Schiffner E, Latz D, Karbowski A, Grassmann J P, Thelen S, Windolf J, Jungbluth P, Schneppendahl J
Department of Trauma and Handsurgery, Heinrich Heine University Hospital Duesseldorf, Moorenstr. 5, 40225, Duesseldorf, Germany.
Department of Orthopaedic Surgery, Krankenhaus der Augustinerinnen, Jakobstraße 27-31, 50678, Cologne, Germany.
J Clin Orthop Trauma. 2020 Mar;11(Suppl 2):S234-S238. doi: 10.1016/j.jcot.2019.05.001. Epub 2019 May 7.
When revision surgery is needed in total knee arthroplasty (TKA) the most frequent reasons are aseptic loosening (AL) and periprosthetic joint infection (PJI). However preoperative distinction between AL and PJI remains challenging. Aim of this study is to determine the incidence of PJI in patients with suspected AL after TKA and to evaluate a diagnostic algorithm for reliable differential diagnosis.
In this study a total of 149 symptomatic patients with radiographic signs of prosthetic loosening and suspected AL were included. Preoperatively all patients underwent a standardized diagnostic algorithm. For each patient demographics, as well as the results of laboratory and microbiological testing were collected from the medical records.
Of the included patients 117 (78.5%) were diagnosed with AL and 32 (21.5%) with PJI. The latency period from primary arthroplasty to the presentation with symptomatic implant loosening was significantly shorter for PJI compared to AL (p < 0.05). The initial CRP values were significantly higher in patients with PJI compared to patients with AL (p < 0.05). Elevated count of white blood cells or percentage of neutrophils within the synovial fluid support the diagnosis of PJI. The sensitivity of synovial cell count (CC) count for PJI in patients with radiographic signs of loosening was 0.84 (CI 0.81-0.87) with a specificity of 0.96 (CI 0.92-0.98). The single best measure for the diagnosis of PJI was synovial fluid cultures with a specificity of 1, however this measure provides poor sensitivity.
Patients with radiographic signs of loosening in TKA need thorough diagnostics. Information about primary TKA, serological testing, and results of joint aspiration can rule out a PJI in most cases.
全膝关节置换术（TKA）需要翻修手术时，最常见的原因是无菌性松动（AL）和假体周围关节感染（PJI）。然而，术前区分AL和PJI仍然具有挑战性。本研究的目的是确定TKA术后疑似AL患者中PJI的发生率，并评估一种用于可靠鉴别诊断的诊断算法。
本研究共纳入149例有假体松动影像学征象且疑似AL的有症状患者。术前所有患者均接受标准化诊断算法。从病历中收集每位患者的人口统计学信息以及实验室和微生物学检测结果。
纳入的患者中，117例（78.5%）被诊断为AL，32例（21.5%）被诊断为PJI。与AL相比，PJI从初次关节置换到出现有症状的植入物松动的潜伏期明显更短（p<0.05）。PJI患者的初始CRP值明显高于AL患者（p<0.05）。滑液中白细胞计数升高或中性粒细胞百分比升高支持PJI的诊断。在有假体松动影像学征象的患者中，滑膜细胞计数（CC）对PJI的敏感性为0.84（95%置信区间0.81 - 0.87），特异性为0.96（95%置信区间0.92 - 0.98）。诊断PJI的最佳单一指标是滑液培养，其特异性为1，但该指标敏感性较差。
TKA有假体松动影像学征象的患者需要进行全面诊断。有关初次TKA的信息、血清学检测以及关节穿刺结果在大多数情况下可排除PJI。
