[Objective]To present a validated two-functional spinal unit C4~7 finite element model with simulated placement of a disc prosthesis treatment to predict stresses and strains within adjacent vertebal bodies. [Methods]Two finite element models of C4~7 were generated using the CT scans taken from a male patient following placement of a disc prosthesis treatment,which were included with adjacent bodies,intervertebral discs. Simulations were conducted imposing a compression preload combined to a flexion/extension moment,a pure lateral bending moment and a pure torsion moment,and to quantify the stress levels in intervertebral discs,endplate,cancellous bone,cortical bone and adjacent bodies following placement of a disc prosthesis under clinically relevant loading conditions.[Results]The BryanTM disc prosthesis allows to correctly reproduce a physiological motion at the implanted level,and the changes in stresses and strains in levels adjacent to a placement of a disc prosthesis treatment level were minimal.[Conclusion]The artificial cervical disc prosthesis well restores the biomechanical behavior of the intact spine. Moreover,the selection of surgical indications and proper manipulations shoule bve paid more attehtion to.

Objective To explore a new surgical procedure of open reduction and internal fixation for intraarticular fractures of calcaneus and its clinic outcome. Methods Between August 2004 and August 2005, 54 feet in 44 patients with calcaneal fracture were treated in our department. Based on the results of X-ray and coronal CT scan before and after treatment, small incision (2-3 cm) at lateral sides of calcaneus, self-made calcaneal anatomical plate and stud bolt were used. According to Sanders classification system, there were 12 cases of type Ⅱ, 32 cases of type Ⅲand 10 cases of type Ⅳ. Results The internal fixation with the calcaneal anatomical plate almost restored the height, length, width, Blher's and Gissane's angles of the calcaneus for the 44 patients. No infection of incision happened. The results were evaluated using Maryland Foot Score. 54 fractures were followed up for 2 to 12 months (averaging 8.3 months) after treatment. Excellent results were noted in 26 fractures,good in 24,fair in 4, and the excellent and good rates were 92.6%. Conclusion The open-reduction and internal fixation with self-made calcaneal anatomical plate and stud bolt is one of the best ways for treatment of fracture of calcaneus.

Objective To probe the effects of interlocking intramedullary nail fixation in treatment of long bone fractures, evaluate the application of intramedullary nail fixation treatment of long bone fractures, and explore the complications and their management. Methods Retrospective study of 2126 cases with long bone fracture treated with interlocking intramedullary nail from January 1996 to January 2004 was carried out. Of them, 1089 cases were followed up, and the average follow-up duration was 4 years (1 to 8 years). The locations of fracture were tibial and fibular in 603 cases, which were left in 237 cases and right in 331 cases and bilateral in 35 cases, close fracture in 511 cases of type C 240 cases, type A of 134 cases and type B 137 cases, open fracture 92 cases of Gustilo Ⅰ type 63 cases and Gustilo Ⅱ type 29 cases; femoral fractures in 360 cases, which were left 136 cases, right 205 cases and bilateral 19 cases, close fracture 319 cases of type C 191 cases, type A 103 cases, type B 25 cases; Open fracture 41 cases; Humeral fractures in 126 cases, which were left 49 cases, right 71 cases and bilateral 6 cases, close fracture 113 cases of type C 24 cases, type A 64 cases and type B 25 cases; Open fracture 13 cases. Results Fracture healing rate was 93% in interlocking intramedullary nail fixation treatment of long bone fracture. Complication included fracture nonunion rate 7%, infection rate 3%, fat embolism syndrome 2%, nail and locking bolts broke 2%, iatrogenic fracture 1.3%, knee pain in patients with tibia shaft fracture after interlocking intramedullary nail treatment 35%. Conclusion Interlocking intramedullary nail is more suitable for long bone fracture because it can result in more reliable fixation, less operative trauma. It can be used as the first alternative to treat long bone fractures.

[Objective]To explore a new therapy for postoperative non-union distal humeral frature.[Method]From January 2000 to January 2005,27 cases of non-union after internal fixation operations of distal humeral fractures were treated with retrograde intramedullary nailing combined with bone graft.[Result]All cases were followed up form 6 months to 32 months,with an average of 16 months.All the non-union were healed and joint function resumed to normal.No infection,no nail and locking bolts broken and no humeral distal fracture were found.[Conclusion]Retrograde intramedullary nailing combined with bone graft is an effective therapy for postoperative non-union of distal humeral fracture.

