Iatrogenic Abdominal Aortic Rupture During Transpedicular Bone Grafting for Thoracolumbar Burst Fractures Successfully Treated by Endovascular Stent Implantation.

PURPOSE: Vascular injury resulting from transpedicular bone grafting in the treatment of thoracolumbar burst fractures has not been reported but can be lethal. The management of patients with iatrogenic aortic injury remains a difficult clinical problem. This study describes a case of iatrogenic abdominal aortic rupture at the level of L2 during transpedicular bone grafting for the first time. CASE REPORT: A 55 year-old male patient suffered from a T12 vertebral body mild compression fracture and an L2 vertebral body burst fracture due to falling. This patient was treated with posterior open reduction and pedicle screw fixation combined with transpedicular bone grafting in the L2 vertebrae using a paravertebral approach. Unfortunately, during transpedicular bone grafting, the abdominal aorta was punctured by the tip of the graft funnel. The use of endovascular stent implantation successfully averted a clinical catastrophe. The patient had a good clinical outcome, and no complications associated with vascular trauma were apparent at a 1-year follow-up examination. CONCLUSION: For the repair of vascular injury caused by transpedicular bone grafting, endovascular techniques can provide a safe, minimally invasive, and effective treatment option. CLINICAL IMPACT: Surgeons should carefully evaluate the specificity of the patient's anatomical structures preoperatively and be more cautious during transpedicular bone grafting in the treatment of thoracolumbar burst fractures.

The roles of autophagy in osteogenic differentiation in rat ligamentum fibroblasts: Evidence and possible implications.

Autophagy, a macromolecular degradation process, plays a pivotal role in cell differentiation and survival. This study was designed to investigate the role of autophagy in the osteogenic differentiation in ligamentum fibroblasts. Rat ligamentum fibroblasts were isolated from the posterior longitudinal ligament and cultured in osteogenic induction medium. Ultrastructural analysis, immunofluorescence assay, western blot, flow cytometry, and lysosomal activity assessment were performed to determine the presence and activity of autophagy in the cells. The mineralization deposit and osteogenic gene expressions were evaluated to classify the association between autophagy activity and the bone formation ability of the spinal ligament cells. The influence of leptin and endothelin-1 on the autophagy activity was also evaluated. Our study demonstrated that autophagy was present and increased in the ligament cells under osteogenic induction. Inhibition of autophagy with either pharmacologic inhibitors (Bafilomycin A and 3-methyladenine) or Belcin1 (BECN1) knocking down weakened the mineralization capacity, decreased the gene expressions of COL1A1, osteocalcin (Ocn), and runt-related transcription factor 2 (Runx2) in the ligamentum fibroblasts and increased cell apoptosis. The Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)-BECN1 autophagic pathway was activated in the osteogenic differentiating ligamentum fibroblasts. Leptin significantly increased the autophagy activity in the ligament cells under osteogenic induction. These discoveries might improve our understanding for the mechanism of ossification of the posterior longitudinal ligament (OPLL) and provide new approaches on the prevention and treatment of this not uncommon disease.

Single-stage debridement via autogenous iliac bone graft through the OLIF corridor and lateral fixation in treating spontaneous single-level lumbar pyogenic spondylodiscitis.

BACKGROUND: The aim of the present study was to investigate the efficacy and safety of mini-open oblique debridement and lumbar interbody fusion combined with lateral screw fixation for treating single-level pyogenic spondylodiscitis. METHODS: Twelve patients with single-level lumbar pyogenic spondylodiscitis underwent OLIF combined with lateral screw fixation were analyzed. Patients underwent follow-up for 12 to 24 months. The clinical characteristics, etiological examinations, operative time, intraoperative blood loss, Oswestry Disability Index (ODI), visual analog scale score (VAS), postoperative complications, and the bony fusion rate were recorded. RESULTS: The mean follow-up period of time was 14.8 months. The average operative time and intra-operative blood loss were 129.0 ± 19.76 min and 309.2 ± 92.96 mL, respectively. No severe intra-operative complications were observed during surgery, except in 1 case that develops abdominal pain and distension after surgery, 2 cases that develop left-sided transient thigh pain/numbness and 8 cases that complains of donor site (iliac crest) pain. All of these symptoms disappeared 8 weeks after surgery. Tissue sample cultures were obtained from all patients intraoperatively and four (33.3%) were positive, including 2 with Staphylococcus aureus, 1 with Staphylococcus epidermidis, and 1 with Escherichia coli. During an average of 22.5 ± 2.1 days (range, 14-29 days) after surgery, WBC, CPR, and ESR levels in all patients had returned to normal. All patients were pain free with no recurring infection. Solid bony fusions were observed in all cases within 6 months, including 10 with I grade fusion, 2 with II grade fusion according to the classification suggested by Burkus et al. No fixation failure was observed during follow up and solid bony fusions were observed in all 12 patients at finally follow-up. A significant postoperative increase was also observed in the mean segmental height and lordosis (P < 0.05), followed by a slight decrease of segmental height and lordosis at final follow-up. At the final follow up, the mean VAS (1.5 ± 0.6) and ODI (18.9 ± 7.6) were significantly lower than VAS (8.4 ± 2.7) and ODI (71.2 ± 16.5) before surgery (P < 0.01). CONCLUSION: Single-stage debridement with autogenous iliac bone graft through the OLIF corridor and lateral fixation was a feasible surgical approach in our consecutive 12 cases of pyogenic spondylitis.

