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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Archives of orthopaedic and trauma surgery 106 (1987), S. 94-101 
    ISSN: 1434-3916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Twelve surface replacement arthroplasties were performed on the hips of ten mongrel dogs using scaled-down replicas of the Wagner prosthesis. The contralateral hips and two further animals served as nonoperated controls. Animals were killed 5 months postoperatively. Clinical, radiological, histological and fluorochrome-labelling studies were employed to assess the bony and soft tissue reaction to resurfacing arthroplasty. There was no clinical or radiographic evidence of prosthetic loosening. Histological examination disclosed a thick foreign body and chronic inflammatory membrane containing acrylic cement and polyethylene wear particles at the bone-cement interface of both components. Generally, the bone marrow and trabecula were viable. There was evidence of increased bony remodelling and new bone formation in the subchondral area. The similarity between the above findings and those of aseptic component loosening in man suggests a mechanism whereby wear debris initiate a biological foreign body reaction culminating in component loosening.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Archives of orthopaedic and trauma surgery 104 (1985), S. 150-154 
    ISSN: 1434-3916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to assess the response of bone to low-viscosity polymethylmethacrylate, CMW or Simplex acrylic cement was digitally packed while in a doughy state into drill holes in the proximal diaphysis in each of four long bones (humeri and tibiae) of mongrel dogs. Histological assessment was performed in areas of minimal load at the interface between the viscoelastic bone and the acrylic cement. Decalcified and undecalcified sections were evaluated and a remodeling or activity index calculated. Fluorescent labeling studies were performed in order to assess bone growth. Animals were killed at 2, 4, or 5 months. Histological analysis showed a thin connective-tissue membrane containing scattered giant cells and histiocytes at the bone-cement interface. Inflammation was not an important facet of this response. The marrow and trabecular bone were viable, except for scattered localized areas of marrow necrosis and fibrosis immediately adjacent to the cement. The bone adjacent to the cement showed a lower remodeling or activity index, fewer fluorescent bands, and smaller distances between successive bands, suggesting decreased bone formation and turnover. The etiology of these findings may include vascular disturbance secondary to disruption of the cortical and marrow circulation, temperature effects during cement polymerization, and/or chemical effects from the acrylic monomer.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Archives of orthopaedic and trauma surgery 110 (1991), S. 123-126 
    ISSN: 1434-3916
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Fourteen mature female New Zealand White rabbits underwent implantation of Simplex polymethylmethacrylate (PMMA) powder or particulate (average 67 μn) ultrahigh-molecular-weight polyethylene (UHMWPE) through a drill hole in the proximal right tibia. The left tibia functioned as a prepared but nonimplanted control. Animals were killed after 16 weeks. Histological examination of the bone-implant interface in the particulate PMMA group disclosed a florid foreign-body reaction with the presence of giant cells and histiocytes. The particulate UHMWPE group demonstrated positively bire-fringent UHMWPE fragments, rimmed by foreign-body giant cells and histiocytes, embedded in a loose connective tissue stroma. UHMWPE interfaces were thicker and contained more histiocytes and fibrocytes; PMMA interfaces contained more marrow cells and lymphocytes. This study underscores the importance of biomaterial debris in the process of aseptic loosening of cemented joint arthroplasties.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-0827