Objective To discuss the clinical effect of hallux valgus deformity treated with minimally invasive the first metatarsal distal osteotomy. Methods The data of 375 cases (626 feet) treated with minimally invasive the first metatarsal distal osteotomy was retrospectively analyzed. Hallux valgus angle was21°-65°(mean37.61°±9.25°), intermetatarsal (IM) anglewas7° -21° (mean 13.03°± 3.73°). The preoperative American Orthopaedic Foot and Ankle Society (AOFAS) score was (46.5 ± 9.4) pints. Results The patients were followed up 12-30 months [mean (18.5 ± 6.8) months]postoperation, hallux valgus angle was 7.18°±4.55°,intennetatarsal angle was 5.07°± 1.70°,with a mean angle decreasing 30.54° and 12.33°.The AOFAS score was (84.8±7.6) points (P <0.01). Conclusion According to the hallux valgus angle,intermetatarsal angle and the length of the first metatarsal,decide the place and method of osteotomy, the hallux valgus can be corrected in three-dimensional and get an excellent effect.

BACKGROUND: Vascular endothelial growth factor (VEGF) is able to effectively treat the ischemic heart disease, but in vivo VEGF cannot be maintained effective concentration. OBJECTIVE: To detect the expression of VEGF mRNA and protein in human bone marrow mensenchymal stem cells transferred by VEGF-165 gene. DESIGN, TIME AND SETTING: The empirical study was conducted from March 2006 to April 2007 at Shanghai Chest Hospital. MATERIALS: Human bone marrow mesenchymal stem cell line and VEGF were offered by Basic Laboratory, Thoracic Tumor Institute, Shanghai Chest Hospital. METHODS: hVEGF165 gene was reconstructed in pcPGK-vector and transferred into human bone marrow mensenchymal stem cells (BMSCs) by liposome-mediated method, clone screening by G418. MAIN OUTCOME MEASURES: The mRNA and protein of VEGF gene in transferred cells was detected by reverse transcription-polymerase chain reaction (RT-PCR), Real time PCR, Western Blot, enzyme linked immunosorbent assay (ELISA) in 3 stem cells of pcPGK-VEGF165-IRES-GFP and pcPGK- IRES-GFP, respectively. RESULTS: pcPGK-hVEGF165 vector was reconstructed and transferred into hMSCs successfully. The expression of hVEGF165 in the transfected hMSCs was demonstrated with RT-PCR and Real time PCR. Western Blot and ELISA demonstrated that the expression of hVEGF165 in the transfected hMSCs and VEGF protein in supernatant were significantly more than untransfected hMSCs. CONCLUSION: hVEGF165 can be successfully transfected into BMSCs by using liposome mediated gene transfer. Stably expressed VEGF165 cell line can be obtained..

Objective To measure the normal sagittal and coronal diameters of thumb and great toe distal phalanx bottom by ultrasonography. Methods One hundred and twenty volunteers' sagittal and coronal diameters of thumb and great toe distal phalanx bottom were measured by ultrasonography. The measurements was analysed by the statistical method. Results The thumb and great toe distal phalanx bottom showed hyperechoic zone,clear boundary with the adjacent fascia and tendon tissue showed low echo area at cross section by high frequency ultrasound. The sagittal diameters of thumb distal phalanx bottom was (8. 07 ± 0. 67)mm in men, while that of great toe distal phalanx bottom was (8. 34 ± 1. 02) mm( t = 1.73, P =0.86).The coronal diameters of thumb distal phalanx bottom was (11.61 ±0.89)mm in men, while that of great toe distal phalanx bottom was (14. 25 ± 0. 84)mm( t = 16. 77, P = 0. 00). The sagittal diameters of thumb distal phalanx bottom was (7. 52 ± 0. 62) mm in women, while that of great toe distal phalanx bottom was (7. 72 ± 0. 67) mm( t = 1. 72, P =0. 14). The coronal diameters of thumb distal phalanx bottom was (10.94 ± 0.97) mm in women, while that of great toe distal phalanx bottom was (13. 51 ±0. 75) mm( t =16.21, P = 0.00). Conclusions The normal sagittal and coronal diameters of thumb and great toe distal phalanx bottom measured by the ultrasonography can guide the operation of wrap-around flap of a great toe with phalanx ungual for thumb II degree defect reconstruction.

