Schlemmer B, Dosch J C, Gicquel P, Boutemy P, Wolfram R, Kempf J F, Sick H
Institut d'Anatomie Normale, Faculté de Médecine, 4, rue Kirschleger, 67085 Strasbourg.
Rev Chir Orthop Reparatrice Appar Mot. 2002 Oct;88(6):553-60.
Analysis of the anatomic relations of the humeral head and the glenoid cavity is particularly important for clinical study of shoulder arthroplasty and glenohumeral instability. Analysis of humeral retroversion and glenoid retroversion is quite difficult and data in the literature are scarse. We conducted a computed tomography (CT) analysis of stable shoulders to detail retroversion of the entire height of the glenoid cavity and to measure humeral retrotorsion using two comparative methods. We also compared glenoid retroversion and humeral retrotorsion observed in individual subjects.
This prospective study used a standardized CT analysis method. Both shoulders of 30 persons free of glenohumeral instability were studied. Two methods, described by Dähnert and Bernageau, were used to analyze humeral retrotorsion. The Benageau method was used to analyze glenoid retroversion.
According to the Dähnert method, humeral retrotorsion was 10 degrees +/- 13 degrees; it was 24 degrees +/- 13 degrees with the Bernageau method; data dispersion was 60 degrees and 65 degrees respectively. According to the Dähnert method, retrotorsion was more pronounced on the dominant side compared with the non-dominant side. There was a significant correlation between retrotorsion values for the two sides. For 95% of the shoulders, glenoid retorversion decreased progressively from the superior part of the glenoid cavity (12.8 degrees +/- 6.4 degrees ) to the lower part (3.1 degrees +/- 4.4 degrees ). Glenoid retroversion was greater on the dominant side. For 21 of the 30 persons (70%), there was a significant correlation between retroversion for the two sides. Correlation coefficients between glenoid retroversion and humeral retrotorsion were negative. Greater humeral retrotorsion was thus related with less pronounced glenoid retroversion and vice versa.
This study allowed quantification of glenoid retroversion and humeral retrotorsion. There is a spiral twist in the joint surface of the glenoid cavity with progressive decrease in glenoid retorversion from the upper to the lower part of the cavity for 95% of the shoulders. To our knowledge, this spiral twist in the glenoid cavity is not taken into consideration in any of the currently available implants. The correlation for both parameters between the right and left side is probably determined genetically. The influence of dominance could be explained by adaptation to more or less pronounced stress. The negative correlation between humeral retrotorsion and glenoid retroversion would improve glenohumeral stability. A comparative study with unstable shoulders would be required to verify this hypothesis. The validity of the Dähnert method for assessing humeral retorversion is, in our opinion, insufficiently established. The Bernageau method, which provides a direct measurement, appears to be preferable despite the difficulty in identifying anatomic landmarks.
分析肱骨头与关节盂的解剖关系对于肩关节置换术和盂肱关节不稳的临床研究尤为重要。分析肱骨后倾和关节盂后倾相当困难，且文献中的数据稀少。我们对稳定的肩关节进行了计算机断层扫描（CT）分析，以详细了解关节盂整个高度的后倾情况，并使用两种比较方法测量肱骨扭转角度。我们还比较了个体受试者中观察到的关节盂后倾和肱骨扭转角度。
这项前瞻性研究采用了标准化的CT分析方法。对30例无盂肱关节不稳的受试者的双侧肩关节进行了研究。使用Dähnert和Bernageau描述的两种方法分析肱骨扭转角度。使用Bernageau方法分析关节盂后倾。
根据Dähnert方法，肱骨扭转角度为10°±13°；采用Bernageau方法时为24°±13°；数据离散度分别为60°和65°。根据Dähnert方法，优势侧的扭转角度比非优势侧更明显。两侧的扭转角度值之间存在显著相关性。对于95%的肩关节，关节盂后倾从关节盂上部（12.8°±6.4°）到下部（3.1°±4.4°）逐渐减小。优势侧的关节盂后倾更大。在30名受试者中的21名（70%），两侧的后倾之间存在显著相关性。关节盂后倾与肱骨扭转角度之间的相关系数为负。因此，肱骨扭转角度越大，关节盂后倾越不明显，反之亦然。
本研究实现了对关节盂后倾和肱骨扭转角度的量化。关节盂关节面存在螺旋扭曲，95%的肩关节其关节盂后倾从关节盂上部到下部逐渐减小。据我们所知，目前任何可用的植入物均未考虑关节盂中的这种螺旋扭曲。左右两侧这两个参数之间的相关性可能由基因决定。优势的影响可以通过对或多或少明显应力的适应来解释。肱骨扭转角度与关节盂后倾之间的负相关将提高盂肱关节的稳定性。需要与不稳定的肩关节进行比较研究以验证这一假设。我们认为，Dähnert方法评估肱骨扭转角度的有效性尚未充分确立。尽管难以识别解剖标志，但能提供直接测量的Bernageau方法似乎更可取。
