Fuchs M, Faschingbauer M, Riklin-Dold M, Morovic P, Reichel H, Trampuz A, Karbysheva S
RKU University Department of Orthopaedics, University of Ulm, Ulm, Germany.
Center for Musculoskeletal Surgery, Charité - Universitaetsmedizin Berlin, Berlin, Germany.
Front Surg. 2022 Dec 8;9:1082591. doi: 10.3389/fsurg.2022.1082591. eCollection 2022.
Reliable biomarkers for the diagnosis of periprosthetic joint infection (PJI) are of paramount clinical value. To date, synovial fluid leukocyte count is the standard surrogate parameter indicating PJI. As D-lactate is almost solely produced by bacteria, it represents a promising molecule in the diagnostic workflow of PJI evaluation. Therefore, the purpose of this study was to assess the performance of synovial fluid D-lactate for diagnosing PJI of the hip and knee.
These are preliminary results of a prospective multicenter study from one academic center. Seventy-two consecutive patients after total hip arthroplasty (THA) or total knee arthroplasty (TKA) were prospectively included. All patients received a joint aspiration in order to rule out or confirm PJI, which was diagnosed according to previously published institutional criteria. Synovial fluid D-lactate was determined spectrophotometrically at 450 nm. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance.
Eighteen patients (25%) were diagnosed with PJI and 54 patients (75%) were classified as aseptic. Synovial fluid D-lactate showed a sensitivity of 90.7% (95% CI: 79.7%-96.9%) and specificity of 83.3% (95% CI: 58.6%-96.4%) at a cut-off of 0.04 mmol/L. The median concentration of D-lactate was significantly higher in patients with PJI than in those with aseptic conditions (0.048 mmol/L, range, 0.026-0.076 mmol/L vs. 0.024 mmol/L, range, 0.003-0.058 mmol/L, < 0.0001). The predominat microogranisms were staphylococci, followed by streptococci and gram-negative bacteria.
D-lactate bears a strong potential to act as a valuable biomarker for diagnosing PJI of the hip and knee. In our study, a cutoff of 0.04 mmol/L showed a comparable sensitivity to synovial fluid leukocyte count. However, its specificity was higher compared to conventional diagnostic tools. The additional advantages of D-lactate testing are requirement of low synovial fluid volume, short turnaround time and low cost.
用于诊断人工关节周围感染（PJI）的可靠生物标志物具有至关重要的临床价值。迄今为止，滑液白细胞计数是指示PJI的标准替代参数。由于D-乳酸几乎完全由细菌产生，它在PJI评估的诊断流程中是一个有前景的分子。因此，本研究的目的是评估滑液D-乳酸对诊断髋和膝关节PJI的性能。
这些是来自一个学术中心的前瞻性多中心研究的初步结果。前瞻性纳入了72例全髋关节置换术（THA）或全膝关节置换术（TKA）后的连续患者。所有患者均接受关节穿刺以排除或确诊PJI，PJI根据先前发表的机构标准进行诊断。滑液D-乳酸通过分光光度法在450 nm处测定。进行受试者操作特征（ROC）分析以评估诊断性能。
18例患者（25%）被诊断为PJI，54例患者（75%）被分类为无菌性。滑液D-乳酸在截断值为0.04 mmol/L时显示出90.7%的敏感性（95%CI：79.7%-96.9%）和83.3%的特异性（95%CI：58.6%-96.4%）。PJI患者的D-乳酸中位浓度显著高于无菌性患者（0.048 mmol/L，范围0.026-0.076 mmol/L vs. 0.024 mmol/L，范围0.003-0.058 mmol/L，P < 0.0001）。主要微生物是葡萄球菌，其次是链球菌和革兰氏阴性菌。
D-乳酸有很大潜力作为诊断髋和膝关节PJI的有价值生物标志物。在我们的研究中，截断值为0.04 mmol/L时显示出与滑液白细胞计数相当的敏感性。然而，与传统诊断工具相比，其特异性更高。D-乳酸检测的其他优点是所需滑液量少、周转时间短和成本低。
