[Measurement of humeral head retroversion angle with multislice spiral computerized tomography volume rendering...

To verify the accuracy of measurement of humeral head retroversion angle with multislice spiral computerized tomography (MSCT) volume rendering technique.

Twenty cadaveric humeri, 9 left and 11 right, free from traumatic or degenerative disfigurement, were harvested from embalmed cadavers. Before all soft tissues were removed by sharp dissection these humeri were scanned with 16 slice spiral CT scanner (CT1 group); then underwent anatomical measurement (anatomical measuring group); and at last, these humeri with marked anatomic neck were scanned with 16 slice spiral CT scanner again (CT2 group). The measurement was done by 2 orthopedists independently so as to diminish the measuring error. The differences in the humeral head retroversion angle between the CT1 group and anatomical measuring group, and the CT2 group and anatomical measuring group were analyzed with paired-samples T test.

It showed that the results have no significant difference among them. The difference in the average value of humeral head retroversion angle between the CT1 group and anatomical measuring group was 1.64 degrees, and that between the CT2 group and anatomical measuring group was 0.65 degrees.

Simple, fast, and precise, and suitable for clinical application, MSCT volume rendering technique can be used preoperatively, thus helping to realize the idea of individualization of shoulder arthroplasty and shoulder prosthesis. Although this technique is easy to be influence by the subjective factors of the observers, increase of experience and rational measurement may minimize the measurement error.