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Objective To evaluate the advantage of 3D printing technique in treatment of complicated ace-tabula fracture,we compared the early clinical outcomes of surgical treatment for complex acetabula fracture with traditional surgery(group A)and that assisted by 3D printing technique(group B).Methods A prospective anal-ysis of 35 complicated acetabula fractures was performed at our department,13 patients cured assisted with 3D printing technique. The other 22 patients performed traditional surgery. Surgical trauma,systematic inflammation, immediate reduction effect were evaluated by Matta image assessment standard,and rehabilitation functional status evaluated by Harris score system and Merled' Aubigne and Postel Grading standard. Results There were signifi-cant differences between the two groups regarding intraoperative blood loss,postoperative drainage,operation time (P<0.05),and group B was superior to group A.C reactive protein,leucocyte and creatine kinase MM in periph-eral blood in group A were much higher than those in group B at 24 hours postoperatively(P<0.01).The result of reduction of fracture is poor in group A,but excellent rate of reduction is about 84% in group B. The result of Merled' Aubigne and Postel scores grading was superior in group B(P = 0.013). The excellent and good rate of Harris function score in B group was significantly higher than that in group A(P=0.027).Conclusion The treat-ment of complicated acetabula fracture assisted by 3D printing is excellent in short-term follow up,achieving good reduction with limited trauma,long-term prognosis needs to be further followed up.
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[Objective]To provide a precise individualized design proposal for locating acetabular prosthesis by means of 3D reconstruction,reverse engineering software and rapid prototyping technology.[Method]3D CT scan pelvis image data were obtained from six patients,which displayed osteonecrosis of femoral head on one side.The data were transferred via a DICOM network into a computer workstation.A 3D model of hip was reconstructed using Amira 3.1 software,and saved in STL format.Then the 3D model was imported into Imageware 12.0 software.The normal hip joint centre of abnormal side was determined and the best orientation of the prosthesis(which was central axial ray of acetabula)was defined using reverse engineering.Locating template was designed according to the anatomic features of the acetabula and the central axial ray.Entity model was produced by rapid prototyping technology.The orientation of the prosthesis was located by matching the model to acetabular concavity at operation.[Result]By measuring postoperative standard hip anteroposterior film,the abduction angle of acetabular prosthesis was(46.00?2.49)? and the anteversion angle was(15.68?2.85)?.The expected result was obtained.[Conclusion]The navigation template designed and constructed preoperatively can provide precise location for acetabular prosthesis and avoid procedural errors at operation.
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Objective To study the influence of periacetabular muscle contraction on acetabular] fractures.Methods Twenty intact adult cadaveric pelvis(40 hip joints)treated antiseptically with bilat- eral 1/2 femoral shafts were selected and divided randomly into two groups(20 hip joints in each group). Then,the specimens were trimmed to fit the RMT-150B rock mechanics measuring system and the special in- creasing pressure system.After pressure of 3 500 N was pressed to the control group and pressure of 4500 N to the experimental group,acetabular fracture model was made by beatening with special striking machine,when striking force was recorded.Results We made forty aeetabular fracture models from 40 cadaveric hips. Pearson correlation coefficient of pressing force and striking force was -0.923(P＜0.01).The striking force of the control group and the experimental group was 445-550 N and 290-400 N,respectively(t= 14.727,P＜0.01).Conclusion The increase of contraction force of the periaeetabular muscles can decrease aeetabular stress and strain,influence the result of violent injury and play a vital role in inducing acetabular fractures.
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Objective To evaluate mid-term(5-6 years)clinical and radiographic outcomes of cementless acetabular prosthesis in total hip arthroplasty(THA)and discuss the factors affecting postop- erative effect.Methods THA with cementless acetabular was used to treat 139 cases(148 hips)from January 1998 to May 1999.A retrospective study was done to analyze clinical effect and X-ray manifesta- tion of 109 cases(116 hips)that were followed up.Clinical evaluation was based on Harris hip score. The radiographical evaluation was performed according to orthotropia and lateral images of hip joint to ob- serve acetabular migration and bone changes around the hip and measure the polyethylene wear rate and direction of the acetabular polyethylene wear.Results The mean Harris score before operation was 44 points(10-70 points)but that after operation increased to 92.4 points(80-100 points)at latest follow up.Radiographical evaluation showed one hip with focal osteolysis,mean linear wear rate of 0.15 mm/ year and mean 10.4?for angle with vertical line.Abduction angel of the acetabula was mean 46?,with 10.5 mm for vertical distance and 8.7 mm for level distance.There was no revision of a fixed acetabulum component because of pelvic osteolysis secondary to polyethylene wear.No acetabular component was re- vised because of aseptic loosening or acetabular component migration at the latest follow up.Conclu- sions Cementless acetabular prosthesis in THA can successfully have good fixation.A long term follow up for cementless acetabular prosthesis is necessary because of potential factors like polyethylene wear and osteolysis.