Objective Currently, there are few researches on lordosis associated with scol iosis. To explore the effects of nickel-titanium memory alloy staple (Staple) on the growth of thoracic lordosis by observing the histological changes of cartilage cells in the osteoepiphysis of the thoracic vertebrates in goats. Methods Eighteen 2-3 months old female goats, weighing 8-12 kg, were randomly divided into long staple group (n=6), short staple group (n=6), and blank control group (n=6). Long staple (7 mm) and short staple (4 mm) were implanted into T6-11 segments of goats in long and short staplegroups by anterior approach, respectively. The blank control group was not treated. The X-ray examination was performedpre-operatively and at 3 months post-operatively to observe the changes of Cobb angle. Then the growth plates and inferior facet processes of the apex vertebral body were harvested to observe the histological grades of cartilage by HE staining, and to observe prol iferation and apoptosis of chondrocytes through immunohistochemistry double label ing staining with poly-ADPribose- polymerase-p85 and prol iferating cell nuclear antigen. Results At 3 months after operation, the T6-11 Cobb angles were significantly higher than those of pre-operation in short staple group and long staple group, which were significantly higher than those in blank control group (P lt; 0.05), but there was no significant difference between short staple group and long staple group (P gt; 0.05). The results of HE staining and immunohistochemistry double staining showed that the number of chondrocytes were reduced obviously with irregular columnar arrangement and increased volume ratio of surrounding extracellular matrix in prol iferative zone and hypertrophic zone of growth plate and inferior articular process in both long and short staple groups, and this tendency was more noticeable in long staple group. There were significant differences in the grades of prol iferation viabil ity of chondrocytes between 2 staple groups and blank control group (P lt; 0.05), but there was no significant difference tewteen long staple group and short staple group (P gt; 0.05). The prol iferation viabil ities of chondrocytes in growth plate and inferior articular process were significantly higher in blank control group than in 2 staple groups (P lt; 0.01), but there was no significant difference between long staple group and short staple group (P gt; 0.05). Conclusion The histological evidences prove that the Staple implantation by anterior approach can reduce prol iferation viabil ity of chondrocytes in growth plate and inferior articular process of the thoracic vertebrates in goats, which conduces the growth direction of thoracic vertebrates to kyphosis.
Objective To design an open shape memory alloy artificial vertebral body that can be used to reconstruct the vertebral body in spine diseases, such as thoracic-lumbar spine tumors, burst fracture of the vertebrae, kyphosis and scol iosis, and to evaluate the biomechanical stabil ity of lumbar functional segment unit after insertion with the shape memoryalloy artificial vertebral body. Methods The open shape memory alloy artificial vertebral body with nickel-titanium (NiTi)alloy was made. Eight fresh spine specimens (T14-L5) from normal adult porcine were used to detect the range of motion (ROM) in 4 models and were divided into 4 groups: intact vertebrae served as group A; pedicle screw fixation of T15, L1, L3, and L4 was given in group B; after total resection of L2, it was reconstructed by open shape memory alloy artificial vertebral body combined with pedicle screw fixation of T15, L1, L3, and L4 in group C; and after total resection of L2, it was reconstructed by titanium cage vertebral body combined with pedicle screw fixation of T15, L1, L3, and L4 in group D. The three-dimensional ROM of flexion, extension, left/right lateral bending, and left/right rotation in T15-L1, L1-3, and L3,4 segments were detected in turn by the spinal three-dimensional test machine MTS-858 (load 0-8 N•m). Results Compared with group A, groups B, C, and D had good stabil ity in flexion, extension, left/right lateral bending, and left/right rotation, showing significant differences (P lt; 0.05). There was no significant difference in the degree of each motion between group B and group C (P gt; 0.05). Group C had less degree of motion in T15-L1 and L3,4 segments than group D, showing significant differences (P lt; 0.05), but there was no significant difference in L1-3 segment (P gt; 0.05). Conclusion The open shape memory alloy artificial vertebral body has a reasonable structure and good biomechanical stabil ity, it can be used to stabil ize the spinal segment with pedicle screw fixation.
Objective To observe the effect of biological fixation of femoral stem prosthesis with multilayer macropores coating by combined use of autologousbone grafting. Methods The reconstructing femoral stem prostheses were designed personally, proximal 2/3 surfaces of which were reformed by thick multilayer stereo pore structure. Twentyfour adult mongrel canines underwent right femoralhead replacement and were divided randomly into two groups. The autogenous bonemud of femoral head and neck were not used in the control group. The histologicexamination, roentgenograms and biomechanical test were carried out in the 1st,3rd and 6th month after operation to observe the bone formation and fixation inthe exterior and interior sides of the prostheses. Results Onthe whole view,bone reconstruction occurred in experimental group in the 3rd and 6th month. Roentgenograms also proved to be superior to the control group. Histological examinationshowed that both the maximum bone inserting depth（μm） and average engorging ratio(%) of newly formed bone in experimental group surpassed those in the control group. The maximum shear strength of prosthesisbone interface in experimental group was significantly higher than that in the control group（Plt;0.01）. Conclusion Intensity of biological fixation can be strengthened remarkably by using femoral stem prothesis with multilayer macropores coating by combined use of autologous bone grafting.
