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Total Hip Arthroplasty (total + hip_arthroplasty)
Selected AbstractsTETRAPLEGIA IN A PATIENT WITH HUGE HETEROTOPIC OSSIFICATION OF THE HIP JOINT AFTER TOTAL HIP ARTHROPLASTY: ADDITION OR REINFORCEMENT OF HANDICAPSJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 8 2003Satoshi Ishikawa MD No abstract is available for this article. [source] Variation in the TNF Gene Promoter and Risk of Osteolysis After Total Hip ArthroplastyJOURNAL OF BONE AND MINERAL RESEARCH, Issue 11 2003FRCS, J Mark Wilkinson PhD Abstract Genetic factors may influence implant failure caused by osteolysis after THA. In an association study of 481 subjects after THA, we found that carriage of the TNF - 238A allele was associated with an increased incidence of osteolysis versus noncarriage (odds ratio, 1.7) and was independent of other risk factors. Genetic and environmental factors influence implant survival after THA. Introduction: Tumor necrosis factor (TNF) is thought to play a role in osteolysis, the major cause of implant failure after total hip arthroplasty (THA). Natural sequence variations at ,238 and ,308 in the TNF gene promoter are associated with differences in susceptibility to several TNF-mediated diseases. We tested whether these polymorphisms are associated with osteolysis after THA. Materials and Methods: A total of 481 whites (214 with failed versus 267 with intact implants) were recruited 11.7 ± 4 years after cemented THA. Genomic DNA was extracted from peripheral blood and genotyped for the ,238 and ,308 polymorphisms using the Taqman 5, nuclease method. Healthy controls (n = 500) from the background population were also genotyped to establish the local prevalence of these alleles. Results: The carriage of ,238A was 8.8% in the background population and 10.9% in the THA controls (p > 0.05). Carriage of ,238A in the osteolysis group was 17.3% (odds ratio, 1.7; 95% CI, 1.0,2.9). Carriage was highest (20.5%) in patients with more widespread osteolysis (OR, 2.1; 1.2,3.8). The association of ,238A with osteolysis was independent of other risk factors for osteolysis (logistic regression analysis: OR, 1.8; 1.0,3.2). Carriage of ,308A was not associated with osteolysis. Conclusion: Genetic, as well as environmental factors, influence implant failure after THA. Whether the TNF - 238 polymorphism causes a biological change that predisposes to loosening or is in linkage disequilibrium with such a locus is not yet known. [source] Metaphyseal-Loading Anterolaterally-Flared Femoral Stem in Cementless Total Hip Arthroplasty: Five- to Eleven-Year Follow-Up EvaluationARTIFICIAL ORGANS, Issue 5 2010Hideo Kawahara Abstract Using a nonlinear three-dimensional finite element analysis simulating loading conditions, we designed a new type of proximal-fitting, anterolaterally-flared, arc-deposit hydroxyapatite-coated anatomical femoral stem (FMS-anatomic stem; Japan Medical Materials, Osaka, Japan) for cementless total hip arthroplasty (THA) for Japanese patients with dysplastic hip osteoarthritis. The aim of the present study was to analyze the clinical and radiographic outcomes of the new stem. We reviewed 143 consecutive patients (164 hips; 13 men, 14 hips; 130 women, 150 hips; age at surgery, 56.6 ± 7.6 years, mean ± SD, range, 30,74) who underwent cementless THA using the FMS-anatomic stem at a single institution, with a follow-up period of 7.6 ± 1.6 years (range, 5.3,11.0). Harris Hip score improved from 46.1 ± 12.6 before surgery to 90.0 ± 8.9 points post-THA. The 7.6-year survival rate of the stem was 99.0% after revision for aseptic loosening. Radiographs at follow-up confirmed the stability of the femoral stems within the femoral canal in all cases, with sufficient bone ingrowth. None of the patients had subsidence of the stem exceeding 2.0 mm within the femoral canal or changes in varus or valgus position of more than 2.0°. The FMS-anatomic stem provided excellent results in patients with dysplastic hip osteoarthritis. Our analysis confirmed reduced radiolucency around the stem in Gruen zones, minimal subsidence, appropriate stress shielding, and promising medium-term stability within the femoral canal in our patients. [source] Rapidly destructive arthropathy of the hip in haemophiliaHAEMOPHILIA, Issue 1 2001N. Ishiguro The aetiology of rapidly destructive arthropathy is still being debated. We report a 48-year-old male haemophiliac who exhibited hip arthropathy that was similar to rapidly destructive arthropathy. The hip joint was destroyed 6 months after the onset of symptoms. Results of clinical and laboratory examinations did not