Research Department, Spine Centre of Southern Denmark, Hospital Lillebaelt, Middelfart, Institute of Regional Health Services Research, University of Southern Denmark, Clinical Locomotion Science Network, Ostre Houghvej 55, 5550, Middelfart, Denmark.
Eur Spine J. 2013 Apr;22(4):690-6. doi: 10.1007/s00586-013-2674-z. Epub 2013 Feb 10.
To investigate the prevalence of infected herniated nucleus material in lumbar disc herniations and to determine if patients with an anaerobic infected disc are more likely to develop Modic change (MC) (bone oedema) in the adjacent vertebrae after the disc herniation. MCs (bone oedema) in vertebrae are observed in 6 % of the general population and in 35-40 % of people with low back pain. These changes are strongly associated with low back pain. There are probably a mechanical cause and an infective cause that causes MC. Several studies on nuclear tissue from herniated discs have demonstrated the presence of low virulent anaerobic microorganisms, predominantly Propionibacterium acnes, in 7-53 % of patients. At the time of a herniation these low virulent anaerobic bacteria may enter the disc and give rise to an insidious infection. Local inflammation in the adjacent bone may be a secondary effect due to cytokine and propionic acid production.
Patients undergoing primary surgery at a single spinal level for lumbar disc herniation with an MRI-confirmed lumbar disc herniation, where the annular fibres were penetrated by visible nuclear tissue, had the nucleus material removed. Stringent antiseptic sterile protocols were followed.
Sixty-one patients were included, mean age 46.4 years (SD 9.7), 27 % female. All patients were immunocompetent. No patient had received a previous epidural steroid injection or undergone previous back surgery. In total, microbiological cultures were positive in 28 (46 %) patients. Anaerobic cultures were positive in 26 (43 %) patients, and of these 4 (7 %) had dual microbial infections, containing both one aerobic and one anaerobic culture. No tissue specimens had more than two types of bacteria identified. Two (3 %) cultures only had aerobic bacteria isolated. In the discs with a nucleus with anaerobic bacteria, 80 % developed new MC in the vertebrae adjacent to the previous disc herniation. In contrast, none of those with aerobic bacteria and only 44 % of patients with negative cultures developed new MC. The association between an anaerobic culture and new MCs is highly statistically significant (P = 0.0038), with an odds ratio of 5.60 (95 % CI 1.51-21.95).
These findings support the theory that the occurrence of MCs Type 1 in the vertebrae adjacent to a previously herniated disc may be due to oedema surrounding an infected disc. The discs infected with anaerobic bacteria were more likely (P < 0.0038) to develop MCs in the adjacent vertebrae than those in which no bacteria were found or those in which aerobic bacteria were found.
研究腰椎间盘突出症中感染性突出核物质的流行情况，并确定患有厌氧感染性椎间盘的患者在椎间盘突出后是否更有可能在相邻椎体中发生 Modic 改变（MC）（骨水肿）。在普通人群中，6%的人会出现 MC（骨水肿），在腰痛人群中，35-40%的人会出现 MC。这些变化与腰痛密切相关。可能存在机械原因和感染原因导致 MC。几项对椎间盘核组织的研究表明，在 7-53%的患者中存在低毒厌氧微生物，主要是痤疮丙酸杆菌。在突出发生时，这些低毒厌氧细菌可能进入椎间盘并引起隐匿性感染。相邻骨中的局部炎症可能是由于细胞因子和丙酸产生的继发效应。
在单个脊柱水平对腰椎间盘突出症患者进行初次手术，这些患者的 MRI 证实有腰椎间盘突出症，且可见核组织穿透环形纤维，将核物质切除。严格遵循无菌消毒协议。
共纳入 61 例患者，平均年龄 46.4 岁（标准差 9.7），女性占 27%。所有患者均具有免疫能力。无患者接受过硬膜外类固醇注射或接受过背部手术。总共，28 例（46%）患者的微生物培养阳性。26 例（43%）患者的厌氧菌培养阳性，其中 4 例（7%）存在双重微生物感染，含有一种需氧菌和一种厌氧菌。没有组织标本中发现超过两种类型的细菌。两种（3%）培养物仅分离出需氧菌。在有厌氧细菌的椎间盘，80%的患者在先前椎间盘突出的相邻椎体中出现新的 MC。相比之下，在有需氧菌的患者中无一例出现新的 MC，而在培养阴性的患者中仅有 44%出现新的 MC。厌氧菌培养与新 MC 之间存在高度统计学显著关联（P=0.0038），优势比为 5.60（95%置信区间 1.51-21.95）。
这些发现支持以下理论，即在先前突出的椎间盘相邻椎体中出现 MC 1 型可能是由于感染性椎间盘周围的水肿所致。与未发现细菌或发现需氧菌的椎间盘相比，感染厌氧菌的椎间盘更有可能（P<0.0038）在相邻椎体中出现 MC。
