The Clinical Study Of The Measurement Of The Rotational Axis Of Femoral Epicondyle By 2-D And 3-D Images

Part one: The study of the measurement of the rotational axis of femoral epicondyle by 2-D and 3-D images Objectives1,To compare the accuracy of two reference axes,i.e.the transepicondylar axis (the surgical transepicondylar axis and the clinical transepicondylar axis)and the Whiteside's line,to determine the rotational alignment of the femoral prosthesis and to compare the angles respectively.2,To discuss the measurement method of 3-D reconstruction images. Methods1,Select 80 normal human knees as subjects,Age from 17 to 45 years, the average age is 38.9±3.8.2,Get the images of distal by CT spiral scanning(0.5mm thickness). Scan orientation was adjusted to pallallel with the plane perpendicular to the mechanical axis of tibia, to obtain the accurate cross-sectional images for distal femur.3,Use the Mimics10.01 software to analyze the scales: the posterior condylar angle(PCA),the condylar twist angle (CTA)and the angle between line perpendicularity to APL and PCL(PAPA).The first author measure the angles for three times,and the measurement intervals were no less than one month. The third author measure the angles for the same way.4,To calculate the average scales of PCA, CTA and PAPA by the first author or by the third author.To compare the average angles of PCA, CTA and PAPA whether the significant difference is exist between the first author and the third author in the 2-D images. To calculate the average angles of the measurement results by two different authors.5,Use the Mimics10.01 software to calibrate the femoral condyle line of the surgical transepicondylar axis,the clinical transepicondylar axis and the anterior posterior line in 3-D images reconstruction, then import CT imformation to Autocad2008 and use the Autocad2008 programme to analyze the scales of PCA, CTA and PAPA for the same way.Calculate the angles of PCA, CTA and PAPA and the average angles of PCA, CTA and PAPA respectively by two different authors.To compare the average angles of PCA, CTA and PAPA whether the significant difference is exist between the first author and the third author in the 3-D images. Then to calculate the average angles of PCA,CTA and PAPA by two different authors.6,To analyse the significant differences of the average angles of PCA, CTA and PAPA if by 2-D images or 3-D reconstruction images.7,To analyse the datas Using spss16.0 software,use x±s to compute statistical description,use t test to compute statistical analysis.The significant difference standard is p<0.05.Results1,In 2-D images:There was no statistics meaning on the difference between the first author and the third author for the average posterior condylar angle(P>0.05); There was statistics meaning on the difference between the first author and the third author for the average condylar twist angle and the average angle between line perpendicularity to APL and PCL(P<0.05).2,In 3-D images: There was no statistics meaning on the difference between the first author and the third author for the average posterior condylar angle,the average condylar twist angle line and the average angle between line perpendicularity to APL and PCL(P>0.05).3,There was no statistics meaning on the difference between 2-D images and 3-D images for the average posterior condylar angle and the average condylar twist angle(P>0.05). There was statistics meaning on the difference between 2-D images and 3-D images for the average angle between line perpendicularity to APL and PCL(P<0.05).Part two: measure the rotational axis of femoral epicondyle by 3-D images for the seriously damaged knees ObjectivesTo measure the function of 3-D reconstruction technique during TKA for the seriously damaged knees.To explore the advantages of 3-D reconstruction images in determining the angle of rotational axis of femoral epicondyle of the commonly used methods.MethodsMeasure the posterior condylar angle by 3-D reconstruction image before operation and determine how much the femoral protheses should be externally rotated in TKA for a patient,and check the trajectory of patella,then postoperative follow-up for 1 year. and discuss the advantages of 3-D reconstruction images in determining the angles of rotational axis of femoral epicondyle of the commonly used methods.ResultsPreoperative measurement of PCA for the 4.5°.the HSS score was 39 and the knee activity was 62.0°before operation . the HSS score was 79 and the knee activity was 105.0°after operation . She felt pain of the left knee,and it disappeared after treatment, then it was no other significant patellofemoral joint syndrome symptoms.To the last vist,the average HSS score was 81 and the knee activity was 110°after 1 year. Conclusions1,PCA as the best rotational axis of femoral epicondyle was measured constantly and reliably, and it was strong measued repeatability.2,It can be used to guide the rotational axis of femoral epicondyle in TKA to measure PCA by 2-D images or 3-D reconstruction images.3,For thoses whose knees have been seriously damaged , 3-D reconstruction can be used as a useful method to determine the femoral prothesis's rotation during TKA. It is useful in determining the angles of rotational axis of femoral epicondyle by 3-D reconstruction images and made up other measurement methods. It can be intuitive, clear indication of 3-D femoral condyle shapes and reflect the spatial relationships.It provided a reliable help for the clinicians rapidly and it provided a accuraty measurement for PCA preoperatively.