show any features of neuropathic, inflammatory or septic arthropathy, except for coagulopathy. Magnetic resonance imaging revealed an expansive joint capsule with synovial proliferation in the affected hip joint. Total hip arthroplasty was carried out successfully with total resection of the synovial tissue and joint capsule. A histological examination revealed bone necrosis, nonspecific inflammation, haemosiderosis and synovial hypertrophy. The recurrent bleeding into the hip joint induced pronounced inflammation with synovial proliferation and acute destruction of bony tissue. [source] Patients undergoing total hip arthroplasty: a perioperative pain experienceJOURNAL OF CLINICAL NURSING, Issue 4 2006Margareta Warrén Stomberg PhD Aim., The aim was to evaluate patient's perioperative pain experience after total hip replacement and patients' satisfaction with pain management. Background., Total hip arthroplasty is a common surgical procedure intended to reduce pain and return patients to better function. Realistic expectations about total hip arthroplasty is important for optimal postoperative recovery and the information must be adapted to fit the individual patient. Methods., A descriptive design was used comparing patients outcome data. Pitman's test was used for statistical analyses. Adult patients (n = 112) undergoing surgical hip replacement procedures answered a 17-item questionnaire on the fourth postoperative day. The questionnaire included given alternatives and visual analogue scales (0,100 mm) for the pain assessment. Result., The patients' postoperative pain experience after hip replacement surgery was in average low, 33·1 mm on a 100 mm visual analogue scale. Patient's pain experience was reported to be highest on the first postoperative day for most of the patients. The preoperative pain experience tends to be higher than the postoperative pain experience. Older patients reported less average pain level postoperatively. Satisfaction with pain management was high. Conclusion., The pain experience tends to be higher preoperatively than postoperatively. Patients who reported a higher pain experience postoperatively reported that their pain experience was significant higher than preoperative expected. Relevance to practice., It is important for the postoperative outcome measure that the patients have a realistic expectation of pain experiences after total hip arthroplasty. The nurse is one of the staff members responsible for information to the individual patient. [source] Transfer of metallic debris from the metal surface of an acetabular cup to artificial femoral heads by scraping: Comparison between alumina and cobalt,chrome headsJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2008Chong Bum Chang Abstract We aimed to investigate the transfer of metal to both ceramic (alumina) and metal (cobalt,chrome) heads that were scraped by a titanium alloy surface under different load conditions. The ceramic and metal heads for total hip arthroplasties were scraped by an acetabular metal shell under various loads using a creep tester. Microstructural changes in the scraped area were visualized with a scanning electron microscope, and chemical element changes were assessed using an energy dispersive X-ray spectrometry. Changes in the roughness of the scraped surface were evaluated by a three-dimensional surface profiling system. Metal transfer to the ceramic and metal heads began to be detectable at a 10 kg load, which could be exerted by one-handed force. The surface roughness values significantly increased with increasing test loads in both heads. When the contact force increased, scratching of the head surface occurred in addition to the transfer of metal. The results documented that metallic debris was transferred from the titanium alloy acetabular shell to both ceramic and metal heads by minor scraping. This study suggests that the greatest possible effort should be made to protect femoral heads, regardless of material, from contact with metallic surfaces during total hip arthroplasty. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source] Human monocyte response to retrieved polymethylmethacrylate particlesJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 3 2002Masatsugu Miyaguchi Abstract The purpose of this study was to compare retrieved polymethylmethacrylate (PMMA) particles from failed total hip arthroplasties in terms of size, shape, and the response of human monocytes with commercially available particles. PMMA particles were isolated from peri-implant tissues of five failed cemented total hip arthroplasties using tissue digestion and a sucrose density gradient technique. Prepolymerized cement powder and those from which barium sulfate had been removed were examined for comparison. After exposure of peripheral human monocytes to PMMA particles, tumor necrosis factor-, and interleukin-6 in medium were measured by using enzyme-linked immunosorbent assays. Image analysis revealed that retrieved particles were larger (retrieved: 1.24 ,m; prepolymerized cement powder: 0.83 ,m; barium sulfate-free powder: 0.87 ,m) and were more irregular in shape and rougher than commercially available particles. Cytokine release was increased by all PMMA particle species. However, commercially available PMMA particles stimulated the release of necrosis factor-, and interleukin-6 more strongly than did retrieved particles at very high doses. The observed difference in monocyte response might be due to the volume of the challenged particles. Another possible reason for the difference might be alteration of the surface chemistry of particles in situ and the difference in surface morphology between them. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 331,337, 2002 [source] The superolateral approach for aspiration of total hip arthroplastiesJOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 3 2000Wendy E McCurdy SUMMARY Hip aspiration for exclusion of infection is a common procedure prior to revision arthroplasty. Some patients with total hip arthroplasties develop superomedial migration of the prosthesis, while others can have extensive heterotopic bone formation. The traditional approaches may be contraindicated due to overlying bowel or bone anterior/lateral to the prosthesis. These patients are candidates for the superolateral approach. With the patient supine marks are made on the skin at (i) the greater trochanter and (ii) a superior site that aligns with the neck of the prosthesis and soft-tissue window. The needle enters the lateral skin parallel to the table top. Usually only one pass is necessary. [source] Total joint arthroplasty in haemophiliaHAEMOPHILIA, Issue 5 2000Beeton In severely affected haemophilic patients arthropathy is a common problem which can lead to considerable pain and functional deficit. Surgical management, including total joint arthroplasty, can be undertaken if conservative management fails. A search of the literature showed that a number of studies describing the use of total knee arthroplasty (TKA) and total hip arthroplasty (THA) in haemophilia have been published, whereas shoulder, elbow and ankle arthroplasties are confined to case reports. This paper reviews the functional outcome of arthroplasty in the different joints, the postoperative and long-term complications, and the impact of HIV. Although complications are commonly described and the surgery is technically demanding, the results suggest that arthroplasty, particularly of the hip and knee, can be a valuable option in the management of severe haemophilic arthropathy. [source] The effect of desmopressin on blood loss in patients with rheumatoid arthritis undergoing hip arthroplastyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 7 2010K. A. LEINO Background: Blood loss is an important issue for patients with rheumatoid arthritis undergoing hip surgery. We hypothesised that intraoperative desmopressin treatment would result in a reduction in blood loss in rheumatoid patients undergoing total hip arthroplasty. Methods: Seventy-five patients scheduled for elective total hip arthroplasty were randomised to three groups to receive 0.4 ,g/kg desmopressin (D 0.4), 0.2 ,g/kg desmopressin (D 0.2) or placebo intraoperatively in a double-blind fashion. Blood transfusions were based on calculated safe allowable blood loss and haemoglobin measurements (trigger 90 g/l, 5.59 mmol/l). The primary endpoint was the total blood loss measured till the end of the fourth post-operative day. Secondary endpoints included red cell transfusion requirements and haemoglobin. Results: Total blood loss during the study period was not significantly different between the groups (D 0.4 1829 ± 1068; D 0.2 2240 ± 843 and placebo 2254 ± 1040 ml; P= 0.50). The total amount of red cell transfusions was fewer in group D 0.4 (3.6 ± 1.6 U) when compared with D 0.2 (4.4 ± 1.7 U; P=0.009) and placebo (4.5 ± 2.0 U; P= 0.011) groups. Haemoglobin concentration was lower in the placebo group in the first (5.42 ± 1.16 vs. 5.98 ± 0.47 mmol/l; P=0.033) and the second (6.28 ± 0.66 vs. 6.69 ± 0.47 mmol/l; P=0.033) post-operative mornings compared with group D 0.4. Conclusion: Despite a lack of difference in the primary outcome, total blood loss, intraoperative