Method of Measuring Scapula Glenoid Version Angle by Multiplanar Reformation of Multi-Slices Spiral CT

Objective:To evaluate the method of measuring the scapula glenoid version angle bymultiplanar reformation(MPR) of multi-slices spiral CT(MSCT).Methods:20 dry scapula specimens and 24 anticorrosive shoulder joint specimens were scanned with 16-slices spiral CT scanner,the scapula glenoid was reconstructed 11 slices on axial plane with MPR of MSCT from top to bottom.The scapula glenoid version angle was measured from NO.2 slice to NO.10 slice,the total slices for measurement was nine,NO.2 slice was the first slice for measurement.NO.10 slice was the ninth slice for measurement.The nine groups′ data of the glenoid version angle were analyzed by the Statistics.Results:The scapula glenoid version angle of nine groups were respectively-17.13°±11.22°,-7.42°±7.32°,-1.99°±5.37°,-1.65°±4.84°,-2.27°±4.83°,-1.82°±4.93°,-1.71°±5.10°,2.05°±5.11°,-2.20°±5.77° from the top slice of scapula glenoid to bottom slice.The Statistics showed that the scapula glenoid version angle of the first slice for measurement was the greatest variable:-34.60°～17.50°(the scapula glenoid retroversion was expressed as negative value,anteversion as positive value),the result had significant difference between the first slice for measurement and the second slice,the result of the first slice for measurement and the second slice had significant difference compared with the other 7 slices(P0.05),the result among the other 7 slices for measurement had no significant difference.Conclusion:The method of measuring the scapula glenoid version angle by(MPR) of MSCT is simple,fast and accurate.The glenoid fossa exhibits retroversion and a spiral twist in the horizontal plane,this anatomy property should be considered in the design of shoulder prosthesis.