Department of Neurosurgery, K.E.M. Hospital and Seth G.S. Medical College, Parel, Mumbai, India.
Department of Neurosurgery, K.E.M. Hospital and Seth G.S. Medical College, Parel, Mumbai, India.
World Neurosurg. 2021 Jul;151:e170-e177. doi: 10.1016/j.wneu.2021.03.155. Epub 2021 Apr 24.
The potential significance of relationship of atlantoaxial instability with retro-odontoid pseudotumor, pannus, and/or cyst (RPC) is analyzed.
We searched the database of patients with craniovertebral junction-related instability treated by atlantoaxial fixation from January 2000 to March 2020. We identified 63 patients in whom there was an RPC in the region posterior to the odontoid process or posterior to the posterior aspect of the C2 body.
The RPC was solid in 10 patients, predominantly cystic in 39 patients, and had both solid and cystic components in 14 patients. The vertical dimension of the RPC varied from 4.5 to 10.5 mm (average, 7.9 mm) and the transverse dimension ranged from 2 to 5.2 mm (average, 3.4 mm). In 51 patients, the RPC was in the midline and in 9 patients, it was eccentric in location. In 38 patients, there was erosion of the C2 body adjoining the RPC. Analysis of investigations showed that in 100% of patients, the dome of the RPC was in line with the most susceptible point of potential bone compression of neural structures. The RPC was eccentric in location in 9 patients presenting with torticollis. RPC indicated the presence of atlantoaxial instability even when there were no other positive and validated radiologic indicators. After atlantoaxial stabilization, the RPC spontaneously regressed or disappeared. Direct resection of the RPC was neither performed nor was necessary in any case.
RPCs are secondary consequences of atlantoaxial instability and need not be primarily addressed by surgical resection. Their location suggests that they might have a neural protective function.
分析寰枢椎不稳与齿状突后 Retro-odontoid 假瘤、滑膜、和/或囊肿（RPC）之间关系的潜在意义。
我们检索了 2000 年 1 月至 2020 年 3 月期间因颅颈交界区相关不稳定而行寰枢固定治疗的患者数据库。我们确定了 63 例齿状突后或 C2 体后部存在 RPC 的患者。
RPC 在 10 例患者中为实性，在 39 例患者中以囊性为主，在 14 例患者中既有实性成分也有囊性成分。RPC 的垂直径从 4.5 至 10.5mm（平均 7.9mm），横径从 2 至 5.2mm（平均 3.4mm）。在 51 例患者中，RPC 位于中线，在 9 例患者中，RPC 位于偏心位置。在 38 例患者中，RPC 毗邻的 C2 体有侵蚀。分析研究表明，在 100%的患者中，RPC 的穹顶与神经结构潜在骨压迫的最易受影响点一致。在 9 例出现斜颈的患者中，RPC 位于偏心位置。即使没有其他阳性和经证实的影像学指标，RPC 也表明存在寰枢椎不稳。寰枢椎稳定后，RPC 会自发消退或消失。在任何情况下都没有进行也没有必要进行 RPC 的直接切除。
RPC 是寰枢椎不稳的继发性后果，不需要通过手术切除来主要解决。它们的位置表明它们可能具有神经保护功能。