administration of 0.4 ,g/kg desmopressin resulted in fewer total red cell transfusion requirements in rheumatoid patients undergoing total hip arthroplasty when compared with 0.2 ,g/kg treatment and placebo. [source] A test of two methods of radiographically deriving long bone cross-sectional properties compared to direct sectioning of the diaphysisINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 5 2002Jay T. Stock Abstract Numerous studies have made use of cross-sectional geometry to describe the distribution of cortical bone in long bone diaphyses. Several methods can be used to measure or estimate cross-sectional contours. Direct sectioning (DSM) of the diaphysis is not appropriate in most curatorial contexts, and is commonly substituted with methods based upon bi-planar radiography: a latex cast method (LCM) or an eccentric elliptical method (EEM). Previous studies have demonstrated that the EEM provides accurate estimates of area measurements, while providing less accurate estimates of second moments of area (Biknevicius & Ruff, 1992; Runestad et al., 1993; Lazenby, 1997). The LCM has been commonly employed, as a way to estimate section contours more accurately, yet the validity of this method has not been adequately documented. This study measures the agreement of these methods against DSM of long bone diaphyses using 21 sections of canine tibiae derived from a study of total hip arthroplasty. The accuracy and agreement of these methods is evaluated using reduced major axis regression, paired sample t-tests and tests for agreement (Bland & Altman, 1986). The results illustrate that the LCM provides a reasonable estimate of cross-sectional dimensions, producing cross-sectional properties that are on average within 5% of properties derived from the DSM. The EEM is found to provide adequate estimates of true cross-sectional areas, but poor estimates of second moments of area. The use of the LCM is supported for all cross-sectional properties, but the EEM is only accurate in total area, cortical area and percent cortical area estimates. Copyright © 2002 John Wiley & Sons, Ltd. [source] Wear particle analysis of highly crosslinked polyethylene isolated from a failed total hip arthroplastyJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2008Yukihide Minoda Abstract Polyethylene wear particles are one of the most important factors affecting the results of total hip arthroplasty (THA). To reduce wear generation and to achieve better long-term results of THA, highly crosslinked polyethylene (HXPE) has recently been introduced and come into wide use. Thus far, however, there have been no reports on in vivo analysis of HXPE wear particles. We isolated HXPE wear particles from periprosthetic tissue of a failed THA and analyzed using scanning electron microscope. The number of particles was 5.33 × 107 g,1. Particle size (equivalent circle diameter) was 0.66 ± 0.40 ,m (mean ± standard error). Aspect ratio and roundness were 1.37 ± 0.26 and 1.44 ± 0.67, respectively. All the particles were round shaped, and "fibrils" or "shreds" were not detected. Thus far, this was the first report on in vivo wear particle analysis of HXPE. HXPE generated less, smaller, and rounder particles, compared with the corresponding reported values for particles generated from conventional polyethylene. These characteristics might affect macrophage response, osteolysis, and long-term results of THA with HXPE. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source] Vitamin D Receptor Expression in Human Muscle Tissue Decreases With Age,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 2 2004HA Bischoff-Ferrari Abstract Intracellular 1,25-dihydroxyvitamin D receptor (VDR) is expressed in human skeletal muscle tissue. However, it is unknown whether VDR expression in vivo is related to age or vitamin D status, or whether VDR expression differs between skeletal muscle groups. Introduction: We investigated these factors and their relation to 1,25-dihydroxyvitamin D receptor (VDR) expression in freshly removed human muscle tissue. Materials and Methods: We investigated biopsy specimens of the gluteus medius taken at surgery from 20 female patients undergoing total hip arthroplasty (mean age, 71.6 ± 14.5; 72% > 65 years) and biopsy specimens of the transversospinalis muscle taken at surgery from 12 female patients with spinal operations (mean age, 55.2 ± 19.6; 28% > 65 years). The specimens were obtained by immunohistological staining of the VDR using a monoclonal rat antibody to the VDR (Clone no. 9A7). Quantitative VDR expression (number of VDR positive nuclei) was assessed by counting 500 