Orthopaedic Department, Center for Musculoskeletal Surgery, Charité-University Medicine Berlin, Chariteplatz 1, 10117 Berlin, Germany.
Knee Surg Sports Traumatol Arthrosc. 2012 Sep;20(9):1803-8. doi: 10.1007/s00167-011-1774-8. Epub 2011 Nov 17.
Because of the multiple possible aetiologies of painful total knee arthroplasty (TKA), the diagnosis and treatment of such patients are challenging. In a considerable number of patients, an intraarticular pathology is present, although not verifiable with clinical and diagnostic imaging techniques as in cases of primary arthrofibrosis. In these patients, the differentiation between intra- and extraarticular causes of pain remains difficult. Until now, little attention has been paid to changes of the synovial fluid and tissue in these knees. The objective of this study was to analyse the changes of the synovial environment in patients suffering from arthrofibrosis after TKA in comparison with knees with referred pain suffering from hip arthritis. The changes of the synovial environment probably provide additional diagnostic information to verify an intraarticular pathology.
The synovial fluid of 10 consecutive knees in 10 patients presenting with a primary arthrofibrosis after TKA without signs of infection, instability, malalignment, or loosening was analysed and compared to the synovial fluid of 10 knees with referred pain serving as controls. The BMP-2 concentration was measured in the synovial fluid, and the presence of cytokines leading to an overexpression of BMP-2 was detected by measuring the change of BMP-2 expression in a synoviocyte cell line following exposing to the synovial fluid of the patients.
The concentration of BMP-2 in the synovial fluid was significantly higher in arthrofibrotic TKA knees (24.3 ± 6.9 pg/mL), compared with the control group 5.9 ± 4.8 pg/mL (P < 0.001). Corresponding to this finding, BMP-2 expression in synoviocytes was upregulated 11.5-fold (P < 0.05) by synovial fluid of patients suffering from arthrofibrosis after TKA, compared with the control group with referred pain.
BMP-2 is overexpressed and its concentrations are consequently higher in patients suffering from arthrofibrosis after TKA. The synovial BMP-2 concentration may be a potential marker for differentiating between intra- and extraarticular causes of pain.
II.
由于疼痛性全膝关节置换术（TKA）有多种可能的病因，因此此类患者的诊断和治疗具有挑战性。在相当数量的患者中，尽管临床和诊断影像学技术无法证实存在关节内病理学，但仍存在关节内病理学。在这些患者中，区分疼痛的关节内和关节外原因仍然很困难。到目前为止，人们对这些膝关节的滑液和组织的变化关注甚少。本研究的目的是分析 TKA 后发生纤维性关节僵硬的患者的滑膜环境变化，并与髋关节关节炎引起的牵涉痛的膝关节进行比较。滑膜环境的变化可能提供额外的诊断信息来验证关节内病理学。
分析了 10 例 TKA 后原发性纤维性关节僵硬且无感染、不稳定、对线不良或松动迹象的连续 10 例患者的膝关节滑液，并与 10 例作为对照的有牵涉痛的膝关节滑液进行比较。测量滑液中的 BMP-2 浓度，并通过测量患者滑液暴露于滑膜细胞系后 BMP-2 表达的变化来检测导致 BMP-2 过度表达的细胞因子。
与对照组 5.9±4.8pg/mL 相比，纤维性关节僵硬 TKA 膝关节滑液中的 BMP-2 浓度明显更高（24.3±6.9pg/mL，P<0.001）。相应地，与对照组相比，TKA 后纤维性关节僵硬患者的滑膜细胞中 BMP-2 表达上调了 11.5 倍（P<0.05）。
BMP-2 在 TKA 后发生纤维性关节僵硬的患者中过度表达，浓度较高。滑膜 BMP-2 浓度可能是区分关节内和关节外疼痛原因的潜在标志物。
II 级。
