Objective To explore the effect of immunogenicity of freeze-dried bone allograft on different in vitro experimental models. Methods The lymphocytes were obtained respectively from 10 healthy young human volunteers, 10 Balb/c and 10 C57 mice and 10 New Zealand rabbits. The experiment was carried out in 6 groups: positive control group (PHA/ConA+lymphocyte), negative control group (Hydroxyapatite powder + lymphocyte), allogeneic bone group A (Freeze-dried bone powder 2. 0 g/L + lym-phocyte), allogeneic bone group B (Freeze-dried bone powder 1.0 g/L + lymphocyte), allogeneic bone group C (Freeze-dried bone powder 0.5 g/L + lymphocyte), and negative control group (culture solution + lym-phocyte). Lymphocyte transformation test (Alamarblue) was conducted to culture the 6 kinds of experimental materials in vitro. After 72 hours, samples were scanned with ELISA muhiscan at wave lengths 570 nm and 600 nm to fetal the light absorption value. Pearson analyses were performed 10 determine the relationships a-mong the 3 animals and 1 human groups and find out which animal would be highly correlated to human. Results In the human and Balb/c mice lymphocyte transformation tests, there was no significant difference (P > 0.05) between allogeneic bone groups A, B, C and negative control group (HA) ; but there was sig-nificant difference (P < 0.001) between allogeneic bone groups A, B, C and positive control group (PHA/ConA); there was no significant difference between the 3 allogeneic bone groups (P > 0.05). There was no significant difference among the 6 groups of C57 mice and New Zealand rabbits (P > 0.05). The coefficient r between Balb/c mice and human groups was 0.959, P = 0.003, showing a highly positive correlation. The coefficient r between C57 mice and human groups was 0.527, P = 0.283, while the coefficient r between New Zealand rabbits and human groups was 0.866, P =0.026. Conclusions The immunogenicity of freeze-dried bone powder in this experiment may not be sufficient enough to induce significanrt immunologic response. Balb/c mice may be preferable for immunogenicity related experiments.

Objective To evaluate the functional recovery of unstable ankle fractures prospectively after early weight-bearing and cast immobilization. Methods From October 2003 to October 2007, 100 patients who had sought medical management in our department for unstable ankle fractures were enrolled in this prospective study. All patients were treated with open reduction and internal fixation (ORIF), according to the AO/ASIF principles. They were randomized into 2 even groups, one receiving early weight-bearing and the other cast immobilization. The functional recovery was evaluated in terms of Olernd score, Tegner score, pain intensity[merical rating scale (NRS)], full weight-bearing time, return-to-work time, and hospital stay time. Results Forty-six patients in early weight-bearing group and 45 patients in immobilization group finished follow-ups. There was no difference in Olernd score, Tegner score or NRS between the 2 groups, and all pa-tients got a good Olerud score and returned to work. Total weight-beating time in early weight-beating group was 4 weeks less than in immobilization group. Conclusion Early weight-bearing may be recommended for patients who have got a stable osteosynthesis of their fractured ankles as judged by their responsible surgeons, fine compliance, and a high motivation.

Objective To analyze epidemiologie and injury characteristics of traffic injuries in Shenzhen through emergency department. Methods A questionnaire was pre-designed to collect data of patients admitted to six general emergency departments of six district in Shenzhen from January 2007 to December 2007 for clinical analysis. Results There were 1 328 patients with road traffic injuries, at age range of 2-84 years (average 31 years). According to occupation, most patients were local workers and migrant workers (57.8%). The accidental vehicles were mostly cars (48.5%). Most accidents (78.6%) occurred in urban streets. As for time distribution of traffic injuries, most injuries happened on Friday and Saturday (accounting for 17.8% and 18.7% respectively), especially on Friday (r = 0.166 0, P <0.01). There was central tendency around 15:35 p.m. in one day (r = 0.285 6, P < 0.01). The age of male was (32.36±8.70) years and that of female (29.96±4.32) years, with statis-tical differences (P < 0.05). Of patients followed up, 84.4% patients could work on their original jobs, 8.5% needed ehange of their jobs and 7.1% lost the ability of work. Conclusions It is neeessary to strengthen road safety education among local workers and migrant workers to improve their awareness of road safety. Traffic administrators and road safety marks should be added in the chief period and districts where road traffic injuries happen most frequently. Controlling the number of small cars may be effective to reduce traffic accidents.

