Biomechanical Evaluation of 2 Endoscopic Spine Surgery Methods for Treating Lumbar Disc Herniation: A Finite Element Study.

OBJECTIVE: This study aimed to evaluate the effects of 2 endoscopic spine surgeries on the biomechanical properties of normal and osteoporotic spines. METHODS: Based on computed tomography images of a healthy adult volunteer, 6 finite element models were created. After validating the normal intact model, a concentrated force of 400 N and a moment of 7.5 Nm were exerted on the upper surface of L3 to simulate 6 physiological activities of the spine. Five types of indices were used to assess the biomechanical properties of the 6 models, range of motion (ROM), maximum displacement value, intervertebral disc stress, maximum stress value, and articular protrusion stress, and by combining them with finite element stress cloud. RESULTS: In normal and osteoporotic spines, there was no meaningful change in ROM or disc stress in the 2 surgical models for the 6 motion states. Model N1 (osteoporotic percutaneous transforaminal endoscopic discectomy model) showed a decrease in maximum displacement value of 20.28% in right lateral bending. Model M2 (unilateral biportal endoscopic model) increased maximum displacement values of 16.88% and 17.82% during left and right lateral bending, respectively. The maximum stress value of L4-5 increased by 11.72% for model M2 during left rotation. In addition, using the same surgical approach, ROM, maximum displacement values, disc stress, and maximum stress values were more significant in the osteoporotic model than in the normal model. CONCLUSION: In both normal and osteoporotic spines, both surgical approaches were less disruptive to the physiologic structure of the spine. Furthermore, using the same endoscopic spine surgery, normal spine biomechanical properties are superior to osteoporotic spines.

Interleukin-1ß induces apoptosis in annulus fibrosus cells through the extracellular signal-regulated kinase pathway.

PURPOSE: The loss of intervertebral disc (IVD) cells due to excessive apoptosis induced by inflammatory cytokines is a major cause of IVD degeneration. This study aims to explore the mechanism of interleukin-1ß (IL-1ß)-induced apoptosis of annulus fibrosus cells (AFCs). It's hypothesized that IL-1ß induces apoptosis through the extracellular signal-regulated kinase (ERK) pathway in AFCs. METHODS: The mRNA and protein expression levels of apoptosis-associated genes were analyzed by quantitative real-time PCR and Western blotting. The apoptotic rate was measured by flow cytometry. Three experimental groups were established, including Control, IL-1ß, and IL-1ß+U0126 groups, respectively. RESULTS: Increase in the expression of apoptosis-associated genes including B-cell lymphoma-2 associated X (Bax), caspase-3, and caspase-9, and meanwhile, decrease in the expression of B-cell lymphoma-2 (Bcl-2) gene were found in patients with degenerative IVDs. In in vitro tests, both apoptosis and phosphorylated ERK expression in rat AFCs decreased in the IL-1ß+U0126 group compared with the IL-1ß group. The expression levels of Bax, caspase-3, and caspase-9 in AFCs decreased significantly in the IL-1ß+U0126 group compared with those in the IL-1ß group. The expression level of Bcl-2, on the other hand, significantly increased. CONCLUSIONS: Findings from this study suggest that IL-1ß induces apoptosis in AFCs through the ERK pathway, and therefore, ERK inhibition may provide certain protection against the adverse effects of IL-1ß.

Recombinant human platelet-derived growth factor-BB versus autologous bone graft in foot and ankle fusion: A systematic review and meta-analysis.

Today, autogenous bone graft (ABG) is still considered as the gold standard for joint fusion. Recombinant human platelet-derived growth factor-BB (rhPDGF-BB) which is of chemotactic and mitogenic to mesenchymal stem cells and possesses outstanding osteogenetic potentials has been used for ankle and foot fusion in recent years. The goal of this article is to evaluate the safety and efficacy of rhPDGF-BB versus ABG in foot and ankle fusion. The PubMed MEDLINE, EMBASE, Web of Science, and Cochrane Library were systematic searched. Finally, three randomized controlled trials (RCTs) with 634 patients were enrolled in this study. Results of radiologic effectiveness which included CT and radiographic union rates revealed that there was no significant difference between rhPDGF-BB approach and ABG approach. Analysis of clinical results held the same outcomes expect that ABG group was superior in long-term Short Form-12 physical component scores. The pooled results also demonstrated that rhPDGF-BB was as safe as ABG in foot and ankle surgery. However, autograft harvesting procedure has some drawbacks such as donor-site pain and morbidity, additional operation time, blood loss, and scarring, which can be overcome by rhPDGF-BB. Thus, rhPDGF-BB is a viable alternative to autograft in foot and ankle fusion surgery. Yet, more high-quality RCTs with long-term follow-up are still required to make the final conclusion.

