Objective To study the methods for reconstruction of pelvic ring after subtotal sacrectomy of primary sacral bone tumor.Methods The pelvic ring of nine patients with primary sacral bone tumor were reconstructed by internal fixation after sacrectomy.Results In 9 patients,all were followed-up and got satisfactory functional recovery, the pelvic ring was stable without dislocation.Conclusions Operation should be considered and adopted for primary sacral bone tumor. Reconstruction of sacrum with internal fixation can improve the stability of the pelvis.

Objective To study the methods for treatment of distal femoral complicated fractures.Methods Twenty-seven cases were treated using condyle sustain plate after open reduction.Results In 27 patients,all were followed-up for average 1 5 years,complications included two cases of phocomelia and another two patients with valgus deformity.According to Merchan standards,the rate of the excellent and the good was 73 9%.Conclusion Sustain plate is an excellent alternative for the treatment of distal femoral supracondylar fracture and intercondylar comminuted fracture.

[Objective]Design the Static Three Dimensional Screw-Plate system(STDSP), bring a new instrument for the treatment of femoral neck fractures, which has good biome chanical features of axial loading and rotation stability and can reestablish the loss of support of the posterior neck of fracture with posterior comminution. [Method]Design the STDSP. To the fracture group,one femur of each pair was randomly selected to be stabilized by STDSP, and the other was fixed by the three cancellous lag screws(TCS). Then the constructions were tested with axial loading or rotation to failure. The intact group were fixed and then taken out with the two methods, then tested with axial loading. [Result] (1)Rotation test: Compare the loads of the same rotation angle and the loads of the same width the anterior gap of the osteotomy open, STDS group is bigger than TCS group(PTCS group (P

0.05).There were significant differences between group B and C pre and postoperatively(P

[Objective]To explore the curative effect of lumbar discogenic low back pain treated with posterior lumbar interbody fusion(PLIF)and transpadicular instrumentation.[Method]Thirty-six patients with lumbar discogenic low back pain were treated with disc excision,lumbar interbody fusion and transpedicular instrumentation.The clinical results were evaluated by pre-and post-operative VAS(visual analogue scale),and the fusion rates were evaluated by X-ray of the lumbosacral spine.[Result]The average period of follow-up was 16 months,ranging from 8 to 28 months.Low back pain basically disappeared in 33 patients treated with PLIF,mild back pain occurred in 3 patients;the VAS after operation decreased significantly in comparison with that of preoparation(P

Peripheral blood mononuclear cells from 32 cases of osteosarcoma and 20 normal controls were separated and induced by lipopolysaccharide, followed by 48 hour incubation in vitro, then the supernatant were collected. The levels of IL-6 were measured by enzyme linked immunosorbent assays, the concentrations of NO were measured by Griess methods. The results were as follows: The concentrations of IL-6 and NO were significantly higher than those in normal contrls (P<0.01). There were positive correlation between the levels of IL-6 and NO in patients with osteosarcoma (r=0.652, P<0.01). The results suggest that the immune function of peripheral mononuclear cell in patients with osteosarcoma was disordered. It may activate peripheral mononuclear cells to produce high levels of IL-6 and NO, which may take part in the pathogenesis of osteosarcoma.

BACKGROUND: The commonly used research methods of lumbar biomechanics are animal model,physical model and corpse model respectively. However, each model has its own disadvantages.OBJECTIVE: To establish the finite element model of lumbarmotionsegments in order to provide theoretical basis for biomechanical research of lumbar.DESIGN: Single sample study based on healthy volunteer.SETTING: Orthopaedic department of a university hospital.PARTICIPANTS: The experiment was completed in the Orthopaedic Department of Xiangya Hospital of Central South University from December 2003to August 2004. A healthy male volunteer was chosen as a mock object.METHODS:CT scanning was conducted to the spine(T12 - S1) of a healthy volunteer by 2 mm layer and got 264 images. The 3D model of normal Chinese male L4 5 motion segments was built by combininglumbar images scanned by CT and anatomic data through 3DSMAX software. Then it was transferred into finite elementmodel by finite element analyzing software SAP2000.MAIN OUTCOME MEASURES: ① Vertebral body model andintervertebraldisc model built by 3DSMAX software; ② Finite element model of motion segment made by SAP2000 software.RESULTS:The finite element model of lumbar L4-5 segments had been built. It had totally 2 120 nodes that include 1 728 Solid units, 592 Area units and 50 Link units.CONCLUSION: The finite element model of lumbar motion segments can be established through CT scanning, digital image processing and computer aid design to further study the biomechanics of spine.

