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Meng Chen,1,2 Yang Li,1,2 Wen-Xiu Hou,3 Da-Yong Peng,1,2 Jing-Kun Li,1,2 Hao-Xuan Zhang1,2 1Department of Orthopedic Surgery, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong Province, 250014, People’s Republic of China; 2Department of Orthopedic Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong Province, 250014, People’s Republic of China; 3Department of Spine Surgery, Shandong University Qilu Hospital, Jinan, Shandong, 250000, People’s Republic of ChinaCorrespondence: Hao-Xuan Zhang, Department of Orthopedics, The First Affiliated Hospital of Shandong First Medical University, No. 16766, Lixia District, Jingshi Road, Jinan, Shandong Province, 250014, People’s Republic of China, Tel/Fax +86531-89268540, Email hoho0605@126.comPurpose: The repair and treatment of infected bone defects (IBD) is a common challenge faced by orthopedic clinics, medical materials science, and tissue engineering.Methods: Based on the treatment requirements of IBD, we utilized multidisciplinary knowledge from clinical medicine, medical materials science, and tissue engineering to construct a high-efficiency vancomycin sustained-release system with nanodiamond (ND) and prepare a composite scaffold. Its effect on IBD treatment was assessed from materials, cytology, bacteriology, and zoology perspectives.Results: The results demonstrated that the Van-ND-45S5 scaffold exhibited an excellent antibacterial effect, biocompatibility, and osteogenesis in vitro. Moreover, an efficient animal model of IBD was established, and a Van-ND-45S5 scaffold was implanted into the IBD. Radiographic and histological analyses and bone repair-related protein expression, confirmed that the Van-ND-45S5 scaffold had good biocompatibility and osteogenic and anti-infective activities in vivo.Conclusion: Collectively, our findings support that the Van-ND-45S5 scaffold is a promising new material and approach for treating IBD with good antibacterial effects, biocompatibility, and osteogenesis.Graphical Abstract: Keywords: antibacterial effect, nanodiamond, scaffold, infected bone defects

BACKGROUND: Total cervical artificial disc replacement (TDR) has been considered a safe and effective alternative surgical treatment for cervical spondylosis and degenerative disc disease that have failed to improve with conservative methods. Positioning the surgical patient is a critical part of the procedure. Appropriate patient positioning is crucial not only for the safety of the patient but also for optimizing surgical exposure, ensuring adequate and safe anesthesia, and allowing the surgeon to operate comfortably during lengthy procedures. The surgical posture is the traditional position used in anterior cervical approach; in general, patients are in a supine position with a pad under their shoulders and a ring-shaped pillow under their head. AIM: To investigate the clinical outcomes of the use of a modified surgical position versus the traditional surgical position in anterior approach for TDR. METHODS: In the modified position group, the patients had a soft pillow under their neck, and their jaw and both shoulders were fixed with wide tape. The analyzed data included intraoperative blood loss, position setting time, total operation time, and perioperative blood pressure and heart rate. RESULTS: Blood pressure and heart rate were not significantly different before and after body positioning in both groups (P > 0.05). Compared with the traditional position group, the modified position group showed a statistically significantly longer position setting time (P < 0.05). However, the total operation time and intraoperative blood loss were significantly reduced in the modified position group compared with the traditional position group (P < 0.05). CONCLUSION: The clinical outcomes indicated that total operation time and intraoperative blood loss were relatively lower in the modified position group than in the traditional position group, thus reducing the risks of surgery while increasing the position setting time. The modified surgical position is a safe and effective method to be used in anterior approach for TDR surgery.

A time-domain discontinuous Galerkin Poggio–Miller–Chang–Harrington–Wu integral equation method, which is based on marching-on-in-degree (MOD) scheme, is proposed to simulate electromagnetic pulse (EMP) responses of arbitrarily shaped dielectric objects, where half Rao–Wilton–Glisson basis functions are chosen as the spatial basis ones. Both electric and magnetic current continuities between adjacent elements are guaranteed by introducing additional interior penalty terms. Therefore, three-dimensional dielectric structures with either conformal or nonconformal meshes can be treated. Meanwhile, the weighted Laguerre polynomials are chosen as the temporal basis functions and implemented for the MOD scheme, and stable EMP responses can be captured. Since our method is based on the surface integral equation with the objects’ surface meshed, the number of unknowns are significantly reduced in comparison with that of the volume integral equation method. Some numerical examples are presented to validate both stability and accuracy of the developed algorithm.

