Mikkeli Central Hospital, Mikkeli, Finland.
Acta Orthop. 2010 Aug;81(4):420-6. doi: 10.3109/17453674.2010.492765.
Primary and dynamically maintained periprosthetic bone formation is essential for osseointegration of hip implants to host bone. Bone morphogenetic proteins (BMPs) play a role in osteoinductive bone formation. We hypothesized that there is an increased local synthesis of BMPs in the synovial membrane-like interface around aseptically loosened total hip replacement (THR) implants, as body attempts to generate or maintain implant fixation.
We compared synovial membrane-like interface tissue from revised total hip replacements (rTHR, n = 9) to osteoarthritic control synovial membrane samples (OA, n = 11. Avidin-biotin-peroxidase complex staining and grading of BMP-2, BMP-4, BMP-6, and BMP-7 was done. Immunofluorescence staining was used to study BMP proteins produced by mesenchymal stromal/stem cells (MSCs) and osteoblasts.
All BMPs studied were present in the synovial lining or lining-like layer, fibroblast-like stromal cells, interstitial macrophage-like cells, and endothelial cells. In OA and rTHR samples, BMP-6 positivity in cells, inducible by the proinflammatory cytokines tumor necrosis factor-alpha and interleukin-1beta, predominated over expression of other BMPs. Macrophage-like cells positive for BMP-4, inducible in macrophages by stimulation with particles, were more frequent around loosened implants than in control OA samples, but apparently not enough to prevent loosening. MSCs contained BMP-2, BMP-4, BMP-6, and BMP-7, but this staining diminished during osteogenesis, suggesting that BMPs are produced by progenitor cells in particular, probably for storage in the bone matrix.
原发性和动态维持的假体周围骨形成对于髋关节植入物与宿主骨的骨整合至关重要。骨形态发生蛋白（BMPs）在诱导成骨中起作用。我们假设，在无菌性松动的全髋关节置换（THR）植入物周围的类似滑膜的界面中，会增加 BMP 的局部合成，因为机体试图产生或维持植入物固定。
我们比较了翻修全髋关节置换术（rTHR，n=9）的类似滑膜界面组织与骨关节炎对照滑膜样本（OA，n=11）。进行了 BMP-2、BMP-4、BMP-6 和 BMP-7 的亲和素-生物素-过氧化物酶复合物染色和分级。免疫荧光染色用于研究间充质基质/干细胞（MSCs）和成骨细胞产生的 BMP 蛋白。
研究的所有 BMP 均存在于滑膜衬里或类似衬里的层、成纤维细胞样基质细胞、间充质巨噬细胞样细胞和内皮细胞中。在 OA 和 rTHR 样本中，细胞中 BMP-6 的阳性表达（由促炎细胞因子肿瘤坏死因子-α和白细胞介素-1β诱导）超过了其他 BMP 的表达。在松动的植入物周围，刺激巨噬细胞产生的 BMP-4 阳性的巨噬细胞样细胞比对照 OA 样本更常见，但显然不足以防止松动。MSCs 含有 BMP-2、BMP-4、BMP-6 和 BMP-7，但这种染色在成骨过程中减少，表明 BMP 是由祖细胞产生的，特别是可能用于骨基质的储存。
