Fujiyoshi Takayuki, Yamazaki Masashi, Kawabe Junko, Endo Tomonori, Furuya Takeo, Koda Masao, Okawa Akihiko, Takahashi Kazuhisa, Konishi Hiroaki
Spine Section, Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chuo-ku, Chiba, Japan.
Spine (Phila Pa 1976). 2008 Dec 15;33(26):E990-3. doi: 10.1097/BRS.0b013e318188b300.
To report a new index, the K-line, for deciding the surgical approach for cervical ossification of the posterior longitudinal ligament (OPLL).
To analyze the correlation between the K-line-based classification of cervical OPLL patients and their surgical outcome.
Previous studies showed that kyphotic alignment of the cervical spine and a large OPLL are major factors causing poor surgical outcome after laminoplasty for cervical OPLL patients. However, no report has evaluated these 2 factors in 1 parameter.
The K-line was defined as a line that connects the midpoints of the spinal canal at C2 and C7. Twenty-seven patients who had cervical OPLL and underwent posterior decompression surgery were classified into 2 groups according to their K-line classification. OPLL did not exceed the K-line in the K-line (+) group and did exceed it in the K-line (-) group. By intraoperative ultrasonography, we evaluated the posterior shift of the spinal cord after the posterior decompression procedure. The Japanese Orthopedic Association scores before surgery and 1 year after surgery were evaluated, and the recovery rate was calculated.
Eight patients were classified as K-line (-), and 19 patients were classified as K-line (+). The mean recovery rate was 13.9% in the K-line (-) group and 66.0% in the K-line (+) group (P < 0.01). Ultrasonography showed that the posterior shift of the spinal cord was insufficient in the K-line (-) group.
The present results demonstrate that a sufficient posterior shift of the spinal cord and neurologic improvement will not be obtained after posterior decompression surgery in the K-line (-) group. Our new index, the K-line, is a simple and practical tool for making decisions regarding the surgical approach for cervical OPLL patients.
报告一种用于确定后纵韧带骨化症（OPLL）颈椎手术入路的新指标——K线。
分析基于K线对颈椎OPLL患者进行分类与手术结果之间的相关性。
先前的研究表明，颈椎后凸畸形和较大的OPLL是导致颈椎OPLL患者行椎板成形术后手术效果不佳的主要因素。然而，尚无报告在一个参数中评估这两个因素。
K线定义为连接C2和C7椎管中点的一条线。27例患有颈椎OPLL并接受后路减压手术的患者根据其K线分类被分为两组。在K线（+）组中，OPLL未超过K线；在K线（-）组中，OPLL超过了K线。通过术中超声检查，我们评估了后路减压手术后脊髓的后移情况。评估术前及术后1年的日本骨科学会评分，并计算恢复率。
8例患者被分类为K线（-）组，19例患者被分类为K线（+）组。K线（-）组的平均恢复率为13.9%，K线（+）组为66.0%（P<0.01）。超声检查显示，K线（-）组脊髓的后移不足。
目前的结果表明，K线（-）组后路减压手术后无法获得足够的脊髓后移和神经功能改善。我们的新指标K线是一种简单实用的工具，可用于决定颈椎OPLL患者的手术入路。
