Ghaly R F, Lissounov A
Ghaly Neurosurgical Associates, Aurora, Illinois, USA.
Surg Neurol Int. 2017 Jun 5;8:98. doi: 10.4103/sni.sni_433_16. eCollection 2017.
Occipitocervical instability may be attributed to congenital, bony/ligamentous abnormalities, trauma, neoplasm, degenerative bone disease, and failed atlantoaxial fixation. Indications for occipitocervical fixation include the prevention of disabling pain, cranial nerve dysfunction, paralysis, or even sudden death.
The screw trajectory for the modified transcondylar screw (mTCS) is optimally planned utilizing a three-dimensional skull reconstructed image.
The modified mTCS technique is helpful where there is a loss of bone, such as after prior suboccipital craniotomy and/or an inadequate occipital condyle. The new proposed technique is similar to the classical transcondylar screw placement but follows a deeper course along the bony lip of foramen magnum toward clivus from a dorsolateral approach.
The modified mTCS technique allows for direct visualization and, therefore, helps to avoid damage to the hypoglossal nerve and lateral aspect of brain stem.
枕颈不稳可能归因于先天性、骨/韧带异常、创伤、肿瘤、退行性骨病以及寰枢椎固定失败。枕颈固定的适应证包括预防致残性疼痛、脑神经功能障碍、瘫痪甚至猝死。
利用三维颅骨重建图像对改良经髁螺钉（mTCS）的螺钉轨迹进行最佳规划。
改良的mTCS技术在存在骨质丢失的情况下很有帮助，例如在先前枕下开颅术后和/或枕髁不足时。新提出的技术类似于经典的经髁螺钉置入，但从背外侧入路沿着枕骨大孔的骨缘向斜坡走行更深。
改良的mTCS技术可实现直接可视化，因此有助于避免损伤舌下神经和脑干侧面。
