Objective To explore the mechanisms of posterior pilon fractures and evaluate the curative effects of different types of fixation on the treatment of posterior pilon fractures.Methods We included in this retrospective study 20 patients with posterior pilon fracture who had been treated from January 2012 to January 2015 at our department.They were 10 men and 10 women,from 23 to 77 years of age (average,50.6 years).According to the classification by Yu Guangrong,5 cases belonged to type Ⅰ,3 to type Ⅱa,4 to type Ⅱb,and 7 to type Ⅲ.One was not indentified because of lacking CT examination.The mechanisms included ground level fall in 2 cases,motor vehicle accident in 7,fall off stairs in 5,sport injury in 2,fall from a bike in one and fall from a height in 3.More than 25％ of the articular surface was involved in 13 patients.Syndesmosis injury was identified in 6 patients by Cotton test during operation.Internal fixation varied accordingly.We recorded the mechanism,classification,proportion of the articular surface involved (more or less than 25％),and syndesmosis injury to figure out the characteristics of posterior pilon fractures.We used the Burwell-Charnley radiographic criteria to assess the postoperative reduction of the articular surface,and the Olerud-Molander scoring scale and visual analogue scale (VAS) to assess the ankle function.The curative effects of different types of fixation on the treatment of posterior pilon fractures were compared.Results Of the 20 patients,17 were available for follow-up for 6 to 36 months (average,17.8 months).Two patients received reoperation because of implant failure after cannulated screw fixation from anterior to posterior.The Burwell-Charnley radiographic evaluation revealed 12 anatoinical reducations and 8 fair reductions.The mean Olerud-Molander score for the 17 patients at the final follow-ups was 81.5 (range,from 35 to 100) and the mean walking VAS was 1 (from 0 to 3).Conclusions Posterior pilon fractures are mostly caused by medium to high energy violence,resulting from a combination of rotational and vertical forces.Since there is a high risk of implant failure,the cannulated screw fixation from anterior to posterior is not recommended.Good clinical outcomes are observed in the cannulated screw fixation from posterior to anterior and the plate/cannulated screw fixation for posterior pilon fractures.

AIM: Bone morphogenetic protein (BMP) as polyphenic morphogen can induce the formation of bone and cartilage. This study investigates the effect of BMP on articular cartilage regeneration after periosteal graft. METHODS: Experiments were performed at the Animal Laboratory (absl-3) of Weifang People's Hospital from September 2006 to January 2007. Sixteen New Zealand white rabbits (32 knees) (2.5-3.0 kg) were divided into experimental and control groups randomly, each 8 rabbits (16 knees). The 3.5 mm in diameter of full-thickness articular cartilage defect was made on femoral intercondylar fossa in all rabbits, and 3.5 mm in diameter of periosteum was cut out from the anteromedial part of the upper tibial bone. In the experimental group, the cartilage defect was covered with periosteum, into which 20 ?g BMP and 20% Pluronic were injected. In the control group, the cartilage defect was covered with periosteum, into which the same dosages of 9 g/L saline and 20% Pluronic were injected. All the rabbits were sacrificed in 4, 8 and 12 weeks postoperatively. Motion of joint, conjunction of repair tissue and perienchyma were examined macroscopically. Haematoxylin-eosin staining and toluidine blue staining were used to observe the characteristics of repair tissues. Histological scores on samples in each group were measured by Wakitani score standard at different time points with light microscope. Ultramicrostructure of transplanted tissues was observed with scanning electron microscopy (SEM). RESULTS: Sixteen rabbits were included in the final analysis. Macroscopic observation: 4 weeks after the surgery, the defect was covered with tissue like cartage in the experimental group, and with periosteum in the control group. 8 weeks after the surgery, the surface of the defect was smooth, with boundary unclear in the experimental group. In the control group, the outcome was the opposite. In 12 weeks, cartilage had formed in the experimental group, and tissue like cartilage began to happen in control one. Histological observation: 4 weeks after the surgery, the defect was filled with cells and matrix with abundant proliferation of periosteal cambium layer in the experimental group, and slight proliferation in the control group. 8 weeks after the surgery, the periosteum in the experimental group became fibrocartilage with little hyaline cartilage. Just little fibrocartilage with on hyaline one was detected in the control group. In 12 weeks, the repair tissue in the experimental group approached to normal cartilage. Just fibrous tissue with little fibrocartilage was detected in the control group. Regenerative repair of cartilage defect was better in the experimental group than in the control group (P

Articular cartilage defects are common, which is one of the important factors leading to joint degeneration. Due to lack of vascular supply, the ability to regenerate itself is limited. SO the surgeons try a variety of ways to repair these defects. What specific methods are adopted should be based on the pathological types of cartilage defect in order to develop optimal strategies.

Objective:To study the effects of pulse electro-magnetic fields (PEMFs) on the healing of tibial condylar osteochondral in rabbits.Methods:Sixteen rabbits were divided into two groups,and osteochondral fractures of left tibia condyle were created,internal fixation was performed with steel wire.Group 1 was constantly treated with PEMFs six hours per day;group 2 was not treated.The results were studied by gross morphology,light microscopy and elect ro-microscopy.Results:75% and 13% fractures were repaired by hyalin-like cartilage in group 1 and in group 2 respectively.Conclusion:PEMFs are essential to facilitation of the cartilage repair.

