Biomechanical analysis and clinical application of 3D printed bone tumor prosthesis of lower limb / 中华骨科杂志

Objective:To design 3D printed prosthesis in an individualized way and explore the short-term clinical efficacy of reconstruction of segmental defect after resection of bone tumor in lower extremities with 3D-printed prosthesis.Methods:From January 2017 to June 2019, 6 patients with lower limb bone tumor who met the inclusion criteria were recruited, including 3 males and 3 females, aged 8.67±1.11 years (range 6-11 years). All 6 cases were primary bone tumors, and the Enneking stages were all IIB, including 3 cases of left tibial tumors, 2 cases of right tibial tumors, and 1 case of right femoral tumor. These 3D-printed prostheses were designed based on the preoperative imaging data. The mechanical stability of the prosthesis was evaluated by three-dimensional finite element analysis. After tumor resection, the 3D-printed prosthesis was installed and fixed to reconstruct the segmental bone defect. All patients were clinically followed up and evaluated by imaging regularly after operation. The functional status was assessed by the Musculoskeletal Tumor Society (MSTS) score. Oncology results and complications were recorded in detail.Results:All operations were successfully performed, including 3 cases underwent left tibial tumor resection, 2 cases underwent right tibial tumor resection, and 1 case underwent right femoral tumor resection. The length of the bone defect after tumor resection was 18.19±3.74 cm, the average operation time was 165.83±54.17 min, and the average intraoperative bleeding was 233.33±133.33 ml. These finite element analysis data show that the overall stress of these prostheses are lower than the maximum mechanical strength of the corresponding materials. These 3D printed prostheses match well with the excision defect and meet the expected effect. There were no adverse reactions during the operation. The mean follow-up period was 16.83±7.17 months. At the last follow-up, all patients survived without tumor recurrence or metastasis. Postoperative imaging results showed that all the implants were stable without complications such as peripheral infection, aseptic loosening, prosthesis fracture. These 3D-printed prostheses composite resulted in substantial bone integration at follow-up. The average MSTS score was 83.67%±9.11%.Conclusion:The individualized 3D printed prosthesis can be used to reconstruct the bone defect after the resection of osteosarcoma in the lower extremities, and the clinical efficacy was satisfactory in the short-term follow-up.

A multicenter retrospective study of artificial joint replacement on giant cell tumor in distal femur / 中华骨科杂志

Objective To analyze clinical efficacy of artificial prosthesis in giant cell tumor in distal femur,and to investigate risk factors affecting prosthesis failure and functional outcomes.Methods 42 patients with giant cell tumor of bone in distal femur,who had undergo prosthesis replacement from January 2002 to May 2015,were enrolled in this study.There were 24 males and 18 females,with an average age of 38.53± 12.87 years.There were 28 primary patients and 14 relapsed patients,including 11 cases of recurrence once and 3 cases of twice.Three-dimensional finite element model was used to analyze the effect of different angles of deviation of the spinal needle on the deformation of the bone wall.The correlations between the factors such as age,sex,occupation,prosthesis type,and other factors on prosthesis loosening were compared.Biomechanical effect of lower limbs caused by prosthesis offset angle was analyzed through gait analysis.Analyzed the effects of primary tumor or recurrence,prosthesis service status,and length of surgical osteotomy on joint function.Results A total of 42 patients were followed up by 20-158 months,with an average of 68.7 months.The 3 year survival rate of prosthesis was 83.33％ for 3 years and 57.14％ for 5 years.The major reason of prosthesis failure was loose (18/42,42.8％).X-ray films showed 19 cases of prosthetic intramedullary nail and sagittal bias of medullary force line angle ＞ 3° in the first follow-up.Osteotomy length (OR=0.132,P=0.0027) and offset angle of needle (OR=25.000,P=0.000) were significantly correlated to prosthesis loose.A length more than 12 cm and angle more than 3° were easier to result in prosthesis loose.There were no significant correlation between prosthesis failure and patients age,gender,occupation and prosthesis type.Gait analysis shows that the unsuitable bias angle of the prosthesis can significantly change the joint force of the prosthesis.The average score of MSTS 93 function evaluation was 25.43±4.256,excellent in 33 cases,good in 7 cases and poor in 2 cases.Function of patients with primary GCT were better than that of recurrent ones.Patients with one 1 times recurrence were better than that of recurrence twice (P=0.003).Patients without prosthesis loosening and revision were better than that with loosening (P=0.001).Patients with an osteotomy length less than 12 cm had a poorer function than that with more than 12 cm (P=0.002).Conclusion The main factors affecting distal femoral prosthesis replacement therapy of GCT is loosening,which was caused by broach and medullary cavity mismatch,osteotomy length,prosthesis rotation,prosthesis position.The function of the prosthesis is mainly affected by operation times,prosthesis status,osteotomy length and low patella.

