Clinical reviews: particulate debris and failure of total hip replacements.
Explore the source record for details and available documents.
Hip Prosthesis↗
Biomedical subjects
M Jasty
Publications and source records attributed to M Jasty.
Comparison of bone ingrowth into cobalt chrome sphere and titanium fiber mesh porous coated cementless canine acetabular components.
Bone ingrowth into uncemented hemispherical canine acetabular components porous-coated with cobalt chrome spheres was compared to those porous-coated with titanium fiber mesh. While good bone ingrowth was noted in both types of porous coatings at 6 weeks after surgery with no difference in the histologic quality of the ingrown bone, quantitation of bone ingrowth showed that significantly more bone grew into titanium fiber mesh porous-coated components. The mean amount of bone ingrowth measured 10.5% of the area of the porous coating with fiber mesh coatings and only 5.5% of the area of the porous coating with spherical coatings (significant difference at P < .0005). The mean area density of the ingrown bone inside the pores measured 21.5% of the pore area with fiber mesh coatings, also significantly greater than 13.4% of the pore area with sphere coatings (P < .025). The ingrown bone penetrated a mean 66% of the depth of the porous layer with fiber mesh coatings compared to 32% of the depth of the porous layer with spherical coating (significant difference at P < .0005). The mean extent of the periphery of the porous layer with bone ingrowth was 88% for the mesh coatings and 55% for the spherical coatings (also a significant difference at P < .01).
Acetabulum↗
Challenge to the concept that UHMWPE acetabular components oxidize in vivo.
Severe wear of the ultra-high molecular weight polyethylene (UHMWPE) components of total joint replacements limits their long-term success. In previous studies, the infrared spectra obtained on retrieved UHMWPE components were interpreted as evidence that the UHMWPE oxidizes in vivo. In direct contrast, infrared spectroscopy of the retrieved UHMWPE acetabular components examined in this study demonstrated adsorbed esterified fatty acids, readily extractable by hexane, and no substantial evidence of in vivo oxidation. This emphasizes that special care must be taken when using infrared spectroscopy to assess retrieved components.
Adult↗
High failure rate of bulk femoral head allografts in total hip acetabular reconstructions at 10 years.
The authors evaluated the radiographic appearance and functional performance of 30 cemented total hip arthroplasty acetabular reconstructions in 28 patients in whom bulk, weight-bearing, femoral head allografts were used to augment severe acetabular bone deficiency with a mean follow-up period of 10 years (range, 8-13.3 years). The average age of the patients was 51 years. The current study group represents the 10-year subset of a larger series of 38 hip reconstructions previously reported. The graft was bolted within the acetabulum in 12 hips and to the lateral wing of the ilium in the other 18 hips. On average, these grafts supported approximately 60% of the acetabular component. All grafts united. Failure of fixation of the acetabular component occurred in 47% of the acetabular reconstructions (14 hips in 14 patients). Four were diagnosed as loose on the basis of radiographic criteria alone and the other 10 hips had a loose acetabular component at reoperation. Loosening occurred in 58% (7 of 12) of the sockets with intraacetabular graft and in 40% (7 of 18) of those bolted to the lateral ilium. The failure rate of 47% in these reconstructions at 10 years is in sharp contrast to high success rates at less than 5 years and argues against the use of bulk weight-bearing allografts for most situations unless the only alternative is resection arthroplasty.
Acetabulum↗
The contribution of the nonporous distal stem to the stability of proximally porous-coated canine femoral components.
The contribution of the distal nonporous-coated stem to the stability of the uncemented femoral components, which were porous coated only proximally, was investigated under two conditions: (1) immediately after insertion and (2) at 6 months, 1 year, and 2 years after surgery in a canine model. The relative motion of the femoral components at the bone porous-coating interface under loads simulating the canine midstance was measured at these time periods using displacement transducers. The measurements were repeated after severing the connection between the porous-coated proximal body and the nonporous-coated distal stem through a small hole in the anterior cortex. The results showed that while the distal nonporous-coated stem enhanced the immediate stability of the proximally porous-coated uncemented femoral components, it contributed little to the long-term stability of the femoral components after bony ingrowth had occurred in vivo. The mean relative motion between the body of the prosthesis and the cortical bone increased from 12 microns (+/- 7 microns) to 31 microns (+/- 34 microns) in the posterior transverse direction when the stem was immediately severed after the surgery. However, at 6 months, 1 year, and 2 years after surgery, extensive bone ingrowth had occurred into the proximal porous-coated regions of the body and provided excellent stability to the femoral components. With bone ingrowth, the mean relative motion was less than 5 microns at any site. Under these conditions, severing the stem did not increase the relative motion of the prostheses significantly.(ABSTRACT TRUNCATED AT 250 WORDS)
Alloys↗
Autopsy studies of the bone-cement interface in well-fixed cemented total hip arthroplasties.
