多层螺旋CT容积再现技术测量肱骨头扭转角的研究

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

目的探讨多层螺旋CT容积再现技术测量肱骨头扭转角的准确性，并且通过与解剖测量比较分析产生误差的原因，以期为临床提供快捷、准确的测量方法。方法随机选取20例成人肩关节防腐湿标本，其中左侧9例，右侧11例。所有标本经X线片排除骨折及其他异常。所有的标本先后用3种不同的方法测量，即带软组织的标本用多层螺旋CT三维重建测量（CT1组）；将标本的软组织剔除游离出肱骨，再进行直接解剖测量（裸测组）；直接解剖测量之后标记解剖颈平面，再次用多层螺旋CT三维重建测量（CT2组）。由两名骨科医师完成测量，消除组间误差，将所测值取均值参与统计分析，CT1组与裸测组、CT2组和裸测组分别进行配对t检验。结果CT1组与裸测组、CT2组和裸测组差异无统计学意义。CT1组（21．8°±9．0°）与裸测组（23．4°±9．7°）均值差异为1．64°，CT2组（22．8°±10．1°）和裸测组均值差异为0．65°。结论多层螺旋CT容积再现技术测量肱骨头扭转角是一个准确、简便、临床实用性强的方法，对于术前准确测量肱骨头关节面的扭转角，实现患者个性化肩关节置换和指导假体设计是很有意义的。同时，该技术容易受测量者主观因素的影响，但是通过测量经验增加和合理的测量组织是可以将误差降到最小的。

Objective To verify the accuracy of measurement of humeral head retroversion angle with multislice spiral computerized tomography （MSCT） volume rendering technique. Methods 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 pairedsamples T test. Results 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°, and that between the CT2 group and anatomical measuring group was 0.65% Conclusion 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.