Study on using CT to locating mark of sustentaculum tali and the parameter measurement / 重庆医学

ABSTRACT

Objective To use CT and 3D reconstruction technique to locating mark of sustentaculum tali ,and measure the an‐gle & length of the specified point of the lateral wall of the calcaneus to sustentaculum tali for providing .To basis for the operation of calcaneus .Methods Thirty adult ankle wet specimens were chosen and scanned with CT ,and the dicom data were converted into the software to 3D‐reconstruction ,the observation and measurement to find new methods of locating mark of sustentaculum tali ;Forty adult calcaneus dried specimens were chosen and scanned with CT .The dicom data were converted into the software to 3D‐re‐construction ,using a workstation software measure the angle and length of the line which from the center of the sustentaculum tail to each point on the calcaneal lateral wall .Results First ,in the function of ankle joint position ,with the foot medial surface as “sag‐ittal reference plane” measurement ,the vertical line passing through the leading edge of medial malleols and the coronal line passing through the leading edge of sustentaculum tali intersect at a point .The vertical distance of the point to leading edge of medial malle‐ols was (34 .95 ± 2 .60) mm ,the length of sustentaculum tali was (21 .44 ± 1 .89) mm ,the height of sustentaculum tali was (10 .17 ± 1 .16) mm ,the anteversion of sustentaculum tali was (35 .31 ± 3 .73)° .Second ,in front of calcaneus ,upward angel of points G ,E were (28 .78 ± 3 .90 )° ,(29 .47 ± 2 .96 )° respectively .Frontward angle of points G ,E were ( - 19 .83 ± 4 .60 )° , ( - 11 .02 ± 4 .74)° respectively .Under the posterior articular surface ,upward angel of points C ,K ,I ,J were(2 .52 ± 2 .46)° ,(2 .92 ± 2 .28)° ,(14 .98 ± 2 .49)° ,(14 .38 ± 1 .90)° respectively .Frontward angle of points C ,K ,I ,J were(7 .32 ± 1 .66)° ,(19 .25 ± 1 .98)° , (10 .30 ± 2 .63)° ,(19 .33 ± 1 .97)° respectively .The length of screw was about 40 - 44 mm .The length of C point to the sustentacu‐lum tail was minimum ,and the length of G was maximum .Conclusion In the function of ankle joint position ,the sustentaculum tail can be located with the leading edge of medial malleols as a surface landmarks .The measurement of the angle and length of which from each point on the calcaneal lateral wall to sustentaculum tail by using CT .