Is lumbar facet fusion biomechanically equivalent to lumbar posterolateral onlay fusion?
Is lumbar facet fusion biomechanically equivalent to lumbar posterolateral onlay fusion?
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腰椎小关节融合在生物力学上等同于腰椎后外侧嵌体融合吗？
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
A. Simon Turner
中科院分区：
文献类型：
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作者：
J. Toth;K. Foley;Mei Wang;H. Seim;A. Simon Turner
目的：1）在绵羊腰椎小关节融合模型上，观察重组人骨形态发生蛋白-2（rhBMP-2）在可吸收胶原海绵（ACS）上进行小关节融合的效果，2）比较rhBMP-2/ACS与髂嵴植骨（ICBG）小关节融合的影像学和组织学效果;比较rhBMP-2/ACS与ICBG腰椎后外侧融合术（PLF）的生物力学差异。方法在绵羊腰椎融合模型中评价3种治疗方法诱导融合的有效性。8只绵羊在L2-3节段植入了10 cm 3/侧ICBG作为PLF的覆盖移植物。在相邻L3-4节段，放置0.5 cm 3/侧ICBG进行小关节融合。最后，在L4-5放置0.5 cm 3/侧rhBMP-2/ACS（0.43 mg/ml）进行小关节融合。在术后2、4和6个月时进行CT扫描，由2名审查员对所有治疗脊柱节段的6个月结果进行评价。在6个月时处死所有8只绵羊，并在此时取出所有后外侧器械。然后通过L3-4对脊柱进行切片，以便对L2-3和L4-5节段进行非破坏性无约束生物力学测试。使用不脱钙组织学和相应的显微放射照相术分析所有治疗的脊柱节段。在治疗组之间进行统计学比较。结果ICBG PLF组和rhBMP-2小关节融合组的刚度水平相似，rhBMP-2小关节融合组在所有6个载荷方向上的刚度平均略高。自体植骨关节突融合治疗组的所有8个节段均显示CT影像学和组织学融合。rhBMP-2小关节组的所有8个节段均显示双侧CT影像学和组织学融合。6/16例rhBMP-2/ACS治疗的关节面缺损显示小的骨内血肿或血清肿。ICBG PLF治疗组的8个节段中有4个（50%）显示双侧组织学融合。ICBG PLF治疗组8个节段中有3个节段显示单侧融合。ICBG PLF治疗组的8个节段中有1个节段显示双侧组织学不融合。结论：rhBMP-2/ACS和自体移植物在器械固定的绵羊模型中用于关节突融合时表现出100%的有效性。然而，ICBG PLF治疗组仅显示出50%的双侧融合率。在生物力学方面，ICBG PLF和rhBMP-2小关节组在所有6个载荷方向上表现出相似的刚度，rhBMP-2小关节组在所有方向上的刚度平均略高。
OBJECTIVE This study was designed with the following research objectives: 1) to determine the efficacy of facet fusion with recombinant human bone morphogenetic protein-2 (rhBMP-2) on an absorbable collagen sponge (ACS) in an ovine lumbar facet fusion model; 2) to radiographically and histologically compare the efficacy of lumbar facet fusion with rhBMP-2/ACS to facet fusion with an iliac crest bone graft (ICBG); and 3) to biomechanically compare lumbar facet fusion with rhBMP-2/ACS to lumbar posterolateral fusion (PLF) with ICBG. METHODS The efficacies of the 3 treatments to induce fusion were evaluated in an instrumented ovine lumbar fusion model. Eight sheep had 10 cm3/side ICBG placed as an onlay graft for PLF at L2-3. At the adjacent L3-4 level, 0.5 cm3/side ICBG was placed for facet fusion. Finally, 0.5 cm3/side rhBMP-2/ACS (0.43 mg/ml) was placed for facet fusion at L4-5. CT scans were obtained at 2, 4, and 6 months postoperatively with 2 reviewers conducting an evaluation of the 6-month results for all treated spinal levels. All 8 sheep were killed at 6 months, and all posterolateral instrumentation was removed at this time. The spines were then sectioned through L3-4 to allow for nondestructive unconstrained biomechanical testing of the L2-3 and L4-5 segments. All treated spinal levels were analyzed using undecalcified histology with corresponding microradiography. Statistical comparisons were made between the treatment groups. RESULTS The PLF with ICBG (ICBG PLF group) and the rhBMP-2 facet fusion (rhBMP-2 Facet group) treatment groups demonstrated similar levels of stiffness, with the rhBMP-2 Facet group having on average slightly higher stiffness in all 6 loading directions. All 8 levels in the autograft facet fusion treatment group demonstrated CT radiographic and histological fusion. All 8 levels in the rhBMP-2 Facet group showed bilateral CT radiographic and histological fusion. Six of 16 rhBMP-2/ACS-treated facet defects demonstrated small intraosseous hematomas or seromas. Four of the 8 levels (50%) in the ICBG PLF treatment group demonstrated bilateral histological fusion. Three of 8 levels in the ICBG PLF treatment group showed unilateral fusion. One of the 8 levels in the ICBG PLF treatment group demonstrated bilateral histological nonfusion. CONCLUSIONS Both rhBMP-2/ACS and autograft demonstrated 100% efficacy when used for facet fusion in the instrumented ovine model. However, the ICBG PLF treatment group only demonstrated a 50% bilateral fusion rate. Biomechanically, the ICBG PLF and rhBMP-2 Facet groups demonstrated similar stiffness in all 6 loading directions, with the rhBMP-2 Facet group having on average slightly higher stiffness in all directions.