Elliott Robert E, Tanweer Omar, Frempong-Boadu Anthony, Smith Michael L
*Neurosurgical Care, LLC, Royersford, PA †Department of Neurosurgery, New York University Langone Medical Center ‡Bellevue Hospital, New York, NY.
J Spinal Disord Tech. 2015 Jun;28(5):171-85. doi: 10.1097/BSD.0b013e3182898aa9.
Literature review and meta-analysis.
To compare clinical and radiographic outcomes of patients treated with C1 lateral mass screws (C1LMS), analyzing the impact of screw starting point and C2 nerve sectioning on malposition, vertebral artery injury (VAI), and C2 neuralgia and numbness.
Various starting points have been suggested for C1LMS insertion. Some advocate sectioning the C2 nerve root to ease placement.
Online databases were searched for English language articles between 1994 and 2012 reporting on C1LMS. Forty-two studies describing 1471 patients instrumented with 2905 C1LMS met inclusion criteria. Three surgical techniques included posterior arch starting point and center of lateral mass with nerve root preservation or sacrifice.
All studies provided class III evidence. Three injuries to the vertebral artery occurred secondary to C1LMS insertion (0.1%) and 5 instances of clinically significant screw malpositions (0.2%). Postoperative imaging revealed 45 malpositioned screws (1.6%) without clinical consequences. Meta-analysis techniques demonstrated that sacrifice of the C2 nerve root caused greater postoperative numbness but less neuralgia and fewer screw malpositions. Similar rates of screw malposition and VAI arose with posterior arch screws and those starting below the arch with C2 nerve preservation, but the latter had greater numbness and pain.
A thorough understanding of atlantoaxial anatomy and modern surgical techniques renders the insertion of C1LMS safe and accurate. The incidence of clinically significant malpositioned screws or VAI is <0.5%. Sacrifice of the C2 nerve root did result in fewer malpositioned screws. Numbness occurred in 11% of patients, an outcome that may be unacceptable to certain patient populations, but neuropathic pain was nearly absent with nerve sectioning. C2 nerve preservation and retraction for C1 screw placement may have higher incidence of neuropathic pain. Posterior arch screws are a viable option for patients with arches that are of adequate height.
文献综述与荟萃分析。
比较接受C1侧块螺钉（C1LMS）治疗的患者的临床和影像学结果，分析螺钉起始点和C2神经根切断对位置不当、椎动脉损伤（VAI）以及C2神经痛和麻木的影响。
对于C1LMS植入已提出了各种起始点。一些人主张切断C2神经根以方便植入。
在在线数据库中检索1994年至2012年间报道C1LMS的英文文章。42项描述1471例接受2905枚C1LMS植入术患者的研究符合纳入标准。三种手术技术包括后弓起始点以及保留或牺牲神经根的侧块中心。
所有研究均提供了III级证据。C1LMS植入术后发生3例椎动脉损伤（0.1%）和5例具有临床意义的螺钉位置不当（0.2%）。术后影像学显示45枚螺钉位置不当（1.6%）但无临床后果。荟萃分析技术表明，牺牲C2神经根会导致术后麻木更严重，但神经痛更少且螺钉位置不当更少。后弓螺钉与在弓下方起始并保留C2神经的螺钉出现螺钉位置不当和VAI的发生率相似，但后者麻木和疼痛更严重。
对寰枢椎解剖结构和现代手术技术的透彻理解使C1LMS的植入安全且准确。具有临床意义的螺钉位置不当或VAI的发生率<0.5%。牺牲C2神经根确实导致螺钉位置不当减少。11%的患者出现麻木，这一结果对于某些患者群体可能是不可接受的，但切断神经后几乎没有神经性疼痛。保留C2神经并将其牵开以进行C1螺钉植入可能神经性疼痛发生率更高。对于具有足够高度弓的患者，后弓螺钉是一种可行的选择。