Clinical significance of peripheral blood circulating tumor cells detection in osteosarcoma patients / 中华骨科杂志

Objective To discuss the correlations amongst the count,molecular and clinicopathological characteristics of circulating tumor cells (CTCs),and the feasibility of using CTC as an aid to judge the metastasis of osteosarcoma,evaluate the therapeutic effect,and predict the prognosis of patients.Methods Retrospective analysis of 30 patients with newly diagnosed osteosarcoma diagnosed from January 2015 to June 2016,there were 17 males and 13 females.The average age was 13.77±4.31 years old (ranged from 7 to 21 years).There were 21 cases of Ennecking stage Ⅱ,including 2 cases of ⅡA,19 cases of ⅡB,and 9 cases of Ennecking Ⅲ.Peripheral blood of all patients was obtained and processed using CanPatrolTM System at baseline,pre-and post-operation.Multiplex RNA-in situ hybridization (RNA-ISH) assay was used to characterize the molecular markers.Combined with clinical data,the relationship between peripheral blood CTC counts,count changes,molecular characteristics,tumor metastasis,chemotherapy effects,and prognosis of patients with osteosarcoma was analyzed and compared.Results The CTC count in peripheral blood was 10.44±5.70 in Ennecking stage Ⅲ patients and 4.76±3.56 in stage Ⅱ patients.The increase or decrease in CTC counts was associated with good or poor neoadjuvant chemotherapy (P=0.002).In patients with good chemotherapy effect,the CTC count in peripheral blood was decreased after chemotherapy.The mean progression-free survival time was 11.85±4.93 months for patients with CTC number ≥7,and the average progression-free survival time was 15.53±4.09 months for patients with CTC number ＜ 7 (P=0.012).The proportion of interstitial CTC in Ennecking stage Ⅲ was 40.42％,which was higher than that of Ennecking ⅡB stage 23.00％.The difference was statistically significant (P=0.010).The positive rate of metastasis-associated gene 1 (MTA1) in interstitial CTC was 85.50％,and the positive rate of other types of CTC was 66.67％.The difference was statistically significant (P=0.000).Conclusion The counting and typing of peripheral blood CTC in osteosarcoma patients can be used as a complement to the commonly used imaging examinations,and they can play an auxiliary role in judging tumor metastasis,curative effect observation and prediction of poor prognosis.

Aplication of 3D-printed prosthesis on construction of long segmental bone defect after tumor resection / 中华骨科杂志

Objective To explore the feasibility and clinical efficacy of long-segmental bone defects after en bloc tumor resection of lower limb segment with composite of titanium alloy 3D printed prosthesis and vascularized fibular autograft and bioceramics.Methods 5 patients with lower extremity tumor (1 high grade chondrosarcoma,1 Ewing sarcoma,1 single metastatic tumor and 2 osteosarcoma) were treated by en bloc resection and precise reconstruction with segmental 3D-printed,custom-made prosthesis from August 2015 to November 2016,which composed of 1 male and 4 females,ranged from 16 to 56 years old,the average was 32± 19.3 years old.Three-dimensional computed tomography reconstructed images of patients' tumors were built before surgery.Custom-made prostheses were manufactured based on the patients' reconstructed images with micro-pores on the surface.After en bloc tumor resection with the help of osteotomy guide plate,the defects were reconstructed with 3D-printed,custom-made prostheses.Vascularized fibular autografts were put inside the prostheses,and the interval space among them was filled with bioceramics.Results All the 5 cases were performed surgical planning before the surgery with prosthesis and guide plate were designed at the same time.After verification of the finite element analysis SLM (2 cases) and the EBM (3 cases) were used to process prosthesis,and were designed into porous sharp with 210.98±66.16 mm in length and 26 901.76±12 903.96 mm3 in volume.Then the prosthesis would be cleaned and sterilized.All 5 operation were proceeded according to the plan of preoperative.The intra-operative guide plate were installed on the bone surface stably.The bone cutting was guided according to the plan of preoperative.By intra-operative frozen pathological examination,there were no malignant tissues in near and far marrow cavity.Unfolded fibular flap with 168.75±49.07 mm in length and porous tricalcium phosphate particle composite implants with 10±4.08 g were used in 4 cases and bone cement was used in 1 cases of metastatic tumor.The average operation time was 261±85 min and average blood loss was 540±182 ml.After a mean follow-up time of 6.4 months (1-15 months),all 5 cases survived with no local recurrence and pulmonary metastasis tumor.2 cases with vascular pedicle fibular transplant confirmed the survival of fibula via bone scan 3 months after operation.All cases were no infection,fractures,prosthesis loosening,except broken screw in 1 case.The Musculoskeletal Tumor Society (MSTS) 93 score was 17-26.Conclusion Long segment tubular titanium alloy 3D printed prosthesis with vascularized fibular autograft and bioceramics could reconstruct the segmental defects caused by tumor resection.

