Increased metal allergy in patients with failed metal-on-metal hip arthroplasty and peri-implant T-lymphocytic inflammation.

BACKGROUND: In 16 patients with revised metal-on-metal arthroplasty and peri-implant lymphocytic inflammation, we verified the role of metal hypersensitivity by patch testing (PT) and lymphocyte transformation test (LTT). METHODS: In the 16 patients with lymphocyte dominated periprosthetic inflammation, allergy history was obtained by a questionnaire, specific serum IgE to aeroallergens was measured to assess atopy, PT to standard and metal series was performed and metal sensitivity was further assessed by LTT using blood mononuclear cells. RESULTS: Revision surgery was performed because of pain (8/16), osteolysis (4/16), dislocation (3/16) and loosening of the stem (1/16). Histological examination showed perivascular infiltrates of T lymphocytes, high endothelial venules, fibrin exudation and accumulation of macrophages with drop-like inclusions. Five patients had a history of cutaneous metal allergy and atopy was found in 25% of the patients. In 13/16 patients (81%), systemic metal sensitivity was found based on PT and/or LTT. Patch test reactions were seen in 11/16 patients (69%; partly multiple reactions/patient): 7/16 to Cobalt (Co), 7/16 to Chromium (Cr), 4/16 to Nickel (Ni), and one each to Molybdenum (Mo) and Manganese (Mn). Ten of 16 patients (62%) showed enhanced LTT reactivity to metals: 7/16 to Ni, 7/16 to Co, 5/16 to Cr, 5/16 to Mo and 4/16 to Mn. CONCLUSIONS: The lymphocyte dominated peri-implant inflammation may well reflect an allergic hyper-reactivity in these patients, given the high rate of concomitantly found metal allergy. Despite the overall incidence of metal implant allergy being low, allergic reactions should be included as differential diagnosis in failed metal-on-metal arthroplasty.

An unusual lymphocytic perivascular infiltration in tissues around contemporary metal-on-metal joint replacements.

BACKGROUND: Metal-on-metal bearing surfaces have been reintroduced for use during total hip replacement. To assess tissue reactions to various types of articulations, we studied the histological appearance of periprosthetic tissues retrieved from around metal-on-metal and metal-on-polyethylene total hip replacements and compared these findings with the appearance of control tissues retrieved at the time of primary arthroplasty. METHODS: Periprosthetic tissues were obtained at the time of revision of twenty-five cobalt chromium-on-cobalt chromium, nine cobalt chromium-on-polyethylene, and ten titanium-on-polyethylene total hip arthroplasties. Control tissues were obtained from nine osteoarthritic hips at the time of primary total hip arthroplasty. Each tissue sample was processed for routine histological analysis, and sections were stained with hematoxylin and eosin. Quantitative stereological analysis was performed with use of light microscopy. RESULTS: Tissue samples obtained from hips with metal-on-metal implants displayed a pattern of well-demarcated tissue layers. A prominent feature, seen in seventeen of twenty-five tissue samples, was a pattern of perivascular infiltration of lymphocytes. In ten of the tissue samples obtained from hips with metal-on-metal prostheses, there was also an accumulation of plasma cells in association with macrophages that contained metallic wear-debris particles. The surfaces of tissues obtained from hips with metal-on-metal prostheses were more ulcerated than those obtained from hips with other types of implants, particularly in the region immediately superficial to areas of perivascular lymphocytic infiltration. The lymphocytic infiltration was more pronounced in samples obtained at the time of revision because of aseptic failure than in samples retrieved at the time of autopsy or during arthrotomy for reasons other than aseptic failure. Total-joint-replacement and surface-replacement designs of metal-on-metal prostheses were associated with similar results. Tissue samples obtained from hips with metal-on-polyethylene implants showed far less surface ulceration, much less distinction between tissue layers, no pattern of lymphocytic infiltration, and no plasma cells. The inflammation was predominantly histiocytic. Tissues retrieved from hips undergoing primary joint replacement showed dense scar tissue and minimal inflammation. CONCLUSIONS AND CLINICAL RELEVANCE: The pattern and type of inflammation seen in periprosthetic tissues obtained from hips with metal-on-metal and metal-on-polyethylene implants are very different. At the present time, we do not know the prevalence or clinical implications of these histologic findings, but we suggest that they may represent a novel mode of failure for some metal-on-metal joint replacements.

