ObjectiveTo study of the impact on dose distribution by electron width of energy spectrum and angular distribution using Monte Carlo simulation.MethodsThe simulated electron energy spectrum and angular distributions was as the input parameters and percentage depth dose (PDD) and offaxis curves were simulated by a modified PENELOPE code package. Results PDD and off-axis dose distribution curves are almost the same and are not sensitive to energy spectrum width and angular distribution with the exception of energy spectrum width of 2.5 MeV with obviously different curves.ConclusionsIn the situation of clinical treatment,spectrum and angular distributions can be ignored when their width are not very large.It is helpful to save about 9％ time by using monoenergy beams in treatment planning system development.

Objective To retrospectively analyze the short-term clinical effects of the two-stage cementless total hip arthroplasty in the treatment of chronic infection after the internal fixation of the adult proximal femoral fracture.Methods From June 2006 to June 2011,9 patients who had suffered a chronic infection after an internal fixation of the proximal femoral fracture,including 8 males and 1 female,aged from 31 to 74 years (average,52.6 years),were treated with two-stage cementless total hip arthroplasty.There were 3 cases of femoral neck fracture,and 6 cases of intertrochanteric fracture.In the first stage,after surgical debridement and thorough removal of all the implants,an antibiotic-loaded cement spacer was implanted.All patients postoperatively underwent intravenous and oral antibiotics,and the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) were tested.When the values of ESR and CRP become normal,the second stage operation using cementless components was performed.Results The presence of infection was confirmed by a positive culture of joint fluid obtained intraoperatively in two cases;one case was staphylococcus aureus and another one was staphylococcus epidermidis.The second stage arthroplasty was performed 6-14 months (average,9 months) after the first stage operation.All 9 patients were followed up for an average of 23.2 months (range,6 to 50 months).No recurrent infection,component loosening,bone osteolysis and cement spacer or component dislocation occurred.The Harris score improved from 74.6 (range,64 to 86) before the first stage operation to 90.9 (range,86 to 97) at the final follow-up.Conclusion The two-stage cementless total hip arthroplasty is an effective strategy for the treatment of chronic infection after the internal fixation of the adult proximal femoral fracture.

Objective To study the early diagnosis and treatment of the blunt popliteal artery injury without fracture or dislocation of the knee. Methods From March 1984 to November 2002, 11 cases of blunt popliteal artery injury without fracture or dislocation of the knee were diagnosed as earlier as possible based on clinical analysis including injury condition, clinical examination and Doppler-Duplex ultrasonography and treated with early repair of the injured arteries, intraoperative or postoperative anticoagulation, immediate fasciotomy and thorough debridement of the ischemic and necrotic muscules and soft tissue. Results There was one with amputation and two with slight dysfunction of the lower extremity, as did not affect normal daily lives. One case had serious dysfunction of the lower extremity due to thrombosis at the injured popliteal artery after first operation and had to receive second operation so as to remove thrombus and repair the popliteal by autograft of the saphena magna vein. However, there left severe function disorder of the extremities. Conclusion A rational and prompt diagnosis and treatment for blunt popliteal artery injury without fracture or dislocation of the knee will decrease the adverse effect of ischemia and reduce overall morbidity.

Objective To investigate the expression of CEA, NSE and CYFRA21-1 in lung cancer, and the significance of combined determination of three tumor markers in the detection of lung cancer. Methods CEA, NSE and CYFRA21-1 levels in serum of 65 patients with lung cancer, 50 patients with benign lung diseases and 38 normal adults were measured by enzyme linked immunosorbent assay (ELISA). The association of CYFRA21-1, NSE, and CEA level with the type of lung cancer in pathology were also studied. Results In comparison, the serum levels of CEA, CYFRA21-1 were increased more obviously in patients with lung cancer than that of patients with benign lung diseases and the normal adults (P<0.01). The levels of serum and the sensitivity of CEA, NSE and CYFRA21-1 were related to pathology type. The sensitivity and specificity increased by combined measurement of CEA, NSE, and CYFRA21-1. Conclusion These findings suggest that the serum CEA, NSE and CYFRA21-1 levels is increased in patients with lung cancer, and the increasing extents is not same in lung cancer with different pathology types. CEA, NSE and CYFRA21-1 are significant in adjuvant diagnosis of lung cancer.