nuclei per specimen and person. Serum concentrations of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were assessed at day of admission to surgery. Results: All muscle biopsy specimens stained positive for VDR. In the univariate analyses, increased age was associated with decreased VDR expression (r = 0.5: p = 0.004), whereas there were no significant correlations between VDR expression and 25-hydroxyvitamin D or 1,25-dihydroxyvitamin D levels. VDR expression did not differ between patients with hip and spinal surgery. In the multivariate analysis, older age was a significant predictor of decreased VDR expression after controlling biopsy location (gluteus medius or the transversospinalis muscle), and 25-hydroxyvitamin D levels (linear regression analysis: ,-estimate = ,2.56; p = 0.047). Conclusions: Intranuclear immunostaining of the VDR was present in muscle biopsy specimens of all orthopedic patients. Older age was significantly associated with decreased VDR expression, independent of biopsy location and serum 25-hydroxyvitamin D levels. [source] Variation in the TNF Gene Promoter and Risk of Osteolysis After Total Hip ArthroplastyJOURNAL OF BONE AND MINERAL RESEARCH, Issue 11 2003FRCS, J Mark Wilkinson PhD Abstract Genetic factors may influence implant failure caused by osteolysis after THA. In an association study of 481 subjects after THA, we found that carriage of the TNF - 238A allele was associated with an increased incidence of osteolysis versus noncarriage (odds ratio, 1.7) and was independent of other risk factors. Genetic and environmental factors influence implant survival after THA. Introduction: Tumor necrosis factor (TNF) is thought to play a role in osteolysis, the major cause of implant failure after total hip arthroplasty (THA). Natural sequence variations at ,238 and ,308 in the TNF gene promoter are associated with differences in susceptibility to several TNF-mediated diseases. We tested whether these polymorphisms are associated with osteolysis after THA. Materials and Methods: A total of 481 whites (214 with failed versus 267 with intact implants) were recruited 11.7 ± 4 years after cemented THA. Genomic DNA was extracted from peripheral blood and genotyped for the ,238 and ,308 polymorphisms using the Taqman 5, nuclease method. Healthy controls (n = 500) from the background population were also genotyped to establish the local prevalence of these alleles. Results: The carriage of ,238A was 8.8% in the background population and 10.9% in the THA controls (p > 0.05). Carriage of ,238A in the osteolysis group was 17.3% (odds ratio, 1.7; 95% CI, 1.0,2.9). Carriage was highest (20.5%) in patients with more widespread osteolysis (OR, 2.1; 1.2,3.8). The association of ,238A with osteolysis was independent of other risk factors for osteolysis (logistic regression analysis: OR, 1.8; 1.0,3.2). Carriage of ,308A was not associated with osteolysis. Conclusion: Genetic, as well as environmental factors, influence implant failure after THA. Whether the TNF - 238 polymorphism causes a biological change that predisposes to loosening or is in linkage disequilibrium with such a locus is not yet known. [source] Adding Gabapentin to a multimodal regimen does not reduce acute pain, opioid consumption or chronic pain after total hip arthroplastyACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 8 2009H. CLARKE Background: Gabapentin (GPN) is effective in reducing post-operative pain and opioid consumption, but its effects with regional anesthesia for total hip arthroplasty (THA) are not known. We designed this study to determine whether (1) gabapentin administration reduces pain and opioid use after THA using a multimodal analgesic regimen including spinal anesthesia; (2) pre-operative administration of gabapentin is more effective than post-operative administration. Methods: After REB approval and informed consent, 126 patients were enrolled in a double-blinded, randomized-controlled study. Patients received acetaminophen 1 g per os (p.o.), celecoxib 400 mg p.o. and dexamethasone 8 mg intravenously, 1,2 h pre-operatively. Patients were randomly assigned to one of three treatment groups (G1: Placebo/Placebo; G2: GPN/Placebo; G3: Placebo/GPN). Patients received gabapentin 600 mg (G2) or placebo (G1 and G3) 2 h before surgery. All patients had spinal anesthesia [15 mg (3cc) of 0.5% hypobaric bupivacaine with 10 ,g of fentanyl]. In the post-anesthetic care unit, patients received gabapentin 600 mg (G3) or placebo (G1 and G2). On the ward, patients received acetaminophen 1000 mg p.o. q6h, celecoxib 200 mg p.o. q12h and a morphine PCA device. Patients were