Objective To compare the placement of peripherally inserted central catheters(PICC)by using vascular ultrasound guidance system and traditional method.Methods Totally 938 patients undergoing PICC were divided into the traditional method group and the vascular ultrasound system and microintroducer techniques group according to the puncture time.The differences in the one-attempt success rate and the overall success rate of the placement and the incidences of complications were compared between the two groups.Results The one-attempt success rate was 93.01％ in the traditional method group and 98.76％ in the vascular ultrasound system and microintroducer techniques group(P =0.005).The successful rate of PICC placement was 100％.The incidence of complication was 11.29％ in the traditional method group and 2.47％ in the vascular ultrasound system and microintroducer technique group(P =0.000).Conclusion The PICC placement using vascular ultrasound guidance system and microintroducer techniques can increase one-attempt success rate and decrease complications.

We studied Yersinia infection and carriage in shepherd dog on the natural foci of Marmota himalayana plague and investigated the substitution or antagonism relationship among three pathogenic Yersinia in nature,providing a novel approach for prevention and control of plague.Blood sample and rectal swab specimens from shepherd dogs were collected.Rectal swab specimens were detected and isolated for Y.enterocolitican and Y.pseudotuberculosis.IHA was used to measure the positive rate of F1 antibody.Results showed that among 88,94,70 and 64 serum specimens respectively from Akesai,Subei,Sunan,and Tianzhu,IHA positive rates were 31.82％,32.98％,2.86％ and 1.56％ separately.A total of 236 anal swab specimens of shepherd dog were collected,among which one Y.kristensenii strain and 2 non-pathogenic Y.enterocolitica strain were recovered from Akesai and Subei respectively,where plague was violently prevalent in animals.All the results indicate that shepherd dogs in natural foci of M.himalayana plague where plague in animals are prevalent with non-pathogenic Y.enterocolitica,is an evidence of antagonism relationship in three pathogenic Yersinia.

ObjectiveTo compare the outcomes and indications between exchange nailing (EN) and augmentation plating (AP) with a nail left in situ for femoral shaft hypertrophic nonunion after femoral nailing. MethodsFrom April 1998 to June 2009, 20 patients with femoral shaft hypertrophic nonunions after femoral nailing were treated with EN (11 patients) and AP (9 patients) respectively. There were no significant differences between the two groups with respect to the patient's age, gender, associated injuries, anatomical location and type of femoral fracture. Patients were evaluated by imaging and clinical function at 1, 2, 3, 4,6, and 12 months after surgery, and then every year postoperatively, to observe the callus and the recovery condition of the affected limb function. Fisher exact test and t'-test were performed to compare the outcome and complications respectively. ResultsAn unpaired t'-test showed no significant differences with respect to follow-up time, operating time, intraoperative blood loss, postoperative drainage, length of stay, time to radiographic union, time to clinical union, and AAOS score between the two groups. The cost of hospitalizations in the EN group was higher than in the AP group(t'=16.4, P=0.013). Four nonunions in the EN group failed to achieve union, which 3 patients were subsequently treated with AP and simultaneous autogenous bone grafting and 1 patient was treated with nail dynamization. All 9 hypertrophic nonunions in the AP group obtained osseous union. Fisher exact test showed a higher nonunion rate of EN compared with AP (χ2=6.01 ,P=0.008). ConclusionEN has been an excellent choice for aseptic isthmal femoral nonunion without a large bone defect subsequent to intramedullary fracture fixation, and AP can be an effective solution in cases of nonisthmal femoral nonunion and bone defect and failed exchange nailing.

Objective: To make a study of density and affinity of IL-6R in human leukemic cell lines, and discuss the affection of high affinity IL-6R to the targeted treatment of leukemia with IL-6-PE40 fusion protein. Methods: Radial binding assay with scatchard plot and FACS were used to analysis the density and affinity of IL-6R and protein expression of IL-6Rα and β subunits in totally 8 representative human leukemic cell lines. Results: Myelocytie, monocytic and erythrocytic leukemic cell lines U937, HL-60, KG1 and TF1 express high affinity IL-6R, whose average density per cell is 2 502,2 874, 2 319 and 9 329 respectively, however no 125I-IL-6 binding was detected on chronic myelocytic leukemic cell line K562 and lymphoblastic leukemic cell lines such as Raji, CEM and HUT28. These results correlate with those of FACS highly. Conclusion:These observations suggest that acute nonlymphoblastic leukemic cells may be more suitable for targeted treatment with IL-6-PFA0 fusion protein.

Objective To investigate the operative indications and operation techniques for augmentative plate fixation in treatment of femoral shaft atrophic nonunions subsequent to intramedullary fixation. Methods Twelve femoral nonunions after internal fixation with intramedullary nailing were treated with augmentative plate internal fixation and bone graft from June 1999 to June 2008. All femoral nonunions were caused by insecure fixation of the intramedullary nailing, in which a rotational instability of the fracture site was verified in all the patients during operation. Minimally invasive removal of the granulation tissue at fracture site and the sclerotic bone was dccorticated. The adequate lilac bone was tiled longitudinally on the nonunion gap and the cortical bone bed. The fixation involved the limited-contact dynamic titanium plate with 5-6 holes, 3.0 mm Kirschner wire and 4-6 double cortex cortical screw fixation.Protective weight-bearing was given after surgery and the tunction was evaluated at 1,3, 6 and 12 months with imaging. Results All patients were followed up for 7-26 months ( average 17.4 months), which showed radiological solid union (7-12 months, average 9.4 months) and clinical union (5-9 months, average 7.1 months ). The operation lasted for 50-120 minutes ( average 77.5 minutes), with blood volume of 150-350 ml ( average 252 ml). There were nine patients with bone pain, of whom the pain was relieved within one month in seven patients and three months in two. No infection, hardware loosening or breaking were found. Conclusion The plate augmentation and cancellous bone grafting leaving the nail in situ can be an effective solution for nonisthmal femoral nonunion, bone defect and failed exchange nailing.