Presti Mirco Lo, Vasco Cosimo, Neri Maria Pia, Solito Ludovica, Pellicanò Davide, Minerba Marco, Goracci Gabrio, Zaffagnini Stefano
IIa Clinica Ortopedica e Traumatologica, IRCCS Istituto Ortopedico Rizzoli, Via Pupilli 1/10, 40136, Bologna, Italy.
Ospedale Santa Maria della Scaletta, Via Montericco 4, 40026, Imola, Italy.
Arch Orthop Trauma Surg. 2025 Jan 23;145(1):141. doi: 10.1007/s00402-024-05657-z.
Two-stage revision is considered the gold standard treatment in chronic periprosthetic joint infection (PJI) but no specific criteria or examination exist to determine infection eradication before reimplantation. This study aimed to assess the diagnostic performance of leukocyte scintigraphy after the first-stage procedure in two-stage revision for chronic PJI.
Patients studied with leukocyte scintigraphy after cement spacer insertion for knee PJI from January 2012 to December 2021 were retrospectively included. Infection was diagnosed using the criteria of the 2018 International Consensus Meeting. When 1 or more minor criteria were positive but the score was < 6, patients were considered not infected if there was no recurrence of infection at least 24 months after the second-stage procedure. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were found.
The final cohort included 67 cases in 61 patients (M: F = 32:35; mean age 74 years). There were 43 true negatives, 8 true positives, 12 false negatives, and 4 false positives. The sensitivity and specificity of leukocyte scintigraphy in diagnosing PJI were respectively 40.0% and 91.5%, PPV was 66.7%, NPV was 78.2%, and accuracy was 76.1%. Staphylococcus Epidermidis was the most frequently isolated microorganism (50%).
Due to the high costs and the difficulty in its execution, LLS should not be used routinely but it could represent an additional criterion in doubtful cases. In any case, a thorough evaluation of other pre- and intra-operative tests is essential to determine whether reimplantation or spacer renewal is the best course of action. Special consideration should be given to positive LLS, as its results are highly specific and have a low rate of false positives. Conversely, in over half of infected patients, LLS could give false negatives, making negative LLS results less relevant.
两阶段翻修术被认为是慢性人工关节周围感染（PJI）的金标准治疗方法，但在再次植入前，尚无确定感染根除的具体标准或检查方法。本研究旨在评估白细胞闪烁扫描术在慢性PJI两阶段翻修术第一阶段手术后的诊断性能。
回顾性纳入2012年1月至2021年12月因膝关节PJI植入骨水泥间隔物后接受白细胞闪烁扫描术检查的患者。根据2018年国际共识会议的标准诊断感染。当1项或多项次要标准为阳性但评分<6分时，如果在第二阶段手术后至少24个月没有感染复发，则患者被认为未感染。计算敏感性、特异性、阳性预测值（PPV）、阴性预测值（NPV）和准确性。
最终队列包括61例患者的67个病例（男：女 = 32:35；平均年龄74岁）。有43例假阴性、8例假阳性、12例真阴性和4例真阳性。白细胞闪烁扫描术诊断PJI 的敏感性和特异性分别为40.0%和91.5%，PPV为66.7%，NPV为78.2%，准确性为76.1%。表皮葡萄球菌是最常分离出的微生物（50%）。
由于成本高昂且实施困难，白细胞闪烁扫描术不应常规使用，但在可疑病例中它可以作为一项附加标准。无论如何，对其他术前和术中检查进行全面评估对于确定再次植入或更换间隔物是否是最佳行动方案至关重要。应特别考虑白细胞闪烁扫描术结果为阳性的情况，因为其结果具有高度特异性且假阳性率低。相反，超过一半的感染患者白细胞闪烁扫描术可能会出现假阴性，使得白细胞闪烁扫描术结果为阴性的相关性降低。