Although knowledge of the clinical status of the implant is important, only instrumented mechanical testing of retrieved specimens provides quantitative assessment of implant fixation. This measurement allows placement of the implant along a continuum of loosening and is the foundation for the interpretation of subsequent findings. Analysis of implants that have been proven to be well fixed by instrumented testing reveals significant differences in the initial events in the loosening of femoral and acetabular components. Although radiolucencies were observed around all of these well-fixed femoral and acetabular components, the histology (and therefore the etiology) of the radiolucency is different and variable on the two sides of the articulation. The majority of femoral radiolucencies appear to be due to age and stress-related remodeling while particulate-induced bone resorption plays an important role in acetabular radiolucencies. A finding common to both sides of the articulation in these stable components, however, was intimate contact of bone with cement without any interposed soft tissue even after 17.5 years of service. Primary incompatibility and/or failure of the cement was not identified as a factor in initiating either femoral or acetabular component loosening. These studies document the long-term compatibility of bone with cement in bulk form. Improvements in cemented femoral component fixation should focus on stem design and cementing technique. Long-term acetabular component fixation can be improved by reduction or elimination of polyethylene wear and optimization of the bone-implant interface.
Biocompatible Materials↗
Histological and radiographic assessment of well functioning porous-coated acetabular components. A human postmortem retrieval study.
Nine porous-coated acetabular components were retrieved post mortem. All components had been inserted at our institution and had been in situ for a mean of fifty months (range, seventeen to eighty-seven months). Clinical records revealed that all had been functioning well at the time of death, and clinical radiographs showed signs that all had been stable. Standard backscattered scanning electron microscopy was used to quantitate the amount of bone ingrowth into the porous coating. For each component, the histological appearance of the bone-metal interface was compared with the appearance on clinical radiographs. Light microscopy was used to study the non-ossified areas. Every component had growth of bone into the porous coating, with the ingrowth occupying a mean of 32 per cent (range, 3 to 84 per cent) of the fields that were examined. In areas where bone ingrowth had occurred, the mean area density was 48 per cent (range, 26 to 65 per cent). Use of radiographs consistently led to an underestimation of the presence of gap areas and an overestimation of the occurrence of bone apposition. When fibrous tissue was present in non-ossified areas, it was extremely dense and well organized. Within the limits of light microscopic examination, there was no evidence of granulomatous formation in the non-ossified regions. This is particularly encouraging since the fibrous tissue-bone interfaces seem to prohibit the deposit of particulate debris.
Acetabulum↗
Production of cytokines around loosened cemented acetabular components. Analysis with immunohistochemical techniques and in situ hybridization.
The chronic inflammatory response to wear particles from orthopaedic joint implants is believed to cause osteolysis and to contribute to prosthetic loosening. Previous in vitro experiments have demonstrated that particulate debris from joint implants causes cells in culture to release products that have been implicated in this pathological bone resorption. The purpose of the current study was to investigate the in vivo features of this complex process in patients who had had a total hip replacement. Membraneous tissue was obtained from the cement-bone interface of ten polyethylene acetabular components that had been revised for aseptic loosening in ten patients. The immunoperoxidase technique, which involves the use of specific antibodies for each cell type, showed that macrophages were the predominant cellular constituents but also that fibroblasts, many of which were not identified on plain histological study, were present and were actively producing collagen. T lymphocytes were present variably, but they generally composed less than 10 percent of the cells. Particulate debris (polyethylene, methylmethacrylate, and metal) was present in all membrane specimens but was intracellular only in macrophages and multinucleated giant cells. 35S-labeled nucleic-acid probes, complementary to human interleukin-1-beta and to platelet-derived growth-factor-2 messenger RNA (mRNA), were hybridized with serial tissue sections. Hybridization demonstrated interleukin-1-beta mRNA predominantly in macrophages, and not in fibroblasts or in T lymphocytes to any major extent. In contrast, immunolocalization demonstrated interleukin-1-beta protein on both macrophages and fibroblasts, suggesting that macrophages release interleukin-1-beta, which then binds to both fibroblasts and macrophages. Platelet-derived growth-factor transcripts were found in both macrophages and fibroblasts.
Aged↗
Histology of porous-coated acetabular components. 25 cementless cups retrieved after arthroplasty.