Objective To introduce an augmentation technique with 4-strand semitendinesus ten-don in treatment of partial anterior cruciate ligament (ACL) injury of under arthroscope and investigate the clinical outcome of the technique. Methods A total of 26 patients with posterolateral bundle rup-tures of ACL were treated arthroscopically with 4-strand semitendinosus tendon augmentation. The Inter-nationnal Knee Documentation Committee (IKDC) and Lysholm knee score scale were used for evaluation of knee function. The side-to-side difference in anterior knee laxity was examined by KT-1000 (25 de-grees flexion and 301b). Results There was no knee extension limitation, with knee flexion of 130°-150 °(average 142°). The patients were followed up for 12-18 months, which showed grade A in 25 pa-tients (96%) and grade B in one (4%) according to IKDC grade at final follow-up. The subjective IK-DC score was increased from preoperative (71.4±3.7) points to (95.8±3.4) points at final follow-up (t =9.836,P <0.01). The average side-to-side difference in maximal manual test with KT-1000 ar-thrometer at 25° flexion decreased from preoperative (5.1±1.2) mm to (2.1±1.3)mm at final follow-up (t = 10.48 ,P < 0.01). The Lysholm score of all patients was (76.7±3.2) preoperatively and (95. 7±2.4) at final follow-up (t =7.356,P<0.01). Conclusion Augmentation with 4-strand semiten-dinosus tendon under arthroscope can attain excellent clinical results and good anterior stability in treat-ment of partial tears of posterolateral bundle of ACL.

Objective To discuss the value of preoperative digital design of struetund bone graft for acetabular wall defects. Methods The . dieom data from spiral CT scans were imported into Mimics 10.0 to build the 3D solid model of the pelvis of an old female patient with left acetabular wall defects. The 3D solid model of the defect area was built by Mirror and 3D mask editing. A simulated bone graft was conducted on the 3D model by segmentation and trimming according to the data measured on the reconstructed model. Results The reconstructed 3D model of the patient's pelvis could be presented in different colors, transparenees, or combinations of interested tissues. The acetabular wall defects could be visualized very clearly at different angles. The geometric data of the bone graft could be measured to ensure the bone graft would fit the defects accurately. Conclusion Preoperative digital design based on 3D com-puterized reconstruction of acetabular wall defects may provide a valuable aid to clinical treatment, because it is a simple, rapid, and accurate method of increasing the fitness of bone graft and the defects,

Objective To discuss the feasibility of Shuyisha as hemostasis and repair material for liver wound. Methods Hemolysis rate, acute toxicity and eytotoxicity of Shuyisha were measured. A hemorrhage model was established by making an open wound (5 mm× 3 nun ×2 mm) on the left liver lobe of mice. Hemostasis was performed with Shuyisha in experimental group and with Surgicel in control group, when the hemostatic time and total blood loss (TBL) were accurately recorded and regular macro-scopic and histological observation carried out. Results The hemolysis rate of Shuyisha was 2.33%, with maximum tolerance does of over 0.48 g/kg and the eytotoxicity at zero. The hemostatie time of Shuy-isha was (5.00 ±0.00) s, with total blood loss of (0.88±0.18) g/kg, better than Surgicel (P< 0.05). Shuyisha was degraded completely within 14 days, with the wound healed within 21 days in ex-perimental group, much better than Surgieel. Conclusions The hemolysis rate, acute toxicity and cy-totoxicity of Shuyisha are up to the requirement of biomedical materials. Shuyisha has effective hemosta-sis, which may be related to its molecular structure and adhesion.

Objective To observe change of T regulatory cells (Tregs) and its relation with in-jury severity and sepsis following severe muhiple injury. Methods A total of 60 patients were em-ployed in the study and divided into severe group (30 patients) and critical group (30 patients) based on ISS scores and into sepsis group (22 patients) and non-sepsis group (38 patients) based on complication of sepsis. The proportion of Tregs in peripheral blood in different groups was detected by flow cytometry at days 1,3,5 and 8 after injury. Results The proportion of Tregs was significantly increased at day 5 postinjury, with statistical difference compared with that at day 3 postinjury (P < 0.01). The proportion of Tregs remained increasing at day 8 pestinjury (P < 0.05). At day 8 postinjury, the proportion of Tregs in critical group was significantly higher than that in severe group (P < 0.01). At the same time, the proportion of Tregs in sepsis group was significantly higher than that in non-sepsis group (P < 0.05). Spearman correlation analysis showed a positive correlation of Tregs proportion with ISS score (rs =0.654, P < 0.01). Conclusions Tregs play an important role in suppression of T cell-mediated im-munity after severe injury. The variation of Tregs can help evaluate prognosis and predict the risk of com-plicating sepsis in patients with severe multiple injury.

