| ObjectiveTo verify the accuracy of three-dimensional reconstruction of multi-slicespiral CT in measurement of acetabular abduction angle and acetabularanteversion,which were measured by actual measurements and radiologicalmeasurements respectively.To provide a scientific basis for guidance ofacetabular prosthesis accurate placement in total hip replacement.To provides asimple and accurate method for the actual measurement of anatomy in the pelvisspecimens by comparison of MSCT new method and digital goniometer results.Methods1.The research objects were60acetabulars of30pelvic specimens, anteriorplane of pelvis as a reference plane, acetabular abduction angle and acetabularanteversion were measured respectively by actual measurements andradiological measurements.The first method using a protractor and digitalgoniometer two methods,which were using homemade pelvic three-dimensionalmeasurement frame to exclude orthostatic measurements of acetabular.Thesecond one using digital X-ray photography and three-dimensionalreconstruction of multi-slice spiral CT.2.In order to reduce measurement errors and to achieve measurementstandardization, a slice measured parallel was chosed to the front plane andpelvis, espectively the acetabular leading and trailing edge respectively in theMSCT research.Abduction angle were measured at the leading edge ofacetabular notch point level, the trailing edge point level and acetabular on polelevel direct measurement respectively in actually measurement.The connection of upper pole and lower pole in the DR-chip with bilateral teardrop includedangle is the abduction angle.3.The maximum level (middle level) wich was acetabulum leading edgepoint and trailing edge point level and a level above it (above the level) and thenext level (lower level) in acetabular anteversion measurement by Actual andMSCT methods.Among these levels,the thickness are5mm.Complementaryangle of the angle between the edge points around the edge of the point ofconnection in the largest section perpendicular to the pelvis before the plane’ship acetabular acetabular acetabular connection as anteversion were taken on inthe next three levels measured and calculate the complementary angle andaveraged.DR method using the Mclaren formulas,RA=arcsin(d/D), is calculatedRA, and by RA=Tan-1(tanAA×sinRI) calculated AA, with the actualmeasurement France and MSCT France measurement results for comparison.Results1.There were no significant difference in the acetabular abduction anglebetween actual measurement method and MSCT at the acetabular leading edge(P>0.05)， the same to trailing edge(P>0.05).The MSCT measured meanacetabular abduction angle between leading edge and trailing edgemeanis(48.61±2.31)°,abduction angle measurement were(48.74±3.16)°and(49.20±3.92)°by digital goniometer and protractor respectively, threecomparison and there is no significant difference (P>0.05). Abduction anglewas(49.39±3.43)°by DR measurement.2.The mean anteversion was （15.82±4.62)°by MSCT, the anteversionswere (16.44±4.82)°and (16.24±4.74)°directly measured by the digitalgoniometer and the protractor, three showed no significant difference (P>0.05).Acetabular anteversion that was transformed by the formula was (16.34±4.92)°by DR measurement.3.There was no statistically significant difference of acetabular abductionanglebetween actual measurement and radiological measurement(P>0.05, F=0.78). So was to acetabular anteversion (P>0.05), and verify the accuracy ofMSCT.ConclusionsThe measurement of acetabular abduction angle and anteversion by MSCT three-dimensional reconstruction were accurate，which provide a new method ofmeasurement of acetabular abduction angle and anteversion for THA.Thismethod is expected to achieve a standardized measurement of acetabularabduction angle and anteversion preoperative and postoperative accurateevaluation. The digital goniometer provide an accurate and convenient newmethod for specimens’ tanatomical measurements... |
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