Detection and clinical significance of circulating tumor cells in osteosarcoma using immunofluorescence combined with in situ hybridization / 中华肿瘤杂志

Objective@#To investigate the clinical significance of detection of circulating tumor cells (CTCs) in peripheral blood from patients with osteosarcoma (OS) using the iFISH (immunofluorescence and fluorescence in situ hybridization) method.@*Methods@#The live cells recovery rate of immune-magnetic beads was evaluated by live-cell fluorescent tracer technology. The expression of CD45 and CK18 on the cell surface of HOS and HepG2 cells was measured by flow cytometry. And the chromosome aneuploidy was detected by centromeric FISH probe CEP8. Subsequently, 23 OS patients were enrolled and divided into two groups, relapse or metastasis group and primary group. And the prognostic significance of CTCs numbers was analyzed.@*Results@#The live cells recovery rate of immune-magnetic beads was higher than 90%. The flow cytometry results showed that HOS cells were double negative for the surface biomarkers of CD45 and CK18. In addition, the FISH-CEP8 signal abnormality rate were 96.5% in HOS cells. Thus, CTC was identified using the criteria as follows: the cells with CEP8-positive signal >2 accounted for more than 96.5% of the total cells, of which the cells with >3 positive signal were more than 65.0%. Among the enrolled patients, 19 patients had detectable CTCs in the peripheral blood. The CTCs numbers in the relapse or metastasis group and primary group were 2.846±1.281 and 1.400±1.506, respectively. The results showed that the CTCs in patients with recurrence or metastasis were significantly higher than those in primary patients (P=0.021).@*Conclusions@#To our knowledge, this is the first evidence of existence of CTCs in OS patients. The CTCs numbers were positively associated with disease progression and poor prognosis. These results may provide a potential prognostic tool for monitoring metastasis and recurrence in OS patients.@*Trial registration@#Chinese Clinical Trial Registry, ChiCTR-OOC-15005925

The combinative biological reconstruction of bony defect following limb bone tumor resections / 中华骨科杂志

Objective To analyze the image and histological results of the combined use of allograft/extracorporeally frozen tumor-bearing bone and vascularized fibular flap for the reconstruction of bony defects following tumor resection,guiding clinical practice.Methods From March 2007 to June 2013,we enrolled 63 patients who had combinative biological reconstruction after bone tumor resection (11 in humerus,22 in femur,21 in tibia,4 in calcaneus).There were 36 male and 27 female in this series.The average age at time of operation was 20 years,ranging from 9 to 48 years.The follow-up ranged from 16 to 102 months with average of 48 months.We investigated the X-ray and CT images for all patients and histological findings of two patients.Patients were assessed functionally with the Musculoskeletal Tumor Society 93 score.Results Three patients with local soft tissue recurrence and one patient with infection underwent amputation.The survival of construct was 93.6％.Bone union achieved in all cases with the average MSTS score of 92.8％.Bone union ranged from 11 to 28 months in allograft group and 9 to 14 months in devitalized tumor bearing bone group.Significant difference of bone union time was found between two groups (Z=-3.638,P=0.000).Viability of the fibular grafts was verified in 58 of 63 patients (92％).Three types of images were observed in complex.Osteopenia and spongy change in fibula were found in 51 patients (81％) with stable fixation of the complex.Five complexes with failed blood supply of fibula and stable fixation revealed no density change of fibula,small amount of callous formation and relative delayed union.In seven complexes (11％) with unstable complex due to patients' incompliance,fibula reacted with dense hypertrophy and microfracture.Fusion of grafts with amount of callus was obviously observed.Union at allograft-host bone junctions occurred by residual host bone-derived external callus and fibular-derived internal callus that bridged the junction and filled the gap between abutting cortices.Callus from fibular graft was mature than that from periosteum of residual host bone.Internal repair was observed at the internal surface of the allografts.Fibula showed significant spongy changes.Conclusion Recycled tumor-bearing bone in combined with fibular flap is a reliable reconstruction as an alternative to traditional Capanna technique.The survival of the fibula is a cornerstone in success of complex reconstruction.Sponginess of fibula and internal repair of allograft compromise the intensity of complex,necessitating the strong instrumentation during reconstruction.