Photopenia in chronic vertebral osteomyelitis with technetium-99m-antigranulocyte antibody (BW 250/183).

UNLABELLED: Photon-deficient areas in 99mTc/111 in white blood cell (WBC) images for diagnosing vertebral osteomyelitis have been published often. This study retrospectively evaluated whether the use of 99mTc-labeled monoclonal antigranulocyte antibodies (BW 250/183) is superior to WBC and whether it offers higher specificity. METHODS: The study included 81 patients (46 men, 35 women; mean age 55 +/- 2 yr; from 1989 to 1995) with clinically suspected vertebral osteomyelitis who underwent scintigraphic imaging after intravenous injection of 555 MBq 99mTc-labeled monoclonal antigranulocyte antibodies. Forty patients suffered from osteomyelitis (20 men, 20 women; mean age 56 +/- 6 yr), 6 patients had metastases, 28 patients had spondylosis and disk herniation and 5 patients vertebral compression fractures. Diagnosis was not histologically verified in 2 patients. Planar imaging was performed at 4 and 24 hr postinjection. Histology of osteomyelitis was available in 30 patients, clinical follow-up in 10 patients. Visual uptake scores and quantitative uptake scores of the suspected areas were calculated. The results were compared to a semiquantitative histological score (high, medium, low grade) as well as to the scintigraphic scores. RESULTS: Scintigraphy showed photopenia in all patients with histologically proven vertebral osteomyelitis, independent of the grade of infection. A quantitative evaluation of 4 and 24 hr postinjection demonstrated a 58% increase of the uptake score in cases of histologically proven high-grade infections. This increase was seen predominantly in the thoracic spine but not in lumbar spine. All nonosseous paravertebral abscesses (n = 2) showed positive images and an increasing uptake over 24 hr. CONCLUSION: Paravertebral soft tissue infections can be differentiated excellently, whereas vertebral osteomyelitis, vertebral tumors or fractures can be localized, but no differentiation is possible.

[Cementless implantation of Zweymueller-Endler total endoprosthesis of the hip. Clinical, radiologic and scintigraphic follow-up of 2 years]. / Zementfreie Implantation von Zweymüller-Endler-Totalendoprothesen der Hüfte--Klinische, röntgenologische und szintigraphische Verlaufs kontrolle über zwei Jahre.

Sixty-four patients with cementless Zweymueller-Endler total endoprostheses of the hip underwent follow-up postoperatively for 2 years. In 3 patients loosening or infection occurred. In 61 patients no complications were observed. However, in 74% of these patients increasing activity uptake at the tip of the shaft was found by scintigraphy. This was associated with hypertrophy of the corticalis and/or with a marrow cavity reaction, observed radiologically. The results show that scintigraphic evaluation of cementlessly implanted Zweymueller-Endler endoprostheses of the hip must be interpreted differently compared to isoelastic or to cemented prostheses.

Longitudinal limb deficiencies and the sclerotomes. An analysis of 378 dysmelic malformations induced by thalidomide.

The pathogenesis of longitudinal reduction deformities of the limbs, or dysmelia, is still a matter of debate. Their morphological pattern was defined from a large collection of radiographs of children with dysmelia following the thalidomide disaster. We compared radiographs of 378 of these limbs with the sclerotomes which are areas of segmental sensory innervation of the limb skeleton defined by the radiation of referred pain. The pattern of dysmelia matched the sclerotomes closely in 279 limbs (73.5%). The principles of skeletal reduction in dysmelia are explained by the arrangement of the sclerotomes. The congruence between two separate and independent data sets shows that both patterns are expressions of the underlying segmental sensory innervation of the skeleton, and that the sensory nervous system is involved in the process of limb morphogenesis and teratogenesis.

