A Novel Semi-Cannulated Screw Enhanced Bone Cement Augmentation and Pullout Strength in Posterior Cervical Lateral Mass Screw Fixations: An In Vitro Biomechanical and Morphological Study.

Objective: To develop a novel semi-cannulated lateral mass screw (SC-LMS) for cervical posterior fixations and compare the fixation stability and safety of SC-LMS with regular solid lateral mass screw (S-LMS) in bone cement augmentation and pullout strength using fresh cadaveric cervical vertebrae.

Methods: The conventional multiaxial screw for cervical lateral mass fixation was modified to a cannulated screw with two lateral holes, used for bone cement injection in situ. Eight fresh human cervical vertebrae (C3, C4, and C5) were collected and used.

Pathogen detection in suspected spinal infection: metagenomic next-generation sequencing versus culture.

Purpose: The aim is to compare the pathogen detection performance of metagenomic next-generation sequencing (mNGS) and the culturing of percutaneous needle biopsy samples obtained from an individual with a suspected spinal infection.

Methods: A retrospective study of 141 individuals with a suspected spinal infection was conducted, and mNGS was performed. The microbial spectra and detection performance between mNGS and the culturing-based method were compared, and the effects of antibiotic intervention and biopsy on the detection performance were assessed.

Study of Degradation and Cytocompatibility of Ceramics/PLA Composite Coating on Pure Zinc for Orthopedic Application.

Zinc and its alloys are considered to be next-generation materials for fabricating absorbable biomedical devices. However, cytotoxicity has been reported to be associated with rapid degradation. To address these issues, a composite coating (PLA/Li-OCP) consisting of CaHPO conversion coating (Ca-P) and polylactic acid (PLA) decorated with Li-octacalcium phosphate particles was constructed on pure zinc.

Facile Fabrication of 3D-Printed Porous Ti6Al4V Scaffolds with a Sr-CaP Coating for Bone Regeneration.

To improve osseointegration caused by the stress-shielding effect and the inert nature of titanium-based alloys, in this work, we successfully constructed a strontium calcium phosphate (Sr-CaP) coating on three-dimensional (3D)-printed Ti6Al4V scaffolds to address this issue. The energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) results indicated that the coatings with and without Sr doping mainly consisted of CaHPO. The bonding strength of Sr doping coating met the required ISO 13 779-4-2018 standard (≥15 MPa).

Alkaline-phosphatase triggered self-assemblies enhances the anti-inflammatory property of methylprednisolone in spinal cord injury.

Methylprednisolone sodium phosphate (MP) is an anti-inflammatory corticosteroid which is used in the treatment of spinal cord injury (SCI), however the overdose of MP has toxic effects Therefore it is prerequisite to develop novel approaches to overcome the side effects of MP and enhance its efficacy. In the present work, we have developed alkaline phosphatase (ALP) trigger self-assembly system of oligopeptides to physically entrap and locally deliver MP. The synthesis of Nap-Phe-Phe-Tyr(HPO)-OH (1P) was achieved using solid phase peptide synthesis and was characterized using mass spectroscopy.

Finite Element Assessment of the Screw and Cement Technique in Total Knee Arthroplasty.

Background: The screw and cement technique is a convenient method used to rebuild medial tibial plateau defects in primary total knee arthroplasty (TKA). The objective of this study was to perform a finite element assessment to determine the effect of different numbers of screws on the stability of TKA and to determine whether differences exist between two different insertion angles.

Method: Six tibial finite element models with defects filled with screws and cement and one model with defects filled only with cement were generated.

Comparison of the Pull-Out Strength between a Novel Micro-Dynamic Pedicle Screw and a Traditional Pedicle Screw in Lumbar Spine.

Objective: This study aimed to investigate the strength of a novel micro-dynamic pedicle screw by comparing it to the traditional pedicle screw.

Methods: Forty-five lumbar vertebrae received a traditional pedicle screw on one side and a micro-dynamic pedicle screw on the other side as follows (traditional group vs micro-dynamic group): 15 vertebrae underwent instant pull-out testing; 15 vertebrae underwent 5000-cyclic fatigue loading testing; and 15 vertebrae underwent 10,000-cyclic fatigue loading testing and micro-computed tomography (micro-CT) scanning. The peek pull-out force and normalized peek pull-out force after instant pull-out testing, 5000-cyclic and 10,000-cyclic fatigue loading testing were recorded to estimate the resistance of two types of screws.

Association between lumbar sacralization and increased degree of vertebral slippage and disc degeneration in patients with L4 spondylolysis.

Objective: The aim of this study was to evaluate the effect of lumbar sacralization on the level of vertebral slip and disc degeneration in patients with L4 spondylolysis.

