MLK3 silence suppressed osteogenic differentiation and delayed bone formation via influencing the bone metabolism and disturbing MAPK signaling.

Background: Mixed lineage kinase 3 (MLK3) is a member of a serine/threonine MAP3K family, and it has been demonstrated to play critical roles in various biological activities and disease progression. Previous studies showed that impaired skeletal mineralization and spontaneous tooth fracture in the MLK3-deficient mice, suggesting MLK3 actively participated in the bone formation. However, the detailed function and underlying mechanisms remain obscure. Methods: The MLK3 knockout (KO) mouse was applied in the present study, and multi-omics were performed to compare the metabolites and gene expression between wild type (WT) and KO mice. The bone fracture model was successfully established, and the healing process was evaluated by X-ray, micro-CT examination, histomorphometry and immunohistochemistry (IHC) staining. On the other hand, the effects of MLK3 on osteogenic differentiation were assessed by alkaline phosphatase (ALP) activity, Alizarin red S (ARS) staining and qRT-PCR examination. Finally, the downstream signaling pathways were screened out by RNA-sequencing (RNA-seq) and then validated by Western blotting. Results: In the present study, imbalanced bone metabolism was observed in these MLK3 KO mice, suggesting MLK3 may participate in bone development. Moreover, MLK3 -/- mice displayed abnormal bone tissues, impaired bone quality, and delayed fracture healing. Further investigation showed that the inhibition of MLK3 attenuated osteoblast differentiation in vitro. According to the RNA-seq data, MAPK signaling was screened out to be a downstream pathway, and its subfamily members extracellular signal-regulated kinase (ERK), p38 and Jun N-terminal protein kinase (JNK) were subjected to Western blotting examination. The results revealed that although no differences in their expression were observed between MSCs derived from WT and KO mice, their phosphorylated protein levels were all suppressed in MLK3 -/- MSCs. Conclusion: In conclusion, our results demonstrated that loss of MLK3 suppressed osteoblast differentiation and delayed bone formation via influencing metabolism and disturbing MAPK signaling. The translational potential of this article: The findings based on the current study demonstrated that MLK3 promoted osteogenesis, stimulated new bone formation and facilitated fracture healing, suggesting that MLK3 may serve as a potential therapeutic target for bone regeneration. MLK3 activator therefore may be developed as a therapeutic strategy for bone fracture.

Posterior cervical fixation following laminectomy: a stress analysis of three techniques.

The aim of this study was to compare the following three main fixation techniques: pedicle screw (PS) technique, lateral mass screw (LS) technique, and transarticular screw (TS) technique. A detailed, geometrically accurate, nonlinear C3-C7 FE model had been successfully developed and validated. Then three finite element (FE) models were reconstructed by different fixation techniques following C4-C6 level laminectomy. A compressive preload of 74 N combined with a pure moment of 1.8 Nm in flexion, extension, left-right lateral bending, and left-right axial rotation was applied to the models. The results showed that maximum von Mises stress on the fixation devices was much higher in the FE models of TS technique, compared with the models of PS and LS techniques. Furthermore, the screws inserted by TS technique had high stress concentration at the middle part of the screws. Screw inserted by PS and LS techniques had high stress concentration at the actual cap-rod-screw interface. The highest level of maximal stress was obtained with the fixation device of the TS technique. TS technique induces noticeable differences in the stress compared to the posterior cervical fixation technique, regarding the higher stress level on fixation devices.

Troxerutin Stimulates Osteoblast Differentiation of Mesenchymal Stem Cell and Facilitates Bone Fracture Healing.