Surgical technique and clinical efficacy of giant cell tumor of axis / 中华骨科杂志

Objective To evaluate the prognostic effects of treatment of giant cell tumor of axis by tumor resection associated with biological reconstruction and internal fixation.Methods From 2009 to 2013,5 patients that had giant cell tumor of axis underwent combined anterior and posterior surgery program.The posterior use pedicle screw system to stabilize the cervical spine,then the anterior use stemocleidomastoid inner edge of the mandibular angle approach to reveal the axis.When the cortex of vertebrae was relatively complete,.When the cortical bone was destroyed,vertebra was resected and the ilium was taken to reconstruct the defect.Adjuvant radiotherapy and diphosphate treatment was used postoperatively.Regular follow-up for X-ray,3D CT and MRI examination were done to observe the tumor recurrence,healing of biological reconstruction and function of cervical vertebra.Results The follow-up time was 12-60 months.No recurrence of the tumor was observed in all patients.The 3 patients accepted beta-TCP implanting after curettage was observed with fuzzy internal structure 3 months after surgery,and the grafted bone fusion can be found 12 months after surgery.The 2 ilium grafted patients can be found with bone fusion with the adjacent vertebrae 6 months after surgery.The bend and stretch function of cervical vertebrae of the 5 patients returned to normal after 3months.The biological healing of bone graft,cervical stability and activity were satisfied.The local pain and neurological symptoms were relieved.Conclusion Anterior and posterior surgery program in combination with biological reconstruction and adjuvant radiotherapy provide an excellent option for treatment of giant cell tumor of axis.The dens could be retained to keep the function of occipital cervical when the odontoid bone cortex is not destructed.

Therapeutic evaluation of the polylactic acid gel (PLA-G) used for preventing skin flap adhesion in modified radical mastectomy / 生物医学工程学杂志

The present preliminary study was to observe the feasibility of the use of polylactic acid gel (PLA-G) in modified radical mastectomy and the ability of the PLA-G in the prevention of flap adhesion after operation. Sixty-eight patients were diagnosed with breast cancer, and received modified radical mastectomy from Jan. 2004 to Dec. 2006. The patients were divided randomly into a treatment group and a control group (with 34 cases each). The PLA-G was used under the surface of the auxiliary operative wound in the treatment group, and nothing was used in the control group. The wound healing, the wound complication, the amount of drainage solution, the indwelling time of the drainage tube and the auxiliary skin adhesion were evaluated after operation in both groups. There were no statistical difference on wound healing between the first intension (29:27) and the second intention (5:7), and the wound dehiscence after taking the stitches out (0:0) between the two intensions, the hematoma (0:1) and the effusion of the wound (5:6), and the flap necrosis (1:2) between two groups. There were also no statistical difference on the amount of drainage solution per day (6 +/- 3) and indwelling time of the drainage tube (6 +/- 4) after operation between the two groups (P > 0.5). After the operation, the case load with no flap adhesion in the treatment group was significant higher compared with the control group (22:8). The case load with complete acquired skin flap adhesion in the treatment group was visibly lower than in the control group (3:19), which proved that there was a significant statistical difference between the two groups (P < 0.05). This study suggested that the using of PLA-G in the breast cancer modified radical mastectomy could prevent skin flap adhesion without any harmful effects in the wound healing.