A case report of intracardiac bone cement embolization after posterior decompression and cement-enhanced pedicle screw fixation for osteoporosis and lumbar degeneration.

RATIONALE: Bone cement leakage is a common complication of percutaneous kyphoplasty (PKP) and percutaneous vertebroplasty (PVP) surgery and has also been reported in posterior decompression and cement-enhanced pedicle screw fixation. When bone cement leaks through the venous system, it will have serious consequences and even endanger the life of the patient, especially when the bone cement causes intracardiac embolism. PATIENT CONCERNS: A 70-year-old woman developed chest tightness and decreased blood oxygen saturation following posterior decompression and cement-enhanced pedicle screw fixation. DIAGNOSIS: After the patient was given symptomatic treatment, the symptoms were not relieved, the high-sensitivity troponin I level continued to rise, the electrocardiogram results were abnormal, and chest computed tomography (CT) revealed multiple flaky and strip-shaped dense shadows in the heart. INTERVENTION: The patient underwent removal of foreign bodies from the heart under cardiopulmonary bypass and tricuspid valvuloplasty, removal of intracardiac bone cement, and repair of the tricuspid valve and chordae. OUTCOME: The patient recovered well postoperatively and was discharged from the hospital after 3 weeks. There were no intracardiac foreign bodies observed on chest CT after the operation. LESSONS: For patients with cardiopulmonary discomfort after posterior decompression and bone cement-enhanced pedicle screw fixation, in view of the limitations of radiographic examination, we recommend performing chest CT examination to confirm the diagnosis. For patients with intravascular foreign body embolism, multidisciplinary team joint treatment saves lives.

Spinal Metastatic Melanoma with Unknown Primary Lesions Presenting as Radiculopathy: Case Report and Literature Review.

BACKGROUND: Metastatic malignant melanoma of the spine is rare, while the spinal metastatic melanoma with unknown primary lesions presenting as radiculopathy is even rarer. Summarizing and analyzing this disease can provide insight into disease development and allow optimization of clinical management. CASE DESCRIPTION: A 55-year-old male patient was admitted to our institution presenting with lower back pain that had persisted for 3 years. It was aggravated, with radiating pain in bilateral lower extremities lasting 2 weeks. Neurologic examination revealed bilateral L5 motor deficit with paresis. Radiologic findings showed an irregularly destructive lesion of the L5 vertebral body, and the lesion extended dorsally, obstructing the spinal canal. The patient underwent complete resection of the L5 vertebral tumor with titanium mesh implantation and posterior fusion and instrumentation from L3-S2. The pathologic diagnosis after surgery was malignant melanoma. No obvious primary lesion was detected anywhere on the skin surface, mucosa, and retina. A postoperative positron emission tomography-computed tomography scan of the whole body displayed no abnormal uptake in other parts of the body. However, the patient didn't receive any chemotherapy or radiotherapy. Five months after operation, the tumor recurred and metastasis was detected in other sites. CONCLUSIONS: Although spinal metastatic melanoma with unknown primary lesions presenting as radiculopathy is rare, effective management and treatment of these patients remains an important challenge for surgeons. Surgical resection can alleviate patients' chief complaints and improve their quality of life. However, it may not prolong the survival period and improve the prognosis. Postoperative radiotherapy and/or chemotherapy may be needed.

Autophagy in spinal ligament fibroblasts: evidence and possible implications for ossification of the posterior longitudinal ligament.