Can Unilateral Kyphoplasty Replace Bilateral Kyphoplasty in Treatment of Osteoporotic Vertebral Compression Fractures? A Systematic Review and Meta-analysis.

BACKGROUND: Kyphoplasty has been proven to be an efficient method to relieve patient suffering from osteoporotic vertebral compression fractures (OVCFs). Because of its technological superiority, unilateral kyphoplasty consumes less operative time and bone cement than traditional bilateral kyphoplasty. However, there is controversy about which method is most efficient in the treatment of OVCFs. Thus, an overall analysis should be performed to shed light on the facts corroborating both procedures. OBJECTIVE: To evaluate the safety and efficacy of unipedicular kyphoplasty versus bipedicular kyphoplasty in treating OVCFs. STUDY DESIGN: Inclusion criteria were randomized controlled trials focusing on comparing unilateral versus bilateral balloon kyphoplasty in treatment of OVCFs. The exclusion criteria contained infection, neoplastic etiology, traumatic fracture, neural compression, neurological deficit, spinal stenosis, previous surgery at the involved vertebral body, long-term use of steroids, and kyphoplasty with other invasive or semi-invasive intervention treatment. Retrospective studies, reviews, technology introductions, and biochemical trials were also excluded. SETTINGS: The PubMed MEDLINE, Cochrane Library, Web of Science, and EMBASE were systematic searched. Only randomized controlled trials published up to June 2015 comparing unilateral kyphoplasty with bilateral kyphoplasty in treatment of OVCFs were identified. METHODS: Two researchers independently screeded the works for inclusion and data extraction. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system was used to assess the methodological quality and evidence synthesis. RESULTS: Six articles with 563 patients were enrolled in this study. Results showed that the unilateral approach required less surgical time (MD, -23.19; 95% CI, [-27.08, -19.31]; P < 0.00001) and cement consumption (MD, -2.07; 95% CI, [-2.23, -1.91]; P < 0.00001), as well as a reduced cement leakage ratio (RR, 0.59; 95% CI, [0.35, 0.99]; P < 0.05) and improved short-term general health (MD, 1.48; 95% CI, [0.02, 2.93], P < 0.05). No significant difference was found in the visual analog scale score (short-term and long-term), Oswestry Disability Index score (mid-term and long-term) kyphotic angle reduction, restoration rate of anterior vertebral height, vertebral height loss rate, postoperative adjacent-level fractures, or in other assessments of 36-Item Short Form Health Survey parameters (short-term and long-term). LIMITATIONS: Only 6 studies were included, so that the sample size was still relatively small and publication bias could not be revealed in this study. Observation time of some data was inconsistent. All of these problems could influence the reliability of the results. CONCLUSION: Both unilateral kyphoplasty and bilateral kyphoplasty are safe and effective treatments for OVCFs. However, when operative time, cement volume, cement leakage, short-term general health, radiation dose, and hospitalization costs are taken into consideration, unilateral kyphoplasty may be the better choice. Yet, more high-quality RCTs with long-term follow-up are still required to make the final conclusion.Key words: Kyphoplasty, unilateral approach, bilateral approach, osteoporotic vertebral compression fractures, meta-analysis.

[Sonographically guided intralesional sclerotherapy for venous malformation].

OBJECTIVE: To investigate the safety and efficacy of sonographically guided percutaneous intralesional sclerotherapy for peripheral venous malformations. METHODS: From March 2004 to October 2007, 32 patients with venous malformations of soft tissues were treated with sonographically guided intralesional sclerotherapy. The malformed venous space was identified intraoperatively by duplex scanning, the gauge 7 needle was inserted into this venous space under real-time ultrasound visualization, and sclerosants were infused in the space gently. Absolute alcohol and bleomycin acted as sclerosants here, combined the two (for type I malformation) or bleomycin only (for type II malformation). The treatment could be repeated if the lesion was not cured in 3 weeks. All patients were followed up for 6 months to 2 years. RESULTS: Of the group, each patient received 1 - 6 times of the therapy (mean, 3 times). Twenty-seven patients achieved a complete response, and 5 achieved partial response. No major complications occurred. CONCLUSIONS: Sonographically guided percutaneous intralesional sclerotherapy for peripheral venous malformation is a simple, effective, safe therapy with minimal invasion, lower morbidity rate, and can be repeated.