Feasibility study of hallux valgus measurement with a deep convolutional neural network based on landmark detection.

OBJECTIVE: To develop a deep learning algorithm based on automatic detection of landmarks that can be used to automatically calculate forefoot imaging parameters from radiographs and test its performance. MATERIALS AND METHODS: A total of 1023 weight-bearing dorsoplantar (DP) radiographs were included. A total of 776 radiographs were used for training and verification of the model, and 247 radiographs were used for testing the performance of the model. The radiologists manually marked 18 landmarks on each image. By training our model to automatically label these landmarks, 4 imaging parameters commonly used for the diagnosis of hallux valgus could be measured, including the first-second intermetatarsal angle (IMA), hallux valgus angle (HVA), hallux interphalangeal angle (HIA), and distal metatarsal articular angle (DMAA). The reference standard was determined by the radiologists' measurements. The percentage of correct key points (PCK), intragroup correlation coefficient (ICC), Pearson correlation coefficient (r), root mean square error (RMSE), and mean absolute error (MAE) between the predicted value of the model and the reference standard were calculated. The Bland-Altman plot shows the mean difference and 95% LoA. RESULTS: The PCK was 84-99% at the 3-mm threshold. The correlation between the observed and predicted values of the four angles was high (ICC: 0.89-0.96, r: 0.81-0.97, RMSE: 3.76-6.77, MAE: 3.22-5.52). However, there was a systematic error between the model predicted value and the reference standard (the mean difference ranged from - 3.00 to - 5.08°, and the standard deviation ranged from 2.25 to 4.47°). CONCLUSION: Our model can accurately identify landmarks, but there is a certain amount of error in the angle measurement, which needs further improvement.

Evaluation of relationship between KEAP1 gene and genetic susceptibility of deep vein thrombosis after orthopedic surgery in Han Chinese population.

Deep vein thrombosis (DVT) is the blood clot formed in a vein deep in body, mostly occurred in the lower leg or thigh. Early studies indicate that DVT is a complex disorder affected by both environmental and genetic factors. Previous biological evidence have indicated that KEAP1 gene may play an important role in the pathogenesis of DVT. In the present study, we aimed to investigate the genetic association between genetic polymorphisms of KEAP1 gene and the risk of DVT in Han Chinese population. A total of 2558 study subjects comprised of 660 DVT following orthopedics surgery cases and 1898 controls were recruited as discovery sample. In addition, we have also recruited another independent sample sets including 704 DVT following orthopedics surgery cases and 1056 controls for replication. Ten tag SNPs located on KEAP1 gene were selected for genotyping. Single marker based association analyses were conducted at both allelic and genotypic levels. SNPs that passed the Bonferroni correction in the discovery stage were genotyped in the replication dataset. Bioinformatics tools including PolymiRTS, GTEx, STRING and Gene Ontology database were utilized to investigate the functional consequences of the significant SNPs. SNP rs3177696 was identified to be significantly associated with risk of DVT in the study subjects. The G allele of SNP rs3177696 was significantly related to decreased risk of DVT. Functional consequences of SNP rs3177696 were obtained based on bioinformatics analyses. The G allele of SNP rs3177696 was related to the increased gene expression level of KEAP1. In summary, we have identified KEAP1 gene to be a potential susceptible locus for DVT in Han Chinese population. Further bioinformatics analyses have provided supportive evidence for the functional consequence of the significant SNP.

Predictive Nomogram for Midterm to Long-Term Prognosis in Patients with Papillary Renal Cell Carcinoma Based on Data from the Surveillance, Epidemiology, and End Results (SEER) Program.

