Zumstein Valentin, Kraljević Marko, Huegli Rolf, Muller-Gerbl Magdalena
Anatomical Institute, University of Basel, Pestalozzistrasse 20, 4056, Basel, Switzerland.
Surg Radiol Anat. 2011 Nov;33(9):775-9. doi: 10.1007/s00276-011-0819-5. Epub 2011 May 18.
Pathologic changes of the glenohumeral joint, like a long-standing overloading or an accident often lead to severe glenohumeral osteoarthritis, and a glenohumeral joint replacement could be necessary. Joint instability and glenoid loosening are the most common post-operative complications, which can be caused by eccentric loading of the glenoid, if the humeral head is malcentered. If these malcentered cases could be identified pre-operatively, the pathologic position of the humeral head could be fixed intra-operatively and complication may be prevented. Computed tomography osteoabsorptiometry (CT-OAM) is a useful method to determine the distribution of mineralisation in the subchondral bone as a marker for the long-term loading history of a joint. The objective of this study was to gain information about the mineralisation distribution in the subchondral bone plate of the humeral head.
By the use of CT-OAM, the distribution of the subchondral mineralisation of 69 humeral heads was investigated and groups of mineralisation patterns were built. To evaluate if differences in age exist, the mean values of the two groups were compared using t test.
49 humeral heads (71% of 69 specimens) showed bicentric subchondral mineralisation patterns with ventral and dorsal maxima, 20 humeral heads (29% of 69 specimens) could be classified as monocentric with a centro-dorsal maximum. We found no statistical significant difference between the age of the monocentric and the bicentric group on a significance level of 95%.
We could show that stress distribution at the humeral head is typically bicentric with a ventral and dorsal maximum. However, other mineralisation patterns may occur under pathologic circumstances. The pre-operative identification of such cases by the use of CT-OAM could help to improve the post-operative results in shoulder surgery.
肩肱关节的病理变化，如长期负荷过重或意外事故，常导致严重的肩肱关节骨关节炎，可能需要进行肩肱关节置换。关节不稳定和肩胛盂松动是最常见的术后并发症，如果肱骨头中心位置异常，可能是由肩胛盂的偏心负荷引起的。如果这些中心位置异常的情况能够在术前被识别出来，术中就可以固定肱骨头的病理位置，从而预防并发症。计算机断层扫描骨吸收测量法（CT-OAM）是一种有用的方法，可用于确定软骨下骨矿化的分布，作为关节长期负荷历史的标志物。本研究的目的是获取有关肱骨头软骨下骨板矿化分布的信息。
通过使用CT-OAM，研究了69个肱骨头的软骨下矿化分布，并建立了矿化模式组。为了评估年龄是否存在差异，使用t检验比较了两组的平均值。
49个肱骨头（69个标本的71%）显示出双中心软骨下矿化模式，腹侧和背侧有最大值，20个肱骨头（69个标本的29%）可归类为单中心，中心背侧有最大值。在95%的显著性水平上，我们发现单中心组和双中心组的年龄之间没有统计学上的显著差异。
我们可以表明，肱骨头的应力分布通常是双中心的，腹侧和背侧有最大值。然而，在病理情况下可能会出现其他矿化模式。通过使用CT-OAM术前识别此类病例有助于改善肩部手术的术后结果。
