Department of Neurosurgery, University Hospital, 12 de Octubre, Avda de Córdoba S/N, 28041, Madrid, Spain.
Department of Neurosurgery, Complejo Universitario Hospital Albacete, Calle Hermanos Falcó 37, 02008, Albacete, Spain.
Eur Spine J. 2023 May;32(5):1818-1829. doi: 10.1007/s00586-023-07628-1. Epub 2023 Mar 10.
Low-virulent microorganisms identified on pedicle screws by sonication fluid culture (SFC) are an important cause of implant loosening. While sonication of explanted material improves the detection rate, the risk of contamination exists and no standardized diagnostic criteria for chronic low-grade spinal implant-related infection (CLGSII) are stablished. Besides, the role of serum C-reactive protein (CRP) and procalcitonin (PCT) in CLGSII has not been adequately investigated.
Blood samples were collected prior to implant removal. To increase sensitivity, the explanted screws were sonicated and processed separately. Patients exhibiting at least one positive SFC were classified in the infection group (loose criteria). To increase specificity, the strict criteria only considered multiple positive SFC (≥ 3 implants and/or ≥ 50% of explanted devices) as meaningful for CLGSII. Factors which might promote implant infection were also recorded.
Thirty-six patients and 200 screws were included. Among them, 18 (50%) patients had any positive SFCs (loose criteria), whereas 11 (31%) patients fulfilled the strict criteria for CLGSII. Higher serum protein level was the most accurate marker for the preoperative detection of CLGSSI, exhibiting an area under the curve of 0.702 (loose criteria) and 0.819 (strict criteria) for the diagnosis of CLGSII. CRP only exhibited a modest accuracy, whereas PCT was not a reliable biomarker. Patient history (spinal trauma, ICU hospitalization and/or previous wound-related complications) increased the likelihood of CLGSII.
Markers of systemic inflammation (serum protein level) and patient history should be employed to stratify preoperative risk of CLGSII and decide the best treatment strategy.
通过超声液培养（SFC）从椎弓根螺钉中鉴定出低毒微生物是导致植入物松动的一个重要原因。虽然对取出的材料进行超声处理可以提高检测率，但存在污染风险，并且尚未建立慢性低度脊柱植入物相关感染（CLGSII）的标准化诊断标准。此外，血清 C 反应蛋白（CRP）和降钙素原（PCT）在 CLGSII 中的作用尚未得到充分研究。
在取出植入物之前采集血样。为了提高敏感性，单独对取出的螺钉进行超声处理和处理。表现出至少一个阳性 SFC 的患者被归类为感染组（松动标准）。为了提高特异性，严格标准仅将多个阳性 SFC（≥3 个植入物和/或≥50%的取出装置）视为 CLGSII 的有意义。还记录了可能促进植入物感染的因素。
共纳入 36 例患者和 200 枚螺钉。其中，18 例（50%）患者的任何 SFC 均为阳性（松动标准），而 11 例（31%）患者符合 CLGSII 的严格标准。术前检测 CLGSSI 时，血清蛋白水平是最准确的标志物，其诊断 CLGSII 的曲线下面积分别为 0.702（松动标准）和 0.819（严格标准）。CRP 仅显示出中等准确性，而 PCT 不是可靠的生物标志物。患者病史（脊柱创伤、ICU 住院和/或以前的伤口相关并发症）增加了 CLGSII 的可能性。
应采用全身炎症标志物（血清蛋白水平）和患者病史来分层 CLGSII 的术前风险，并决定最佳治疗策略。