Troxerutin (TRX), a semi-synthetic derivative of the natural bioflavonoid rutin, is a bioactive flavonoid widely abundant in various fruits and vegetables. Known as vitamin P4, TRX has been demonstrated to have several activities including anti-inflammation, anti-oxidants, vasoprotection, and immune support in various studies. Although rutin, the precursor of troxerutin, was reported to have a protective role against bone loss, the function of TRX in skeletal system remains unknown. In the present study, we found that TRX promoted osteogenic differentiation of human mesenchymal stem cells (MSCs) in a concentration-dependent manner by stimulating the alkaline phosphatase (ALP) activity, calcium nodule formation and osteogenic marker genes expression in vitro. The further investigation demonstrated that TRX stimulated the expression of the critical transcription factor ß-catenin and several downstream target genes of Wnt signaling, thus activated Wnt/ß-catenin signaling. Using a femur fracture rats model, TRX was found to stimulate new bone formation and accelerate the fracture healing in vivo. Collectively, our data demonstrated that TRX could promote osteogenesis in vitro and facilitate the fracture healing in vivo, indicating that TRX may be a promising therapeutic candidate for bone fracture repair.

[Indication of fusion for degenerative lumbar spinal stenosis treated by "windows technique" laminoforaminotomy].

OBJECTIVE: To explore the indications of fusion for degenerative lumbar spinal stenosis treated by "windows technique". METHODS: From December 1999 to December 2005, 145 consecutive patients who were treated by primary decompression with "windows technique" laminoforaminotomy for degenerative lumbar spinal stenosis, a retrospective study, were divided into 3 groups (A and B and C) by preoperative lumbar conditions and surgical methods. In group A, 39 patients with spinal instability or degenerative lumbar spondylolisthesis or scoliosis underwent decompression and fusion; in group B, 31 patients with spinal instability or degenerative lumbar spondylolisthesis or scoliosis underwent decompression alone; In group C, 75 patients without spinal instability or degenerative lumbar spondylolisthesis or scoliosis were treated by decompression without fusion. On hospital medical records to review, they were followed up by telephone and out-patient referral. Statistics the duration of hospitalization, operative time, estimated blood loss; Observed recrudescence and reoperation and complication; and using Oswestry Disability Index and Visual Analog Scale and satisfaction rate for efficacy assessment, application SPSS 13.0 software. RESULTS: All 145 patients had at least a 3-year follow-up (ranging 37 to 108 months). In the group C, the duration of hospitalization less than in the group A or B (P < 0.05); In the group A, the operative time and estimated blood loss greater than in the group B or C (P < 0.05); The group B treated by decompression alone in the presence of instability or spondylolisthesis or scoliosis showed the worst results by the Oswestry Disability Index or Visual Analog Scale or ate of satisfaction (P < 0.05). The same good results can be obtained in the group A and C. There were not different about recrudescence or reoperation or complication in the three groups. CONCLUSIONS: Fusion should be performed on patients with instability or degenerative lumbar spondylolisthesis or scoliosis after primary decompression with "windows technique" laminoforaminotomy. The patient with simple lumbar spinal stenosis undergone primary surgery does not require fusion.

TGF-ß1, in association with the increased expression of connective tissue growth factor, induce the hypertrophy of the ligamentum flavum through the p38 MAPK pathway.

Hypertrophy of the ligamentum flavum (LF) is one of the key pathomechanisms of lumbar spinal stenosis (LSS). Transforming growth factor (TGF)-ß1 is abundantly expressed in hypertrophied degenerative LF tissues from LSS. However, the molecular mechanisms underling the association between TGF-ß1 and LF hypertrophy have not yet been fully elucidated. In this study, we investigated the important role of the mitogen-activated protein kinase (MAPK) pathway in the pathogenesis of LSS by analyzing the expression of connective tissue growth factor (CTGF) and extracellular matrix (ECM) components (collagen I and collagen III) in TGF-ß1-treated LF cells. Cell growth assay revealed that TGF-ß1, in association with CTGF, enhanced the the proliferation of LF cells, and we found that TGF-ß1 also elevated CTGF expression and subsequently enhanced the mRNA expression of collagen I and collagen III. The increased mRNA expression levels of CTGF, collagen I and collagen III were abolished by p38 inhibitors. Both immunofluorescence imaging and western blot analysis of p38 and p-p38 revealed the increased expression and phosphorylation of p38. Silencing the expression of p38 by siRNA in LF cells decreased the protein expression of p38, p-p38 and CTGF, as well as the mRNA expression of CTGF, collagen I and collagen III. Taken together, our findings indicate that TGF-ß1, in association with the increased expression of CTGF, contribute to the homeostasis of the ECM and to the hypertrophy of LF through the p38 MAPK pathway.