BACKGROUND This study aimed to develop a predictive nomogram for midterm to long-term prognosis in patients with papillary renal cell carcinoma (RCC) based on data from the US Surveillance, Epidemiology, and End Results (SEER) program. MATERIAL AND METHODS Clinical pathology data and follow-up information were obtained from the SEER database for patients with papillary RCC between 1997-2014. Univariate and multivariate Cox regression models evaluated the independent prognostic factors, and the nomogram was constructed to predict the 3-year, 5-year, and 10-year survival rates. Multiple parameters were estimated to evaluate the predictive values, including the concordance indices (C-indices), calibration plots, area under the receiver operator characteristics (ROC) curve, net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision curve analysis (DCA). RESULTS The study included 13,926 patients with papillary RCC. Univariate and multivariate Cox regression analysis developed the nomogram that relied on the predictive variables of age, Fuhrman grade, TNM stage, surgery of the primary site, lymphadenectomy, and marital status. The C-indices of the novel model in the validation cohort were more satisfactory than those of the TNM classification. Accurate discrimination and calibration by the nomogram were identified in both cohorts. The NRI and IDI supported prediction improvements, and the DCA supported the nomogram's clinical significance. CONCLUSIONS A nomogram was developed to evaluate the prognosis of papillary RCC and to identify the patients who required specialized treatment. However, external validation of the predictive nomogram is required that also includes patients from other countries.

Chitin Oligosaccharide (COS) Reduces Antibiotics Dose and Prevents Antibiotics-Caused Side Effects in Adolescent Idiopathic Scoliosis (AIS) Patients with Spinal Fusion Surgery.

Antibiotics are always considered for surgical site infection (SSI) in adolescent idiopathic scoliosis (AIS) surgery. However, the use of antibiotics often causes the antibiotic resistance of pathogens and side effects. Thus, it is necessary to explore natural products as drug candidates. Chitin Oligosaccharide (COS) has anti-inflammation and anti-bacteria functions. The effects of COS on surgical infection in AIS surgery were investigated. A total of 312 AIS patients were evenly and randomly assigned into control group (CG, each patient took one-gram alternative Azithromycin/Erythromycin/Cloxacillin/Aztreonam/Ceftazidime or combined daily), experiment group (EG, each patient took 20 mg COS and half-dose antibiotics daily), and placebo group (PG, each patient took 20 mg placebo and half-dose antibiotics daily). The average follow-up was one month, and infection severity and side effects were analyzed. The effects of COS on isolated pathogens were analyzed. SSI rates were 2%, 3% and 8% for spine wounds and 1%, 2% and 7% for iliac wound in CG, EG and PG (p < 0.05), respectively. COS reduces the side effects caused by antibiotics (p < 0.05). COS improved biochemical indexes and reduced the levels of interleukin (IL)-6 and tumor necrosis factor (TNF) alpha. COS reduced the antibiotics dose and antibiotics-caused side effects in AIS patients with spinal fusion surgery by improving antioxidant and anti-inflammatory activities. COS should be developed as potential adjuvant for antibiotics therapies.

MicroRNA-150 functions as a tumor suppressor in osteosarcoma by targeting IGF2BP1.

Osteosarcoma (OS) is the most common primary malignant bone tumor with high morbidity in young adults and adolescents. Increasing evidence has demonstrated that aberrant microRNA (miRNA) expression is involved in OS occurrence and development. miR-150 has been recently widely studied in many cancers, but not including OS. This study is aimed to investigate the expression and biological role of miR-150 in OS. Here, we found that miR-150 expression was consistently downregulated in OS tissues and cell lines compared with the matched adjacent normal tissues and human normal osteoblast cells (NHOst), and its expression was significantly correlated with lymph node metastasis and tumor-node-metastasis (TNM) stage. Functional study showed that restoration of miR-150 expression in OS cells could inhibit cell proliferation, migration, and invasion and induced apoptosis in vitro as well as suppressed tumor growth of OS in vivo. Mechanistically, IGF2 mRNA-binding protein 1(IGF2BP1) was confirmed to act as a direct target of miR-150, and the IGF2BP1 mRNA expression was inversely correlated with the level of miR-150 in OS tissues. In addition, downregulation of endogenous IGF2BP1 exhibited similar effects of overexpression of miR-150. Taken together, these findings suggest that miR-150 functions as a tumor suppressor in OS partially by targeting IGF2BP1.

Correlations Between Abnormal Glucose Metabolism and Bone Mineral Density or Bone Metabolism.