The preliminary report of a randomized controlled multicenter study of first-line chemotherapy regimen combined with angiogenesis inhibitor for osteosarcoma of the extremities / 中华骨科杂志

Objective To evaluate effect and safety of first-line chemotherapy regimen combined with rh-endostatin for osteosarcoma of the extremities.Methods Sixty three patients with osteosarcoma were randomly divided into experiment group and control group.There were 32 patients in experiment group,and 31 patients in control group.Nine patients 9 were rejected because they did not meet the standard.Finally,54 patients were enrolled in this study,including 29 patients in experiment group,and 25 patients in control group.In the experiment group,the patients were treated with rh-endostatin combined with MTX,IFO,DDP,and ADM,while patients in control group were treated with MTX,IFO,DDP,and ADM.Several indexes including median progression-free survival time,clinical benefit rate,progression-free survival rate,limb salvage rate,and survival rate were used to assess clinical effect.The safety of rh-endostatin was evaluated by comparing incidence of adverse events in the two groups.Results The median progression-free survival time of experiment group and control group was 18.9 months and 13.1 months,respectively; there was no significant difference.In the experiment group,the clinical benefit rate,progression-free survival rate,survival rate and limb salvage rate were 89.7％,37.9％,65.5％,and 89.7％,respectively; while in the control group,the clinical benefit rate,progression-free survival rate,survival rate,and limb salvage rate were 88.0％,36.0％,68.0％,and 96.0％,respectively.There was no significant difference in 4 indexes mentioned above between two groups.Conclusion After being combined with first-line chemotherapy regimen,rh-endostatin doesn't show significant advantage in controlling tumour progression and improving survival rate.No more toxicity and new side effects are found after using rh-endostatin.

Motion parameters analysis and pilot clinical trials of the dual mobility hemi-knee artificial prosthesis / 中华骨科杂志

ObjectiveAim at the problems in the treatments of the children malignant bone tumor of distal femur,we put forward the concept of the dual mobility hemi-knee prosthesis and try to perform the motion parameters analysis and the pilot clinical trials.MethodsBase on the CT data from samples of knee joint in adult,we adopted the Mimics/Geomagic/Pro-E software and computer numerical control milling machine technology to design and produce the dual mobility hemi-knee artificial prosthesis,and then motion parameters was analyzed in vitro test,and at last pilot clinical trial was performed.ResultsIn vitro experiment showed that the displacement of the internal femoral condyle flexion facet center was(2.59±0.43) mm in normal knee group,(2.22±0.52) mm in dual mobility hemi-knee prosthesis group,and (1.18±0.43) mm in total knee arthroplasty group; the displacement of the external femoral condyle flexion facet center was (11.95±6.62) mm in normal group,(11.25±6.19) mm in dual mobility hemi-knee prosthesis group,and (1.26±0.42) mm in total knee arthroplasty group; the maximum relative rotation angle was 13.17°±7.58° in normal knee group,11.69°±6.49° in dual mobility hemi-knee prosthesis group,and 5.40°±1.29° in total knee arthroplasty group.After that,we accomplished the pilot clinical trials successfully for a patient with malignant bone tumor in distal femur.The patient recovered well and the treatment outcome was satisfactory.ConclusionThe motion parameters analysis showed that the motion mode of the dual mobility hemi-knee prosthesis is similar with that of the normal knee.The dual mobility hemi-knee prosthesis provides a whole new concept and method for the treatment of malignant bone tumor of distal femur in children,and the device and concept of ligament reattachment provide a solution to the reconstruction of knee ligament.

The combination of a vascularized fibula with a massive allograft for reconstruction after intercalary resection of long bone tumor in extremities / 中华骨科杂志