PLK2 phosphorylates and inhibits enriched TAp73 in human osteosarcoma cells.

TAp73, a member of the p53 tumor suppressor family, can substitute for p53 function, especially in p53-null and p53-mutant cells. However, TAp73 enrichment and phosphorylation change its transcriptional activity. Previously, we found that the antitumor function of TAp73 was reactivated by dephosphorylation. Polo-like kinase 2 (PLK2) plays an important role in bone development. Using a biological information database and phosphorylation prediction software, we hypothesized that PLK2 phosphorylates TAp73 and inhibits TAp73 function in osteosarcomas. Actually,we determined that PLK2 physically binds to and phosphorylates TAp73 when TAp73 protein abundance is up-regulated by cisplatin. PLK2-phosphorylated TAp73 at residue Ser48 within the TA domain; phosphorylation of TAp73 was abolished by mutating this residue. Moreover, PLK2 inhibition combined with cisplatin treatment in osteosarcoma Saos2 cells up-regulated p21 and puma mRNA expression to a greater extent than cisplatin treatment alone. Inhibiting PLK2 in TAp73-enriched Saos2 cells resulted in inhibited cell proliferation, increased apoptosis, G1 phase arrest, and decreased cell invasion. However, these changes did not occur in TAp73 knockdown Saos2 cells. In conclusion, these findings reveal a novel PLK2 function in the phosphorylation of TAp73, which prevents TAp73 activity in osteosarcoma cells. Thereby, this research provides an insight into the clinical treatment of malignant tumors overexpressing TAp73.

Anatomical basis of a proximal fasciocutaneous extension of the distal-based posterior interosseous flap that allows exclusion of the proximal posterior interosseous artery.

OBJECTIVE: The objective of this study was to provide anatomical information for the repair of small tissue defects in the hand with posterior interosseous artery chain-link perforator flaps, a proximal fasciocutaneous extension of the distal-based posterior interosseous flap, which allows the exclusion of the proximal posterior interosseous artery. METHODS: Fourteen posterior interosseous artery chain-link perforator flaps taken from human cadavers were studied by the following three methods: latex perfusion for microanatomy analysis, denture material and vinyl chloride mixed packing for cast analysis, and latex perfusion for the production of clearance specimens. Statistical analysis was performed on cutaneous perforators coming from the intermuscular septum of the extensor carpi ulnaris and the extensor digitorum communis. A cluster analysis was conducted to determine the overall distribution of perforators. RESULTS: There are two main clusters of perforators at a relative distance of 21% and 48% along the ulnar head-to-lateral epicondyle interval. On average, the posterior interosseous artery extends six cutaneous perforators through the intermuscular septum of the extensor carpi ulnaris and the extensor digitorum communis. Of these six arteries, two are clinically significant perforators (0.5 mm or more in diameter) and are located 6 ± 2 cm proximal to the head of the ulna and 10 ± 1 cm distal to the lateral epicondyle of the humerus. Their mean diameters are 0.5 ± 0.1 and 0.6 ± 0.1 mm, with pedicle lengths of 16.8 ± 5.1 and 21.2 ± 12.3 mm, respectively. At the two main clusters of perforator-intensive sites, the vessel chains formed by adjacent perforators are parallel to the intermuscular septum of the extensor carpi ulnaris and the extensor digitorum communis. CONCLUSIONS: This study demonstrates that the posterior interosseous artery has two main clusters of perforators in the middle and distal one-fifth of the forearm, which can be used for repairing hand defects with posterior interosseous artery chain-link perforator flaps.

