A Research Of Transverse Acetabular Ligament Alignment For Acetabular Component In Total Hip Arthroplasty

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Research of acetabular Inclination and Anteversion via 3D-Slicer and MatlabObject: Inclinations and anteversions are pivot factors which determine the acetabulum.Poor inclination and anteversion may cause dislocation after total hip arthroplasty.Inclination and anteversion measurements included anatomic,operational and radiographic ones,and our research purpose to exhibit divergence of inclination and anteversion in the three measurements.Method: Anatomical inclination is the angle between the acetabular axis and longitudinal axis and anteversion is the angle between acetabular axis and coronal plane.Operative inclination is defined as the angle between the acetabular axis and sagittal plane and anteversion the angle between the acetabular axis that is projected on to the sagittal plane and longitudinal axis.The radiographic inclination is the angle between the acetabular axis projected on the coronal plane and longitudinal axis and the radiographic anteversion is the angle between the acetabular axis and the coronal plane.Three-dimensional model of CT data of pelvic are generated via 3D-Slicer.Inclinations and anteversions are calculated under the definitions via Matlab.Result: Our research illustrate that Radiographic Inclination has a larger degree than Operational and Anatomical ones,while Operational Anteversion is larger than Radiographic and Anatomical ones.Conclusion: Our finding suggests that inclinations and anteversions of three measurements have a divergence which may interfere decision policy made by orthopedists.Part ? The Hip ROM via Patient-Specific Positioning for Cup Positioning in Total Hip Arthroplasty: a 3D Regeneration ResearchObjective.Orientations of acetabular prothesis are one of the most important factors for total hip arthroplasty(THA).The accepted goal of acetabular orientations are inclination of 40° and anteversion of 15°.Abnormal orientations lead to abnormal range of motions of the hip(hip ROMs)and thereby increase the risk of dislocation.Two anatomical structures,transverse acetabular ligament(TAL)and ischiadic-pubis line(IPL)had been suggested for patient-specific guide for orientations.The purpose of this study was to investigate the hip ROMs after patient-specific guided acetabular prothesis.Method.Forty-seven participants(ninety-four hips)of Computed tomography of lower limb angiography from Union Hospital(Wuhan,China)were imported to Mimics to regenerate pelvis and bilateral femurs by bone segmentation.The goal of orientations was inclination of 40° and anteversion of 15°.Bilateral acetabular prothesis of each participant were guided by TAL and IPL respectively.Inclinations and anteversions of the TAL and IPL guided prothesis were measured and compared with the goal.Hip joints were rotated outward,inward,backward and forward to evaluate four parameters of hip ROMs,abduction,adduction,extension and flexion.Hip joints were performed circumduction to draw boundary map to evaluate overall balance of hip ROMs.Result.The mean inclinations guided by TAL and IPL were 36.35° and 36.90° respectively,slightly but significantly smaller than goal inclination(p = 2.2×10-16 and p = 2.2×10-16 respectively).The mean anteversions by using TAL guide and IPL guide were 23.09° and 20.93°,significantly larger than goal anteversion(p = 2.2×10-16 and 2.2×10-16 respectively).The analysis of ROMs showed that both TAL and IPL guides increased motions of abduction(38.25°±8.30° and 38.47°±8.00° respectively,p<2×10-16 and p<2×10-16,respectively)and flexion(98.47°±9.71° and 100.50°±10.44°,p<2.2×10-16 and p<2.159×10-16,respectively)while decreased motions of abduction(38.25°±8.30° and 38.47°±8.00°,p<2×10-16 and p<2×10-16,respectively)and extension(27.66°±10.18° and 25.93°±9.29°,p<2×10-16 and p<2×10-16,respectively).The boundary map illustrated that both TAL and IPL guide increased the motion of flexion and adduction,but decreased the motion of extension,abduction and their combination.Conclusion.Compared with the goal orientations,the use of TAL and IPL guides obtained more motions in flexion and adduction,obtained less motions in abduction and extension,which might be more suitable for post lateral approach of THA.Part ? A CT Research of Transverse Acetabular Ligament Guide for Acetabular Prothesis in Patients of Dysplasia Development of the HipObjective.Transverse acetabular ligament(TAL)is a reliable reference for anteversion of acetabular component in total hip arthroplasty(TAL).It is debatable,however,whether TAL is reliable for patients of adult dysplasia development of the hip(DDH).The purpose of this study was to determine the risk of postoperative dislocation of the TAL guided acetabular prosthesis in DDH patients by comparing hip range of motion(ROM).Methods.Data of pelvic CT and X-ray of both DDH patients and control patients were collected from Medical Imaging Center of Union hospital(Wuhan,China).Forty-two patients(fifty-eight hips)were collected to DDH group and fifty-one patients were collected to control group.CT data were used to regenerate 3D pelvic models and acetabular prothesis were inserted by using TAL guide.Inclination and anteversion of acetabular prothesis were then measured.Hip joints were rotated outward,inward,backward and forward to evaluate four parameters of hip ROMs,abduction,adduction,extension and flexion.Hip joints were performed circumduction to draw boundary map to evaluate overall balance of hip ROMs.Inclinations and anteversions from pelvic X-ray film were measured and compared to inclinations and anteversions from 3D regenerated pelvic model from CT.Conclusion.On the CT regenerated pelvic model,the inclination of DDH group(37.02°±2.64°)was significantly larger than inclination of control group(35.87°±2.57,P= 0.04116),and the anteversion of DDH group(28.72°±9.80°)was significantly smaller than anteversion of control group(22.53°±4.73°,P=0.03425).The comparison of anteversions between CT regenerated pelvises and AP view of X-ray film showed that anteversion from X-ray film(15.01°±5.61°)was significantly smaller that anteversion from CT pelvic model(P =1.38×10-9).On the aspects of hip ROMs,the abduction of DDH group(44.84°±4.81°)was significantly larger than the abduction of control group(40.92°±3.78°,P=0.03425).The extension of DDH group(19.79°±15.14°)was significantly larger than the extension of control group(25.31°±6.39°,P=0.02654).The flexion of DDH group(89.33°±13.01°)was significantly larger than the flexion of control group(82.15°±15.30°,P=0.02654).The external rotation of DDH group(28.83°±9.53°)was significantly larger than the external rotation of control group(41.55°±9.99°,P=5.737×10-5).Anteversions of DDH group were reduced 6° to measure hip ROMs.Extension of DDH group after adjustment was 31.61°±13.51°,significantly larger than control group(P=5.002×10-6),and external rotation of DDH group after adjustment was 38.39°±14.16°,no significant difference with control group(P=0.006487)Conclusion.For patients with DDH who received treatment of THA,the anteversion of acetabular prothesis were increased,leading to reduction of extension and external rotation,which increased the risk of anterior dislocation after THA.Orthopedists should be careful in determining the anteversion of the acetabular component by using TAL alignment.The goal of a stable hip joint is to obtain comprehensive and maximum hip ROM in every element motion.