Baumbach Sebastian F, Prall Wolf C, Scharpf Andreas M, Hererich Viktoria, Schmidt Maximilian, Suedkamp Norbert P, Stoehr Amelie, Mayr Hermann O
Department of General, Trauma, and Reconstructive Surgery, Munich University Hospital LMU, Nussbaumstrasse 20, 80336, Munich, Germany.
Department of Knee, Hip and Shoulder Surgery, Schön Klinik München Harlaching, Harlachinger Strasse 51, 81547, Munich, Germany.
Arch Orthop Trauma Surg. 2018 Nov;138(11):1583-1590. doi: 10.1007/s00402-018-3032-8. Epub 2018 Sep 4.
The differentiation between stiff-knee and low-grade periprosthetic joint infection (PJI) is the current diagnostic challenge in total knee (TKA) revision arthroplasty. The aim of this study was to investigate the additional value of dry biopsies, compared to wet biopsies, in patients presenting with knee stiffness following primary TKA.
Single center, prospective observational study. Consecutive patients with joint stiffness of unknown origin following primary TKA were enrolled. Patient assessment followed the diagnostic standard algorithm. During diagnostic arthroscopy, synovial fluid (synovial WBC, PMN%) and five dry biopsies (dry) were collected. Then fluid was infused and another five microbiology (wet) and five histological biopsies gathered, all from identical locations. The primary outcome parameter was the difference between the pathogens in wet and dry biopsies.
71 patients (61% females, 67 ± 10 years) were eligible. Preoperative blood serology mean CRP (0.7 ± 1.5 mg/dl; p = 0.852), WBC (6.6 ± 1.7 G/l; p = 0.056), and synovial fluid mean WBC (1639 ± 2111; p = 0.602), PMN% (38 ± 28; p = 0.738) did not differ between patients with negative, positive wet or dry biopsies. The histology was in 11% positive (p = 0.058). In 32% at least one pathogen was detected, 48% from wet, 44% from dry biopsies. An inhomogeneous distribution was found. Cutibacterium acnes (100%) was solely found in wet, Micrococcus luteus (75%), Staphylococcus capitis (67%), and Micrococcus lylae (100%) were predominantly found in dry biopsies. Additional dry biopsies increased the pathogen detection rate by 49%.
The addition of dry biopsies to the current standard diagnostic algorithm for PJI increased the pathogen detection rate by 49%.
僵硬膝与低度假体周围关节感染（PJI）的鉴别是全膝关节（TKA）翻修术中当前面临的诊断挑战。本研究的目的是调查与湿活检相比，干活检在初次TKA后出现膝关节僵硬的患者中的附加价值。
单中心前瞻性观察研究。纳入初次TKA后出现不明原因关节僵硬的连续患者。患者评估遵循诊断标准算法。在诊断性关节镜检查期间，收集滑液（滑膜白细胞、中性粒细胞百分比）和五份干活检样本（干）。然后注入液体，再从相同部位收集五份微生物学样本（湿）和五份组织学活检样本。主要结局参数是湿活检和干活检中病原体的差异。
71例患者（61%为女性，67±10岁）符合条件。术前血液血清学中，平均C反应蛋白（0.7±1.5mg/dl；p=0.852）、白细胞（6.6±1.7G/l；p=0.056）以及滑液平均白细胞（1639±2111；p=0.602）、中性粒细胞百分比（38±28；p=0.738）在湿活检或干活检阴性、阳性的患者之间无差异。组织学检查11%呈阳性（p=0.058）。32%的患者至少检测到一种病原体，48%来自湿活检，44%来自干活检。发现分布不均匀。痤疮丙酸杆菌（100%）仅在湿活检中发现，藤黄微球菌（75%）、头状葡萄球菌（67%）和莱氏微球菌（100%）主要在干活检中发现。额外的干活检使病原体检测率提高了49%。
在当前PJI标准诊断算法中增加干活检可使病原体检测率提高49%。