Detection of gene expression pattern in the early stage after spinal cord injury by gene chip.

OBJECTIVE: To study the changes of the gene expression pattern of spinal cord tissues in the early stage after injury by DNA microarray (gene chip). METHODS: The contusion model of rat spinal cord was established according to Allen's falling strike method and the gene expression patterns of normal and injured spinal cord tissues were studied by gene chip. RESULTS: The expression of 45 genes was significantly changed in the early stage after spinal cord injury, in which 22 genes up-regulated and 23 genes down-regulated. CONCLUSIONS: The expression of some genes changes significantly in the early stage after spinal cord injury, which indicates the complexity of secondary spinal cord injury.

[Cause-specific treatment for nonspecific low back pain].

Nonspecific low back pain has long been a troublesome clinical entity in that the diagnoses are usually hard to define, and the effect of treatment unsure. We have been conducting long-term basic and clinical research in Zhujiang Hospital in an effort to find the exact mechanism for this disease and to explore its causal treatment. On the basis of literature review and treatment result evaluation, we recommend the following approaches for origin-specific diagnosis and treatments: (1) For spinal nerve dorsal ramus syndrome caused by mechanical stimulation on the stem part of the dorsal ramus, freezing the dorsal ramus with liquid-nitrogen may constitute the primary treatment. (2) In cases of low back pain originated from the lumbar disc due to degeneration of discs, treatment may be implemented through disc resection with or without arthrodesis. (3) Facet syndrome, a condition with low back pain that is seldom caused by pathological changes in the facet itself, but mostly by the pulling of the dorsal ramus due to the dislocation of the facet, should be attributed to the dorsal ramus syndrome. (4) Lumbar vertebra instability arising from loosened intervertebral conjunction calls for arthrodesis as the primary choice. (5) Interspinal ligaments injury can be most effectively treated by the combination of blocking and needle knife loosing. (6) Low back pain with underlying causes in the internal organs is often caused by diseases in the pelvic organs, and only these diseases are cured can the back pain be relieved. These origin-specific diagnosis and treatments we proposed here await further investigation and comments from our peers interested in this problem.

[Finite element analysis of shape memory alloy intrasegmental fixator for lumbar spondylolysis].

OBJECTIVE: To study the tensile strength of shape memory alloy intrasegmental fixator and tensile stress distribution in the device during force loading with finite element method (FEM). METHODS: The designed parameters, scanning image, and mechanical properties of shape memory alloy intrasegmental fixator were input into computer for the construction of the FEM model of the device in inherent coordinate of ANSYS. The model was extended with restriction in different parts, and the tensile strength and the distribution of tensile stress in the model was calculated. RESULTS: When the device was loaded with pulling force to induce a relative displacement of 2 mm between the 2 hooks along the two midpoints, the pull was about 281 N, and the tensile stress concentrated more on the middle of device than on the two sides. CONCLUSION: The shape memory alloy intrasegmental fixator is strong enough against tensile stress, which concentrates in the middle portion of the device where fatigue breakage is liable to occur when excessive force is loaded.

[Surgical therapy of lumbar disk herniation in 6 815 cases].

OBJECTIVE: To explore the surgical therapy for lumbar disc herniation (LDH). METHODS: Under local anesthesia by blocking the posterior branches of spinal nerves, 3 surgical approaches were adopted in 6 815 LDH cases, namely discectomy by lateral and interlamina access, double fenestration and enhanced decompression for broad central LDH, and removal of nucleus pulposus with small incision and fenestration. RESULTS: Follow-up study was conducted in 5 324 cases for the duration varying from 6 months to 14 years, averaging 6.3 years. Excellent results were achieved in 4 260 cases (80.02%), good in 855 cases (16.06%) with another 209 cases (3.92%) showing symptomatic improvement. X-ray examination in these cases revealed narrowed intervertebral spaces of different degrees without lumbar instability or spondylolisthesis. CONCLUSION: In comparison with conventional approaches, the 3 surgical approaches for LDH management may preserve the utmost integrity of the posterior lumbar structures and cause less traumatic injuries with shortened operation time and quick recovery.