Objective To evaluate the results of using focus clearance and morselized bone graft to treat a well-fixed socket osteolysis after total hip arthroplasty (THA) during cementless acetabular revisions.Methods From March 2006 to March 2009, 23 patients (23 hips) who had an acetabular revision hip arthroplasty of well-fixed socket for osteolysis were retrospectively reviewed, including 13 males and 10 females with an average age of 46.6 years (range, 39-54), and the mean interval from primary to revision THA was 5.5 years (range, 4.6-7.4). The preoperative Harris hip score was 74. The operative technique included debridement of soft tissues with removal of granulomata and packed tightly with morselized cancellous allograft through ilioinguinal approach, and exchanging the liner and femoral head through the posterior-lateral approach of the hip. Results The mean duration of follow-up after revision was 28 months (range, 8-38). At final follow-up, all hip were functioning well and the average Harris hip score was 93.8. Osteogenesis in bone graft were well-developed in 16 patients. Twelve bone grafts were completely incorporated into surrounding bone through creeping substitution. All acetabular components remain radiographically well-fixed and no loosening and shifting. There were no new osteolytic lesions, ectopic ossification, deep venous thrombosis, hip dislocation or infection during follow-up. Conclusion Our revision strategies included debridement and bone grafting, a revision of femoral heads and polyethylene liner and retention of the cups and femoral stems. The method can reduce the amount of the wear particle from polyethylene. The short-term outcome is excellent.

Diagnostic Errors ; Female ; Femoral Neck Fractures ; diagnosis ; diagnostic imaging ; Femur Neck ; diagnostic imaging ; injuries ; Humans ; Radiography ; Young Adult

Objective To investigate the feasibility of the virtual source model in Monte Carlo dose calculation for clinical radiotherapy.Methods The Monte Carlo simulation was used to obtain the phase space files which recorded the physical properties of the particles emitted by a medical linear accelerator, and the information on the type, energy spectrum, and distribution of particles were extracted from these files and analyzed to establish the semi-empirical model of virtual two-photon source.The GMC dose calculation engine was used to obtain the 3 cm×3 cm, 5 cm×5 cm, 10 cm×10 cm, 20 cm×20 cm, and 30 cm×30 cm fields of radiotherapy and the results of Monte Carlo simulation of dose distribution in three-dimensional water phantom in 2 intensity-modulated radiotherapy ( IMRT) plans.These results were compared with the results of water phantom measurement or the results of Elekta Monaco planning system to verify the accuracy of Monte Carlo dose calculation based on a virtual source.Results As for the percentage depth-dose distribution curves of the central axis of the water phantom and the off-axis dose curves at different depths in the five fields for radiotherapy, the difference between the results of Monte Carlo simulation and the results of measurement was within 1%.As for the two IMRT plans, the three-dimensional passing rates of Monaco calculation results and Monte Carlo simulation results were 98.9%and 99.4%, respectively, for 3%/3 mm, and 95.1%and 95.4%, respectively, for 2%/2 mm.Conclusions Monte Carlo simulation based on the virtual source model can obtain accurate results of radiotherapy dose calculation.

Objective To study the impacts of different applicators on dose distribution in 192 Ir brachytherapy. Methods The inner tubes of two cylinder applicators from Nucletron,#101?001 and#084?350, were made of plastic and stainless steel, respectively. The cylinder parts of them were made of plastic, and had four different radiuses:1?00 cm, 1?25 cm, 1?50 cm, and 1?75 cm. EGSnrc program was used to simulate dose distribution when applicators were present in a phantom, and the results calculated by the treatment planning system were compared with the results of EGSnrc. The impacts of applicators on dose distribution were analyzed with different materials, thickness, and numbers of resident source. Results There was no significant relationship between dose deviation and the radius for the two applicators. When an applicator was present, the actual dose delivered to a patient was smaller than the planned dose. The dose deviation of the applicator#101?001 was no more than 1%, while the dose deviation of the applicator#084?350 was close to 3%. The dose deviation remained the same when the number of resident source changed. Conclusions The plastic applicator, if possible, is the best choice for brachytherapy right now. In a long term, in order to promote the accuracy of brachytherapy, current dosimetry algorithm should be improved, and the impacts of the applicator made of metal, such as stainless steel, on dose distribution should be taken into account.