Objective To investigate the effects of combined use of an allograft and vascularized fibular flap for the reconstruction of bone defects after intercalary resection of long bone malignancy.Methods From April 2006 to October 2009,19 patients that had intercalary resection of long bone malignancy (5 in humerus,7 in femur,7 in tibia)underwent reconstruction with an allograft and vascularized fibula construct,including 11 males and 8 females with an average age of 18.5 years.The average length of the defect was 13.2±4.3 cm.Free vascularized fibula flaps were used in 16 patients and ipsilateral pedicle vaseularized fibula grafts in 3.Time to union was recorded through evaluation of plain radiographs.Bone scan was used to evaluate the viability of the vascularized fibula.Patients were examined oncologically and radiographically and were assessed functionally with MSTS-93.Results The mean follow-up time was 27.5 months.The average length of the fibula flap was 17.9±5.2 cm.Viability of the fibular grafts was verified in all cases.The average time for bone union at allograft-host junction was 11.3±2.8 months in femur,14.1±3.3 in tibia,6.8±1.4 in humerus,respectively.The MSTS-93 average score at final follow-up was 95.2% in upper extremity and 91.8% in lower extremity.The oncology result in patients with follow-up more than 2 years was continuous disease free in 11 patients.no evidence of disease after recurrence following resection in 1,alive with tumor in 1,and died of lung metastasis in 1.Conclasion Vascularized fibular flap in combination with massive allograft provide an option for reconstruction of large bony defects after long bone malignancy extirpation.The viability of the fibula is a cornerstone in success of reconstruction that prevents allograft nonunion and result in decreased time to bone healing,leading to earlier patient's recovery of function.

A prospective,randomized controlled clinical study to evaluate porous β-tricalcium phosphate for lacunar bone defects repair / 中华骨科杂志

Objective To evaluate the clinical outcomes of a hovel porous β-tricalcium phosphate (β-TCP)and control allograft for the repair of lacunar bone defects caused by solitary bone cyst curettage.Methods From January 2003 to December 2008,the patients with solitary bone cyst were randomized into an experimental(55 cases)and a control(40 cases)group.The control group received particulate allograft bone as the graft material,and the experimental group received β-TCP.At 1 week,1,2,3,6,12,24,48months after surgery,a new radiographic scoring system was employed to calculate the biodegradation of bone graft and evaluate the influence of multiple factors.Histologic characteristic of the degradation process of β-TCP were also evaluated.Results All the cases were followed up for average 28.4 months.Radiographic semi-quantitative analysis revealed that the biodegradation effieiencies were not significantly difierent between β-TCP and allografts(P=0.424).Degradation percentage of the implanted β-TCP or allograft was higher in younger patients than those in the older ones.Degradation of β-TCP was significantly higher than that of allografts over 3 years after surgery(P=0.04).In the experimental group,β-TCP degradation was greater in the loose packing treatment than that in the dense packing treatment (P=0.03).Histological observation demonstrated that the process of new bone formation accompanied the degradation of β-TCP.Conclusion The interporous β-TCP could be an advantageous alternative to allografts for repair bone defects caused by bone cyst.The clinical application of β-TCP is safe and reliable,which shows better biodegradation and osteogenesis than allografts in long-term follow-up.

Hemostatic effect and biocompatibility of RT-Q medical biomembrane / 中国组织工程研究

BACKGROUND: RT-Q medical biomembrane, the novel copolymer synthesized from lactic acid and hyaluronic acid, not only possesses the advantages of hyaluronic acid, such as multiple biological functions, excellent flexibility and biocompatibility, but also has the merits of polylactic acid fragments to be easily processed and transformed to membrane when encountering water. OBJECTIVE: To investigate the hemostatic effect of RT-Q medical biomembrane in rat external jugular vein hemorrhage model, and to evaluate its histocompatibility by locally applying it to rat muscle. DESIGN: Randomized controlled animal trial.SETTING: Department of Pharmacology, Department of Pharmacognosy, West China School of Pharmacy, Sichuan University.MATERIALS: 130 male Wistar rats aged 6 weeks, weighing 170-210 g, were selected. Eighty rats were used for evaluation of hemostatic effect, and the other fifty were used in biocompatibility experiment. Animal intervention met the animal ethical standard. RT-Q aerosol composed of DL-lactic acid and hyaluronic acid, α-cyanoacrylate, acetone (solvent), freon (propellant) and excipient aerosol composed of acetone and freon (propellant) (Batch number 20050311) were provided by Department of Pharmaceutics, West China School of Pharmacy, Sichuan University.α-cyanoacrylate medical adhesive(SUNCON medical adhesive) (Batch number 20050930) was produced by Beijing Suncon Medical Adhesive Science and Technology Development Co., Ltd. METHODS: Haemostatic effect: Eighty male rats were randomly divided into four groups, served as RT-Q, SUNCON (positive control), excipient group and non-treatment group (negative control), twenty in each group. After anesthesia was induced, external jugular vein of rats was exposed, and an approximately 0.6 cm incision was made to create hemorrhage. The bleeding areas were blotted by antiseptic gauze. After removing the gauze, the bleeding surfaces were immediately treated with RT-Q aerosol in the RT-Q group, excipient aerosol in the excipient group, 0.15 mL SUNCON medical adhesive in the SUNCON group, or no agent in non-treatment group, respectively. Then, injury surfaces were covered by gauze. In the non-treatment group, bleeding was left to naturally stop. Bleeding time and blood loss (gauze weight after hemostasia - that before hemostasia) were determined. Local histocompatibility: Rats were divided into A and B groups. Incision was made in rat post-leg muscle after anesthesia was induced. Left bleeding surfaces were treated with excipient aerosol, and right bleeding surfaces were treated with RT-Q aerosol in group A (n=30). The same incision as the group A was made, but no intervention was performed in the group B (n=20). Tissues were possessed and HE-stained for pathological observation under light microscope at days 1, 2, 3, 4, 5, 6, 7, 15, 23, 30 after the surgery. Effect of biomembrane on wound healing, degradation and toxicity to tissues surrounding injuries were observed. MAIN OUTCOME MEASURES: Bleeding time and blood loss in hemostatic experiment; wound healing, biodegradation and toxicity to tissues surrounding injuries in local histocompatibility experiment. RESULTS: 130 rats were involved in the result analysis. Histopathologic examination showed RT-Q membrane had no effect of promoting or delaying wound healing. Membrane formed by RT-Q aerosol began to degrade on the 15th day, absorbed completely during 3-4 weeks, and had no toxicity to surrounding tissues. Bleeding time and blood loss were reduced in the RT-Q group than in the non-treatment group and the excipient group (P < 0.01). There was no significant difference between the RT-Q group and the SUNCON group (P > 0.05).CONCLUSION: RT-Q medical biomembrane as α-cyanoacrylate medical adhesive has significant hemostatic effects on topical bleeding, and possesses good histocompatibility.