[Treatment of lumbar spondylolisthesis by Socon internal fixator: report of 18 cases].

OBJECTIVE: To evaluate the therapeutic effect of Socon transpedicle internal fixators in the treatment of spondylolisthesis in the lumbar spine. METHODS: Fixation with Socon internal fixators along with posterior decompression and fusion was performed in 18 patients with degenerative spondylolisthesis in the lumbar spine. The symptoms, signs and X-ray manifestations observed preoperatively and postoperatively were compared, and a follow-up study of all cases lasting for 6 to 18 month was conducted. RESULTS: Anatomical restoration of the involved vertebrae was achieved in all the cases, of them 15 had out-standing and 2 had fairly good clinical results without incidences of any complications during or after the operation. CONCLUSION: Socon internal fixator is an excellent modality for treatment of lumbar spondylolithesis.

[Effect of nitric oxide on the invasive ability of human osteosarcoma through a filter membrane: an in vitro study].

OBJECTIVE: To study the effect of nitric oxide on the in vitro invasiveness of human osteosarcoma cell line (OS-732). METHODS: In vitro cultured OS-732 cell suspensions containing different concentrations of sodium nitroprusside (SNP) or PBS (control group) were used to assess the in vitro invasiveness of the tumor cells utilizing Boyden's chamber assay. The tumor cells growing across the filter membrane were counted by means of HE staining and compared between the groups. RESULTS: With the increase of SNP concentration in the cell suspension, the number of tumor cells growing across the membrane tended to decrease. With the exception of the cell suspension containing 500 micromol/L SNP that had a cell number across the membrane significantly different from those of any other groups, significant difference was not observed between any adjacent groups. Between the groups with SNP concentrations that did not come adjacent, however, significant differences were noted. CONCLUSION: Nitric oxide can depress the invasiveness of OS-732 cells across the membrane in vitro.

Three-dimensional porous poly-DL-lactide/basic fibroblast growth factor composites for bone defect repair: an experimental study.

OBJECTIVE: To investigate the osteoinductive ability of the composites consisting of basic fibroblast growth factor (bFGF) and porous poly-DL-lactide (PDLLA) for the development of a new absorbable osteosynthesis material. METHODS: Highly porous foams of PDLLA with the pore size ranging from 150 to 300 microm were prepared by a solvent-casting, particulate-leaching technique with NaCl as the leachable component. Animal models of radial diaphyseal defects of 1.0 cm with complete removal of the periosteum were induced in 45 rabbits, which were randomly divided into 3 groups to receive the defect repair with PDLLA and PDLLA/bFGF respectively, leaving one group untreated to serve as the control group. The implant specimens were harvested at 2, 4, 8, and 12 weeks respectively after the surgery and X-ray, histological and scanning electron microscopic (SEM) examinations were performed to evaluate the effectiveness of defect repair. At 8 and 12 weeks after implantation, biomechanical test (for three-point bending strength) was employed to study the quality of bone formation. RESULTS: PDLLA/bFGF composite stimulated more bone formation and had higher bending strength than PDLLA (P<0.05), and the bone formation induced by both materials was significantly more than that observed in the control group in every postoperative stage (P<0.05). CONCLUSION: PDLLA possesses good biocompatibility and absorbability, and when prepared into a porous material, it exhibits good osteoconductibility. As a good bFGF carrier, the foam of PDLLA with three- dimensional structure shows good osteoinductive ability with regard to the rapidity, quantity and quality of the bone formation.

[Role of antisense oligodeoxynucleotide of inducible nitric oxide synthase in the apoptosis and p-p38 MAPK signal transduction in rat neurons after spinal cord injury].