BACKGROUND: The aim of this meta-analysis was to explore the correlations of abnormal glucose metabolism (AGM) with bone mineral density (BMD) and bone metabolism. MATERIAL/METHODS: Relevant studies were identified using computerized and manual search strategies. The included studies were in strict accordance with inclusion and exclusion criteria. Statistical analyses were conducted with the Comprehensive Meta-analysis 2.0 (Biostat Inc., Englewood, NJ, USA). RESULTS: Our present meta-analysis initially searched 844 studies, and 7 studies were eventually incorporated in the present meta-analysis. These 7 cohort studies included 1123 subjects altogether (560 patients with AGM and 563 healthy controls). The results showed that bone mass index (BMI), insulin, and insulin resistance (IR) of patients with AGM were significantly higher than that of the population with normal glucose metabolism (BMI: SMD=1.658, 95% CI=0.663~2.654, P=0.001; insulin: SMD=0.544, 95% CI=0.030~1.058, P=0.038; IR: SMD=8.767, 95% CI=4.178~13.356, P<0.001). However, the results also indicated there was no obvious difference in osteocalcin (OC) and BMD in patients with AGM and the population with normal glucose metabolism (OC: SMD=0.293, 95% CI=-0.023~0.609, P=0.069; BMD: SMD=0.805, 95% CI=-0. 212~1.821, P=0.121). CONCLUSIONS: Our meta-analysis results suggest that AGM might lead to increased BMI, insulin, and IR, while it has no significant correlation with BMD or bone metabolism.

Evaluation of a new Mg-Zn-Ca-Y alloy for biomedical application.

In this study, a new Mg-Zn-Ca-Y alloy was evaluated for blood compatibility and in vivo biocompatibility in rabbits after implantation in the sacral crest muscle. Blood test and HE staining was performed to examine the host response, and scanning electron microscope was used to observe the fibrous membrane and corrosion of the magnesium alloy. The results showed that hemolysis rate decreased with the Mg(2+) concentration, in particularly, the hemolysis rate was 47.24 % for the magnesium alloy 100 % mixture solution, while was 0.1372 % for the 1 % extract solution. After implantation, the rabbits showed generally good condition, without swelling and wound secretions. One week after implantation, in the experimental group, a few lymphocytes and macrophages could be observed around the local muscle tissue, and fiber membrane structure had not yet formed; after 2 weeks, loose fiber membranes formed, while the number of inflammatory cells decreased; the fiber membrane became thinner at 4 and 12 weeks,. The fiber membrane thickness at 24 weeks were measured by scanning electron microscopy, at about 15-25 µm, which accord with the U.S. ASTM-F4 implant requirements (<30 µm). Acceptable degradation and corrosion were observed after implantation into rabbits. Through the in vivo study, the new magnesium alloy exhibited good biocompatibility and non-toxic in the experimental animals. Addition of Zn, Ca and Y can slow the degradation rate, and have acceptable side effects in vivo, resulting in improved corrosion properties and desirable biocompatibility at the same time.

The ferric iron chelator 2,2'-dipyridyl attenuates basilar artery vasospasm and improves neurological function after subarachnoid hemorrhage in rabbits.

We investigated the efficacy of the ferrous iron (Fe(2+)) chelator 2,2'-dipyridyl (DP) to attenuate cerebral vasospasm after subarachnoid hemorrhage (SAH). Thirty-six New Zealand white rabbits were randomly assigned to four groups: untreated control, SAH, SAH + dimethyl sulfoxide (DMSO) vehicle, and SAH + DP. SAH was induced by injection of autologous blood into the cisterna magna and then DP or vehicle was infused into the cistern magna for 5 days (20 mg/kg/day or an equal volume of DMSO). Neurological deficit score (NDS) was used to assess neurological function and cerebral angiography to measure basilar artery (BA) diameter following SAH. TUNEL staining was used to detect BA endothelial cell apoptosis, and immunohistochemistry and Western blotting to assess changes in caspase-3 protein levels 5 days post-SAH. The SAH + DP group had a significantly larger mean BA diameter and lower mean NDS post-SAH compared to the SAH + DMSO and SAH groups (p < 0.05). TUNEL-positive cell numbers and caspase-3 levels were significantly reduced in BA endothelial cells of the SAH + DP group as compared to the SAH and SAH + DMSO groups (p < 0.05). The iron chelator DP reduced vasospasm and neurological sequelae in rabbits, likely by chelating the Fe(2+) in oxyhemoglobin and reducing oxidative stress-induced endothelial cell apoptosis.

