Increased expression of EMMPRIN in the tissue around loosened hip prostheses

Matrix metalloproteinases (MMPs) have been shown to play a role in aseptic loosening of total hip replacement (THR). Extracellular matrix metalloproteinase inducer (EMMPRIN) can upregulate expression of several MMPs but has little effect on their tissue inhibitor (TIMP). Using the avidin-biotin-peroxidase complex immunostaining method, we detected strong immunoreactivity of EMMPRIN in the lining-like layers, sublining area and vascular endothelium of synovial membrane-like interface tissue around loosened prostheses. In contrast, EMMPRIN staining was very weak in the synovial samples from patients with hip arthrosis. Double immunofluorescence labeling revealed EMMPRIN/MMP-1 double-positive cells in lining-like layers and the sublining area of interface tissue. Our findings indicate that EMMPRIN expression is upregulated in interface tissue, and that locally accumulated EMMPRIN may modulate MMP-1 expression. An imbalance in the activity of MMPs and TIMP may lead to tissue destruction and periprosthetic osteolysis. These biological responses, combined with mechanical stress caused by micromotion and oscillating fluid pressure, may eventually cause aseptic loosening of THR.     

Increased expression of EMMPRIN in the tissue around loosened hip prostheses

Matrix metalloproteinases (MMPs) have been shown to play a role in aseptic loosening of total hip replacement (THR). Extracellular matrix metallo-proteinase inducer (EMMPRIN) can upregulate expression of several MMPs but has little effect on their tissue inhibitor (TIMP)- Using the avidin-biotin-per-oxidase complex immunostaining method, we detected strong immunoreactivity of EMMPRIN in the lining-like layers, sublining area and vascular endothelium of synovial membrane-like interface tissue around loosened prostheses. In contrast, EMMPRIN staining was very weak in the synovial samples from patients with hip arthrosis. Double immunofluorescence labeling revealed EMMPRIN/MMP-1 double-positive cells in iining-iike layers and the sublining area of interface tissue.

Our findings indicate that EMMPRIN expression is upregulated in interface tissue, and that locally accumulated EMMPRIN may modulate MMP-1 expression. An imbalance in the activity of MMPs and TIMP may lead to tissue destruction and periprosthetic osteolysis. These biological responses, combined with mechanical stress caused by micromotion and oscillating fluid pressure, may eventually cause aseptic loosening of THR.     

No lymphokines in T-cells around loosened hip prostheses

Research results have been contradictory about the role of lymphocytes and immune response in aseptic loosening of total hip replacement (THR). Conclusive evidence is still lacking in spite of extensive in vivo and in vitro studies. Our study was designed to check whether T-cells were activated and if they produced lymphokines in synovial membrane-like interface tissue around loosened THRs. Tissue sections were stabilized and permeabilized to allow the cytokine-specific antibodies to penetrate through the cell membrane and the membranes of intracellular organelles. This technique, combined with computer-assisted image analysis, permits the detection and quantitation of lymphokine-producing cells. We found that the number of T-cells was low, and none of the T-cells was activated, as shown by the absence of interleukin-2 receptor (IL-2R) immunoreactivity. There was no cell producing lymphokines, such as interleukin-2 (IL-2), interferon-gamma (IFN-gamma), and tumor necrosis factor-beta (TNF-beta). Our results suggest that T-cell-mediated immune response is not actively involved in aseptic loosening of THR.     

No lymphokines in T-cells around loosened hip prostheses

Research results have been contradictory about the role of lymphocytes and immune response in aseptic loosening of total hip replacement (THR). Conclusive evidence is still lacking in spite of extensive in vivo and in vitro studies. Our study was designed to check whether T-cells were activated and if they produced lymphokines in synovial membrane-like interface tissue around loosened THRs. Tissue sections were stabilized and permeabilized to allow the cytokine-specific antibodies to penetrate through the cell membrane and the membranes of intracellular organelles. This technique, combined with computer-assisted image analysis, permits the detection and quantitation of lymphokine-producing cells. We found that the number of T-cells was low, and none of the T-cells was activated, as shown by the absence of interleukin-2 receptor (IL-2R) immunoreactivity. There was no cell producing lymphokines, such as interleukin-2 (IL-2), interferon-gamma (IFN-γ), and tumor necrosis factor-beta (TNF-β). Our results suggest that T-cell-mediated immune response is not actively involved in aseptic loosening of THR.     

