Relation Between Laminectomy and Development of Adjacent Segment Instability After Lumbar Fusion With Pedicle Fixation

Lai, Po‐Liang; Chen, Lih-Huei; Niu, Chi‐Chien; Fu, Tsai-Sheng; Chen, Wen-Jer

doi:10.1097/01.brs.0000144408.02918.20

Cited by 119 publications

(79 citation statements)

References 17 publications

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“…It could be that the loss of posterior tension band function creates instability and, hence, accelerated disc degeneration. The finding is in accordance with radiological data showing that a disruption of the posterior ligamentous complex leads to instability of the motion segment [23]. An alternative explanation is that the mechanical removal of the complete loose lamina can be compared with loss of posterior column support and a tendency to mechanical failure in compression.…”

Section: Discussionsupporting

confidence: 90%

A prospective randomised study on the long-term effect of lumbar fusion on adjacent disc degeneration

et al. 2009

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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.

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Section: Discussionsupporting

confidence: 90%

A prospective randomised study on the long-term effect of lumbar fusion on adjacent disc degeneration

et al. 2009

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“…Known risk factors of ASD at the upper adjacent segment include facet joint violation during the placement of the cephalad-most screws [1], fusion above L5 [2], preexisting facet degeneration [3], coexistence of laminar horizontalization and facet tropism [4], length of fusion [5], posterior interbody fusion rather than anterior interbody fusion [6], and performing an additional laminectomy adjacent to a fusion [7]. ASD at the lower adjacent segment may also occur due to failure of the most distal fixation, positive sagittal balance, younger age, or preoperative radiographic degeneration [8,9].…”

Section: Introductionmentioning

confidence: 99%

Effects of rod stiffness and fusion mass on the adjacent segments after floating mono-segmental fusion: a study using finite element analysis

Jin

Kim²,

Seo³

et al. 2012

Eur Spine J

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Purpose The aims of the present study were to compare the biomechanical effects on the adjacent segments after mono-segmental floating fusion with posterior semi-rigid or rigid stabilization, and to evaluate the effect of the amount of fusion mass on the biomechanical differences. Methods A detailed, nonlinear L1-S1 finite element model had been developed and validated. Then five models were reconstructed by different fixation techniques on the L3-L4 level: rigid fixation with an interbody spacer (Ti ? IS), rigid fixation with a large interbody spacer (Ti ? IS_all), semi-rigid fixation with an interbody spacer (PEEK ? IS), semi-rigid fixation with a large interbody spacer (PEEK ? IS_all), and semi-rigid fixation only (PEEK). Analyses were conducted for the case of erect standing position, flexion, and extension motion. Results At L1-L2 and L2-L3, PEEK ? IS demonstrated less inter-segmental rotation and nucleus pressure increments from the intact model compared with Ti ? IS. The L4-L5 and L5-S1 levels showed slightly higher values with PEEK ? IS, but these differences among the instrumented models were not significant. The motion difference based on the fusion mass at the adjacent levels was at most 3 %. All instrumentation cases generated a 55 % higher facet contact force at the lower adjacent level (L4-L5) compared to that of the intact model during 26°e xtension and the largest increment was detected at the upper adjacent level (L2-L3) in the Ti ? IS. Instrumentation with Ti ? IS markedly increased the stress in the intervertebral disk at the upper adjacent level, while the stress with PEE-K ? IS appeared largest at the lower adjacent level. Conclusions Posterior instrumentation with semi-rigid rods may lower the incidence of disk and facet degeneration in the upper adjacent segment compared to rigid rods. On the other hand, the possibility of facet degeneration will be similar for all instrumentation devices in the lower adjacent segment in the long-term. The stiffness difference between rigid and semi-rigid rods on the changes in the adjacent motion segments was more crucial than amount of fusion mass.

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“…Ekman reported that patients who undergo total laminectomy above the level of PLF had a significantly higher incidence of ASD as compared to nonlaminectomy patients [10]. Lai concluded that damaging the integrity of the posterior complex at adjacent segments by total laminectomy led to adjacent instability in a retrospective study of 101 patients who had undergone PLF [27]. This was the first study to evaluate whether multiple segments' decompression surgery combined with fewer segments' PLIF surgery increases the rate of complications in adjacent segments.…”

Section: Discussionmentioning

confidence: 99%

Additional decompression at adjacent segments leads to adjacent segment degeneration after PLIF

et al. 2013

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Purpose Adjacent segment degeneration (ASD) is one of the major complications of lumbar fusion. Several previous retrospective studies reported ASD after PLIF. However, few reports evaluated whether decompression surgery combined with fusion surgery increases the rate of complications in adjacent segments. The purpose of the current study was to investigate the degeneration in decompressed adjacent segments after PLIF. Methods A total of 23 patients (12 men, 11 women; average age, 58.6) who underwent PLIF surgery [1 level (n = 9), 2 levels (n = 8), 3 levels (n = 4), 4 levels (n = 2)] were included. Additional adjacent decompression above or below the level of interbody fusion was performed at 25 levels and no adjacent decompression was performed at 15 levels. We retrospectively investigated ASD by X-ray films of all 40 adjacent segments (above and below fusion level) and clinical outcomes of all 23 cases.Results Of the 40 adjacent segments, 19 (47.5 %) showed ASD and 9 (22.5 %) showed symptomatic ASD. In the 19 segments with ASD, ASD occurred in 16 of 25 (64.0 %) segments at decompressed sites compared with 3 of 15 (20.0 %) non-decompressed sites. The ratio of ASD in adjacent segments was significantly higher at decompressed sites than at non-decompressed sites (p \ 0.01). Conclusion ASD occurs frequently in association with additional decompression above or below the level of PLIF. In cases in which the adjacent segments require decompression, a surgical strategy that preserves as much of the posterior complex as possible should be selected.

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Relation Between Laminectomy and Development of Adjacent Segment Instability After Lumbar Fusion With Pedicle Fixation

Cited by 119 publications

References 17 publications

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

Effects of rod stiffness and fusion mass on the adjacent segments after floating mono-segmental fusion: a study using finite element analysis

Additional decompression at adjacent segments leads to adjacent segment degeneration after PLIF

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