O'Connell J X, Nielsen G P, Rosenberg A E
Department of Pathology, Vancouver General Hospital, University of British Columbia, Canada.
Am J Surg Pathol. 1999 Feb;23(2):192-7. doi: 10.1097/00000478-199902000-00008.
Although arthritis is often associated with synovial inflammation, the osseous changes in inflammatory and degenerative arthritis are principally reactive, and typically lack an acute inflammatory component. We have recently encountered several osteoarticular specimens removed at the time of large joint arthroplasty that have shown a distinctive pattern of subchondral acute inflammation (SCAI) resembling acute bacterial osteomyelitis. These microscopic findings heretofore have not been recognized as a component of the histopathology of arthritis. To determine the frequency of SCAI, we examined slides (mean four per case) from 164 hip arthroplasties performed at one of our institutions in a single year. A total of 10 cases of SCAI, including the 4 original examples (2 humeral head specimens, 2 femoral head specimens) and 6 identified from the slide review are described in this report. Eight patients were female and two were male (ages 54-86 years, mean 70, median 70). All had severe degenerative joint disease, six had rheumatoid arthritis, and three had osteonecrosis. In none was there a clinical or intraoperative suspicion of infection. Cultures of joint fluid or bone were not performed. In all cases, the inflammation was subchondral (within 1.0 cm of the joint surface), and it was frequently associated with subchondral cysts. In osteonecrotic foci, the suppurative inflammation was diffuse within the marrow space, whereas in viable bone it was nodular and vaguely granulomatous. Special stains for organisms were negative. None of the patients was treated with long-term IV antibiotics. There has been no septic loosening of the prostheses at follow-up intervals ranging from 5 to 36 months (mean: 17 months). Our observations, to the best of our knowledge, are novel. Although we cannot definitively exclude bacterial infection as a cause of SCAI, the histologic and clinical features suggest that SCAI likely represents a noninfectious sterile form of inflammation. Subchondral acute inflammation is possibly secondary to synovial fluid insudation into subchondral cancellous bone in the setting of severe osteoarthritis and/or rheumatoid arthritis.
尽管关节炎常与滑膜炎症相关，但炎症性和退行性关节炎中的骨改变主要是反应性的，通常缺乏急性炎症成分。我们最近遇到了几例在大关节置换时切除的骨关节标本，这些标本显示出一种类似于急性细菌性骨髓炎的独特的软骨下急性炎症（SCAI）模式。迄今为止，这些微观发现尚未被认为是关节炎组织病理学的一部分。为了确定SCAI的发生率，我们检查了我们机构在一年中进行的164例髋关节置换术的切片（平均每例4张）。本报告描述了总共10例SCAI病例，包括最初的4例（2例肱骨头标本，2例股骨头标本）以及通过切片复查确定的6例。8例患者为女性，2例为男性（年龄54 - 86岁，平均70岁，中位数70岁）。所有患者均患有严重的退行性关节疾病，6例患有类风湿关节炎，3例患有骨坏死。无一例有临床或术中感染怀疑。未进行关节液或骨培养。在所有病例中，炎症均位于软骨下（距关节表面1.0 cm内），且常与软骨下囊肿相关。在骨坏死灶中，化脓性炎症在骨髓腔内弥漫，而在存活骨中则呈结节状且隐约呈肉芽肿性。针对病原体的特殊染色均为阴性。所有患者均未接受长期静脉抗生素治疗。在5至36个月（平均17个月）的随访期间，假体均未发生感染性松动。据我们所知，我们的观察结果是新颖的。尽管我们不能明确排除细菌感染是SCAI的病因，但组织学和临床特征表明SCAI可能代表一种非感染性无菌性炎症形式。软骨下急性炎症可能继发于严重骨关节炎和/或类风湿关节炎时滑膜液渗入软骨下松质骨。