A low-swelling hydrogel as a multirole sealant for efficient dural defect sealing and prevention of postoperative adhesion.

Dural defects and subsequent complications, including cerebrospinal fluid (CSF) leakage, are common in both spine surgery and neurosurgery, and existing clinical treatments are still unsatisfactory. In this study, a tissue-adhesive and low-swelling hydrogel sealant comprising gelatin and o-phthalaldehyde (OPA)-terminated 4-armed poly(ethylene glycol) (4aPEG-OPA) is developed via the OPA/amine condensation reaction. The hydrogel shows an adhesive strength of 79.9 ± 12.0 kPa on porcine casing and a burst pressure of 208.0 ± 38.0 cmH2O. The hydrogel exhibits a low swelling ratio at physiological conditions, avoiding nerve compression in the limited spinal and intracranial spaces. In rat and rabbit models of lumbar and cerebral dural defects, the 4aPEG-OPA/gelatin hydrogel achieves excellent performance in dural defect sealing and preventing CSF leakage. Moreover, local inflammation, epidural fibrosis and postoperative adhesion in the defect areas are markedly reduced. Thus, these findings establish the strong potential of the hydrogel sealant for the effective watertight closure of dural defects.

Late presentation of dural tears: Two case reports and review of literature.

BACKGROUND: The late presentation of dural tears (LPDT) has a low incidence rate and hidden symptoms and is easily ignored in clinical practice. If the disease is not treated in time, a series of complications may occur, including low intracranial pressure headache, infection, pseudodural cyst formation, and sinus formation. Here, we describe two cases of LPDT. CASE SUMMARY: Two patients had sudden fever 1 wk after lumbar surgery. Physical examination showed obvious tenderness in the operation area. The patients were confirmed as having LPDT by lumbar magnetic resonance imaging and surgical exploration. One case was caused by continuous negative pressure suction and malnutrition, and the other was caused by decreased dural ductility and low postoperative nutritional status. The first symptom of both patients was fever, with occasional headache. Both patients underwent secondary surgery to treat the LPDT. Dural defects were observed and dural sealants were used to seal the dural defects, then drainage tubes were retained for drainage. After the operation, the patients were treated with antibiotics and the patients' surgical incisions healed well, without fever or incision tenderness. Both recovered and were discharged 1 wk after the operation. CONCLUSION: LPDT is a rare complication of spinal surgery or neurosurgery that has hidden symptoms and can easily be overlooked. Since it may cause a series of complications, LPDT needs to be actively addressed in clinical practice.

Peptide/glycyrrhizic acid supramolecular polymer: An emerging medical adhesive for dural sealing and repairing.

Medical adhesives have emerged as potential materials for sealing, hemostasis and wound repairing in modern clinical surgery. However, most of existing medical adhesives are still far away from the clinical requirements for simultaneously meeting desirable tissue adhesion, safety, biodegradability, anti-swelling property, and convenient operability. Here, we present an entirely new kind of peptide-based underwater adhesives, which are constructed via cross-linked supramolecular copolymerization between cationic short peptides and glycyrrhizic acid (GA) in an aqueous solution. We revealed the unique molecular mechanism of the peptide/GA supramolecular polymers and underlined the importance of arginine residues in the enhancement of the bulk cohesion of the peptide/GA adhesive. We thus concluded a design guideline that the peptide sequence has to be encoded with multiple arginine termini and hydrophobic residues. The resulting adhesives exhibited effective tissue adhesion, robust cohesion, low cell cytotoxicity, acceptable hemocompatibility, inappreciable inflammation response, appropriate biodegradability, and excellent anti-swelling property. More attractively, the dried peptide/GA powder was able to rapidly self-gel into adhesives by absorbing water, suggesting conveniently clinical operability. Animal experiments showed that the peptide/GA supramolecular polymers could be utilized as reliable medical adhesives for dural sealing and repairing.

Interpretable machine learning models for predicting in-hospital death in patients in the intensive care unit with cerebral infarction.

