Hori Takeshi, Kawaguchi Yoshiharu, Kimura Tomoatsu
Department of Orthopaedic Surgery, University of Toyama, Toyama, Japan.
Spine (Phila Pa 1976). 2007 Sep 1;32(19):E551-6. doi: 10.1097/BRS.0b013e31814614f3.
Retrospective case series.
To investigate the progression of the thickness of the ossification area over time following cervical laminoplasty.
Cervical laminoplasty has become the standard technique for the treatment of patients with myelopathy due to ossification of the posterior longitudinal ligament (OPLL). However, OPLL is a progressive disease, and an increase in the area of ossification following laminoplasty affects the surgical results. To date, complete analysis of the thickness of OPLL progression has not been undertaken because changes in the ossification thickness are minor compared with those of the longitudinal axis.
Fifty-five patients who were available for serial radiographs more than 5 years after cervical laminoplasty were included. The extent of ossification thickness was assessed using lateral radiographs of the cervical spine and computer software. The neurologic evaluation was graded using the Japanese Orthopedic Association score (JOA score). The associations between the progression of OPLL and the clinical and radiologic data were analyzed. We also evaluated the progression of the thickness of the ossification area over time following surgery.
Twelve patients (21.8%) had progression in the OPLL thickness. Progression was marked in younger patients with the mixed or continuous types of OPLL. C3 involvement was also common in the patients with the OPLL progression. The progression of OPLL thickness was not directly related to the score-based recovery rate. The progression of OPLL was frequently observed at C2, C3, and C4 levels. Progression in OPLL thickness was detected in 42.1% of C2 ossifications, 13.3% of C3, 11.9% of C4, 4.1% of C5, 5.5% of C6, and 6.6% of C7.
Young patients with continuous or mixed-type OPLL and C3 involvement of ossification had a risk for progression in OPLL thickness following surgery. As the increased thickness of ossified lesions directly causes the narrowing of the spinal canal, it is important to pay attention to these risk factors and the increase in ossification before and after cervical laminoplasty in the surgical treatment of patients with OPLL.
回顾性病例系列研究。
探讨颈椎椎板成形术后骨化区域厚度随时间的进展情况。
颈椎椎板成形术已成为治疗后纵韧带骨化（OPLL）所致脊髓病患者的标准技术。然而，OPLL是一种进行性疾病，椎板成形术后骨化面积增加会影响手术效果。迄今为止，由于骨化厚度的变化与纵轴变化相比很小，尚未对OPLL进展的厚度进行完整分析。
纳入55例颈椎椎板成形术后5年以上可获得系列X线片的患者。使用颈椎侧位X线片和计算机软件评估骨化厚度范围。采用日本骨科协会评分（JOA评分）对神经功能进行分级。分析OPLL进展与临床及影像学数据之间的关联。我们还评估了手术后骨化区域厚度随时间的进展情况。
12例患者（21.8%）的OPLL厚度有进展。年轻的混合型或连续型OPLL患者进展明显。C3受累在OPLL进展患者中也很常见。OPLL厚度进展与基于评分的恢复率无直接关系。OPLL进展常见于C2、C3和C4水平。在C2骨化中，42.1%检测到OPLL厚度进展，C3为13.3%，C4为11.9%，C5为4.1%，C6为5.5%，C7为6.6%。
连续型或混合型OPLL且C3骨化受累的年轻患者术后有OPLL厚度进展的风险。由于骨化病变厚度增加直接导致椎管狭窄，在OPLL患者的手术治疗中，关注这些危险因素以及颈椎椎板成形术前后骨化的增加情况很重要。
