脊髓受压部位MRIT2WI高信号对人工颈椎间盘置换术疗效的影响

The influence of intramedullary hyperintensity on T2-weighted MRI on the outcome of cervical arthroplasty for cervical spondylotic myelopathy

目的探讨术前MRIT2WI脊髓受压部位高信号对颈椎人工椎间盘置换术治疗脊髓型颈椎病疗效的影响。方法回顾性分析2005年6月至2007年12月69例采用颈椎人工椎间盘置换术治疗脊髓型颈椎病的患者资料，根据患者术前MRIT2WI脊髓信号的表现分为三组：①等信号组，即T2WI脊髓受压部位为等信号；共41例，其中男22例，女19例，年龄27～63岁；单节段34例，双节段5例，三节段2例；术前病程3-72个月。②低亮信号组，即T2WI脊髓受压部位为高信号且边界不清；共18例，其中男9例，女9例；年龄30-61岁；单节段12例，双节段6例；术前病程3-24个月。③高亮信号组，即T2WI脊髓受压部位为高信号且边界清晰；共10例，其中男4例，女6例；年龄28-56岁；单节段8例，双节段2例；病程1-24个月。术前MRI横断面硬膜囊受压比率等信号组43．3％±15．2％，低亮信号组42．4％±10．7％，高亮信号组41．9％±14．8％；术前节段性运动范围等信号组9．6°±2．5°，低亮信号组9．0°±1．7°，高亮信号组9．1°±1．9°。69例患者使用Bryan假体42例，Prodisc．C假体44例。三组患者术前均行X线及MR检查，术后行X线检查。比较三组患者手术后颈椎节段性运动范围，采用日本骨科协会（Japanese Orthopaedic Association，JOA）评分评定患者术前、术后神经功能。结果等信号组病程（24．7±27．9）个月，明显长于低亮信号组（6．6±7．4）个月及高亮信号组（11．1±9．5）个月，三组比较差异有统计学意义。患者随访时间48-86个月，平均61个月。术后节段性运动范围等信号组7．9°±1．4°，低亮信号组8．2°±1．5°，高亮信号组1．9°±1．6°；术前JOA评分等信号组（13．6±1．2）分，低亮信号组（13．1±1．3）分，高亮信号组（12．9±1．8）分；末次随访时JOA评分等信号组（16．2±1．0）分，低亮信号组（15．8±1．2）分，高亮信号组（15．7±1．6）分；以上数据三组间比较差异均无统计学意义。结论术前MRIT2WI脊髓受压部位高信号不影响人工颈椎间盘置换术治疗脊髓型颈椎病的疗效。

Objective To investigate whether the hyperintensity on T2-weighted MRI affects the outcome of cervical arthroplasty （CA） for cervical spondylotic myeiopathy （CSM）. Methods 69 patients with CSM who had undergone CA between June 2005 and December 2007 were retrospectively reviewed. They were divided into three groups according to the intensity of T2- weighted images： Group A, whose intensity of T2-weighted images in spinal cord compression spot was equisignal; Group B, hyperintensity with obscure border; Croup C, hyperintensity with clear border. There were 22 males and 19 females in group A aged from 27 to 63 years old, whose duration of disease was between 3 to 72 months, and there were 34 single-segment cases, 5 doublesegment and 2 triple-segment cases. There were 9 males and 9 females in group B aged from 30 to 61 years old whose duration of disease was between 3 to 24 months, and there were 12 single-segment and 6 double-segment cases. There were 4 males and 6 females in group C aged from 28 to 56 years old whose duration of disease was between 1 to 24 months, and there were 8 single-seg- ment and 2 double-segment cases. Two types of artificial cervical disc were used： Bryan Disc in 42 cases and Prodise-C in 44 eases. The duration of Group A （24.7±27.9 months） was significantly longer than that in Group B （6.6±7.4 months） and Group C （11.1±9.5 months）. The follow-up period was from 48 to 86 months with an average time of 61 months. The preoperative X-ray and MR as well as postoperative X-ray were collected. The history, compress ratio of MRI, the ROM of cervical segments pre and postoperatively were recorded and Japanese Orthopaedic Association （JOA） was used to evaluate the neurological function. Results Preoperative compress ratio of MRI were 43.3±15.2%, 42.4%± 10.7% and 41.9%± 14.8% respectively; preoperative segmental ROM were 9.6°±2.5°, 9.0°±1.7° and 9.1°±1.9° respectively. Preoperative JOA score were 13.6±1.2, 13.1±1.3 and 12.9±1.8, respectively. Postoperative JOA score at the latest follow-up were 16.2±1.0, 15.8±1.2 and 15.7±1.6 respectively. There was no statistic difference among these groups. Preoperative increased signal intensify on T2-weighted MRI in patients with cervical spondylotie myelopathy may not affect the outcome of cervical arthroplasty.