interviewed 6 months post-surgery to determine the incidence and severity of chronic post-surgical pain. Results: Mean±SD cumulative morphine (mg) consumption (G1=49.4±24.8, G2=47.2±30.1 and G3=56.1±38.2) at 48 h and pain scores at 12, 24, 36 and 48 h post-surgery were not significantly different among the groups [G1 (n=38), G2 (n=38) and G3 (n=38)]. Side effect profiles were similar across groups. Six months after surgery, the number of patients who reported chronic post-surgical pain (G1=10, G2=12 and G3=9) and the severity of the pain (G1=4.2±2.9, G2=4.1±2.2 and G3=4.9±2.2) did not differ significantly among the groups (P>0.05). Conclusions: A single 600 mg dose of gabapentin given pre-operatively or post-operatively does not reduce morphine consumption or pain scores in hospital or at 6 months after hip arthroplasty within the context of spinal anesthesia and a robust multimodal analgesia regimen. [source] Patients undergoing total hip arthroplasty: a perioperative pain experienceJOURNAL OF CLINICAL NURSING, Issue 4 2006Margareta Warrén Stomberg PhD Aim., The aim was to evaluate patient's perioperative pain experience after total hip replacement and patients' satisfaction with pain management. Background., Total hip arthroplasty is a common surgical procedure intended to reduce pain and return patients to better function. Realistic expectations about total hip arthroplasty is important for optimal postoperative recovery and the information must be adapted to fit the individual patient. Methods., A descriptive design was used comparing patients outcome data. Pitman's test was used for statistical analyses. Adult patients (n = 112) undergoing surgical hip replacement procedures answered a 17-item questionnaire on the fourth postoperative day. The questionnaire included given alternatives and visual analogue scales (0,100 mm) for the pain assessment. Result., The patients' postoperative pain experience after hip replacement surgery was in average low, 33·1 mm on a 100 mm visual analogue scale. Patient's pain experience was reported to be highest on the first postoperative day for most of the patients. The preoperative pain experience tends to be higher than the postoperative pain experience. Older patients reported less average pain level postoperatively. Satisfaction with pain management was high. Conclusion., The pain experience tends to be higher preoperatively than postoperatively. Patients who reported a higher pain experience postoperatively reported that their pain experience was significant higher than preoperative expected. Relevance to practice., It is important for the postoperative outcome measure that the patients have a realistic expectation of pain experiences after total hip arthroplasty. The nurse is one of the staff members responsible for information to the individual patient. [source] Phylogenetic analysis indicates transmission of hepatitis C virus from an infected orthopedic surgeon to a patientJOURNAL OF MEDICAL VIROLOGY, Issue 4 2002R. Stefan Ross Abstract During recent years, a controversial discussion has emerged in the medical community on the real number and possible public health implications of hepatitis C virus (HCV) transmissions from infected medical staff to susceptible patients. We report here on molecular virological and epidemiological analyses involving 229 patients who underwent exposure-prone operations by an HCV-infected orthopedic surgeon. Of the 229 individuals affected, 207 could be tested. Three were positive for HCV antibodies. Molecular and epidemiological investigation revealed that two of them were not infected by the surgeon. The third patient, a 50-year-old man, underwent complicated total hip arthroplasty with trochanteric osteotomy. He harbored an HCV 2b isolate that in phylogenetic analysis of the hypervariable region 1 (HVR 1) was closely related to the HCV strain recovered from the infected surgeon, indicating that HCV-provider-to-patient transmission occurred intraoperatively. To our knowledge, this is the first documented case of HCV transmission by an orthopedic surgeon. The recorded transmission rate of 0.48% (95% confidence interval: 0.09,2.68%) was within the same range reported previously for the spread of hepatitis B virus during orthopedic procedures. Since the result of our investigation sustains the notion that patients may contract HCV from infected health-care workers during exposure-prone procedures, a series of further retrospective exercises is needed to assess more precisely the risk of HCV provider-to-patient transmission and to delineate from these studies recommendations for the guidance and management of HCV-infected medical personnel. J. Med. Virol. 