[Objective] To explore the possible interest of therapeutic approaches including nitrogen-containing biphosphonate zoledronic acid using osteosarcoma cell lines MG63,and to investigate whether there is a synergism between zoledronic acid and methotrexate.[Method]Zoledronic acid alone or combined with methotrexate was used to treat human ostoesarcoma cells line MG63.The cell growth inhibition was assessed by MTT.[Result]There was a dose-dependent and time-dependent(1-100?mol/L)inhibition of cell proliferation by zoledronic acid.IC50 value of zoledronic acid for therapy of MG63 after 72h was 9.39 ?mol/L.The cell growth inhibition rates of MG63 at 72 h was 48.95% in zoledronic acid(10 ?mol/L)group,and 37.68%,45.93% and 52.42% in methotrexate groups MTX(1,10 and 100 mg/L).When combined treatment of zoledronic acid(10?mol/L)and methotrexate(1,10 and 100 mg/L)was used,the cell growth inhibition rates were 51.96%,66.77% and 69.23%,respectively.The combination of zoledronic acid and methotrexate demonstrated a synergistic effect.The differences were significant(P

[Objective]To discuss the surgical treatment of huge tumor invovled sacrum.[Method]A review of records in 18 patients with tumors invovled sacrum was made.Age at surgery averaged 43 years(range:31~65),eleven patients were male,seven patients were female.In this series,malignant tumor was in 14 cases,according to Enneking classification,these cases were classified toⅠA~ⅠB subtypies,which concluded chordoma(8 cases),giant cell tumor(5 cases)and osteochondroma(1 case).Benign tumor was in 4 cases with neurogenic tumor(3 cases)and aneurysmal bone cyst(1 cases).[Result]Over all,no patients were dead in the operation,no other major complications were occurred,the blood loss during surgery was 1 000 ml to 5 000 ml.All incisional wound were primary healing except 4 cases,two of them gained secondary closure after gluteus maximus pushing flap.Eighteen patients gained follow-up visiting,the average time of follow-up was 30 months,only 2 cases were tumor recurrence.[Conclusion]Huge tumors invovled sacrum present a great challenge,because of many organs surrounding sacrum invovled and complexity in anatomic region,sacrectomy of sacral tumor always complic generous blood loss,disorder of urination and defecation,disorder of sexual function et al.Abdominosacral approach can lead to a safer and relative radical local control of tumor,it is benefit to protect blood vessel and nerves.

BACKGROUND:For the sacroiliac joint has complex structure and locates deep,its biomechanical properties have not been fully understood,even less about the study of reconstruction.OBJECTIVE:To construct a finite element model of pelvis after subtotal sacrectomy,and validate its effectiveness,which is supposed to be useful for evaluating reconstructions of sacroiliac joint.TIME AND SETTING:The establishment and validation of three-dimensional finite element model was performed in the Orthopaedic Laboratory of Changhai Hospital,Second Military Medical University between January and March 2008.MATERIALS:The CT scan images of adult males who had no pathological changes in lumber and pelvis were downloaded from CT work station in Changhai hospital.The CT scan included low lumber and whole pelvis,and got 132 DICOM images in all.METHODS:Two three-dimensional finite element pelvis models were established:① an intact pelvis model,② a defective pelvis model on which subtotal sacrectomy was performed cephalic to the S1 neural foramina.According to the biomechanical experiment of Hugate RR Jr,axial loads of 3 000 N and 1 000 N were applied on intact and defective pelvis models,respectively.The max axial displacements and stiffness on the L5 of two models were calculated and following comparison with the result in the literature.MAIN OUTCOME MEASURES:The max axial displacements and stiffness on the L5 were observed and considered as the index reflecting sacroiliac joint stability.RESULTS:The max axial displacements of the L5 on intact and defective pelvis models were 7.99 mm and 7.68 mm,respectively.The stiffness of the L5 on intact and defective pelvis models were 375 N/mm and 130 N/mm,respectively.The max axial displacements of the L5 on intact and defective pelvis models in the literature were(10.73?5.10) mm and(11.71?5.74) mm,and the stiffness were(353?231) N/mm and(101?49) N/mm,respectivly .CONCLUSION:In this experiment,we were successful to establish the finite element model of pelvis after subtotal sacrectomy.The calculated result was similar with the reference.The model could be used to evaluate different ways to reconstruct the sacroiliac joint.