OBJECTIVE: To study the role of antisense oligodeoxynucleotides (ASODN) of inducible nitric oxide synthase (iNOS) on the apoptosis and p-p38 mitogen-activated protein kinase (p-p38 MAPK) signal transduction of the neurons after spinal cord injury (SCI). METHODS: Antisense and non-sense oligodeoxynucleotides of iNOS were designed and synthesized, and injected into the subarachnoid space 12 h before the compressive injury was given to the rat spinal cord. Reverse transcription-PCR and flow-cytometry were used to examine the iNOS mRNA expression and the apoptosis of the neurons within the injured spinal cord. The changes of p-p38 MAPK signal transduction pathway were detected by Western blotting. RESULTS: Obvious increase in iNOS expression and up-regulated p-p38 MAPK were detected after SCI, and neuronal apoptosis was observed in the injured spinal cord. ASODN-iNOS treatment resulted in decreased expression levels of iNOS mRNA and p-p38 MAPK, and the neuronal apoptosis was alleviated. CONCLUSION: ASODN-iNOS inhibits iNOS expression and neuronal apoptosis following SCI which may be related to the p-p38 MAPK signal transduction pathway.

Effect of pore size of D, L-polylactic acid as bone repair material on bone regeneration.

OBJECTIVE: To study the bone regeneration behavior in porous D,L-polylactic acid (D,L-PLA) with different pore sizes. METHOD: A particulate-leaching method was employed to prepare porous biodegradable D,L-PLA with different pore sizes (75, 250, 400, 750 micrometer) and with porosity of 75% as the materials to repair bone defects in rabbits. The materials were then implanted at random into 40 rabbits with bilateral radius bone defect, leaving another 10 rabbits without implantation as blank control. Gross observation and X-ray and histomorphological examination as well as assessment of the biomechanics of the implants were performed in 2, 4, 8 and 12 weeks respectively after the operation. RESULTS: New bone tissue occurred around the implanted materials with pore sizes of 250, 400 or 750 micrometer 12 weeks after the operation. In the control group and in the rabbits with implants with pore size of 75 micrometer, the bone defect was filled with connective tissues. The implants with 250-micrometer pores had the strongest biomechanical strengths of all the materials (P<0.01) at 8 weeks and 12 weeks after the operation. CONCLUSION: The pore size of the porous implants decides the behavior of bone regeneration, and D, L-PLA polymer with 250-micrometer pores produces the most desired effects.

Effect of aminoguanidine on the recovery of rat hindlimb motor function after spinal cord injury.

OBJECTIVE: To study the effects of aminoguanidine (AG), the inhibitor of inducible nitric oxide synthase (NOS), on the recovery of rat hindlimb motor function after spinal cord injury and explore the possible mechanism. METHODS: Thirty rat models of spinal cord compression injury were established according to Nystrom's method. AG therapy was administered for 4 times at 1 h before and 8, 24, 36 h after the injury, and 24 h after the completion of the therapy, spectrophotography was performed to measure the content of NO and activity of NOS in the injured spinal cord, followed by flow cytometry for determining the apoptotic rate 48 h later. The evaluation of the hindlimb motor function recovery was conducted by electrophysiological method and by measuring the behavior scores. RESULTS: AG significantly decreased the NO content (from 2.2714+/-0.4239 micromol/g.pro to 0.8466+/-0.0477 micromol/g.pro, P <0.05) and NOS activity (from 0.3408+/-0.0228 U/mg pro to 0.2702+/-0.0148 U/mg pro, P <0.05) in the injured spinal cord. The apoptotic rats were also reduced (from 7.88% +/-0.79% to 3.10% +/-0.66%, P <0.05). Four weeks after the therapy, the behavior score of the rats improved from 7.1+/-4.5 to 17.3+/-4.7 (P <0.01), and the latency and amplitude of the motor evoked potentials improved from 0 ms to 8.89+/-0.91 ms and from 0 mv to 1.99+/-0.48 mv respectively, showing significant therapeutic effect of AG (P <0.05). CONCLUSION: AG can improve motor functions of injured spinal cord in rats, possibly resulting from decreased apoptotic cells of the neurons in the spinal cord in the early stages of the injury.

