenomenon has been proposed for these kinds of patients. Severe and rigid scoliosis, as a special disease form, has a unique etiology, clinical manifestations and internal mechanisms distinct from those of AIS. Given the uniqueness of this disease, the mechanism and causes of the distal adding-on phenomenon have been infrequently studied in depth. Objective: To define clinical and radiological factors associated with distal adding-on in patients with severe and rigid scoliosis. Methods: Radiographic parameters and demographic data of patients with severe and rigid scoliosis were evaluated preoperatively, after posterior instrumentation and fusion surgery, and at the final follow-up via radiographs. According to the appearance of distal adding-on at the final follow-up, the patients were grouped into the Adding-on and the Non-adding-on groups. Various radiological parameters were analyzed in stepwise multivariate logistic regression to identify the variables associated with distal adding-on, which were then incorporated into a nomogram. The predictive performance and calibration of the nomograms for distal adding-on were assessed using C statistics and calibration plots. Results: 93 patients (21 in the Adding-on and 72 in the Non-adding-on group) were included. The incidence of distal adding-on was 22.6%. The variables associated with distal adding-on were the anterior release, posterior internal distraction, and later posterior spinal fusion (IP) procedure, the posterior vertebral column resection and posterior spinal fusion (PVCR) procedure, postoperative apical vertebral translation (Post-AVT) and preoperative slope of the line linking the pedicles on the concave side of the upper- and lower-end vertebrae (Tan α). Combining these factors, the nomogram achieved a concordance index of 0.92 in predicting distal adding-on and had well-fitted calibration curves. Conclusions: For patient with a negative Tanα in severe and rigid scoliosis, the risk of distal adding-on tended to increase, and it is recommended to give priority to IP or PVCR. In the final correction, a smaller Post-AVT should not be pursued excessively.

Clinical algorithm for preventing missed diagnoses of occult cervical spine instability after acute trauma: A case report.

BACKGROUND: Missed or delayed diagnosis of cervical spine instability after acute trauma can have catastrophic consequences for the patient, resulting in severe neurological impairment. Currently, however, there is no consensus on the optimal strategy for diagnosing occult cervical spine instability. Thus, we present a case of occult cervical spine instability and provide a clinical algorithm to aid physicians in diagnosing occult instability of the cervical spine. CASE SUMMARY: A 57-year-old man presented with cervical spine pain and inability to stand following a serious fall from a height of 2 m. No obvious vertebral fracture or dislocation was found at the time on standard lateral X-ray, computed tomography, and magnetic resonance imaging (MRI). Subsequently, the initial surgical plan was unilateral open-door laminoplasty (C3-7) with alternative levels of centerpiece mini-plate fixation (C3, 5, and 7). However, the intraoperative C-arm fluoroscopic X-rays revealed significantly increased intervertebral space at C5-6, indicating instability at this level that was previously unrecognized on preoperative imaging. We finally performed lateral mass fixation and fusion at the C5-6 level. Looking back at the preoperative images, we found that the preoperative T2 MRI showed non-obvious high signal intensity at the C5-6 intervertebral disc and posterior interspinous ligament. CONCLUSION: MRI of cervical spine trauma patients should be carefully reviewed to detect disco-ligamentous injury, which will lead to further cervical spine instability. In patients with highly suspected cervical spine instability indicated on MRI, lateral X-ray under traction or after anesthesia and muscle relaxation needs to be performed to avoid missed diagnoses of occult cervical instability.