Objective To evaluate the effect of combined multiple interventional methods in treatment of acute deep venous thrombi (DVT) in lower extremities caused by military training. Meth-ods All 25 patients with DVT were treated with embolectomy by using Fogarty catheter. Of all, three pa-tients were treated only with embolectomy, six underwent embolectomy plus percutaneous transluminal an-gioplasty (PTA), 11 received PTA plus ultrasound ablation and five were implanted with stent-grafts. The clinical results were analyzed retrospectively. Results Based on angiography during operation, the ob-structed iliofemoral vein received complete recanalization in 24 patients, with the perioperative luminal di-ameter ≥71%. Partial recanalization of the entrance of common iliac vein to inferior vena cava was failed in one patient. All 25 patients were followed up for an average 34 months after operation, which showed that 24 patients received satisfactory results with normal military training and that the other one with failed recanalization of vena iliaca still felt swelling pain in lower extremity after training. Conclusion Com-bined multiple interventional methods can remarkably improve the therapeutic effect for DVT caused by military training.

Objective To observe the application and efficacy of dynamic condylar screw (DCS) in treating intertrochanteric fractures of the femur and discuss the fixation principle, feasibility, advanta-ges and related issues. Methods A retrospective analysis was done on 23 patients with intertrochanter-ic fractures of the femur treated with DCS from January 2000 to December 2006. Of all, there were 10 elderly patients with different levels of various kinds of internal diseases and 13 young patients injuried by high-energy such as traffic accidents. According to Boyd' s classfication, there was one patient with type Ⅰ fracture, five with type Ⅱ , nine with type Ⅲ and eight with type Ⅳ. After a detailed pre-operative physical examination and targeted treatment, DCS fixation was employed for intertrochanteric fractures of the femur. Results A follow-up for average 18 months showed no death. Early complications occurred in three patients including two with pulmonary infection and one with urinary tract infection, who got cured after proper treatment. There was one patient with long-term complication, post-traumatic arthritis. All 23 patients got bone healing, with excellenee rate of 96% according to Harris criteria. There were no complications like breakage of nails, nonunion, eoxa yarn deformity, shortening or external rotation of the lower limb. Conclusions DCS has advantages of simple operation, reliable fixation and coincidence with biomechanical characteristics and hence is one of ideal methods for treatment of intertrochanteric frac-ture of the femur, especially for subtrochanteric fracture, contrary chanteric fractur, fracture involving large pyriform troehanteric and comminuted fractures of sub-trochanteric lateral os integumentale.

Objective To evaluate the clinical efficacy of monosegmental pedicle instrumentation in management of thoracolumbar burst fractures. Methods A total of 67 patients with traumatic thora-columbar burst fractures (type A3.1 and A3.2) were treated with monosegmental pedicle instrumentation in our department from October 2003 to February 2008. Imageologic effect was observed by measuring sagittal index and wedge index via X-ray and clinical outcomes evaluated by using low back outcome score. Results All operations were performed successfully, with average operation duration of 93 mi-nutes and average intraoperative blood loss of 157 ml. Of all, 65 patients were followed up for 4-27 months (average 19.8 months), which showed that all the patients achieved bony fusion, with no implant failure except for one with screw loosening. The sagittal index and wedge index were 13.06°and 42.9% preoperatively and 4.47° and 21.78% postoperatively, with statistical difference (P <0.01). The final follow-up showed no significant correction loss except for two patients (P < 0.05). The low back outcome scores of all patients at follow-up were improved significantly (P < 0.05). Conclusions Monoseg-mental pedicle instrumentation has advantages of minimal invasion, short operative duration, less blood loss and less vertebral motion segment loss and hence is an effective and reliable operative technique for thoracolumbar burst fractures.