No lymphokines in T-cells around loosened hip prostheses

Research results have been contradictory about the role of lymphocytes and immune response in aseptic loosening of total hip replacement (THR). Conclusive evidence is still lacking in spite of extensive in vivo and in vitro studies. Our study was designed to check whether T-cells were activated and if they produced lymphokines in synovial membrane-like interface tissue around loosened THRs. Tissue sections were stabilized and permeabilized to allow the cytokine-specific antibodies to penetrate through the cell membrane and the membranes of intracellular organelles. This technique, combined with computer-assisted image analysis, permits the detection and quantitation of lymphokine-producing cells. We found that the number of T-cells was low, and none of the T-cells was activated, as shown by the absence of interleukin-2 receptor (IL-2R) immunoreactivity. There was no cell producing lymphokines, such as interleukin-2 (IL-2), interferon-gamma (IFN-^7;), and tumor necrosis factor-beta (TNF-^6;). Our results suggest that T-cell-mediated immune response is not actively involved in aseptic loosening of THR.     

Histological analysis and biological effects of granulation tissue around loosened hip prostheses in the development of osteolysis

Although aseptic loosening of the prosthesis is a long-term complication after total joint replacement, the detailed mechanism of osteolysis remains unknown. We examined 82 samples from 40 patients with aseptic loosened hip prostheses histologically, and compared the distribution of particles, macrophages/histiocytes, and foreign body giant cells in the retrieved tissue from capsules and around prostheses. Furthermore, to investigate the mechanism of osteolysis, we cultured tissue from a patient with massive osteolysis and examined the effects of the conditioned medium on osteoblasts in vitro. Numerous multinucleated giant cells and histiocytes were present, and polyethylene particles ranging from medium to large were identified in the polarized light. However, the distribution was heterogeneous, and no particles were found microscopically in about 30%–40% of periprosthetic tissues, and in 60% of capsules. The amount of particles correlated with giant cells, but not with histiocytes. The conditioned medium of the granulation tissue culture stimulated osteoblasts to produce interleukin-6 in both protein and mRNA, and this was in part inhibited by anti-tumor necrosis factor- or the interleukin-1 antibody, suggesting that interleukin-6 production is mediated by several cytokines. These findings suggest that interleukin-6, which is produced not only by macrophages but also by osteoblasts, is a contributing factor to aseptic loosening.     

BMPs in periprosthetic tissues around aseptically loosened total hip implants

Background and purpose

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.

Patients and methods

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.

Results and interpretation

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−α and interleukin-1β, 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.     

Presence of interleukin-17C in the tissue around aseptic loosened implants

Purpose

The most common long-term complication of joint arthroplasty is aseptic loosening. The proinflammatory cytokines secreted by macrophages are involved in aseptic loosening. Recently, a novel proinflammatory cytokine IL-17C was reported to participate in inflammatory diseases by synergising with proinflammatory cytokines. However, the relationship between IL-17C and the aseptic loosening is unclear.

Methods

The tissues around aseptic loosened implants were collected during revision surgery and handled by formalin fixation and embedded in paraffin. The presence of IL-17C in the tissues around the aseptic loosened implants was investigated in 12 aseptic loosening patients using immunofluorescence.

Results

The presence of IL-17C protein in the tissues around aseptic loosened implants was detected by immunofluorescence. There are no statistical differences between optical density of IL-17C in aseptic loosening samples and in rheumatoid arthritis samples (positive control).

Conclusions

These results suggest the presence of IL-17C in aseptic loosening. Interleukin-17C was related to the inflammation of aseptic loosening, possibly by contributing to the inflammation and osteolysis in the tissues surrounding aseptic loosened implants.     