    Keywords: Key words: Interleukin-6 — MG-63 cells — Titanium particles — Signal transduction — Transcription factor.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract. Orthopaedic wear debris induces release of bone-resorbing factors from macrophages and fibroblasts. However, the extent to which elemental metallic particles induce bone cells to express factors contributing to implant loosening remains unclear. This study showed that exposure of MG-63 osteoblast-like cells to titanium particles at a concentration of 0.30% v/v resulted in a 15-fold increase in IL-6 release into the culture medium after 24 hours, when compared with cells without particles. Northern blots revealed that exposure of MG-63 cells to titanium particles at a concentration of 0.30% v/v for 24 hours increased IL-6 mRNA signal levels by 9.6-fold, when compared with control cultures. Pretreatment of MG-63 cells with cytochalasin B prevented the particle-induced increase of IL-6 expression but did not alter the basal level of IL-6 release from cells cultured in the absence of particles. The protein kinase C inhibitor, H7, and the serine/threonine kinase inhibitor, genistein, abolished the particle-induced increase in IL-6 release at a concentration of 100 μM for each compound. In contrast, an inhibitor of protein kinase A, HA1004, had no effect on the particle-induced increase in IL-6 release. The transcription factors, nuclear factor IL-6 and nuclear factor kappa B, translocated into the nucleus within 1 hour of particle exposure. This study showed that osteoblast-like cells respond to titanium particles through increased expression of the proinflammatory cytokine, IL-6, in a process requiring phagocytosis and intracellular signaling pathways. These results suggest that osteoblasts play a direct role in implant loosening because of localized release of soluble mediators such as interleukin-6.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Skeletal radiology 10 (1983), S. 201-204 
    ISSN: 1432-2161
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Clinical Anatomy 4 (1991), S. 123-128 
    ISSN: 0897-3806
    Keywords: surgical approach ; cadaveric studies ; dissection ; Life and Medical Sciences ; Miscellaneous Medical
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: The purpose of this anatomical study was to determine the location and course of the superior gluteal nerve in relation to the superior pole of the greater trochanter and the surgical pathway for the direct lateral approach to the hip joint. Twenty adult cadaveric lower extremities in ten patients (five male and five female) were carefully dissected to identify the location of the superior gluteal nerve and its terminal branches. The most inferior branch of the superior gluteal nerve was variable, could be asymmetrical, and was located 3-6.5 cm above the superior tip of the greater trochanter. During the lateral approach to the hip, it is recommended that the proximal extension be limited to 3 cm above the most superior aspect of the greater trochanter.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Biomaterials 3 (1992), S. 59-62 
    ISSN: 1045-4861
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The methods usually employed for the histological processing of orthopaedic specimens of cemented joint arthroplasties involve treatment with methacrylate monomer and organic solvents which dissolve the polymethylmethacrylate cement. This may distort the intimate relationship of the cell layers along the surface of the interface between the bone and the cemented implant. The authors report on a technique for the processing and embedding of cemented orthopaedic implants which permits preservation of the polymethylmethacrylate cement. The method utilizes a modification of Spurr's low viscosity epoxy resin and avoids the use of solvents such as acetone. Undecalcified sections of cemented joint replacements from animal studies and human specimens have been prepared using this method. It is possible to use these sections for detailed histomorphologic and histomorphometric analysis of bone tissue and of the soft tissue membrane adjacent to the polymethylmethacrylate cement.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1045-4861
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: To assess new and existing materials for total joint arthroplasty, the authors performed a comprehensive histomorphologic and morphometric analysis of bone to cylinders implanted transversely in the proximal tibia of mature New Zealand white rabbits. Four sterile, cylindrical implants measuring 6.1 × 3.8mm were manually inserted through drill holes in both tibiae with a „line-to-line fit.“ The materials tested included: ASTM F-75 cast cobalt-chrome-molybdenum alloy, commercially pure titanium wrought zirconium-2.5 niobium alloy, zirconium oxide coated zirconium-2.5 niobium alloy, wrought titanium-13 niobium-13 zirconium alloy, and nitrogen diffusion hardened titanium-6 aluminum-4 vanadium alloy. Control animals with or without drill holes were included. The animals were killed by barbiturate overdose 6 months postoperatively. The upper tibiae were harvested and processed for undecalcified histologic sections that were stained with toluidine blue. The sections were examined by an investigator blind to the identity of the implanted materials. A full necropsy was also performed.A collar of lamellar bone, of variable length and thickness, continuous