BACKGROUND: Research on patients with cerebral infarction in the Intensive Care Unit (ICU) is still lacking. Our study aims to develop and validate multiple machine-learning (ML) models using two large ICU databases-Medical Information Mart for Intensive Care version III (MIMIC-III) and eICU Research Institute Database (eRI)-to guide clinical practice. METHODS: We collected clinical data from patients with cerebral infarction in the MIMIC-III and eRI databases within 24 h of admission. The opinion of neurologists and the Least Absolute Shrinkage and Selection Operator regression was used to screen for relevant clinical features. Using eRI as the training set and MIMIC-III as the test set, we developed and validated six ML models. Based on the results of the model validation, we select the best model and perform the interpretability analysis on it. RESULTS: A total of 4,338 patients were included in the study (eRI:3002, MIMIC-III:1336), resulting in a total of 18 clinical characteristics through screening. Model validation results showed that random forest (RF) was the best model, with AUC and F1 scores of 0.799 and 0.417 in internal validation and 0.733 and 0.498 in external validation, respectively; moreover, its sensitivity and recall were the highest of the six algorithms for both the internal and external validation. The explanatory analysis of the model showed that the three most important variables in the RF model were Acute Physiology Score-III, Glasgow Coma Scale score, and heart rate, and that the influence of each variable on the judgement of the model was consistent with medical knowledge. CONCLUSION: Based on a large sample of patients and advanced algorithms, our study bridges the limitations of studies on this area. With our model, physicians can use the admission information of cerebral infarction patients in the ICU to identify high-risk groups among them who are prone to in-hospital death, so that they could be more alert to this group of patients and upgrade medical measures early to minimize the mortality of patients.

Clinical management of dural defects: A review.

Dural defects are common in spinal and cranial neurosurgery. A series of complications, such as cerebrospinal fluid leakage, occur after rupture of the dura. Therefore, treatment strategies are necessary to reduce or avoid complications. This review comprehensively summarizes the common causes, risk factors, clinical complications, and repair methods of dural defects. The latest research progress on dural repair methods and materials is summarized, including direct sutures, grafts, biomaterials, non-biomaterial materials, and composites formed by different materials. The characteristics and efficacy of these dural substitutes are reviewed, and these materials and methods are systematically evaluated. Finally, the best methods for dural repair and the challenges and future prospects of new dural repair materials are discussed.

Plant Protein-Peptide Supramolecular Polymers with Reliable Tissue Adhesion for Surgical Sealing.

The fusion of protein science and peptide science opens up new frontiers in creating innovative biomaterials. Herein, a new kind of adhesive soft materials based on a natural occurring plant protein and short peptides via a simple co-assembly route are explored. The hydrophobic zein is supercharged by sodium dodecyl sulfate to form a stable protein colloid, which is intended to interact with charge-complementary short peptides via multivalent ionic and hydrogen bonds, forming adhesive materials at macroscopic level. The adhesion performance of the resulting soft materials can be fine-manipulated by customizing the peptide sequences. The adhesive materials can resist over 78 cmH2 O of bursting pressure, which is high enough to meet the sealing requirements of dural defect. Dural sealing and repairing capability of the protein-peptide biomaterials are further identified in rat and rabbit models. In vitro and in vivo assays demonstrate that the protein-peptide adhesive shows excellent anti-swelling property, low cell cytotoxicity, hemocompatibility, and inflammation response. In particular, the protein-peptide supramolecular biomaterials can in vivo dissociate and degrade within two weeks, which can well match with the time-window of the dural repairing. This work underscores the versatility and availability of the supramolecular toolbox in the easy-to-implement fabrication of protein-peptide biomaterials.

Intradural extramedullary spinal choristoma: A case report.