BACKGROUND: Artificial lumbar disc replacement is a novel approach to treat lumbar disc protrusion. But its theoreticalbasis needs further verification.OBJECTIVE:To establish finite element model of lumbar disc replacement for biomechanical studies.DESIGN: A single sample study taking the data of L4-5 three-dimensional infinite element model as object of research.SETTING: Orthopedic Department of Xiangya Hospital of SunYat-sen University.PARTICIPANTS: The trial was conducted in the Laboratory of the Orthopedic Department of Xiangya Hospital from December 2003 through August 2004. A healthy male volunteer served as simulation. His T12-S1 underwent continuous CT scanning. There were altogether 264 images with 2 mm inthickness each. Three-dimensional images were reconstructed every 15° in order to obtain the data for three-dimensional model.METHODS: The CT images and human anatomical data were processed by 3DSMAX software to establish three-dimensional L4-5 model of normal Chinese males. It was then transformed to finite element model after processed by SAP2000 software together with Charite SB Ⅲ disc prosthesis model.MAIN OUTCOME MEASURES: The three-dimensional model and finiteelement model of lumbar spine were successfully established.RESULTS: The finite element model of Charite SB Ⅲ disc replacement in L4_5 spine was established. The total nodes were 2542 and there were 1924Solid units, 592 Area units and 50 link units.CONCLUSION:The finite element model of artificial disc replacement can be established by CT scanning, digital processor and computer aideddesign,and used for further study on spinal biomechanics.

[Objective] To discuss the effect of total hip arthroplasty with structural bone-grafting for high congenital dislocation of adult hip.[Method]From August 2003 to October 2006,22 patients(29 hip)with congenital dislocation of hip were treated with total hip arthroplasty and structural bone-grafting.There were 10 males and 12 females.There were 13 left and 26 right.The ages were from 23 to 42 years old,with the average of 34.6 years.Clinical symptoms included hip pain,hip instability and limping.The preoperative average Harris scores was 46.8.The preoperative average length difference between two legs was 3.8 cm.The femoral head dislocation height from normal position was 3.9 cm on average(range,3.2 to 5.6cm).The average range of motion of the hip:flexion 66.5?,abduction 23.8?,external rotation 20.4?,internal rotation 5.3?.Posterolateral approach was used during operation and all the acetabular cups were reconstructed at the true acetabular location and were covered completely with femoral head autograft.The reduction of prosthesis was achieved by releasing surrouding soft tissue.The acetabular reconstruction was done with the cemented acetabular component in 18 hips,the small acetabular component in 5 and common cementless acetabular component in 6.Cementless shaft was used in 10 hips,common cemented shaft in 13,steno-vertical cemented shaft in 4 and long cemented shaft in 2.The clinical effects were evaluated with operative time,blood loss,Harris scale,joint range of motion,length difference between two legs and complications.[Result]The average operative time was 95 minutes(range from 70 to 135 rain).The average blood loss was 400 ml(range from 300 ml to 650 ml).Primary healing of wound was observed in all patients without infection.Position of prothesis judged by X-ray was fine at 1 week postoperatively,the average abduction angle of the cup was 39?,and the average anterior angle was 13?.Twenty-two cases were followed up from 10 months to 47 months(average 17.6 months)after surgery,the average score was 89.2 points(ranged from 72 points to 93 points),according to the evaluate of Harris.The average range of motion of the hip was 115.3? for flexion,44.6? for abduction,49.5? for external rotation,26.8? for internal rotation.The preoperative average length difference between two legs was 1.2 cm.There were 2 postoperative femoral nerve palsy which resolved completely within 4 months.Femoral head autografts were not absorbed.Neither loosening nor dislocation of the prostheses occurred in the time of follow-up.[Conclusion]Total hip arthroplasty with structural bone-grafting is an effective method for high congenital dislocation of adult hip.It improves symptoms,functions and shapes.Structural bone-grafting can provide reliable acetabular coverage and restore bone stock.In case of the altitude of femoral head dislocation upward from normal position less than 4cm,reduction of prosthesis can achieve by releasing surrouding soft tissue without femoral nerve palsy.

[Objective]To explore the intermediate result of the use of allograft grafting for bone defects in revision total hip arthroplasty.[Methods]A retrospective study was carried out on 22 patients(22 hips) with the use of allograft grafting for bone defects in revision of total hip arthroplasty from April 2000 to April 2005.There were 13 male and 9 female with mean age of 65.5 years.According to the AAOS system,the bone defects in acetabulum were classified into type I in 5 hips,type II 14 hips and type III 3 hips,and on the femoral side,they were classified into type I in 3 hips,type II 12 hips and type III 2 hips.The reconstruction of bone defects in acetabulum contained structural bone graft in 5 hips,impaction bone graft in 12 hips,and metal wire mesh with bone graft in 5 hips.On the femoral side,3 hips were dealed with structural bone graft,12 hips were done with impaction bone graft,and 2 hips were repaired by metal wire mesh with bone graft.Harris Hip Score System and radiography were used to evaluate the clinical efficiency.[Results]The mean follow-up time was 61 months(37～97 months).Harris score improved from 45 points(30～65) pre-revision to 86 points(62～96) at the final follow-up.Insion drainage occurred in one hip.One patient remain slight pain in hip.No prothesis loosening,radiolucent lines were observed during the follow-up.None need to second revision.[Conclusion]During the THA revision surgery,adopting suitable allografts to repair the different types of bone defects is feasible and the mid-term result is good.