Objective: To study characteristics of diagnosis and treatment of arachnoid cysts in the sacral canal. Method: After laminectomy of the sacral canal, arachnoid cysts were treated in three ways: 13 cases underwent excision of the most of the cyst wall and suture of redundant wall around the intracystic nerve; 8 cases underwent the excision of the most of the cyst wall and plugging the communicating hole with a block of muscle; 2 cases underwent excision of most of the cyst wall and leaving them unsutured. Clinical results were evaluated after 30. 2 months' follow-up. Changes in the imaging materials (X-ray, CT, CTM and MRI) were also evaluated. The clinical behaviors, pathologies and complications post-operatively were analyzed. Result: Long T1 and T2 signals of the cysts could be clearly showed in MRI, and the signal density was the same as that of cerebrospinal fluid. Clinical symptoms were caused by compression of sacral nerve. Generally, there were communicating holes between cysts and thecal sacs. There were no statistical differences between first two methods of treatments. The complications post-operatively included erosion of wound skin and intracranial infection. Conclusion: MRI allows us to better illustrate the arachnoid cyst in sacral canal, and the cyst seems to arise as a result of congenital defect of thecal dura. Excision of the most of the cyst wall and plugging the communicating hole with a block of muscle seems to to a reasonable method to treat the carachnoid cysts in the sacral canal. Do not put the drain tube and forbidding patients to lie supinely are better for reducing the complications.

Objective: To treat limb length discrepancy or deformity using external fixation,and Correct potential complications. The authors present their figures for reapplication of external fixator frames in the same bone segment following complications during or after the treatment phase. Methods: Two hundred and sixty-one patients (297 limbs) underwent this type of treatment in our unit between Feb. 1991 and July 1999 with either Orthofix or Ilizarov fixators.228 in children and 69 limb segments in adults. Results: Reapplication of 22 fixators in children (9.65%), and 4 fixators in adults (5.8%) was performed. This gives an overall reapplication rate of 8.75%. The reason for reapplication was fracture and / or deformity of the regenerate (15 segments). Four patients eventually came to amputation. Conclusion: The authors recommended the continue use of this technique for the treatment of severe deformity particularly in congenital disorders.

Giant cell-rich osteosarcoma is a rare osteosarcoma and easily regarded as giant cell tumor of bone by pathematology.Because two deseases have different therapies,misdiagnosis frequendy affect the operator to select suitable surgical procedures.We described the cage of a patient with giant cell-rich osteosarcoma,non vascularised fibular grafts were used as substitutes for repairing and reconstructing caput humeralis and shaft of humerus after resection for bone tumors on proximal humerus,part functions were remained after the operation.

[Objective] High tibial osteotomy is a well accepted procedure for medial compartment osteoarthritis of knees.Over time its results deteriorate and some patients were reoperated with a total knee arthroplasty.To evaluate the results of total knee arthroplasty after a high tibial osteotomy.[Method] Thirty-eight knees were evaluated retrospectively for the results of a total knee arthroplasty after a high tibial osteotomy.They were followed up for an average of 8 years and the mid terra results assessed.[Result] The average Hospital for special surgery score increased to 86.5 points from 39 points pre-operatively.There were 87% excellent and good results.[Conclusion] Mid term results of total knee arthroplasty after hish tibial osteotomy are excellent and are comparable to those without a tibial osteotomy.

[Objective] To evaluate the clinical value of diagnosing osteoporosis with vertebra bone mineral density(BMD) by measurement with quantitative computed tomography (QCT) . [ Method] BMD in of lumbar vertebrae (L<,1～4>)were measured by QCT in 53 healthy middleaged persons or elderly persons (group A) and 68 osteoporosis patients ( groupB) . [Result] BMD in group A declined obviously as age increasing with significant differences (P<0. 01) . In group B,all 68 patients showed osteoporosis according to the diagnostic standard of BMD≤x -2. OSD. Sixty patients showed osteoporosis ifthe diagnostic standard was set to BMD ≤ x -2. 5SD. The BMD values of different age group was lower than the bone quantityblock values. [Conclusion] As a method for diagnosing osteoporosis, QCT has advantages of high sensitation, being precise,being reproducible and is easy for applying. It would be more practical and could decrease mis - diagnosing if the diagnosticstandard was BMD≤x-2.OSD.

[Objective] The efleet of sagittal orientations of articular facet on the contact force and contact regions of a lumbar spine segment was evaluated.[Methods] [Results]Three-dimensional geometrical and mechanical accurate finite element models of the lumbar L4、5 motion segment representing three sagittal-orientations articular facet were generated and invalidated by an effective CAD method.Contact force and contact regions of the articular facets of three finite element models were predicted under the pure shearing loads.[Result] Under anterior shear condition,the contact force on the facet decreased with the increase of sagittal 0rientation of articular facet.however.in posterior shear load,the contact force on the facet increased with the increase of sagittal orientation.Meanwhile,under both pure shear loading,the percentages of the sagittal and the transversal components are increased with the dectease of the sagittal angle.However,under the salne load condition,there are no difference between the contact regions of the three models with different facet joint angle.[Conclusion]The spatial orientation and geometric forms of the coronal facet articular surfaces are more effective in restricting motion in transversal and sagittal planes while assuming a minor role in resisting axial force or motion than sagittal facet articular surface.It Was presumed that anterior shear force play a more prominent contribution on the degeneration of the facet joint with coronal articular surface compared with posterior shear force.