Tibia shaft fracture is the most common long bone fractures clinically and intramedullary nail fixation is the best choice due to superior biomechanical characteristics for unstable tibia shaft fractures.At present,the common approaches for intramedullary nail insertion are divided into supra-patellar approach and infra-patellar approach.The semi-extended position of supra-patellar approach contributes to better fracture reduction but lead to potential patella-femoral cartilage injury.In contrast,flexion or hyper-flexion position of infra-patellar approach might result in unsatisfactory fracture reduction,then have an impact on clinical outcome.Therefore,the clinical outcome might be different because of approach choice.However,there is no consensus about the optimal surgical approach for intramedullary nailing.Thus,we performed the review to discuss the approaches for tibia intramedullary nailing and compare their strengths and weaknesses.

BACKGROUND: There are disputes concerning limb salvage and reconstruction in treating pelvis malignant tumor.OBJECTIVE: To study the surgical treatment following resection of tumor at acetabular region in order to restore pelvic stability with less damage or recurrence.METHODS: Thirty-three patients diagnosed with pelvic tumor at Department of Orthopaedics, First Affiliated Hospital of Second Military Medical University from April 2002 to June 2008 were selected. All patients were received tumor resection and computer-aided prosthetic replacement, 18 patients (8 cases with chondrosarcoma, 2 cases with Ewing sarcoma, 2 cases with osteosarcoma, and 6 cases with malignant fibrous histiocytoma) were combined with antitumor drug treatment. Functional assessment of therapeutic efficacy was divided into 4 levels: excellent, good, moderate, and inferior.RESULTS AND CONCLUSION: Two patients died at months 4 and 6 after prosthetic replacement; 31 cases were followed-up for 8-32 months, mean 12.5 months. Seven cases were recurred chondrosarcoma, the recovery of other patients were as follow: 18 cases were excellent, 4 cases were good, 2 cases were moderate and no case was inferior. Most of limb function and pelvic stability was preserved. The results suggested that malignant fibrous histiocytoma and Ewing sarcoma can receive a high rate of limb preservation if treated by effective chemotherapy with low recurrence; the recurrence of chondrosarcoma was high. Tumor resection combined with computer-aided prosthetic replacement can maximatily reserve limb function and raise life quality.

Objective:To evaluate the effectiveness of TiRobot-assisted surgery by O-arm navigation for minimally invasive treatment of type C pelvic fractures.Methods:A retrospective case control study was conducted on clinical data of 53 patients with type C pelvic ring fractures treated between January 2018 and September 2019 at Shanghai Tenth People’s Hospital. There were 29 males and 24 females，aged 20-68 years［（40.4 ± 15.5）years］. All were diagnosed with AO type C fractures. A total of 32 patients underwent minimally invasive internal fixation by TiRobot orthopedic system assisted with O-arm navigation（TiRobot group），and 21 patients were managed by minimally invasive internal fixation under the fluoroscopy guidance of the C-arm X-ray machine（control group）. The operation time，intraoperative blood loss，fluoroscopy time of screw and good and excellent rate of screw placement were recorded. One week after surgery，the pain intensity was assessed by visual analog scale（VAS），and the fracture reduction quality by Matta radiographic criteria. At the latest follow-up，the recovery of pelvic function was evaluated by Majeed criteria. Complications were recorded after operation and during the follow-up.Results:All patients were followed up for 12-15 months［（13.2 ± 0.3）months］. The operation time was（85.2 ± 6.9）minutes in TiRobot group and（101.0 ± 6.7）minutes in control group（ P < 0.05）. The intraoperative blood loss showed no significant difference between the two groups（ P > 0.05）. The fluoroscopy time of screw placement was 6（5，7）seconds in TiRobot group，compared to 10（10，15）seconds in control group（ P < 0.05）. In TiRobot group，the screw placement was excellent in 30 patients，good in 1，and fair in 1，with the excellent and good rate of 97%（31/32），while in control group，15 patients showed excellent placement of screws，2 good，and 4 fair，with the excellent and good rate of 76%（17/21）（ P < 0.05）. There was no significant difference in VAS between the two groups at postoperative one week（ P > 0.05）.At the latest follow-up，the pelvic reduction quality based on Matta radiographic criteria and pelvic function using Majeed criteria did not differ significantly between the two groups（ P > 0.05）. No complications occurred after operation and during the follow-up，such as loosening or breakage of screws，heterotopic ossification，vascular injury or nerve injury. Conclusion:For type C pelvic fractures，TiRobot-assisted minimally invasive internal fixation by O-arm navigation can shorten operation time and intraoperative fluoroscopy time，and improve the accuracy of screw placement when compared to C-arm fluoroscopy.