ADMATS-7 is known to play an important role in the pathogenesis of various diseases, including cartilaginous diseases. IL-17A is an inflammatory cytokine detected in degenerative disc tissues. However, the interplay between IL-17A and ADMATS-7 in human disc degeneration is still unknown. Samples collected from 50 patients were divided into three groups according to MRI degeneration grading system score. Immunohistochemistry, RT-PCR and western Blotting were used to investigate the expression of ADAMTS-7 in NP tissues. Furthermore, a rat disc degeneration model was established, and the expression level of ADAMTS-7 was assayed using immunohistochemistry, RT-PCR and western Blotting. The human NP cells were cultured in the presence and absence of IL-17A stimulation. RNA extracts were collected, and real-time PCR was performed to determine the expression of ADAMTS-7. Moreover, ADAMTS-7 concentrations were detected in human NP cell culture supernatants by ELISA. After culturing NP cells with IL-17A (with or without Etanercept), ADAMTS-7 levels were detected in each group. ADAMTS-7 expression was dramatically elevated in both human and rat degenerative NP tissues compared with normal controls. The RT-PCR and ELISA results revealed that IL-17A could enhance the production of ADAMTS-7, while ADAMTS-7 expression dramatically decreased in the IL-17A + Etanercept group in comparison to the IL-17A alone group. Our results indicate the presence of ADAMTS-7 in human NP cells and imply its potential role in disc degeneration. Additionally, our results indicate that IL-17A induced ADAMTS-7 expression via TNF-α, which may form a molecular axis in human NP cells.

Total cervical artificial disc replacement (TDR) simulates normal disc structure, thus avoiding the drawbacks of anterior cervical decompression and fusion (ACDF). This prospective, randomized, controlled and multicentre study aimed to evaluate clinical and radiographic outcomes by comparing cervical disc replacement using Mobi-C disc prostheses with ACDF.This prospective, randomized, controlled and multicentre study consisted of 111 patients undergoing single-level Mobi-C disc prosthesis replacement (TDR group, n = 55) or ACDF (n = 56) from February 2008 to November 2009 at 11 medical centres across China. Patients were assessed before surgery, at seven days postoperation and one, three, six, 12, 24, 36 and 48 months postoperation. Clinical and neurological outcome was determined by measuring the Japanese Orthopaedic Association (JOA) scores, visual analogue scale (VAS) and Neck Disability Index (NDI). Static and dynamic radiographs were obtained of the cervical curvature, the functional spinal unit (FSU) angle and range of motion (ROM) of the cervical spine, FSU angle and treated and adjacent segments.A total of 111 patients were included and randomly assigned to either Mobi-C disc prosthesis replacement or ACDF. JOA, VAS and NDI showed statistically significant improvements 48 months after surgery (P 0.05). ROM, FSU angle, treated segment and adjacent segments in the Mobi-C group were not significantly different before and after replacement (p 0.05). ROM in the ACDF group was significantly reduced at one month and remained so throughout the follow-up. By 48-months, more ACDF patients required secondary surgery (four of 56 patients).Although ACDF may increase the risk of additional surgery, clinical outcomes indicated that both Mobi-C artificial cervical disc replacement and ACDF were reliable. Radiographic data showed that ROM of the cervical spine, FSU angle and treated and adjacent segments were relatively better reconstructed and maintained in the Mobi-C group compared with those in the ACDF group.

The composite of poly-lactic- co-glycolic acid (PLGA) and calcium phosphate cements (CPC) are currently widely used in bone tissue engineering. However, the properties and biocompatibility of the alendronate-loaded PLGA/CPC (APC) porous scaffolds have not been characterized. APC scaffolds were prepared by a solid/oil/water emulsion solvent evaporation method. The morphology, porosity, and mechanical strength of the scaffolds were characterized. Bone marrow mesenchymal stem cells (BMSCs) from rabbit were cultured, expanded and seeded on the scaffolds, and the cell morphology, adhesion, proliferation, cell cycle and osteogenic differentiation of BMSCs were determined. The results showed that the APC scaffolds had a porosity of 67.43 ± 4.2% and pore size of 213 ± 95 µm. The compressive strength for APC was 5.79 ± 1.21 MPa, which was close to human cancellous bone. The scanning electron microscopy, cell counting kit-8 assay, flow cytometry and ALP activity revealed that the APC scaffolds had osteogenic potential on the BMSCs in vitro and exhibited excellent biocompatibility with engineered bone tissue. APC scaffolds exhibited excellent biocompatibility and osteogenesis potential and can potentially be used for bone tissue engineering.