Methods: The authors analyzed data from 102 cases in which patients underwent surgical treatment for L4 spondylolysis and spondylolisthesis at their institution between March 2007 and September 2016. Lumbar sacralization was characterized by the presence of pseudarthrosis and/or bony fusion between the L5 transverse process and sacrum, and the type of lumbosacral transitional vertebra (LSTV) was evaluated with the Castellvi classification.

Anterior Transdiscal Axial Screw Fixation for Subaxial Cervical Spine: A Biomechanical Study.

Objective: To evaluate stability of anterior transdiscal axial screw (ATAS) fixation for anterior instrumentation and to compare with standard anterior cervical decompression and fusion and plate (ACDFP) fixation in human subaxial cervical spine.

Methods: Flexibility tests were conducted on 7 cadaveric specimens (C5-T1) in an intact and injured state and instrumented with ACDFP fixation, ATAS fixation, and ACDFP plus ATAS fixation at the C6-7 segment after section of the anterior and posterior longitudinal ligaments and discectomy. A pure moment of ±2.

[Association of vitamin D receptor gene polymorphisms with susceptibility to bone and joint tuberculosis in Chinese Han population].

Objective: To investigate the association between vitamin D receptor (VDR) gene Apa I polymorphism and the susceptibility to bone and joint tuberculosis in Chinese Han population.

Methods: Between May, 2015 and June, 2016, 100 patients with bone and joint tuberculosis and 100 healthy volunteers were recruited concomitantly in Heyuan Hospital of Traditional Chinese Medicine. Vitamin D receptor gene Apa I polymorphisms in these subjects were analyzed using SNaPshot.

Anatomic Study of Anterior Transdiscal Axial Screw Fixation for Subaxial Cervical Spine Injuries.

Anterior transdiscal axial screw (ATAS) fixation is an alternative or supplement to the plate and screw constructs for the upper cervical spine injury. However, no existing literatures clarified the anatomic feasibility of this technique for subaxial cervical spine. Therefore, the objective of this study was to evaluate the anatomical feasibility and to establish guidelines for the use of the ATAS fixation for the subaxial cervical spine injury.

[Fabrication of a new composite scaffold material for delivering rifampicin and its sustained drug release in rats].

Objective: To fabricate a new composite scaffold material as an implant for sustained delivery of rifampicin and evaluate its performance of sustained drug release and biocompatibility.

Methods: The composite scaffold material was prepared by loading poly(lactic-co-glycolic) acid (PLGA) microspheres that encapsulated rifampicin in a biphasic calcium composite material with a negative surface charge. The in vitro drug release characteristics of the microspheres and the composite scaffold material were evaluated; the in vivo drug release profile of the composite scaffold material implanted in a rat muscle pouch was evaluated using high-performance liquid chromatography.

Is duration of preoperative anti-tuberculosis treatment a risk factor for postoperative relapse or non-healing of spinal tuberculosis?

Purpose: This study evaluated the relationship between spinal TB postoperative recurrence or non-healing and duration of preoperative anti-TB treatment (ATT).

Methods: From January 2004 to January 2013, patients who underwent surgery for spinal TB and met this study's inclusion criteria were retrospectively reviewed. Observed parameters were age, sex, initial ESR, preoperative ESR, degree of ESR change, initial CRP, preoperative CRP, degree of CRP change, duration of preoperative ATT, surgical approach, presence of internal fixation, location of spinal lesion, number of involved segments, duration of operation, and intraoperative blood loss.

Clinical outcomes after decompressive laminectomy for symptomatic ossification of ligamentum flavum at the thoracic spine.

Ossification of the ligamentum flavum (OLF) is a rare disease that causes acquired thoracic spinal canal stenosis and thoracic myelopathy. The aim of this study was to investigate clinical outcomes of symptomatic thoracic OLF treated using posterior decompressive laminectomy. We retrospectively analyzed the medical records of 22 patients who underwent posterior decompressive laminectomy for symptomatic thoracic OLF.

Computed Tomographic Morphometric Analysis of Pediatric C1 Posterior Arch Crossing Screw Fixation for Atlantoaxial Instability.

Study Design: A CT-based study of pediatric atlas.

Objective: The aim of this study was to identify morphometric patterns and dimensions of the pediatric C1 posterior arch to establish guidelines for the posterior arch crossing screw (PACS) fixation.

Summary Of Background Data: The PACS fixation is an alternative or supplement to the C1 lateral mass screw or pedicle screw constructs.

Feasibility and trajectory study of anterior transarticular crossing screw placement for atlantoaxial joint instability: a cadaveric study and description of a novel technique.

Purpose: In unique clinical situations where C1-C2 anterior transarticular screw (ATS) fixation is not available or has failed, an anterior transarticular crossing screw (ATCS) with transcorporal pathway of the screws inside the contralateral promontory of C2 may enhance the stabilization and achieve atlantoaxial arthrodesis. The present study was to describe a novel technique of ATCS fixation for atlantoaxial joint instability and its applied anatomy, and compared it with ATS fixation method.

