应用MRI分析腰椎多裂肌-最长肌间隙入口位置

Analysis of the multifidus-longissimus intermuscular cleavage entrance in lumbar spine by magnetic resonance imaging

目的 应用MRI测量腰椎各椎间盘平面多裂肌-最长肌间隙入口与中线的距离,并分析其相关因素。方法 前瞻性选取2012年4月—2013年1月行腰椎MRI检查的200例患者,测量腰椎MRI各椎间盘平面双侧肌间隙入口与中线的距离（D）,并采用单因素方差分析和q检验比较节段间差异,t检验比较左右两侧及不同性别的差异,Pearson相关性检验分析各节段D间的相关性,多元线性回归分析各节段D与患者年龄、身高、BMI的相关性。结果 腰椎各椎间盘平面肌间D从L1/2水平至L5/S1水平逐渐增大,不同节段间D差异有统计学意义（左侧：F=3 614.84,P=0.00;右侧：F=3 411.34,P=0.00）,但左右侧间差异无统计学意义（P＞0.05）,D1仅与D2间存在相关性,而D2~D5间则两两正相关。男性与女性患者仅L4/5节段D差异有统计学意义（t=4.44,P＜0.01）,其他节段D男女间差异均无统计学意义（P值均＞0.05）。各节段D与患者的年龄均无相关性。男性患者D1双侧均与身高呈正相关,女性患者D1L、D1R及D2L与BMI正相关,而D4双侧与身高呈正相关。结论 腰椎多裂肌-最长肌间隙入口位置与患者年龄、性别、身高、BMI等关系不大。在L1-3水平,肌间隙距离正中线较近,适合作单个正中切口;在L4～S1水平则应根据术前测量结果应用双侧切口。

Objective To measure the distances from the intermuscular cleavage to the midline at each intervetebral disc level by MRI, and to analyze the related factors. Methods MRI scans of 200 patients taken during routine care （2012.04-2013.01） were retrospectively reviewed. The distances （D） from the intermuscular cleavage planes to the midline, bilaterally, at each disc level were measured. One-way analysis of variance （ANOVA） and q test were used to compare the difference between the Ds of each intervertebral disc level. Paired t-test and independent t-test were used to compare Ds of different sides and genders. Pearson correlation test was used to analyze the correlation between the Ds of each intervertebral disc level. Multi-linear regression analysis was used to analyze the correlation between the D of each intervertebral disc level and the age, height, and body mass index （BMI）. Results The mean measurements of D increase from L1/2 to L5/S1, and significantly different between all disc levels （left side： F=3 614.84, P=0.00; right side： F=3 411.34, P=0.00）, but the Ds in left side did not significantly differed from that in right side. Ds only differed in L4/5 disc level between males and females （t=4.44, P＜0.01）, while no significant difference was found in the other levels （all P values＞0.05）. No correlation was discovered between ages with respect to measured distances. D1 positively correlated with height in males bilaterally. As in females, positive correlations were discovered between D1L, D1R, D2L and BMI, and bilateral D4 and height. Conclusions Little correlations are discovered between age, gender, BMI or height with respect to measured distances. In the upper levels of the lumbar spine （L1-3）, it prefers approaching through a single midline incision, because of the small distance. In the lower levels of the lumbar spine （L4-S1）, it prefers dual-incision paraspinal approach with preoperative localization via images of MRI or CT.