Objective: To explore the influence of the lower extremity abnormal alignment and the joint surface, and to explore the surgical skills. Methods: Twenty-two cases of tibial plateau Schatzker Ⅵ fracture internal fixation failure revision from January 2012 to January 2017 in Department of Orthopedics, Shanghai 10^th Hospital.One year follow-up after initial surgery to make sure of failure.Three-dimensional CT scan, radiography, infection index, gait analysis, knee joint ROM, femur tibia angle, tibial plateau tibial shaft angle and posterior slope if tibial plateau were observed. The medial approach and bi-planer osteotoma were used.Autogenous iliac bone graft, postoperative fast recovery channel were used.Follow-up point included preoperative and postoperative 7 days, 6 weeks, 3 months, and 6 months.Obvervational index included double lower limbs radiography, knee society score(KSS), complications such as infection, skin necrosis, joint main passive activity, double lower limbs alignment the last follow-up SF-36 scale.Rate was compared by χ² test, measurement data using paired sample t test.Correlation was analyzed by Pearson correlation regression testing. Results: Twenty-two patients received follow-up.KSS, more than 21 cases were benign, with good gait.One case was poor, with claudication gait.Not skin necrosis, no deep infection cases, 1 case get blisters 2 days postoperatively, and disappear after 5 days with detumescence and cold therapy.Whether restoring force line affect the KSS significantly(χ²=22.000, P=0.000). Knee joint ROM, SF-36 score, KSS and lower limb alignment were improved significantly. In different individual the articular surface and anatomical angle recovered greatly but the posterior slope angle was quite difference which has no correlation with KSS and SF-36 scale(P>0.01). Conclusions Revision of Schatzker type Ⅵ tibial plateau fracture failure should focus on the recovery of lower limb alignment.moderate overcorrect bone cutting and joint surface height can bring benefits to the postoperative knee function.Revision surgery patients have greater psychological pressure, more early psychological intervention is necessary.

Objective:To investigate the therapeutic effect of robot-assisted percutaneous screw fixation in LC-II pelvic fractures.Methods:A total of 46 patients with Young-Burgess LC-II pelvic fractures, who underwent surgical treatment at Shanghai Tenth People's Hospital from December 2019 to June 2022, were retrospectively analyzed. Among them, 27 were male and 19 were female, with an average age of 39.78±15.11 years (range, 19-68 years). The causes of injury were traffic accidents (28 cases) and fall from height (18 cases); all the cases were Type B pelvic fractures according to the Tile classification. The patients were divided into two groups based on the surgical approach: the robot group (26 cases) treated by Tianji robot-assisted percutaneous screw fixation, and the actual screw group (20 cases) treated by minimally invasive internal fixation under fluoroscopic guidance. The surgical time, blood loss, number of guide wire adjustments, the success rate of initial screw placement, postoperative vertical and horizontal displacement, and postoperative pelvic fracture reduction quality (Matta score) were compared between the two groups. Visual analogue scale (VAS) was used to assess patients' pain levels before and one week after surgery, and the clinical efficacy was evaluated using the Majeed score at the final follow-up. The occurrence of complications such as infection, vascular and nerve injury, and screw breakage was all recorded during the follow-up.Results:All patients successfully underwent the surgery and were followed up for an average of 11.93±3.09 months (range, 5-15 months). A total of 84 percutaneous screws were applied in the 46 cases, with 47 screws in the robot group and 37 screws in the actual screw group. The surgical time and number of guide wire adjustments were 81.27±4.90 minutes and 0.58±0.76 times in the robot group, 102.95±8.73 minutes and 5.80±2.24 times in the actual screw group, with significant differences ( t=-10.68, P<0.001; t=-11.13, P<0.001). There was no significant difference between the two groups in terms of intraoperative blood loss and postoperative vertical and horizontal displacement ( P>0.05). The success rate of initial screw placement in the robot group was 98% (46/47, 44 excellent, 2 good, 1 poor), while in the actual screw group, it was 86% (32/37, 27 excellent, 5 good, 5 poor), with a significant difference (χ 2=4.05, P=0.044). The VAS scores at one week postoperatively were 3.38±1.20 in the robot group and 6.80±1.61 in the actual screw group, with a significant difference ( t=-8.25, P<0.001). The excellent rate of Matta score after surgery was 92% in the robot group and 85% in the actual screw group, and the Majeed scores at the final follow-up were 86.54±3.10 and 85.7±2.20 respectively, with no significant difference between the two groups ( P>0.05). All patients achieved primary healing; no complications such as infection or screw breakage occurred during the follow-up period. Conclusion:Robot-assisted percutaneous access screw fixation for LC-II pelvic fracture can achieve accurate reduction of pelvic fracture, and is characterized by short operative time, low radiation exposure, and high safety and accuracy.

