Li Haisheng, Zou Xuenong, Laursen Malene, Egund Niels, Lind Martin, Bünger Cody
Orthopaedic Research Laboratory, Orthopaedic Department E, Aarhus University Hospital, Norrebrogade 44, 8000 Aarhus C. Denmark.
Eur Spine J. 2002 Oct;11(5):476-81. doi: 10.1007/s00586-002-0455-1. Epub 2002 Aug 29.
Intervertebral disc has been shown to be related to low back pain and nerve root injury in pathologic conditions. However, little is known about its influence on spinal fusion. With the development of minimal invasive operations, such as laparoscopic anterior spinal fusion with cages, insufficient discectomy may occur. With its inflammatory properties, the residue nucleus pulposus may have an effect on spinal fusion. In this study, a two-level lumbar spine interbody fusion (L3/4, L5/6) with a Brantigan cage was performed on ten Danish Landrace pigs. Each level was randomly assigned to one of the following methods: (1) implantation of Brantigan cage filled with autogenous iliac crest bone graft, or (2) implantation of Brantigan cage filled with a mixture of autograft and the nucleus pulposus tissue harvested from the disc level in which it was to be inserted. Each level was stabilized with two staples. The pigs were followed for 12 weeks in the same standardized condition. After sacrifice, the lumbar spines were taken out, and plain X-ray, computed tomographic (CT) scanning and histomorphometry were performed to study the fusion mass inside the cages. From plain radiographs, new bone formation could be seen inside and around the cage. CT evaluation showed that the nucleus pulposus level had a 20% (2/10) fusion rate, while the pure autograft level had a 70% (7/10) fusion rate ( P=0.07). The histological fusion rate was even lower in the nucleus pulposus level (10%), and was significantly different from the autograft level (70%, P=0.02). Histomorphometric parameters of new bone formation, bone marrow space and fibrous tissue differed significantly between the two levels ( P=0.04; P=0.02; P=0.04 respectively). We conclude that when nucleus pulposus is mixed with the autogenous bone graft, it can delay or decrease the bone formation inside the cage, thus influencing the final fusion.
椎间盘在病理状态下已被证明与腰痛和神经根损伤有关。然而，关于其对脊柱融合的影响却知之甚少。随着微创外科手术的发展，如使用椎间融合器的腹腔镜前路脊柱融合术，可能会出现椎间盘切除不充分的情况。由于残留髓核具有炎性特性，其可能会对脊柱融合产生影响。在本研究中，对10头丹麦长白猪进行了两节段腰椎椎间融合术（L3/4、L5/6），使用Brantigan椎间融合器。每个节段随机分配至以下方法之一：（1）植入填充自体髂嵴骨移植的Brantigan椎间融合器，或（2）植入填充自体移植骨与从拟植入节段椎间盘获取的髓核组织混合物的Brantigan椎间融合器。每个节段用两个吻合钉固定。在相同的标准化条件下对猪进行12周的随访。处死后，取出腰椎，进行X线平片、计算机断层扫描（CT）及组织形态计量学检查，以研究椎间融合器内的融合块情况。从X线平片上可看到椎间融合器内部及周围有新骨形成。CT评估显示，髓核节段的融合率为20%（2/10），而单纯自体移植骨节段的融合率为70%（7/10）（P=0.07）。髓核节段的组织学融合率更低（10%），与自体移植骨节段有显著差异（70%，P=0.02）。两个节段新骨形成、骨髓腔及纤维组织的组织形态计量学参数有显著差异（分别为P=0.04；P=0.02；P=0.04）。我们得出结论，当髓核与自体骨移植混合时，它会延迟或减少椎间融合器内的骨形成，从而影响最终融合。