with the original cortex formed a buttress around the implants. There was no evidence of foreign body or inflammatory reaction. The marrow was slightly fatty, but cells of allthree hematopoietic lines were identifiable. The materials investigated had the following ranking in decreasing order of bone contact: Ti-13Nb-13Zr 〉 nitrogen hardened Ti-6Al-4V 〉 C.P. titanium 〉 Zr 2.5Nb 〉ZrO2 coated Zr-2.5Nb 〉 cast Co—Cr alloy. The difference between the groups was statistically significant (p = 0.05). For the variable „average bone layer thickness“ the ranking in decreasing order was: nitrogen hardened Ti-6Al-4V alloy = C.P. titanium 〉 Ti-13Nb-13Zr 〉 ZrO2/Zr-2.5Nb 〉 Zr-2.5Nb 〉 cast Co—Cr alloy (p = 0.19). For the variable „average bone layer thickness in bone contact regions,“ the ranking of the values, in decreasing order were: nitrogen hardened Ti-6Al-4V 〉 C.P. titanium 〉 ZrO2 coated Zr-2.5Nb 〉 Ti-13Nb-13Zr 〉Zr-2.5 Nb 〉 cast Co—Cr alloy (p = 0.02). The final necropsy reports of the animals identified no adverse findings that were concentrated to any particular implant group. The new, lower modulus materials Ti-13Nb-13Zr and Zr-2.5 Nb, and nitrogen hardened Ti-6Al-4V appear to have a similar or superior bone response to Co—Cr alloy when implanted in the rabbit tibia model. © 1993 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: This study examines the histological effects of different sizes of polyethylene particles implanted into the rabbit tibia. Seventeen mature New Zealand white female rabbits were allocated into three groups. Group 1 (5 rabbits) received polyethylene particles averaging approximately 16 μm in diameter, implanted into the right proximal tibia through a drill hole. Group 2 (5 animals) received particles averaging 26 μm, and Group 3 (7 rabbits) received particles averaging 67 μm. The left tibia was drilled but not implanted. Animals were sacrificed after 16 weeks. Histological analysis disclosed decreased hematopoietic activity within the left tibial drill hole. In all groups, the right tibia demonstrated positively birefringent polyethylene particles surrounded by, and within (smaller particles), histiocytes and giant cells in a fibrous tissue stroma. Statistical analysis disclosed more fibrocytes and less marrow cells at the interface of Group 3 (largest particles) compared to Group 1 and 2. Larger polyethylene particles, being less readily phagocytosed, appear to produce more fibrous encapsulation, compared to particles of a smaller size. The histological reaction stimulated by the different sizes of polyethylene particles resembled the membrane surrounding loose joint arthroplasties in humans.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 24 (1990), S. 1539-1549 
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Twenty-eight mature New Zealand white female rabbits were allocated into 4 groups of 7 rabbits. Group 1 received a coiled wire of cobalt chrome alloy (Vitallium) (16 gauge × 1 cm). Group 2 received an equal weight of cobalt chrome particles averaging 15.4 μm in diameter. Group 3 received a coiled wire implant of commercially pure (C.P.) titanium (16 gauge × 1 cm). Group 4 received the same weight of C.P. titanium particles averaging 3.8 μm. The implants were placed through a drill hole in the proximal right tibia; the left tibia served as a prepared but nonimplanted control. The animals were killed after 16 weeks and quantitative histology was performed on undecalcified sections of the implant area. Bulk cobalt chrome and titanium implants were surrounded by a thin, incomplete, fibrous tissue layer with decreased numbers of cells. Trabeculae of bone were present within this connective tissue envelope. Fingerlike projections of bone enveloped the implant where it abutted endosteal bone. Clumped and loosely scattered cobalt chrome and titanium particles were surrounded by a minimal amount of fibrous connective tissue. Smaller particles were present within cells. Hematopoietic cells abutted the bulk or particulate implants directly. There was no evidence of acute or chronic inflammation or foreign body reaction. These results should be contrasted with those of Howie et al. in which intraarticular cobalt chrome particles stimulated a rapid proliferation of macrophages and synovial degeneration after 1 week. This may be due to a direct toxic effect of metals in an intra-articular environment, the smaller particle size used in that study, or to abrasive injury to the hyaline cartilage and subsequent synovitis. Our results underscore the general inert properties of these metals in the short term, when implanted into bone in the sizes and physical forms chosen.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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