Browsing by Subject "Sonication"

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    A prospective study to identify preoperative serum parameters for spinal implant infection detected by sonication fluid culture
    (Springer, 2023-03-10) García Pérez, Daniel; García Posadas, Guillermo; San Juan, Rafael; Brañas, Patricia; Panero Pérez, Irene; Delgado Fernández, Juan; Paredes, Igor; Farmacología
    Purpose 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. Methods 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. Results 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. Conclusion 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.
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    Implant microbial colonization detected by sonication as a cause for spinal device failure
    (Lippincott, Williams & Wilkins, 2021-11-01) García Pérez, Daniel; Lagares, Alfonso; Castaño León, Ana María; Panero, Irene; Munarriz, Pablo M.; Delgado Fernández, Juan; Jiménez Roldán, Luis; Pérez-Núñez, Ángel; Alén, Jose Antonio F.; Paredes, Igor; Farmacología
    Study Design. A prospective single center observational study. Objectives. The aim of this study was to examine the potential role of sonication in the diagnosis of low-grade infections and its association with pedicle screw (PS) loosening, and to describe risk factors and radiological findings associated with spinal implant infection. Summary of Background Data. Although PS loosening has mainly been attributed to mechanical overload, implant colonization and biofilm formation have recently been suggested. Culturing of sonication fluid implants is promising in the field of spine instrumentation infection, but little data are available. Methods. We prospectively included all patients who were subjected to implant removal. PS loosening was assessed with computed tomography (CT) scan. Different clinical and radiological parameters which could serve as indicators of implant infection were studied. Results. Thirty-eight patients were included in the study and 11 of them (29%) had a positive sonication result. Patients with spinal implant infection were associated with screw loosening (P = 0.005). Particularly, those screws with a positive microbiological culture showed signs of screw loosening in the preoperative CT scan (P < 0.001). Our results also showed that radiological screw loosening at L1-L3 level, and loosened larger constructs were associated with screw microbial colonization. The most common isolated microorganisms were coagulase-negative staphylococci and Cutibacterium acnes. An implant-based multivariate analysis indicated that screw loosening, the absence of prophylactic cefazolin, ICU hospitalization, screw breakage, and L1-L3 spine level were independent risk factors for implant-associated infection. Our model exhibited a high predictive power with an area under the curve of 0.937. Conclusion. As clinical presentation of deep implant chronic infection is unspecific, consideration of these factors enables preoperative prediction and risk stratification of implant colonization, thus helping patient's management. Level of Evidence: 3