The microenvironment around total hip replacement prostheses

The metal stem of the totally replaced hip carries load and resists fatigue, but it is electrochemically corroded. Metallic atoms act as haptens, induce type 1 T-helper cells/Th1-type immune responses and enhance periprosthetic osteolysis. Stiff metal implants, which do not have the same elasticity as the surrounding bone, cause stress shielding. Cyclic loading and lack of ligamentous support lead to mechanical and ischemia reperfusion injury and particle formation from bone, polymethylmethacrylate, and porous implant surfaces, which accelerate third-body polyethylene wear. Surgical injury and micromotion induce the formation of a fibrous capsule interface. Type-B lining cells produce lubricin and surface-active phospholipids to promote solid-to-solid lubrication but may loosen the implant from bone. The pumping action of the cyclically loaded joint and synovial fluid pressure waves dissect the implant-host interface and transports polyethylene particles and pro-inflammatory mediators to the interface. Hyaluronan induces formation of a synovial lining like layer. Because of its localization close to bone, foreign body inflammation at the interface stimulates osteoclastogenesis and peri-implant bone loss. Metal-on-metal and ceramic-on-ceramic pairs might minimize third body wear, but can lead to high-impact load of the acetabulum. Diamond coating of a metal-on-polyethylene couple might solve both of these problems. The basic biomaterial solutions allow good mechanical performance and relatively long life in-service, but surface modifications (porous coating, hydroxyapatite, diamond, bioglass, and others) may facilitate performance of the implant and improve the biomaterial and body interfaces.     

Extracellular matrix metalloproteinases around loose total hip prostheses

We have explored the tissue localization of extracellular matrix metalloproteinases MMP-1 (fibroblast collagenase), MMP-2 (72-kDa gelatinase/Type IV collagenase), MMP-3 (stromelysin), MMP-8 (polymorphonuclear leukocyte collagenase) and MMP-9 (92-kDa gelatinase/Type IV collagenase) in the tissues around loose hip prostheses. The findings were compared with those in synovial tissues obtained from patients with a fractured femoral neck. MMP-type specific antisera were applied in the sensitive avidin-biotin-peroxidase complex methods.

MMP-1 was found in monocyte/macrophages, fibroblasts, and vascular endothelial cells in both interface tissues between bone and acetabular components and the pseudocapsular tissues obtained from loosening of hip prostheses. In these tissues, MMP-8 was occasionally found, but only in polymorphonuclear leukocytes. Cells showing immunoreactivity to 72- and 92-kDa gelatinasenype IV collagenase, MMP-2 and MMP-9, respectively, and stromelysin, MMP-3, were abundant in both interface and pseudocapsular tissues in loose hip prostheses. In contrast, in hip fractures, immunoreactivity to MMP-1, 2, 3, and 9 was weak and only observed in synovial tissues. Immunoreactvity to MMP-8 was confined to polymorphonuclear leukocytes attached to the synovial membrane or in the infiltrate around blood vessels in the subsynovial connective tissues.

The finding of MMP-1, 2, 3, and 9 in the tissues around loose hip prostheses suggests that they play a role in the weakening of connective tissues, and this leads to loosening.     

Bone loss around 2 different types of hip prostheses

Dual energy x-ray absorptiometry (DXA) allows the measurement of bone mineral density (BMD) around an uncemented hip prosthesis. The aims of this study were: 1) to determine the reproducibility of periprosthetic BMD measurements; 2) to delineate the time course of bone loss that occurs after insertion of a hip prosthesis; and 3) to compare the bone loss around two different types of hip prosthesis. We studied 20 patients: 11 had Bateman and 9 had porous-coated anatomic prostheses inserted. The mean bone loss in 20 patients between 6 and 52 weeks after surgery was 6%. The greatest loss during this period was 18% and occurred from the proximal medial cortex. We conclude that measurement of periprosthetic bone mass by DXA is a precise technique. Bone loss was rapid in the first 6 months following total hip replacement. There was no difference in the bone loss occurring around the two prostheses studied.     