Unsuccessful surgical treatment of hip dislocation in congenital sensory neuropathy with anhidrosis. A case report.

A six-year-old girl with congenital sensory neuropathy with anhidrosis (CSNA) presented with bilateral hip dysplasia and subluxation on the right side. Conservative treatment of the hips by closed reduction and a plaster cast was unsuccessful. When aged seven years the patient had an intertrochanteric varus rotation osteotomy on the right side, but subluxation was again evident after five months. A Salter-type pelvic osteotomy was carried out followed by immobilisation, but one year later subluxation was present in the right hip and dislocation in the left. At the age of nine years, the right femoral head resembled a Charcot joint, although walking ability was preserved. In patients with CSNA, surgery may not always be advisable.

Osteosarcoma in children. A study of 125 cases.

A study is presented of the aetiology and results of treatment in a group of 125 proven osteosarcomas present in children under fifteen years of age. These cases have been collected from the records of one English and six European treatment centres. There is a slight male preponderance, but the striking aetiological feature is the very high proportion of tumours of the long bones of the limbs (96 per cent). The two and a half and five year disease-free survival rates were respectively 15 and 12 per cent, with a further 9 per cent still living, but under observation for less than two and a half years. Evidence of metastasis after two and a half years is very unusual, but no child with a tumour of an axial or girdle bone lived this length of time. Although the differences in the results of the different methods of treatment employed are not statistically valid, the largest number of long survivors had been treated by early amputation, which method also provided the lowest rate of local tumour recurrences. Reasons are discussed which indicate that prompt ablation is the treatment of choice, perhaps with certain advantages in the light of recent advances in adjuvant treatment. The past situation in connection with childhood osteosarcoma certainly provides strong support for immediate carefully designed clinical trials of the new adjuvant methods cited.

Changes of concentrations of the elements Co, Cr, Sb, and Sc in tissues of persons with joint implants.

Elevated levels of Co and Cr were found in several organs of decreased implant bearers (CoCr-alloy/polyethylene joint prostheses) by means of instrumental and radiochemical neutron activation analysis as compared to normal persons. For comparative purposes, concentrations of the elements Co, Cr, Sb, and Sc were measured in heart, kidney, liver, and spleen of the patients and normal persons. For Cr determination, a new radiochemical separation technique with sufficiently low determination limit was employed. The importance of such investigations for studying possible carcinogenic effects of corrosion products and wear particles of metallic prostheses is mentioned.

Clinical wear behaviour of ultra-high molecular weight polyethylene cups paired with metal and ceramic ball heads in comparison to metal-on-metal pairings of hip joint replacements.

In the course of 30 years of hip endoprosthetics, a number of material combinations for the cups and balls of total hip prostheses have proven successful under clinical conditions. Favourably priced hip prostheses with polyethylene cups and metal balls are available for older patients with a moderate range of activity. Polyethylene wear of 100-300 microns/year is to be expected with these models. Ceramic balls (aluminium oxide for diameters 32 and 28 mm and zirconium oxide for 22 mm) paired with polyethylene cups are recommended for patients with a life expectancy of 10 to 20 years, because the expected polyethylene wear rate with this material combination is only 50-150 microns/year. In other words, the life cycle of the polyethylene cup is doubled, when it is paired with a ceramic ball. A similar polyethylene wear rate is also to be expected with oxygen-deep-hardened TiAlNb metal balls, which are currently the subject of a clinical field study. Last but not least, CoCrMoC metal-metal and Al2O3 ceramic ceramic pairings, which have the lowest wear rate of 2-20 microns/year, are available for highly active patients with a life expectancy of more than 20 years. As far as the cup-ball pairing is concerned and under the current pressure of costs, the surgeon should be able to select the optimum hip prosthesis model for every patient from these three categories.

Osseointegration of cemented and noncemented implants in artificial hip replacement: long-term findings in man.