RATIONALE: A choristoma is a rare and benign neoplasm characterized by the presence of normal tissue in an anomalous anatomical location. In contrast, choristoma tend to occur in other body regions rather than within the spinal canal. Before our findings, only 4 cases of intraspinal choristoma had been recorded. Because its composition is complex and very rare, routine examinations, such as magnetic resonance imaging, are difficult to diagnose, and the possibility of its occurrence is often missed in clinical diagnosis. If there is no specificity in its components, such as in this case, even pathological examinations can only confirm the diagnosis as choristoma after eliminating other possibilities. Therefore, in clinical practice, when encountering patients with intraspinal tumors, it is essential to consider the possibility of choristoma. In this case, the choristoma lack of specific constituent composition sets it apart from previously reported intraspinal choristoma, significantly raising the diagnostic challenge, which offers valuable insights for clinical diagnosis. PATIENT CONCERNS: A female patient aged 48 years was admitted to our medical center due to experiencing persistent lower back pain accompanied by radiating pain in both legs for 5 months. Based on the findings from the neurological physical examination and magnetic resonance imaging, the patient was diagnosed with an intradural space-occupying lesion located at the level of the first lumbar vertebral body. We performed an enhanced magnetic resonance neurography examination to further determine the positional relationship between the occupation and nerves in preparation for surgery. Postoperative pathological biopsy showed that the mass was an intraspinal choristoma. DIAGNOSIS: Intradural extramedullary spinal choristoma. INTERVENTION: Occupied lesion is removed surgically. OUTCOMES: After surgery, all symptoms were significantly relieved, and when the patient was discharged, all symptoms disappeared completely. There was no sign of recurrence after 1 year of follow-up. LESSONS: Intraspinal choristomas are not specific and need to be diagnosed by pathologic examination. Early detection of and intervention for intraspinal tumors can mitigate nerve dysfunction.

The role of slingshot-1L (SSH1L) in the differentiation of human bone marrow mesenchymal stem cells into cardiomyocyte-like cells.

Adult cardiomyocytes (CMs) have very limited capacity to regenerate. Therefore, there is a great interest in developing strategies to treat infarcted CMs that are able to regenerate cardiac tissue and promote revascularization of infarcted zones in the heart. Recently, stem cell transplantation has been proposed to replace infarcted CMs and to restore the function of the affected tissue. This area of research has become very active in recent years due to the huge clinical need to improve the efficacy of currently available therapies. Slingshot (SSH) is a family of protein phosphatases, which can specifically dephosphorylate and reactivate cofilin and inhibit the polymerization of actin filaments and actively involved in cytoskeleton rearrangement. In this study, we found that SSH1L promoted morphology changes of microfilaments during differentiation but was inhibited by the inhibitors of actin polymerization such as cytochalasin D. Overexpression of SSH1L could promote cardiac-specific protein and genes expression. 5-Aza can induce the differentiation of hMSCs into cardiomyocyte-like cells in vitro. We also observed that SSH1L efficiently promotes hMSCs differentiation into cardiomyocyte-like cells through regulation and rearrangement of cytoskeleton. Our work provides evidence that supports the positive role of SSH1L in the mechanism of stem cell differentiation into cardiomyocyte-like cells.

Osteoporotic Vertebral Fracture Misdiagnosed as Metastatic Vertebral Fracture.

The purpose of this study was to report a patient with osteoporotic vertebral compression fracture (OVCF) which was misdiagnosed as metastatic vertebral compression fracture (MVCF). A 64-year male was admitted to our clinic for complaints of numbness, pain, and activity limitation in bilateral lower extremities. One year ago, he had a medical history of lung adenocarcinoma and bone metastasis. A month ago, he developed back pain and lower-limb paralysis. X-ray, computer tomography (CT), and magnetic resonance imaging (MRI) showed thoracic 11 (T11) vertebral compression fracture. Furthermore, emission computed tomography (ECT) indicated MVCF preoperatively. However, the histopathology findings suggested OVCF postoperatively. Consequently, the patient was discharged without chemoradiotherapy. During the 14-months follow-up period, no relapsed spinal neoplasm or recurrence of vertebral fracture was observed. In conclusion, OVCF in patients with a history of lung cancer is easily misdiagnosed as MVCF. It is important to differentiate OVCF from MVCF by clinical symptoms, laboratory examination, and imaging features before operation. Histological findings are the gold standard for accurate diagnosis. Key Words: Osteoporosis, Vertebral fracture, Metastasis.