无菌性松动假体－骨界面溶骨因子和成骨因子表达的对比研究

目的 对比研究无菌性松动假体周围界膜中溶骨因子和成骨因子的表达,进一步探讨磨损颗粒致界面骨溶解的生物学原因。方法 采用逆转录－聚合酶链反应（ｒｅｖｅｒｓｅ ｔｒａｎｓｃｒｉｐｔｉｏｎ ｐｏｌｙｍｅｒａｓｅ ｃｈａｉｎ ｒｅａｃｔｉｏｎ,ＲＴ－ＰＣＲ）和计算机图像分析的方法,分别检测溶骨区界膜（含磨损颗粒）和非溶骨区界膜中ＰＤＧＦ－Ｂ和ＢＭＰ－７ ｍＲＮＡ的表达量,并以正常滑膜、骨性关节炎（ｏｓｔｅ     

Immune competence of human tissue lymphocytes in contact with loosened hip joint prostheses. On the topic of cellular or humoral rejection reaction as the mechanism of loosening

In several investigations rejections were accused of being a possible cause for the loosening of hip endoprostheses. Using immunocytochemical techniques we studied the number and type of lymphocytes in the tissue adjacent to loosened hip endoprostheses. Tissue samples were taken from 18 patients being reoperated for a loosened endoprostheses. Impressive lymphocyte infiltrates were found in 4 of 18 patients (22%). These infiltrates only consisted of T-cells. In the other samples only few lymphocytes were detected belonging to T- and B-lymphocyte population, respectively. In our patients T-cell mediated rejections were of minor importance for the loosening of total hip replacement. B-cell accumulations were detected in none of the samples.     

人工关节无菌性松动界膜中的免疫反应

目的 探讨人工关节无菌性松动界膜的免疫反应状况及其与无菌性松动的关系。方法 对 9例人工关节无菌性松动界膜标本进行组织学观察 ,并行 T淋巴细胞及其亚群 (CD 3、 CD 4、 CD 8)、 IL－ 2受体 (CD 25)、巨噬细胞 (CD 68)及组织相容性抗原 (HLA－ DR)的免疫组织化学染色,观察 T淋巴细胞的表达情况及其与炎症反应的关系。结果 所有界膜标本中均可见肉芽肿性组织,有大量的巨噬细胞和异物巨细胞浸润,其中 5例 T淋巴细胞数量增加, T淋巴细胞及其亚型的分布大致相同,且 3例 T淋巴细胞呈现 IL－ 2R阳性。 T淋巴细胞的增加及 IL－ 2受体阳性的 T淋巴细胞的表达与巨噬细胞、 HLA－ DR的表达和炎症反应程度有一定的相关性。结论 在部分假体周围存在着针对假体材料的超敏反应,并且可能是导致假体无菌性松动的原因之一。     

无菌性松动假体周围界膜组织中PDGF-B和BMP-7受体的分布及其临床意义

目的 通过对比研究PDGF－B和BMP－7受体在无菌性松动假体周围界膜组织细胞中的分布,探讨骨－假体界膜组织的分化趋势、假体松动的生物学原因并提出防治因界膜形成而导致假体松动的相应措施。方法 以预聚合SABC法,采用PDGF－B受体（PDGFR－β）和BMP－7受体（ActR-I)的多克隆抗体分别对10例无菌性松动假体周围溶骨区和非溶骨区界膜组织行免疫组织化学染色。检测每例每种阳性各100个的相对灰度值,在不同部位的组织和细胞间进行比较。结果 界膜组织中PDGFR－β在不同细胞上的分布没有特异性,但溶骨区界膜中巨噬细胞的成纤维细胞该受体的表达量明显高于非溶骨区（P＜0．01）,并以成纤维细胞表达量较高（P＜0．05）,ActR-I主要分布于无磨损颗粒非溶骨区界中层丰富的间充质细胞或成纤维细胞上,存在磨损颗粒的界膜中细胞也可有表达。结论 溶骨和成骨因子受体在界膜组织细胞上均有分布。磨损颗粒等因素致PCGF－B表达增加可能促进界面骨溶解和纤维增生,从而造成假体的不稳定或松动。而在界面施加成骨因子则可能是在一定程度上削弱人工关节无菌性松动生物学因素的一种尝试。