Implant fixation is of utmost importance for pain-free function of endoprostheses. Primary fixation is achieved during implantation, whereas secondary fixation is a result of repair and bone remodelling during the healing process comparable to fracture healing. The chronologic course of the healing process follows three overlapping phases: (i) an initial phase with destruction and necroses of bone, (ii) a phase of repair with integration of the implant into the bone, and (iii) a phase of stabilization of the permanent implant bed with adaptation to load transfer and possible reactions to irritations of the interface like sepsis, mechanical instability, corrosion and degradation of implant materials, and wear products from articulating and anchoring surfaces.

[Experiences with the German Endoprosthesis Register]. / Erfahrungen mit dem Endoprothesenregister.

The German Endoprostheses Register started its documentation of primary and revision surgery on major joints in 1997. About 7000 primary arthroplasties and 1100 revisions on hip joints as well as 3000 primary arthroplasties and 250 revisions on knee joints are registered annually by 41 hospitals, which amounts to 60% in primary or 80% in revision surgery of the Swedish arthroplasty register. 95% of the revisions are performed on implants which have not been primarily operated on by the hospitals enrolled to the register, normally recruiting the classical "lost-to-follow-up-cases". Especially the removed implants show a conspicuous diversity of models. More than 10 specimens were removed in only 24 of 173 different types of hip-stems and 21 of 133 different types of hip-sockets. Thus, in order to cover not only a small number of types of implants by statistical analysis, large numbers of surgery have to be registered to yield case-numbers which can not be achieved by registers of small countries like the Scandinavian. Germany with approximately 1900 relevant clinical departments owns a slumbering potential that could easily be recruited.

[Exposure of surgical/orthopedic operating room personnel to monomer vapors during the use of bone cements--review of the literature and report of experiences]. / Exposition des chirurgischen/orthopädischen OP-Personals durch Monomer-Dämpfe bei der Anwendung von Knochenzementen--Literaturstudie und Erfahrungsbericht.

PMMA bone cements are used for the fixation of artificial joint replacements. During their application in the operating theater, a small amount of the monomer evaporates. Operating room staff and surgeons are often not adequately informed about the negative properties and the effects on health of these vapours. Basic information about monomers and their toxicity, and safety regulations have been compiled. On the basis of present knowledge, the authors do not regard the repeated use of bone cement throughout the course of a day to represent a hazard to health.

[Clinical Wear Behaviour of UHMW Polyethylene Cups Paired with Metal and Ceramic Ball Heads in Comparison to Metal-on-Metal Pairings of Hip Joint Replacements.]. / Klinisches Verschleissverhalten von UHMW Polyethylen Pfannen in Paarung mit Metall und Keramik Kugeln im Vergleich zur Metallgegen-Metall Paarung beim Hüftgelenkersatz.

In the course of 30 years' hip endoprosthetics, a number of material combinations for the cups and balls of total hip prostheses have proven successful under clinical conditions. Favourably priced hip prostheses with polyethylene cups and metal balls are available for very old patients with a moderate range of activity. Polyethylene wear of 100-300 microm per year is to be expected with these models. Ceramic balls (aluminium oxide for diameters 32 and 28 mm and zirconium oxide for 22 mm) paired with polyethylene cups are recommended for patients with a life expectancy of 10 to 20 years, because the expected polyethylene wear rate with this material combination is only 50-150 microm per annum. In other words, the life cycle of the polyethylene cup is doubled, when it is paired with a ceramic ball. A similar polyethylene wear rate is also to be expected with oxygen-deephardened TiAlNb metal balls, which are currently the subject of a clinical field study. Last but not least, CoCrMoC metal/metal and AI2O3 ceramic/ceramic pairings, which have the lowest wear rate of 2 to 20 microm/year. are available for highly active patients with a life expectancy of more than 20 years. As far as the cup/ball pairing is concerned and under the current pressure of costs, the surgeon should be able to select the optimum hip prosthesis model for every patient from these three categories.