BACKGROUND: The molecular mechanisms of ossification of the posterior longitudinal ligament (OPLL) remain to be elucidated. The aim of the present study was to investigate the autophagy of spinal ligament fibroblasts derived from patients with OPLL and to examine whether autophagy-associated gene expression was correlated with the expression of osteogenic differentiation genes. METHODS: Expression of autophagy-associated genes was detected in 37 samples from 21 OPLL patients and 16 non-OPLL patients. The correlation of autophagy-associated gene expression and the expression of osteogenic differentiation genes was analyzed by Pearson's correlation. The expression of autophagy-associated genes of ligament fibroblasts was assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR), western blotting, and immunofluorescence. The incidence of autophagy was assessed by flow cytometry. After knockdown using small interfering RNA targeting Beclin1, the expression of osteogenic differentiation genes were compared in spinal ligament fibroblasts. RESULTS: In clinical specimens, mRNA expression levels of microtubule-associated protein 1 light chain 3 and Beclin1 were higher in the OPLL group compared with the non-OPLL group. Pearson correlation analysis demonstrated that Beclin1 expression was positively correlated with expression of osteocalcin (OCN) (r = 0.8233, P < 0.001), alkaline phosphatase, biomineralization associated (ALP) (r = 0.7821, P < 0.001), and collagen type 1 (COL 1) (r = 0.6078, P = 0.001). Consistently, the upregulation of autophagy-associated genes in ligament fibroblasts from patients with OPLL were further confirmed by western blotting and immunofluorescence. The incidence of autophagy was also increased in ligament fibroblasts from patients with OPLL. Furthermore, knockdown of Beclin1 led to a decrease in the expression of OCN, ALP, and COL 1 by 63.2% (P < 0.01), 52% (P < 0.01), and 53.2% (P < 0.01) in ligament fibroblasts from patients with OPLL, respectively. CONCLUSIONS: Beclin1-mediated autophagy was involved in the osteogenic differentiation of ligament fibroblasts and promoted the development of OPLL.

Efficacy and Safety of High-Viscosity Bone Cement Vertebroplasty in Treatment of Osteoporotic Vertebral Compression Fractures with Intravertebral Cleft.

OBJECTIVE: To evaluate and compare clinical outcomes and cement leakage of high-viscosity bone cement versus low-viscosity bone cement vertebroplasty in treating osteoporotic vertebral compression fractures with intravertebral cleft. METHODS: The study included 72 patients with osteoporotic vertebral compression fractures with intravertebral cleft, who were divided into high-viscosity cement (HVC) (38 cases) and low-viscosity cement (LVC) (34 cases) groups according to the viscosity of bone cement used. Cement leakage, visual analog scale score, Oswestry Disability Index, and kyphotic angle (KA) were evaluated. RESULTS: All patients were followed for at least 12 months. Overall cement leakage rate was 18.4% in the HVC group, lower than the rate of 61.8% obtained in the LVC group. A statistically significant difference was found in the overall cement leakage rate between the groups (P < 0.05). Visual analog scale and Oswestry Disability Index scores were significantly improved after percutaneous vertebroplasty without significant differences between the HVC and LVC groups (P > 0.05). The KA of patients from both groups was also significantly corrected immediately after surgery. Although the KA gradually increased in both groups during the follow-up period, there was no statistically significant difference between the HVC and LVC groups in KA during follow-up (P > 0.05). CONCLUSIONS: Percutaneous vertebroplasty using HVC to treat osteoporotic vertebral compression fractures with intravertebral cleft significantly reduces cement leakage and improves the safety of the operation. In terms of clinical efficacy and prevention of augmented vertebral recollapse, HVC may not have obvious advantages.

Novel Method for Perceiving Key Requirements of Customer Collaboration Low-Carbon Product Design.

Low-carbon product design is an important way to reduce greenhouse gas emission. Customer collaborative product innovation (CCPI) has become a new worldwide product design trend. Based on this popularity, we introduced CCPI into the low-carbon product design process. An essential step for implementing low carbon CCPI is to clarify key low carbon requirements of customers. This study tested a novel method for perceiving key requirements of customer collaboration low-carbon product design based on fuzzy grey relational analysis and genetic algorithm. Firstly, the study considered consumer heterogeneity, allowing different types of customers to evaluate low carbon requirements in appropriate formats that reflected their degrees of uncertainty. Then, a nonlinear optimization model was proposed to establish the information aggregation factor of customers based on the genetic algorithm. The weight of customers was obtained simultaneously. Next, the key low carbon requirements of customer were identified. Finally, the effectiveness of the proposed method was illustrated with a case related to a low carbon liquid crystal display.