Dipartimento di Bioimmagini e Scienze Radiologiche, Università Cattolica del Sacro Cuore, Policlinico A. gemelli, Largo A. gemelli 1, 00168, Roma, Italy.
Radiol Med. 2012 Jun;117(4):636-53. doi: 10.1007/s11547-011-0746-x. Epub 2011 Nov 17.
Occipitocervical fusion is required when the occipitoatlantal joint is unstable. The purpose of this paper is to discuss the role of imaging in the pre- and postoperative evaluation of posterior occipitocervical fusion (POCF), focusing on contoured loop fixation by Hartshill and Songer instrumentation.
We studied 21 patients (eight males, 12 females; age range 6-70 years; mean age 32.6 years) with craniocervical instability who underwent POCF with Hartshill U-shaped rod and Songer sublaminar wires. Pre- and postoperative radiographic, computed tomography (CT) and magnetic resonance (MR) imaging examinations were performed in all patients. A 3- to 6-month period of external orthosis with halo vest, sterno-occipitalmandibular immobiliser (SOMI) brace or Philadelphia collar followed surgery. Follow-up was 12-96 (mean 53.1) months.
Clinical assessment using the Frankel scale revealed improvement or deterioration arrest in all but two patients: one with C3 failure and halo destabilisation; the other, who had exhibited myelopathy signs on preoperative MR imaging and persistent basilar impression, showed increasing and progressive neurological deficits despite successful POCF.
Pre- and postoperative imaging is extremely useful in patients scheduled to undergo POCF. Preoperative MR screening of basilar impression associated with possible spinal cord lesions appears mandatory to predict possible deterioration and prevent undesired failure of the operation and it may suggest the need for an alternative surgical approach, such as the transoral approach.
寰枕关节不稳定时需要进行枕颈融合。本文旨在讨论影像学在枕颈后路融合术（POCF）术前和术后评估中的作用，重点介绍 Hartshill 和 Songer 器械的轮廓环固定。
我们研究了 21 例颅颈不稳定患者（8 例男性，12 例女性；年龄 6-70 岁；平均年龄 32.6 岁），均行 Hartshill U 形棒和 Songer 椎板下钢丝行 POCF。所有患者均行术前、术后影像学检查，包括 X 线、计算机断层扫描（CT）和磁共振成像（MRI）。术后均采用 Halo 背心、SOMI 支具或 Philadelphia 颈托外固定 3-6 个月。随访时间 12-96 个月（平均 53.1 个月）。
Frankel 量表的临床评估显示，除 2 例患者外，所有患者均有改善或停止恶化：1 例 C3 失败伴 Halo 不稳定；另 1 例术前 MRI 显示有脊髓病变且存在基底凹陷，尽管 POCF 成功，但仍出现进行性和进行性神经功能缺损。
POCF 患者术前和术后的影像学检查非常有用。术前 MRI 筛查基底凹陷伴可能的脊髓病变，对于预测可能的恶化和防止手术不当失败非常必要，也可能提示需要替代手术方法，如经口入路。
