Natsis K, Piagkou M, Skotsimara G, Piagkos G, Skandalakis P
Department of Anatomy, Medical School, Aristotle University of Thessaloniki, Plateia Ippodromiou 17, 54621, Thessaloniki, Greece.
Surg Radiol Anat. 2013 Dec;35(10):925-34. doi: 10.1007/s00276-013-1119-z. Epub 2013 Apr 26.
The foramen magnum (FM), a complex area in craniocervical surgery, poses a challenge for neurosurgeons. The knowledge of the detailed anatomy of the FM, occipital condyles (OC) and variations of the region is crucial for the safety of vital structures. This study focuses on the FM and OC morphometry, highlights anatomical variability and investigates correlations between the parameters studied.
One hundred and forty-three Greek adult dry skulls were examined using a digital sliding calliper (accuracy, 0.01 mm).
Mean FM width and length were found 30.31 ± 2.79 and 35.53 ± 3.06 mm, respectively. The commonest FM shape was two semicircles (25.9 %), whereas the most unusual was irregular (0.7 %). The OC minimum width, maximum width and length were 5.71 ± 1.61, 13.09 ± 1.99 and 25.60 ± 2.91 mm on the right, and 6.25 ± 1.76, 13.01 ± 1.98 and 25.60 ± 2.70 mm on the left side. The commonest OC shape was S-like and the most unusual was ring, bilaterally. The mean anterior and posterior intercondylar distances were 19.30 ± 3.25 and 51.61 ± 5.01 mm, respectively. The OC protruded into the FM in 86.7 % of the skulls. Variations such as a third OC existed in 5.6 % and basilar processes in 2.8 %. Posterior condylar foramina were present in 75.5 %. The gender was correlated with FM width and length, OC length, bilaterally, anterior intercondylar distance (AID) and posterior intercondylar distance (PID). The OC protrusion and existence of posterior condylar foramina were correlated. Bilateral asymmetry for OC shape was statistically significant.
Our results provide useful information that will enable effective and reliable surgical intervention in the FM region with the maximum safety and widest possible exposure.
枕骨大孔（FM）是颅颈手术中的一个复杂区域，给神经外科医生带来了挑战。了解枕骨大孔、枕髁（OC）的详细解剖结构以及该区域的变异情况对于重要结构的安全至关重要。本研究聚焦于枕骨大孔和枕髁的形态测量，突出解剖变异并研究各研究参数之间的相关性。
使用数字游标卡尺（精度为0.01毫米）对143个希腊成人干燥颅骨进行检查。
枕骨大孔的平均宽度和长度分别为30.31±2.79毫米和35.53±3.06毫米。最常见的枕骨大孔形状是两个半圆（25.9%），而最不常见的是不规则形状（0.7%）。右侧枕髁的最小宽度、最大宽度和长度分别为5.71±1.61毫米、13.09±1.99毫米和25.60±2.91毫米，左侧分别为6.25±1.76毫米、13.01±1.98毫米和25.60±2.70毫米。最常见的枕髁形状是S形，最不常见的是环形，双侧均如此。髁间前后平均距离分别为19.30±3.25毫米和51.61±5.01毫米。86.7%的颅骨中枕髁突入枕骨大孔。5.6%的颅骨存在如第三枕髁等变异，2.8%存在基底突。75.5%的颅骨存在髁后孔。性别与枕骨大孔的宽度和长度、双侧枕髁长度、髁间前距（AID）和髁间后距（PID）相关。枕髁突入与髁后孔的存在相关。枕髁形状的双侧不对称具有统计学意义。
我们的结果提供了有用信息，将有助于在枕骨大孔区域进行有效且可靠的手术干预，实现最大程度的安全和尽可能广泛的暴露。
