ABSTRACT
To investigate the clinical results of cross-linked polyethylene (CLPE) and to compare the CLPE wear against zirconia and stainless steel heads, we studied the radiographic wear after a minimum 3-year follow-up in total hip arthroplasty (THA). Ninety-four hips were randomly implanted with a 22.225-mm head cemented THA-the group of non-CLPE against zirconia and CLPE against 2 different zirconias and stainless steel. The linear wear rate was significantly lower in the group of CLPE against zirconia (0.067, 0.059 mm/y) and against stainless steel (0.068 mm/y) compared with non-CLPE against zirconia (0.170 mm/y). In the short-term results, the wear performance of CLPE against zirconia was superior to that of non-CLPE; however, it did not show a better wear rate than CLPE against stainless steel. Furthermore, long-term investigations will be necessary for understanding CLPE wear in vivo.
Subject(s)
Arthroplasty, Replacement, Hip , Biocompatible Materials , Hip Prosthesis , Joint Diseases/surgery , Polyethylene , Prosthesis Failure , Aged , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prospective Studies , Treatment OutcomeABSTRACT
A method has been developed for creating a bioactive coating on titanium by alkaline and heat treatment, and shown that it forms a thin layer of hydroxyapatite (HA) on the surface of implants when soaked in simulated body fluid. A series of 70 cementless primary total hip arthroplasties using this coating technique on a porous titanium surface was performed, and followed up the patients for a mean period of 4.8 years. There were no instances of loosening or revision, or formation of a reactive line on the porous coating. Although radiography just after operation showed a gap between the host bone and the socket in over 70% of cases, all the gaps disappeared within a year, indicating the good osteoconduction provided by the coating. Alkaline-heat treatment of titanium to provide a thin HA coating has several advantages over plasma-spraying, including no degeneration or absorption of the HA coating, simplicity of the manufacturing process, and cost effectiveness. In addition, this method allows homogeneous deposition of bone-like apatite within a porous implant. Although this was a relatively short-term study, treatment that creates a bioactive surface on titanium and titanium alloy implants has considerable promise for clinical application.
Subject(s)
Alkalies , Arthroplasty, Replacement, Hip , Bone Cements , Titanium , Adult , Aged , Female , Humans , Male , Microscopy, Electron, Scanning , Middle AgedABSTRACT
We investigated the gene expression profiles of U937 cells after contact with polyethylene particles. U937 cells were differentiated with phorbol 12-myristate 13-acetate, and cocultured with either retrieved polyethylene particles or commercially produced polyethylene particles (Ceridust 3615, Clariant Japan, Tokyo, Japan). To achieve consistent contact with the polyethylene particles, we used a rotating device. Phagocytosis of the polyethylene particles or retrieved polyethylene particles by differentiated U937 cells stimulated the release of cytokines including interleukin 1beta, interleukin 6, interleukin 8, and vascular endothelial growth factor. Microarray analysis revealed that the expression of IL8, CCL4, CXCR4, and some other genes was up-regulated after contact with retrieved polyethylene particles. This study first reports the gene expression profiles of U937 cells after contact with polyethylene particles. We believe that this experimental model is applicable to all other particulate materials.
Subject(s)
Gene Expression Profiling , Macrophages/metabolism , Microspheres , Polyethylene , Chemokine CCL4/genetics , Chemokine CCL4/metabolism , Humans , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Interleukin-6/genetics , Interleukin-6/metabolism , Interleukin-8/genetics , Interleukin-8/metabolism , Macrophages/pathology , Macrophages/ultrastructure , Oligonucleotide Array Sequence Analysis , Phagocytosis/physiology , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptors, CXCR4/genetics , Receptors, CXCR4/metabolism , U937 Cells , Vascular Endothelial Growth Factor A/genetics , Vascular Endothelial Growth Factor A/metabolismABSTRACT
To determine whether sensitivity to polyethylene particles varies among patients, we studied 25 patients who had undergone total hip arthroplasty. We used pelvic radiographs to measure annual polyethylene wear and the area of osteolysis. The ratio of the area of osteolysis to the volumetric polyethylene wear was defined as sensitivity index. Adherent cells from peripheral blood were cocultured with polyethylene particles, and the amount of bone-resorptive cytokines was measured. The amount of interleukin-6, but not of interleukin-1beta or tumor necrosis factor-alpha, released from adherent cells in the in vitro experiment correlated with the in vivo sensitivity indices. This technique appears capable of predicting the development of polyethylene-induced osteolysis, allowing surgeons to avoid using polyethylene as the bearing surface in patients at risk for osteolysis.
Subject(s)
Arthroplasty, Replacement, Hip/adverse effects , Bone Cements , Hypersensitivity/etiology , Microspheres , Osteolysis/chemically induced , Polyethylene/adverse effects , Adult , Aged , Arthroplasty, Replacement, Hip/methods , Bone Resorption/metabolism , Cells, Cultured , Female , Follow-Up Studies , Hip Joint/diagnostic imaging , Hip Joint/metabolism , Hip Joint/surgery , Humans , Interleukin-6/metabolism , Macrophages/metabolism , Macrophages/pathology , Middle Aged , Osteolysis/diagnostic imaging , RadiographyABSTRACT
We compared the polyethylene wear of acetabular sockets articulated with 22.225-mm alumina heads with the polyethylene wear of those articulated with 22.225-mm zirconia heads in cemented total hip arthroplasty during a mean follow-up period of 5.4 years. Using a computer-aided technique, we measured polyethylene wear radiologically in 46 hips with alumina heads and 58 hips with zirconia heads. The preoperative diagnosis in all cases was osteoarthritis. The mean linear wear rate and mean volumetric wear rate of polyethylene sockets against zirconia heads were 0.133 mm/y and 39.8 mm(3)/y, respectively, significantly greater (P < .01) than the wear rates against alumina heads (0.078 mm/y and 24.2 mm(3)/y, respectively). Age at operation, patient body weight as well as height, thickness of polyethylene, and socket abduction angle did not influence the wear rates. We speculate that the excessive polyethylene wear was caused by phase transformation of zirconia, leading to an increase of surface roughness.
Subject(s)
Aluminum Oxide , Arthroplasty, Replacement, Hip/methods , Hip Prosthesis , Polyethylenes , Zirconium , Analysis of Variance , Cementation , Female , Humans , Male , Middle Aged , Prosthesis Design , Prosthesis Failure , Quality of Life , Surface PropertiesABSTRACT
We report a long-term study of bioactive bone cement (BABC) in a canine total hip arthroplasty (THA) at follow-up of 8 years. Previous studies have shown excellent biomechanical and histological results at follow-up of 6, 12, and 24 months. In the present study, THA was performed in a beagle dog using BABC consisting of an apatite- and wollastonite-containing glass ceramic (AW-GC) powder and SiO2 powder as the filler and a bisphenol-a-glycidyl methacrylate (Bis-GMA) based resin as the organic matrix. Histological examination showed direct bonding between BABC and bone without any intervening soft tissue layer at the BABC-bone interface. A reactive layer, through which BABC bonded to the bone, was observed thicker at 8 years than it was at 24 weeks. No adverse effects of BABC were observed. BABC maintained the high bioactivity and direct bonding to bone in a canine THA at follow-up of 8 years.