Objective To observe the effect of threaded titanium cage and transpedical screw for the treatment of lumbar spondylolisthesis. Methods Eighteen patients with lumbar spondylolisthesis were adopted in this study. Among them, there were 8 males and 10 females, aged from 43 to 62 years old .Roentgenogramshowed that there were 6 cases of Ⅰ° spondylolisthesis, 11 cases of Ⅱ° and 1 case of Ⅲ°. All patients were treated with cages for intervertebral fusion after total laminectomy and pedicle screws for the reduction. Results The cases were followed up from 6 to 12 months with an average of 11 months. The clinical results were excellent in 13 cases and good in 5 cases. All patients achieved successful fusion and bony union . There were no pedicle screw loosening or broken or peripheral nerve dysfunction in this series. Conclusion This method has been proved to be an effective and reliable procedure for treatment of lumbar spondylolithesis. It produces a high fusion rate and clinical success.
Because of its high biological compatibility, titanium has been a good biomaterial. The implanted artificial bone made from titanium can contact with the vital and mature osseous tissue directly within 3-6 months, the so-called osteointergration. In order to promote the process of osteointergration, FDBM of rabbit was prepared and was combined with pure titanium so as to speed up osteointergration. The study focused on bone density, bone intergration rate, new bone growth rate around the pure titanium, and the Ca2+ and PO(4)3- density of titanium-bone interface. A control group of pure titanium inplant without FDBM was set up. The results showed FDBM had no antigenicity. It could induce and speed up the new bone formation at titanium-bone interface. The titanium-bone intergration time was within 2 months. It was suggested that there were more bone morphogenesis protein (BMP) or other bone induction and bone formation factors in brephobone than that in child and adult bone. As a kind of bone induction material, FDBM was easy prepared, cheap in price, easy to storage, no antigenicity and obvious bone-inductive function.
Objective To systematically review the effectiveness and safety of power chain vs. nickel titanium coil springs in closing dental extraction space. Methods Databases including PubMed, EMbase, The Cochrane Library, Chinese Biomedicine Literature Database, Chinese Scientific Journals Full-text Database, and Chinese Journal Full-text Database were searched to collect the randomized controlled trials (RCTs) on comparing power chain with nickel titanium coil springs published before February 2012. Two reviewers independently screened literature, extracted data and assessed the quality of the included studies. Then meta-analysis was conducted using RevMan 5.0 software. Results A total of 4 RCTs involving 122 patients were included. The results of meta-analyses showed that there was a significant difference in the rate of space closure between the two groups (MD=0.30 mm per month, 95%CI 0.17 to 0.44, Plt;0.000 1); The results of subgroup analyses indicated that, both high-quality trials (MD=0.20, 95%CI 0.07 to 0.34, P=0.003) and low quality trials (MD=0.40, 95%CI 0.30 to 0.50, Plt;0.000 01) showed no significant difference in the rate of space closure. Conclusion Current clinical evidence indicates nickel titanium coil spring is superior to power chain in the rate of space closure, but its long-term effect still needs to be proved by more large-scale RCTs.
The rutile structure titanium oxide (Ti-O) film was prepared on the pure titanium material TA2 (99.999%) surface by the magnetic filter high vacuum arc deposition sputtering source. The method can not only maintain the material mechanical properties, but also improve the surface properties for better biocompatibility to accommodate the physiological environment. The preparation process of the Ti-O film was as follows. Firstly, argon ions sputtered to the TA2 substrate surface to remove the excess impurities. Secondly, a metal ion source generated Ti ions and oxygen ions by the RF discharge. Meanwhile a certain negative bias was imposed on the sample. There a certain composition of Ti-O film was obtained under a certain pressure of oxygen in the vacuum chamber. Finally, X-ray diffraction was used to research the structure and composition of the film. The results showed that the Ti-O film of the rutile crystal structure was formed under the 0.18 Pa oxygen partial pressure. A Nano scratch experiment was used to test the coating adhesion property, which demonstrated that the film was stable and durable. The contact angle experiment and the platelet clotting experiment proved that the modified surface method had improved platelet adhesion performance, and, therefore, the material possessed better biocompatibility. On the whole, the evaluations proved the modified material had excellent performance.