Methods: Direct measurements using digital calipers and a goniometer were conducted on 30 pairs of dried human C1 and C2 vertebrae.

Photothermal ablation of bone metastasis of breast cancer using PEGylated multi-walled carbon nanotubes.

This study investigates therapeutic efficacy of photothermal therapy (PTT) in an orthotropic xenograft model of bone metastasis of breast cancer. The near-infrared (NIR) irradiation on Multi-Walled Carbon Nanotubes (MWNTs) resulted in a rapid heat generation which increased with the MWNTs concentration up to 100 μg/ml. MWNTs alone exhibited no toxicity, but inclusion of MWNTs dramatically decreased cell viability when combined with laser irradiation.

[Structural characteristics and biocompatibility of a new nano-Ta-Ti alloy rod fabricated by laser melting technique].

Objective: To evaluate the structural characteristics and biocompatibility of a novel nano-Ta-Ti alloy rod for its potential application in internal fixation.

Methods: Ta coating of a Ti alloy rod with nano-Ta (tantalum) powder was performed using laser melting with symmetrical grooves repleted with nano-Ta powder along the whole length. The microstructure of the cross section of Ta-Ti alloy rod, pore diameter and components of the coating were analyzed using scanning electron microscopy.

Esophageal perforation related to anterior cervical spinal surgery.

Esophageal perforation is an uncommon but potentially fatal complication of anterior cervical spinal surgery. This study aimed to investigate the diagnosis and treatment of cervical esophageal perforation related to spinal surgery. Among 1097 consecutive cases of anterior cervical spinal surgery that were managed at our institution over a 20 year period, five patients with esophageal perforation were identified.

[Biomechanical study on effect of polymethylmethacrylate augmentation on cervical stability after anterior cervical interbody fusion].

Objective: To evaluate the effect of polymethylmethacrylate (PMMA) augmentation on cervical stability after anterior cervical interbody fusion (ACIF) before and after fatigue.

Methods: Twelve porcine cervical spines (C3-7) were subjected to testing angular displacement parameters, including the range of motion (ROM), neutral zone (NZ), and elastic zone (EZ), in nondestructive flexion and extension, right/left lateral bending, and left/right rotation on Motion Analysis motion capture system and MTS-858 servo-hydraulic testing machine. Intact cervical spines served as control group (group A); one-level discectomy and fusion was performed with anterior plate fixation based on group A as group B; flexion and extension, left/right lateral bending (5 000 cycles) fatigue testing based on group B as group C; the augmentation screw channel was used based on group C as group D; and flexion and extension, left/right lateral bending fatigue testing were performed based on group D as group E.

[Expression of hypoxia-inducible factor-1alpha and matrix metalloproteinase-2 in degenerative lumbar intervertebral disc].

Objective: To investigate the expression of hypoxia-inducible factor-1alpha (HIF-1alpha) and matrix metalloproteinase-2 (MMP-2) in degenerative human intervertebral disc.

Methods: Specimens of the nucleus pulposus of the degenerative discs were obtained from patients with lumbar disc herniation (experimental group), and those from young patients suffering thoracolumbal vertebral bursting fracture served as the control. The experimental group was divided into three subgroups according to the magnetic resonance imaging (MRI) results.

[Biological characteristics of human degenerative vertebral endplate cells].

Objective: To observe the morphology and phenotypes of cells extracted from the endplate in the intervertebral discs and identify the factors affecting their biological characteristic.

Methods: The intervertebral disc endplate were digested enzymatically, and the morphology of the obtained cells was examined under light microscope. Immunhistochemical analysis of collagen II and real-time PCR was carried out, and the morphologies, viability, cell growth, apoptosis and chondrocyte matrix production were compared between the cells isolated from the degenerative and normal vertebral endplates.

Morphometry of iliac anchorage for transiliac screws: a cadaver and CT study of the Eastern population.

Objectives: To describe the morphometry of iliac columns for transiliac screw and to testify the conformity among the anatomic measurement, two-dimensional (2D) and three-dimensional (3D) computed tomography.

Methods: We evaluated the length, inner width, and angle of three screw trajectories starting at the iliac tubercle, posterior superior iliac spine, and posterior inferior iliac spine toward the anterior inferior iliac spine. Measurements were made on specimen, two- and 3D computed tomography using 18 embalmed cadaveric pelves.

[Complications of the anterior surgical approach for thoracolumbar spine tuberculosis: causes and countermeasures].

Objective: To assess the effect of the anterior surgical approach for thoracolumbar spine tuberculosis and analyzed the causes of the surgical complications and the countermeasures.

Methods: From Jan 1996 to Dec 2005, 120 patients with thoracolumbar spine tuberculosis underwent operations through the anterior approach either following the primary diagnosis (115 cases) or for recurrence (5 cases).

Results: Intraoperative pleural rupture occurred in 4 cases, and rupture of the external iliac vein occurred 1 case.