The purpose of this study was to compare the biomechanical stability obtained by using our technique featured an anatomical plate and compression bolts versus that of the conventional anatomic plate and cancellous screws in the fixation of intraarticular calcaneal fractures. Eighteen fresh frozen lower limbs of cadavers were used to create a reproductive Sanders type-III calcaneal fracture model by using osteotomy. The calcaneus fractures were randomly selected to be fixed either using our anatomical plate and compression bolts or conventional anatomic plate and cancellous screws. Reduction of fracture was evaluated through X radiographs. Each calcaneus was successively loaded at a frequency of 1 Hz for 1000 cycles through the talus using an increasing axial force 20 N to 200 N and 20 N to 700 N, representing the partial weight bearing and full weight bearing, respectively, and then the specimens were loaded to failure. Data extracted from the mechanical testing machine were recorded and used to test for difference in the results with the Wilcoxon signed rank test. No significant difference was found between our fixation technique and conventional technique in displacement during 20-200 N cyclic loading (P=0.06), while the anatomical plate and compression bolts showed a great lower irreversible deformation during 20-700 N cyclic loading (P=0.008). The load achieved at loss of fixation of the constructs for the two groups had significant difference: anatomic plate and compression bolts at 3839.6±152.4 N and anatomic plate and cancellous screws at 3087.3±58.9 N (P=0.008). There was no significant difference between the ultimate displacements. Our technique featured anatomical plate and compression bolts for calcaneus fracture fixation was demonstrated to provide biomechanical stability as good as or better than the conventional anatomic plate and cancellous screws under the axial loading. The study supports the mechanical viability of using our plate and compression bolts for the fixation of calcaneal fracture.

BACKGROUND : After femoral neck fracture, incidences of ischemic necrosis and bone non-healing are closely related to biomechanical characteristics of internal fixation devices. Compression stress can improve fracture healing, tension force can delay fracture healing, and shear stress can inhibit fracture healing. How to relieve shear stress and expand compression stress is of significance for theories and clinical applications.OBJECTIVE: To compare the biomechanical characteristics of the two geometric configurations of three cannulated compression screws in the fixation for femoral neck fracture and to provide a theoretical foundation in the treatment of femoral neck fracture.DESIGN : Observational contrast study.SETTING: Department of Orthopaedics, the 251 Hospital of Chinese PLA; Department of Orthopaedics, the Third Hospital, Hebei Medical University.PARTICIPANTS: The experiment was carried out in the Hebei Orthopaedic Institute from November 2002 to March 2003. Five cadavers including 4 males and 1 female with similar bone mineral density (BMD) were provided by Department of Anatomy, Hebei Medical University. X-ray photographs proved that all the cadavers did not have rheumatism, tuberculosis, tumor, fracture or deformity.METHODS: Ten femurs were randomly divided into inverted and upright isosceles triangle with 5 in each group. Femur samples with femoral neck fracture were fixed with three cannulated screws and measured with the biomechanical machine (CSS-44020, made in Changchun Experimental Researching Institute, provided by Hebei Orthopaedics Institute). The compression strength, torsibility and the maximal vertical loading were compared between the two configurations of screws.MAIN OUTCOME MEASURES:①Displacement of femoral head at 600 N and 750 N during torsibility test; ②torque-moment at 2°and 4°during torsibility test;③load during maximal vertical loading test.CONCLUSION: The effect of three cannulated compression screws configured as an inverted isosceles triangle on the treatment of femoral neck fracture is superior to that of three cannulated compression screws as an upright isosceles triangle.

Objective To investigate the clinical results of two minimally invasive approaches for calcaneal fractures.Methods The data of 93 patients with displaced intra-articular calcaneal fractures was retrospectively analyzed who were treated from April 2010 to September 2010 in our trauma centre.The patients were divided into two groups according to different minimally invasive approaches.Group A consisted of 50 patients (51 feet) who were treated with the minimally invasive longitudinal approach,including 47 males and 3 females with an average age of 38.22 years.Type Sanders II included 27 feet,type Ⅲ included 18 feet and type Ⅳ included 6 feet.B(o)hler angle was-1.1° on average before operation.Group B consisted of 43 patients (45 feet) who were treated with the sinus tarsi approach,including 42 males and 1 female with an average age of 41.40 years.Type Sanders II included 23 feet,type Ⅲ included 17 feet and type Ⅳ included 5 feet.B(o)hler angle was 2.6° on average before operation.The difference was investigated between the two groups in their operation time,complications and the scores according to the ankle and hindfoot score system of American Orthopaedic Foot and Ankle Society (AOFAS).Results All patients were followed up in the two groups.The average time of follow-up was 28.2 months in Group A and 27.6 months in Group B.The mean operation time was 40.78 mins in Group A and 60.67 mins in Group B.The rate of complications in Group A was 3.92％ (2/51),and 8.89％ (4/45) in Group B.The mean AOFAS score was 85.96 in Group A and 88.60 in Group B.Conclusion No statistically significant difference was found between the mininally invasive longitudinal approach and the sinus tarsi approach in the effect of the treatment for the displaced intra-articular calcaneal fractures.However,the minimally invasive longitudinal approach could be a better choice for its shorter operation time and lower rate of complications than the sinus tarsi approach.