Objective To explore the feasibility of the deep convolutional neural network (DCNN) judging the indications and prognosis of the total knee arthroplasty based on the trained DCNN computer learning system.Methods C1FAR-10 DCNN model based on TensorFlow (an open source system,Google,USA) optimized by Alex Krizhevsky were constructed.There were 400 cases with knee osteoarthritis from different databases used for analysis.Three hundred patients underwent total knee arthroplasty,while 100 did not.X-ray of 200 preoperative cases from the 400 cases and their enlarged image (50 times) were applied for training DCNN,while the enlarged images from other 200 cases were used to test the DCNN.The correlation and the regression between judgment of the DCNN and clinical truth were analyzed.The clinical truths were rechecked three times and were confirmed by treatment results.Pearson correlation and linear regression analysis were used.The relation test of the software was only used as a reference.Results There was no significant difference between the baseline of cases for learning and test.After learning 200 cases,the DCNN judged the 10 000 cases enlarged from remaining 200 cases.The correlation between the DCNN judgment and the clinical truth was not significant (r=0.000,F=0.001,P=0.970).False positive was observed in 1 681 cases,false negative in 3 296.After enlarged to 10 000 images,the correlation between the two judgments was significant (F=11 228.735,P=0.000,r=0.727 and R2=0.529).The software detection precision was 0.860.Conclusion DCNN can be applied in judging the indications of the total knee arthroplasty.Large sample size can improve the accuracy of the judgment significantly.

Accurate classification of the acetabular injuries and appropriate treatment plan are great challenges for orthopedic surgeons because of the irregular anatomical structure of the acetabulum and aggregation of important vessels and nerves around it. Letournel-Judet classification system has been widely applied to classify acetabular fractures. However, there are several limitations, including incomplete inclusion of fracture types, difficulty in understanding and insufficient guidance for surgical treatment, etc. Serious complications such as traumatic arthritis are common due to wrong classification and diagnosis and improper selection of surgical strategy, which brings a heavy burden to the society and families. Three-column classification, based on anatomic characteristics, has advantages of containing more fracture types and being easy to understand, etc. To solve the problems existing in the diagnosis and treatment process based on Letournel-Judet classification, achieve accurate diagnosis and treatment of patients with acetabular fractures, and obtain satisfactory prognosis, the Orthopedic Trauma Emergency Center of Third Hospital of Hebei Medical University and the Trauma Orthopedic Branch of the Chinese Orthopedic Association organized experts from relevant fields to formulate the Expert consensus on the accurate diagnosis and treatment of acetabular fractures based on three-column classification ( version 2023) in terms of principles of evidence-based medicine. Based on the three-column classification, 15 recommendations were proposed, covering the diagnosis, treatment, complication prevention and management, etc, so as to provide reference for accurate diagnosis and treatment of acetabular fractures.