[Retracted] Silencing XIAP suppresses osteosarcoma cell growth, and enhances the sensitivity of osteosarcoma cells to doxorubicin and cisplatin.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that the western blotting data featured in Figs. 2B and 4D, the flow cytometric data in Fig. 4A and the tumour images shown in Fig. 6A were strikingly similar to data appearing in different form in other articles at different research institutes. Owing to the fact that the contentious data in the above article were already under consideration for publication, or had already been published, elsewhere prior to its submission to Oncology Reports, the Editor has decided that this paper should be retracted from the Journal. After having been in contact with the authors, they agreed with the decision to retract the paper. The Editor apologizes to the readership for any inconvenience caused. [the original article was published in Oncology Reports 33: 1177­1184, 2015; DOI: 10.3892/or.2014.3698].

Biomechanical comparison between unilateral and bilateral percutaneous vertebroplasty for osteoporotic vertebral compression fractures: A finite element analysis.

Background and objective: The osteoporotic vertebral compression fracture (OVCF) has an incidence of 7.8/1000 person-years at 55-65 years. At 75 years or older, the incidence increases to 19.6/1000 person-years in females and 5.2-9.3/1000 person-years in males. To solve this problem, percutaneous vertebroplasty (PVP) was developed in recent years and has been widely used in clinical practice to treat OVCF. Are the clinical effects of unilateral percutaneous vertebroplasty (UPVP) and bilateral percutaneous vertebroplasty (BPVP) the same? The purpose of this study was to compare biomechanical differences between UPVP and BPVP using finite element analysis. Materials and methods: The heterogeneous assignment finite element (FE) model of T11-L1 was constructed and validated. A compression fracture of the vertebral body was performed at T12. UPVP and BPVP were simulated by the difference in the distribution of bone cement in T12. Stress distributions and maximum von Mises stresses of vertebrae and intervertebral discs were compared. The rate of change of maximum displacement between UPVP and BPVP was evaluated. Results: There were no obvious high-stress concentration regions on the anterior and middle columns of the T12 vertebral body in BPVP. Compared with UPVP, the maximum stress on T11 in BPVP was lower under left/right lateral bending, and the maximum stress on L1 was lower under all loading conditions. For the T12-L1 intervertebral disc, the maximum stress of BPVP was less than that of UPVP. The maximum displacement of T12 after BPVP was less than that after UPVP under the six loading conditions. Conclusion: BPVP could balance the stress of the vertebral body, reduce the maximum stress of the intervertebral disc, and offer advantages in terms of stability compared with UPVP. In summary, BPVP could reduce the incidence of postoperative complications and provide promising clinical effects for patients.

A comparison of long-term efficacy of K-rod-assisted non-fusion operation and posterior lumbar interbody fusion for single-segmental lumbar disc herniation.

K-rod-assisted non-fusion surgery for the treatment of lumbar disc herniation has been proven to have short-term clinical efficacy. Meanwhile, its long-term effects have not been examined. To observed the long-term clinical efficacy of K-rod-assisted non-fusion operation, this study retrospectively analyzed 22 patients with lumbar disc (L4/5) herniation who underwent K-rod-assisted non-fusion operation (n = 13) or PLIF (n = 9). They were followed-up for more than 5 years. The operation times and blood loss were significantly reduced in the K-rod group compared to the PLIF group. At the last follow-up, the clinical outcomes of the K-rod group were improved compared to those of the PLIF group as observed by the VAS score, JOABPEQ, and ODI. Imaging outcomes at the last follow-up indicated that the loss of height in the L3/4 and L5/S1 intervertebral space, the ROM of L3/4 and L5/S1, and the incidence of adjacent segment degeneration in the PLIF group were significantly higher than those in the K-rod group. According to Pfirrmann grading, Modic changes, and UCLA grading, the incidence of adjacent segment degeneration was 55.6% in the PLIF group and 15.4% in the K-rod group. Changes in spino-pelvic parameters between the two groups were as follows: pelvic index remained unchanged, pelvic tilt angle increased, and lumbar lordosis and sacral slope decreased. Therefore, compared to PLIF, single-segment lumbar disc herniation using K-rod-assisted non-fusion surgery resulted in better long-term clinical efficacy. Our results demonstrate that this procedure can delay adjacent segment degeneration after lumbar surgery.