[Objective]To introduce the surgical technique and its rationale and to evaluate the early and mid-term clinical outcome of routine core decompression and insertion of a biomaterial loaded allograft threaded cage(ATC)in the treatment of necrotic femoral head．[Methods]Seventy-six patients(78 hips)with femoral head necrosis were allocated to a program of either core decompression or core decompression and implantation of ATC．[Results]At review all patients had a minimum follow-up of 24-months(24 to 68 months)．In the control group，no significant improvement in Harris hip score(HHS)was found，and 13 of the 22 hips had deteriorated to stageⅢ．In the treatment group．the mean HHS was improved from 62．8 to 81．6．Collapse was seen in 1 hip，and this collapse Was progressive in 3 hips．[Conclusion]It，s thus evident that the technique is attractive as a salvage procedure．which shows encouraging Success rates and early clinical results.

[Objective]To investigate the protective effect of Tanshinone IIA (TSⅡA) against interleukin-1β (IL-1β) induced obstruction of energy metabolism of rabbit annulus fibrosus cell in vitro.[Methods]Rabbit annulus fibrosus (AF) cells were cultured in 3-dimension alginate beads and randomly divided into 7 groups. Various concentrations of TSⅡA and IL-1β was added to the medium for intervention: no drug was added in group A as normal control, 4 μg/ml TSⅡA in group B, 10 μg/ml IL-1β in group C, and both 10 μg/ml IL-1β and different concentrations of TSⅡA in groups D-G (0.5 μg/ml, 1 μg/ml, 2 μg/ml and 4 μg/ml respectively). After 3 days of incubation, the cells were collected for measuring the activity of Na+-K+-ATPase and succinate dehydrogenase (SDH), MTT assay for cell proliferation, and AnnexinⅤ-PI staining for cell apoptosis.[Results]The activity of Na+-K+-ATPase of group G (10 μg/ml IL-1β+4μg/ml TS IIA; 3.23±0.28 U/mgprot) was increased significantly as compared with group C (10 μg/ml IL-1β; 1.118±0.15 U/mgprot, P＜0.01). The activity of SDH of group G was 12.48±0.97 U/mgprot, which was obviously higher than that of group C (3.03±0.60 U/mgprot, P＜0.01). The absorbance of MTT assay of group G (0.77±0.06) was significantly increased as compared with group C (0.31±0.07,P＜0.01). The absorbance of groups D-G increased as the concentration of TSⅡA increased. The apoptotic cell rate and dead cell rate of group G was 21.08±1.46% and 8.99±0.33%, which were both lower than that of group C (43.11±2.7,P＜0.01 and 11.71±0.32,P＜0.01).[Conclusion]TSⅡA is able to promote cell proliferation and decrease cell apoptosis of AF by alleviating IL-1β induced inhibition on cell energy metabolism.

[Objective]To evaluate the result of operative treatment of tibial plateau fracture and analyze its related factors of influencing the therapeutic effect and provide effective prevntional measures.[Method]Totally 107 cases(male 62 cases;female 45 cases) of tibia plateau fractures were operated with internal fixation from Feb.2000 to Apr.2005 in our hospital.According to Schatzker classification,there were typeⅠfracture 2 cases,typeⅡ 37 cases,typeⅢ 29 cases,type Ⅳ 22 cases,type Ⅴ 10 cases,type Ⅵ 7cases.TypeⅠfractures were treated with cannulated screws,other type fractures were performed with open reduction and internal fixation with buttress plates and autologous and/or allograft bone grafts.Therapeutic effect and its related factors were analyzed concomitantly.[Result]The 107 patients were followed up for 9~64 months(averaged 27 months).The clinical results were assessed according to Hohl scale for knee joint.The excellent and good results was 85.98%.There were obvious complications articular stiffness 1 cases and traumatic arthritis 8 cases including tibia plateau articular depression 4 cases.[Conclusion]Surgical operation is effective methods of treating tibia plateau fracture,The complete fracture reduction suitable internal fixation a good protection and recovery of the soft tissue of the knee joint structure,and correct and effective function rehabilitation are the significant measures for good therapeutic effect in the treatment of tibia plateau fracture.

[Objective]To discuss the effects of DHS and compression screw application on femoral intertrochanteric fracture.[Method]Internal fixation was performed with DHS,DHS and compression screw,Ender nail and proximal femoral anatomical plate in 185 patients with femoral intertrochanteric fracture.The main outcome measures were operation duration,coxa adducta rates and postoperative Sanders scoring.[Result]All patients were followed up for 9-48 months.Operation duration was similar in the four groups.There were significant differences in coxa adducta rates and postoperative Sander's scores.According to the Sander's scores,the excellent to good rates in DHS and compression screw,DHS,Ender nail and proximal femoral anatomical plate groups were 94.6%,85.3%,75.4% and 80.6%,respectively.The coax adducta rates were 2.4%,9.5%,22.2% and 19.2%,respectively.[Conclusion]All the four kinds of internal fixation can be used for femoral intertrochanteric fracture,but DHS and compression screw is the best one for its good restoration of joint function and has no or little complication.