25 hemispherical acetabular components retrieved from patients who had a total hip arthroplasty (THA) were studied histologically. All of the components had titanium fiber metal porous coatings and were implanted with adjuvant screw fixation, 18 in primary THA and 7 in revision THA. None of the cups had been removed because of infection or failure of fixation. The components had been in place an average of 30 (1-140) weeks. 18 cups had bone ingrowth into the porous coating. Up to one third of the available void space within the porous coating was occupied by bone, while the maximal proportion of the area of the bone-implant interface with bone ingrowth was over 80 percent. Bone ingrowth was more often observed at the dome and in the vicinity of sites of screw fixation than elsewhere. Peripherally, bone ingrowth was less consistent, and in isolated areas fibrocartilage and mineralized fibrocartilage were occasionally observed. The longer-term cases had more bone ingrowth than the shorter-term cases. Apparent metallic debris was observed within histiocytes adjacent to screw holes, and the amount of this material increased with duration of implantation.
Acetabulum↗
High assembly strains and femoral fractures produced during insertion of uncemented femoral components. A cadaver study.
The assembly strains produced in cadaver femurs during uncemented femoral arthroplasty were measured using strain gages and photoelastic coatings. Resecting the femoral neck, reaming the canal with power drills, and rasping with an optimal size rasp, as determined by preoperative radiographic templating, produced small assembly strains, up to 300 microstrain. Insertion of an optimal-size prosthesis after preparing the femoral canal with instruments the same size as the prosthesis produced moderate assembly strains, up to 1,000 microstrain. Half a millimeter press-fit of optimal prostheses produced larger assembly strains, up to 2,000 microstrain. Half a millimeter press-fit of a prosthesis that was also one size (1.0 mm) larger than that determined to be optimum produced even larger assembly strains (2,000-6,000 microstrain) and longitudinal linear fractures in the femoral cortex. Insertion of prostheses that were smaller than the rasps produced minimal strains in the femoral cortex. The magnitude of peak strains produced by press-fitting the femoral components and the small amounts of disparity between the size of the recess and the prosthesis necessary to produce these strains show the narrow range of tolerances available to the surgeon. Cementless femoral arthroplasty requires great care in preparing the femoral canal to the appropriate size as determined from preoperative templating, using accurate and precisely toleranced instrumentation and prosthetic components in order to avoid femoral fractures, yet obtain a stable fit.
Adult↗
Techniques of extraction of well-fixed cemented and cementless implants in revision total hip arthroplasty.
Removal of well-fixed cemented and cementless components in total hip arthroplasty is technically demanding and requires a multitude of surgical techniques and tools. The wide array of modular prostheses currently in use adds to the complexity of this task. The authors describe the several techniques that facilitate extraction of well-fixed cemented and cementless total hip prostheses, as well as the bone cement. A working knowledge of these techniques should result in easier implant extraction and less bone destruction during this process.
Acetabulum↗
A fractographic investigation of PMMA bone cement focusing on the relationship between porosity reduction and increased fatigue life.
Fracture surfaces of both monotonic and fatigue loaded bone cement samples were examined to investigate the fractographic characteristics of PMMA. Classic cleavage step river patterns were observed on all monotonically loaded samples, running downstream in the direction of crack propagation. All fatigue cracks initiated at internal pores and the direction of crack propagation of many cracks was discernible. Porosity, pore size, and pore size distribution were found to affect the crack initiation and fatigue behavior of bone cement. Statistical analysis revealed a strong negative correlation between two-dimensional porosity present on the fracture surfaces and the cycles to failure. The fractographic observations of these fatigue samples elucidate one reason why porosity reduction by centrifugation or vacuum mixing increases the fatigue life of PMMA bone cement.
Biocompatible Materials↗
Bone ingrowth into a low-modulus composite plastic porous-coated canine femoral component.
Bone ingrowth into low-modulus canine femoral components made of composite plastics and porous coated with titanium fiber mesh was evaluated and compared to that found in femoral components of the same design made of titanium alloy and porous coated with titanium fiber mesh. Both types of components demonstrated extensive bone ingrowth into the porous coatings at 6 weeks and there were no differences in the histologic appearance of the tissue ingrowth in the two groups. The amount of bone that grew into the porous surface, the areal density of bone within the available pore space, and the extent of the prosthesis periphery with bone ingrowth were not significantly varied in the two different components. The results of this study show that adequate fixation of low-modulus composite femoral components porous coated with titanium fiber mesh by bone ingrowth can occur and that further investigation of these materials for femoral components may be warranted.
Animals↗
Unrecognized femoral fractures during cementless total hip arthroplasty in the dog and their effect on bone ingrowth.
