A prospective randomised study on the long-term effect of lumbar fusion on adjacent disc degeneration
A prospective randomised study on the long-term effect of lumbar fusion on adjacent disc degeneration
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DOI：
10.1007/s00586-009-0947-3
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发表时间：
2009-08-01
影响因子：
2.8
通讯作者：
Hedlund, Rune
中科院分区：
文献类型：
--
作者：
Ekman, Per;Moller, Hans;Hedlund, Rune
腰椎融合后相邻节段椎间盘退变（ASD）加速的存在和重要性以前尚未被RCT证实。本研究的目的是通过前瞻性随机设计，确定腰椎融合术是否会加速相邻椎间盘的退行性变化，以及这是否会影响结局。共111例年龄在18-55岁的峡部裂性腰椎滑脱患者被随机分配至运动组（EX，n = 34）或后外侧融合组（PLF，n = 77），采用（n = 37）或不采用（n = 40）椎弓根螺钉内固定。最低10年随访率为72%，平均随访时间为12.6年（范围10-17年）。采用三种ASD定量的放射学方法，即两种数字放射学测量方法和半定量UCLA分级量表。一种数字测量方法显示EX组平均椎间盘高度降低2%，PLF组平均椎间盘高度降低15%（p = 0.0016），另一种数字测量方法显示PLF的椎间盘高度降低比Ex组多0.5 mm（ns）。UCLA分级量表显示EX组100%的患者椎间盘正常，而PLF组为62%（p = 0.026）。内固定和非内固定患者之间无显著差异。在椎板切除术患者中，我们发现ASD的发生率显著高于非椎板切除术患者（分别为22/47 vs. 2/16，p = 0.015）。在纵向分析中，PLF组的后部和前部椎间盘高度显著降低，而EX组仅后部椎间盘高度显著降低。除了总体结局（无ASD患者显著更好）外，临床结局在有ASD和无ASD患者中无统计学差异。总之，长期随机对照试验表明，与自然病程相比，融合加速了相邻节段的退行性变化。研究表明，不仅融合，而且椎板切除术可能是发病的重要性。ASD的临床重要性似乎有限，只有更严重的形式影响结果。
The existence and importance of an accelerated adjacent segment disc degeneration (ASD) after lumbar fusion have previously not been demonstrated by RCTs. The objectives of this study were, to determine whether lumbar fusion in the long term accelerates degenerative changes in the adjacent disc and whether this affects the outcome, by using a prospective randomised design. A total of 111 patients, aged 18-55, with isthmic spondylolisthesis were randomised to exercise (EX, n = 34) or posterolateral fusion (PLF, n = 77), with (n = 37) or without pedicle screw instrumentation (n = 40). The minimum 10 years FU rate was 72%, with a mean FU time of 12.6 years (range 10-17 years). Three radiographic methods of ASD quantification were used, i.e. two digital radiographic measurement methods and the semi quantitative UCLA grading scale. One digital measurement method showed a mean disc height reduction by 2% in the EX group and by 15% in the PLF group (p = 0.0016), and the other showed 0.5 mm more disc height reduction in the PLF compared to the Ex group (ns). The UCLA grading scale showed normal discs in 100% of patients in the EX group, compared to 62% in the PLF group (p = 0.026). There were no significant differences between instrumented and non-instrumented patients. In patients with laminectomy we found a significantly higher incidence of ASD compared to non laminectomised patients (22/47 vs. 2/16 respectively, p = 0.015). In the longitudinal analysis, the posterior and anterior disc heights were significantly reduced in the PLF group, whereas in the EX group only the posterior disc height was significantly reduced. Except for global outcome, which was significantly better for patients without ASD, the clinical outcome was not statistically different in patients with and without ASD. In conclusion, the long-term RCT shows that fusion accelerates degenerative changes at the adjacent level compared with natural history. The study suggests that not only fusion, but also laminectomy may be of pathogenetic importance. The clinical importance of ASD seems limited, with only the more severe forms affecting the outcome.