Objective To investigate the efficacy and safety of tranexamic acid on bleeding in rheumatoid arthritis (RA) patients undergoing total hip arthroplasty (THA). Methods A retrospective study was performed in 197 RA patients (Steinbrock?er III-IV) following primary unilateral THA from June 2012 to June 2014. The patients were divided to three groups based on the regimen of tranexamic acid:68 patients received a single intravenous dosage of 15 mg/kg tranexamic acid 20 min prior to opera?tion (single dose group);74 patients received an intravenous dosage of 15 mg/kg preoperatively and a second dosage of 10 mg/kg 3 hours postoperatively (repeated dose group);the other 55 patients didn't receive tranexamic acid (control group). The primary out?comes were total blood loss, transfusion rate, the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE). The sec?ondary outcomes were postoperative drainage, hemoglobin (Hb) drop on third day postoperatively and other wound related compli?cations. Results There was less total blood loss (816.80 ± 245.09 ml vs 975.15 ± 216.33 ml vs 1 295.68 ± 263.85 ml), drainage (221.60 ± 70.05 ml vs 337.20 ± 113.10 ml vs 479.74 ± 120.66 ml), transfusion requirement (5.41%vs 10.29%vs 25.45%) and Hb drop (2.71±0.74 g/dl vs 3.18±0.62 g/dl vs 3.83±0.70 g/dl) in experimental group when compared with control group. And the effect was better in repeated dose group, with less total blood loss (816.80 ± 245.09 ml), less transfusion requirement (5.41%) and less postoperative drainage (221.60±70.05 ml). No episode of DVT or PE occurred in either group. There were 8 wound complications in single dose group, 6 in repeated group, and 8 in control group, and there were no statistically difference. Conclusion Intrave?nous administration of tranexamic acid was effective and safe on decreasing blood loss and transfusion requirement in RA patients following THA. Compared with a single dosage of tranexamic acid preoperatively, a second dosage of tranexamic acid 3 hours post?operatively was recommended.

Objective To retrospectively analyze the diagnosis and treatment of the extra-articular inflammatory pseudotumor after well-fixed metal-polyethylene total hip arthroplasty (THA).Methods From March 2006 to June 2011,7 patients (7 hips) who presented with a progressive pain and/or swelling,discomfort in groin or upper thigh after metal-polyethylene THA were admitted to our hospital.There were 2 males and 5 females,with an average age of 48.8 years (range,32-65 years).All 7 patients were identified with a periprosthetic osteolysis at the acetabular and/or femoral components and a mass in the iliac fossa or the thigh; however,the components were all well-fixed.The masses were confirmed by CT scanning and/or ultrasound examination.The revision procedures were done through ilioinguinal approach and posterior-lateral approach,and the pseudotumors were excised and osteolytic lesions were debrided and packed tightly with morselized cancellous allograft.The liner and femoral head were also exchanged at the same time.Clinical and radiographic outcomes of revision THA were evaluated.Results All 7 patients were followed up for 3-42 months (average,30 months).At final follow-up,all hips were functioning well and the average Harris hip score was 92.4.All acetabular components remained radiographically well-fixed.All cavitary defects had complete radiographic incorporation of the bone grafts.There were no new pseudotumor or osteolytic lesions identified,and no revision of the components.Conclusion The presence of abdominal or pelvic pseudotumor in patient with a THA may be associated with polyethylene wear.Once the extra-articular pseudotumor and the periprosthetic osteolysis are identified,the surgical treatment,including pseudotumor excise,osteolytic lesion debride and bone defect grafting and bearing surface exchange,can achieve retention of well-fixed components.