Uncemented straight-stemmed proximally porous-coated femoral components were press fitted into the femoral canals of seven dogs using a rasp 0.5 mm smaller than the components (press-fit group). In seven other dogs the components were fit precisely into the femoral canals using a rasp that was the same size as the components (control group). Using this technique, all of the dogs in the press-fit group developed longitudinal fractures in the femoral cortex, while none of the dogs in the control group developed fractures. None of the fractures were recognized at operation. Two of the dogs in the press-fit group displaced the fractures at 1 week and were sacrificed. The other five dogs were bearing weight on their limbs and completed the 3-week experimental period. Follow-up radiographs of these femurs showed marked periosteal new bone formation, but did not reveal any fractures. Serial sections of these femurs showed longitudinal healing fractures in the anterior cortex. The fractures had an adverse effect on the bone ingrowth into the porous surface of the press-fit group compared to the control group without fractures, and the porous surface adjacent to the fractures was ingrown with fibrous tissue. The amount of bone ingrowth expressed as a percentage of the porous coating area measured, on average, only 3.9% in the press-fit group at 3 weeks compared to 5.6% in the control group--a statistically significant difference at P < .025. This experience in the dog illustrates the inherent risk of driving a larger femoral component into a smaller cavity prepared in the femur.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Wear particles of total joint replacements and their role in periprosthetic osteolysis.
Total joint arthroplasties with metal, plastic, and acrylic materials have revolutionized the surgical treatment of arthritis. Wear of the materials at the articulation and at the sites of attachment to skeleton, however, is a major long-term concern. The particles liberated by fatigue, abrasion, fretting, and corrosion cause foreign body granulomatous reaction in the periprosthetic tissue. This can lead to the activation of cells to produce a variety of cytokines and proteolytic enzymes that can, by complex mechanisms, cause periprosthetic osteolysis and loosening. The mechanisms involved in the production of the wear particles and their biologic consequences are discussed in this report.
Biocompatible Materials↗
The histology of the radiolucent line.
The radiographic and histological features of radiolucent areas at the cement-bone interface were correlated in 15 specimens retrieved at post-mortem from patients who had undergone cemented total hip arthroplasty, two weeks to 15 years prior to death. All but one of the components were securely fixed, as demonstrated by direct measurements of micromotion. Extensive radiolucencies were present in all but one case. In 11 of the 14 specimens with radiolucencies, histological examination showed that the radiolucent areas represented regions of osteoporosis and bone remodelling. The remodelling changes were characterised by osteoporosis, cancellisation and thinning of the endosteal cortex, and osteopenia of the trabecular bone. In two specimens the appearance of radiolucency was found to be due to fibrous tissue at the cement-bone interface and in one specimen there was a mixed picture of osteolysis and fibrosis. The study demonstrates that radiolucent lines can occur with well-fixed components and that they may commonly represent osteoporosis rather than the presence of a fibrous membrane at the cement-bone interface.
Adult↗
Thigh pain despite bone ingrowth into uncemented femoral stems.
Six porous-coated, uncemented femoral components were revised at a mean of 34.5 months for persistent thigh pain. At operation the stems were rigidly stable, difficult to extract, and showed good bony ingrowth. The four men and two women, with an average age of 59 years, all had thigh pain starting within the first year, progressive over time and unresponsive to conservative measures. These cases show that rigid fixation with good bony ingrowth does not guarantee the clinical success of a porous-coated uncemented femoral stem.
Adult↗
Acrylic fragmentation in total hip replacements and its biological consequences.
Loosening of total joint prostheses is in part related to the fragmentation of the acrylic cement mantle surrounding the prosthesis and the biologic consequences to the particulate acrylic. Fractographic studies of femoral cement mantles retrieved at revision surgery and autopsy showed frequent fractures in varying stages of development in the cement and wear at the fracture surfaces. Defects in the cement mantle, thin mantles, sharp corners on the prosthesis, separation at the cement mantle interface, and pores in the cement were frequently associated with cement fractures. The progressive fractures and wear led to the liberation of particulate acrylic debris into the surrounding tissues. The tissues at the bone-cement interface removed at revision surgery showed that a macrophage, giant-cell foreign-body granulomatous reaction occurs in response to the particulate, but not bulk cement. This tissue can produce a variety of chemical mediators of inflammation and bone resorption, and can resorb bone in organ cultures. A granulomatous tissue reaction with a very similar appearance can be produced in experimental animals using particulate-form polymethylmethacrylate (PMMA), but not the bulk form of PMMA. The tissue reaction is not mediated by the classic cell or humeral immune mechanisms. Subcutaneous injection of particulate PMMA powder into fully immunocompetent C3Hf/SED mice as well as three strains of mice with progressive immunologic deficiencies (nude/nude, SCID, and triple deficient Nu-bg-XID/SED mice) led to a foreign-body reaction in all strains at five weeks as shown by histologic and immunohistochemical examination despite the differences in immune deficiency. This, along with the scarcity of lymphocytes in the human tissues, suggests that the biologic reactions to fragmented cement can be produced and sustained by nonimmune phagocytosis and activation by macrophages and giant cells without significant contribution by the immune system.
Aged↗