ObjectiveTo investigate the effectiveness of U-shape titanium screw-rod fixation system with bone autografting for lumbar spondylolysis of young adults. MethodsBetween January 2008 and December 2011, 32 patients with lumbar spondylolysis underwent U-shape titanium screw-rod fixation system with bone autografting. All patients were male with an average age of 22 years (range, 19-32 years). The disease duration ranged from 3 to 24 months (mean, 14 months). L3 was involved in spondylolysis in 2 cases, L4 in 10 cases, and L5 in 20 cases. The preoperative visual analogue scale (VAS) and Oswestry disability index (ODI) scores were 8.0±1.1 and 75.3±11.2, respectively. ResultsThe operation time was 80-120 minutes (mean, 85 minutes), and the blood loss was 150-250 mL (mean, 210 mL). Primary healing of incision was obtained in all patients without complications of infection and nerve symptom. Thirty-two patients were followed up 12-24 months (mean, 14 months). Low back pain was significantly alleviated after operation. The VAS and ODI scores at 3 months after operation were 1.0±0.5 and 17.6±3.4, respectively, showing significant differences when compared with preoperative ones (t=30.523,P=0.000;t=45.312,P=0.000). X-ray films and CT showed bone fusion in the area of isthmus defects, with the bone fusion time of 6-12 months (mean, 9 months). During follow-up, no secondary lumbar spondyloly, adjacent segment degeneration, or loosening or breaking of internal fixator was found. ConclusionThe U-shape titanium screw-rod fixation system with bone autografting is a reliable treatment for lumbar spondylolysis of young adults because of a high fusion rate, minimal invasive, and maximum retention of lumbar range of motion.
ObjectiveTo establish a method to prefabricate titanium plate with three-dimensional (3-D) printing technique for correction of mandibular prognathism in sagittal splint ramous osteotomy (SSRO). MethodsBetween January 2012 and May 2013, 12 patients with mandibular prognathism (Angle III malocclusion) were treated. Among them, 9 cases were male and 3 cases were female. Their ages ranged from 19 to 35 years (mean, 25.6 years). With the 3-D facial CT data of these patients, 3-D printer was used to print the models for preoperational simulation. SSRO was performed on 3-D models, and the titanium plates were prefabricated on the models after the distal segments were moved backward and rotated according to occlusal splint. During operations, the proximal segments were fixed to distal segments by the prefabricated titanium plates. 3-D CT scans were taken to examine the temporomandibular joint position changes before operation and at 6 months after operation. ResultsThe skull models were manufactured by 3-D printing technique, and the titanium plates were reshaped on the basis of them. Twenty-four prefabricated titanium plates were placed during operations, and they all matched with the bone segments well. Evaluation of 3-D CT scans showed that the temporomandibular joint position had no change. All patients were followed up 7-12 months (mean, 10.6 months). The face type and dental articulation were improved greatly. All cases obtained satisfactory opening function and occlusion. ConclusionWith the titanium plate fabricated based on 3-D models, surgeons are able to improve or refine surgical planning so that the operation can be performed according to preoperative simulation precisely and the complications, such as dislocation of temporomandibular joint, can be prevented.
ObjectiveTo investigate the technique and the effectiveness of digital three-dimensional (3-D) titanium mesh in repairing skull defect under the temporalis and reconstructing temporal muscle attachment points. MethodsBetween January 2009 and December 2012, 58 patients with skull defect after decompressive craniectomy at the frontal temporal region were treated. Of 58 patients, 33 were male and 25 were female, aged 17-62 years (mean, 36.2 years). The disease duration was 15 weeks to 25 months (mean, 5.8 months). The size of skull defect ranged from 8 cm×6 cm to 15 cm×12 cm. The patients underwent skull impairment patch surgery with digital 3-D titanium mesh and reconstruction of the temporal muscle attachment points at titanium mesh temporal corresponding position. ResultsThe operation time was 60-100 minutes (mean, 87 minutes). After operation, 2 cases had slight red swelling with little exudation at skin incision margin, which was cured after symptomatic treatment; 2 cases had symptom of headache, which disappeared after incision healing; primary healing of incision was obtained in the other patients. Fifty-eight patients were followed up 6-24 months (mean, 16 months). The patients were satisfied with shaping, and had no chewing pain. Head CT after operation showed good fixation of titanium mesh and titanium nail, and satisfactory skull shape symmetry; no postoperative complication of subcutaneous effusion, intracranial bleeding, titanium mesh loosening, or titanium mesh exposure occurred. ConclusionThe surgery technique of digital 3-D titanium mesh to repair skull defect in frontal temporal region and to reconstruct temporal muscle attachment points at the corresponding position of titanium mesh, basically can obtain anatomical reduction of the skull, frontal temporal, and each layer of scalp. It has the advantages of less complication, less titanium nail, and satisfactory shape.