[Pullout test in expansive unilateral open-door laminoplasty of the cervical spine with OsteoMed M3 plate and screws: the screw orientation matters].

OBJECTIVE: To study the impact of screw orientation on the pullout strength of OsteoMed M3 titanium screws in expansive unilateral open-door laminoplasty of the cervical spine. METHODS: Six fresh human cervical spine specimens were randomly numbered and OsteoMed M3 plate and screws were used for an expansive unilateral open-door laminoplasty. The screws were inserted in the lateral mass at different extraversion angles (0°, 30° and 45°). The maximum pullout strength was tested on the ElectroForce material testing machine. RESULTS: The maximum pullout strength was 81.60∓7.33 N, 150.05∓15.57 N, and 160.08∓17.77 N in extraversion angle 0°, 30°, and 45° groups, respectively. The maximum pullout strength was significantly less in extraversion angle 0° group than in 30° and 45° groups (P<0.05), but similar in the latter two groups. CONCLUSION: The pullout strength of the screws inserted at an extraversion angle over 30° provides stronger fixation than an angle of 0° in the unilateral open-door laminoplasty using OsteoMed M3 titanium plate and screws.

[Placement of short iliac screw using Galveston technique in lumbosacral fusion].

OBJECTIVE: To evaluate the effect of placement of short iliac screw using Galveston technique in lumbosacral fusion. METHODS: From October 2003 to August 2007, 18 consecutive patients (mean age 46 years ranging from 25 to 62 years) received placement of short iliac screw in lumbosacral fusion. The patients were followed up for a mean of 18 months (12-23 months), and the effect of lumbosacral fusion was evaluated according to standing anterior-posterior and lateral plain films taken before and after the operation and at the follow-up and also on the basis of symptom relief. RESULTS: The mean time of surgery was 210 min (180-290 min). No complications occurred during and after the operation. According to the evaluation criteria of surgical treatment of low back pain formulated by the spine group of Chinese Orthopedic Association, excellent clinical outcome was achieved in 12 cases, good outcome in 3 cases, and tolerable outcome in 2 cases, with the excellent and good outcome rate of 83%. CONCLUSION: The Galveston technique for short iliac screw placement can obtain satisfactory outcome in the lumbosacral fusion.

[Three-dimensional visualization of the structures related to the anterior cervical segment approach].

OBJECTIVE: To establish a digital model allowing three-dimensional visualization of the structures involved in the anterior cervical segment approach. METHODS: Based on the imaging data obtained from CT angiography (CTA), magnetic resonance myelography (MRM) and continuous magnetic resonance imaging (MRI) of a healthy volunteer (scanning from the center of the head to the inferior border of the T3 level), image segmentation and reconstruction for the skeleton, arteries, veins, and spinal cord was conducted semi-automatically using the Mimics software according to the different thresholds of the tissues. The cervical plexus, brachial plexus and muscles of the neck were reconstructed with the Nerves pipe editor and the Med CAD module to establishing the three-dimensional model for displaying the structures involved in the anterior cervical segment approach. RESULTS: A three-dimensional digital model of the structures involved in the anterior cervical segment anterior approach was established, which allowed the display of anatomical relations of the skeletal structure, aorta, superior vena cava, thyroid gland, hyoid bone, laryngeal cartilages, trachea, lung, 12 neck muscle groups, as well as the spinal cord, spinal nerves, cervical plexus, brachial plexus, and intervertebral disk of the neck. CONCLUSION: The three-dimensional model established can allow the visualization of the important structures for the anterior cervical segment approach, and provides a medical teaching platform for anatomy and surgical training.