The research of film formation properties of the aerosol of biodegradable multi-function film / 生物医学工程学杂志

The aerosol of biodegradable multi-function film were prepared, whose properties, affective factors and hemostasis effect were studied. Film formation properties were investigated in different lots of aerosols, including film formation time, uniformity, film particle size and film thickness. Young's modulus was about 0. 0373GPa, and elongation at break was 0. 89% by means of tensile method. It is proved that the aerosol of biodegradable multi-function film is easy to form films and its hemostasis effect is well.

Preparation of aerosol of biodegradable multi-function film and investigation of its properties / 生物医学工程学杂志

The aerosol of biodegradable multi-function film was prepared by means of two-step methods, and its properties were investigated. The average loading capacity was 4.8603 g; the average leaking rate was 3.03% per year which was less than 5%. And the average ejecting rate was 0.7380 g/s. The results demonstrate that the aerosol of biodegradable multi-function film has met the principles governing the quality of the aerosols.

A pilot study on soft tissue inflammation of percutaneous implants / 实用口腔医学杂志

Objective:To study the soft tissue inflammation of percutaneous implants using bacteria investigation method, so as to provide basic data for further clinical study of percutaneous implants. Methods: Implants were surgically placed into tibias of the goats. The inflammatory secretion from the peri-implant soft tissue was taken to perform bacteria test on 4, 6 and 9 weeks post-operation. Meanwhile, the soft tissue inflammatory reaction was also observed weekly. Results: 5 of the 16 implants were infected. The soft tissue showed tumefaction and ulceration 2 months post-surgery. As to bacteria investigation, the number of G.Streptococci increased when the inflammation was getting more severe. Conclusion: The extent of the soft tissue inflammation of percutaneous implants probably has positive correlation with the infection of G.Streptococci.

Diagnostic value of needle stereotaction marking by steel wire under mammography for nonpalpable breast carcinoma / 中国普通外科杂志

Objective To explore the diagnostic value of needle stereotaction marking by steel wire(NSMSW) under mammography for nonpalpable early stage breast carcinoma (BC). Methods 29 patients with nonpalpable breast lesions were performed NSMSW under mammography,and the lesions were removed for biopsy to make the diagnosis. Results Nine patients(31.0%) were definited as early stage BC and twenty(69.0%) benign disease.The pathologic results in freezing sections and in parafin sections were the same. Conclusions NSMSW under mammography can resolve the problem of accurate location of nonpalpable breast lesions during operation .It is a credible, useful and practical method for diagnosis of nonpalpable early stage BC.