复发性肩关节前脱位所伴随肱骨头骨性损伤的数字减影测量与分析研究

The arthrosocpic Bankart repair is the most widely used treatment for the patients with recurrent anterior shoulder dislocation. But bony lesion of the humeral head are very common in these patients. And to those with severe bony lesion on the humeral head the recurrent rate after arthroscopic repair is very high. Therefore a careful evaluation of the bony lesion is needed before the surgery. However due to the irregular configuration and diversity of the shape of the bony lesion it is very difficult to make a measurement by conventional imaging techniques. The hypothesis of this study is that the shape of the humeral head of both sides are very similar and the humeral head of the healthy side can be used as a mirror image of the affected humeral head before the recurrent dislocation. Therefore the configuration of the bony lesion can be shown after a subtraction of the image of affcted humeral head from that of the healthy side. A digital subtraction method will be created to show and measure the bony lesion of humeral head in this study. A osteotomy of the humeral head specimen will be done. The parameters of the osteotomized fragment will be measured both in vivo and by using the method of digital subtration and the acurracy of the digital subtrationt technique will be decided after a comparision between the results.The similarity of the shape of the humeral head between two sides of a same individual will be proved after using this technique in contral group with healthy shoulders. Finally the digital subtraction technique will be used to analyse the data of case group to explore the characters of bony lesion of humeral head in this group of patients. The digital subtraction technique developed in this study and the information about the bony lesion of the humeral head got from this study are all very helpful to the research in this topic in the future.

复发性肩关节前脱位是临床上最常见的关节脱位，会明显影响病人生活。关节镜下Bankart修复术是治疗复发性肩关节前脱位的常用方法。由于病人多伴有肱骨头骨性损伤，巨大骨性损伤会明显增加关节镜术后复发率，故术前对其进行准确评估对术式选择至关重要。但这类损伤形态不规则，现临床上尚无法对其进行精确测量。我们认为如能证实健康人双侧肱骨头形态极为近似，可看作互为镜像；则健侧肱骨头可作为患侧损伤前形态的镜像，双侧肱骨头三维图形相减即可得到骨性损伤形态，并进行测量。本研究将建立专用的数字减影技术以求得肱骨头形态差异。通过在尸体骨标本截骨试验中应用该技术以验证其精度。以本方法分析健康对照组双侧肱骨头形态差异以证实双侧外形近似理论。最后，尝试以本数字减影技术精确测量病例组中肱骨头骨性损伤。通过本研究，可建立精确测量肱骨头骨性损伤的方法并初步了解损伤分布位置及其外形参数，为进一步的研究打下基础。

项目背景：. 复发性肩关节前脱位是临床上最常见的关节脱位。由于巨大骨性损伤会明显增加关节镜术后复发率，故术前对其进行精确评估对术式选择至关重要。但这类损伤形态不规则，现尚无法对其进行精确测量。我们认为如能证实健康人双侧肱骨头形态极为近似，可看作互为镜像；则健侧肱骨头可作为患侧损伤前形态的镜像，双侧肱骨头三维图形相减即可得到骨性损伤形态，并进行测量。.主要研究内容：. 本研究将建立专用的数字减影技项术以求得双侧肱骨头形态差异。以本方法分析健康对照组双侧肱骨头形态差异以证实双侧外形近似理论。. 我们与中国科学院软件研究所合作，开发了专用于本研究的软件-VMedViewer。应用该软件，可完成对患者肩关节三维CT数据的分割、填充、三维重建、翻转和配准等步骤，最终获得两者重合度最佳的重叠模型，并进行数字减影。我们采集164例正常人群双侧肱骨近端三维CT数据，通过该软件进行图像处理。同时我们将配准后双侧肱骨近端三维图形数据引入VRmesh软件，得出双侧肱骨近端骨骼表面各对应点间位置平均差异值、最大位置差异值及最大位置差异点在肱骨近端所处部位。. 此外，我们还应用尸体骨标本，制成骨缺损模型。验证了软件法测量骨缺损的精度。并初步尝试了采用软件法测量实际病人的肱骨头骨缺损。.重要结果及关键数据：. 我们发现双侧肱骨头表面各对应点间平均距离为：0.16±0.26mm；各标本中最大对应点间距离平均值：3.27±0.87mm；所有标本中最大的对应点间距离为5.90mm。 在各个标本中，相对距离最大对应点分布于后部大结节11例，后部肱骨头关节面65例，位于结节间沟40例，前部大结节13例，前部肱骨头关节面19例，小结节16例。. 我们还发现，软件法测量的骨缺损部位的底边长度数值与实际手测数值无显著性差异(p=0.489)，显示当骨骼模型在除缺损部位之外其他部位的外形轮廓及体积参数完全一致的情况下，本方法可以准确检测出缺损部位。实际应用软件法测量病人的骨缺损显示，目前该方法在处理实际问题方面仍有一些缺陷，需进一步改进。.科学意义：. 通过该研究，我们发现健康成年人双侧肱骨近端骨性结构外形十分近似，因此健侧可看做是患侧的模板。双侧肱骨近端骨骼表面各对应点间平均误差为0.16±0.26mm，最大误差为5.9mm。