腰椎后路椎间融合术后椎间融合的X线片及三维CT评价

目的 探讨X线片和三维CT(3D-CT)在判定单节段后路腰椎椎间融合术后椎间融合情况的临床价值.方法 选取接受后路腰椎椎间融合术并随访1年以上的患者43例,男19例,女24例;年龄16～74岁,平均47.2岁.峡部裂性滑脱21例,退变性滑脱15例,腰椎间盘突出并不稳症3例,腰椎间盘突出症复发3例,极外侧椎间盘突出症1例.单纯骨粒植骨26例,骨粒加椎间融合器17例.单节段内固定24例,双节段内固定19例.均为单节段椎间融合,其中L_(3,4) 6例,L_(4,5),17例,L_5S_1 20例.应用改良Brantigan评分判定腰椎正侧位X线片及3D-CT扫描所示椎间融合程度;动力位X线片判断椎间稳定性.结果 随访12～85个月,平均18个月.末次随访时X线片及3D-CT所示椎间融合率分别为64%(28/43例)和40%(17/43例).3D-CT的Brantigan评分小于正侧位X线片(P<0.05).根据诊断、固定节段及融合方式不同分组,各组3D-CT评分均低于正侧位X线片(P<0.05).动力位X线片示椎间不稳定者仅3例(7%).结论 腰椎3D-CT能更准确地评价椎间融合情况.拆除内固定前进行3D-CT检查非常必要.拆除内固定前摄动力位X线片对判定椎体间融合的临床意义不大.

Three dimensional computed tomography (3D-CT) and radiographs assessment of interbody fusion after posterior lumbar intervertebral fusion

Objective To evaluate the clinical application of three dimensional computed tomography (3D-CT) and radiographs in assessment of interbody fusion after posterior lumbar intervertebral fusion (PLIF). Methods Forty-three patients, consisting of 19 males and 24 females were treated with PLIF in single segment from March 2000 to June 2007. The mean age was 47.2 years. The interbody fusion was performed by autograft in 26 cases and autograft plus PEEK cages in 17 cases. The preoperative diagnosis were isthmus spondylolisthesis in 21 cases, degenerative spondylolisthesis in 15 cases, Lumbar disc herniation associated with instability in 3 cases, revision after primary lumbar discectomy in 3 cases, and far lateral disc herniation in 1 cases. The interbody fusion levels were L_(3,4) in 6 cases, L_(4,5) in 17 cases,and L_5S_1 in 20 cases. Twenty-four patients underwent two-level internal fixation, while 19 cases accepted three-level fixation. The posterior, lateral static radiograph, flexion-extension radiographs and 3D-CT were performed at follow-up visit . The modified Brantigan grade was used to assess the fusion rate. The interbody stability was assessed by the flexion-extension radiographs. Results The mean follow-up was 18 months (12-85 months). The fusion rates in X-rays and 3D-CT were 64% and 40%, respectively. The mean Brantigan grade in X-rays and 3D-CT were 2.70±1.10 and 2.19±1.16, respectively. The grade was significantly lower in 3D-CT (P< 0.05). The Brantigan grades in 3D-CT were also significantly lower than those in X-ray between the groups of isthmus spondylolisthesis and degenerative spondylolisthesis, two-level and three-level internal fixation, and autograft only and autograft plus PEEK cages. There were only 3 cases showing dynamic instability. The other cases (93%) had no instability according to dynamic X-rays ,even those were comfirmed of nonunion of the bone graft . Conclusion The lumbar 3D-CT is more accurate in assessment of interbody fusion. It is necessary to perform the 3D-CT before removal of the internal fixation.