66:461,467, 2002. © 2002 Wiley-Liss, Inc. [source] Computational assessment of the effect of polyethylene wear rate, mantle thickness, and porosity on the mechanical failure of the acetabular cement mantleJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2010Oliver J. Coultrup Abstract Clinical studies have revealed that aseptic loosening is the dominant cause of failure in total hip arthroplasty, particularly for the acetabular component. For a cemented polyethylene cup, failure is generally accompanied by the formation of fibrous tissue at the cement,bone interface. A variety of reasons for the formation of this tissue have been suggested, including osteolysis and mechanical overload at the cement,bone interface. In this study, a computational cement damage accumulation method was used to investigate the effect of polyethylene cup penetration, cement mantle thickness, and cement porosity on the number of cycles required to achieve mechanical fatigue failure of the cement mantle. Cup penetration was found to increase cement mantle stresses, resulting in a reduction in cement mantle fatigue life of 9% to 11% for a high cup penetration rate. The effect of using a thin (2 mm) over a thick (4 mm) cement mantle also reduced cement mantle fatigue life between 9% and 11%, and greatly raised cancellous bone stresses. Cement porosity was found to have very little effect on cement mantle fatigue life. Failure modes and cement stresses involved suggest that only extreme combinations of a thin cement mantle and high cup penetration may lead to mechanical failure of the cement mantle, thereby allowing wear debris access to the cement,bone interface. A thin cement mantle may also lead to the mechanical overload of the cement,bone interface. In this manner, the authors suggest that the mechanical factors may contribute to the failure mode of cemented polyethylene cups. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:565,570, 2010 [source] Gender-dependent association of the GNAS1 T393C polymorphism with early aseptic loosening after total hip arthroplastyJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 12 2008Hagen S. Bachmann Abstract The G-protein G,s is involved in the physiology and pathophysiology of bone. Especially, G,s is a key regulator of interleukin-6, which is a potent promoter of aseptic loosening. We hypothesized that the common single nucleotide polymorphism GNAS1 T393C could also affect time to aseptic loosening. Caucasian patients were genotyped for the GNAS1 T393C polymorphism. Time and median time to aseptic loosening were analyzed for dependency on GNAS1 genotypes. Time and median time were not significantly associated with genotypes. Additional analysis corrected for gender revealed, that the TT genotype was associated with significantly longer time (p,=,0.048) as well as median time (p,=,0.022) to aseptic loosening in female patients. In contrast to the findings in females, male TT genotype carriers had significantly shorter time (p,=,0.018) and median time (p,=,0.023) to aseptic loosening. Compared with TT genotype carriers heterozygous patients had a 6.25-fold lower risk with a hazard ratio of 0.160 (p,=,0.016) and male patients carrying the CC genotype had an 11-fold lower risk with a hazard ratio of 0.088 (p,=,0.006) in multivariate analysis. The present study suggests a significant gender-dependent role of the T393C polymorphism in aseptic loosening. The apparently contradictory results in women and men and the finding that the GNAS1 T393C genotype is an independent factor for time to aseptic loosening in male patients assigned this polymorphism as an interesting target for further investigations in bone diseases. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source] Variation in the secreted frizzled-related protein-3 gene and risk of Osteolysis and heterotopic ossification after total hip arthroplastyJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 12 2007Andrew Gordon Abstract Secreted frizzled-related protein-3 (sFRP3) antagonizes ligands that promote new bone formation in adult tissues. We examined whether variation in the FRZB gene that encodes sFRP3 is associated with development of osteolysis or heterotopic ossification (HO) after total hip arthroplasty (THA). Genomic DNA was extracted from 609 subjects (osteolysis group n,=,268) at a mean of 11 years following cemented THA for idiopathic osteoarthritis and genotyped for the FRZB Arg200Trp and Arg324Gly polymorphisms. The Brooker classification was used to assess HO following primary THA in 563 of the subjects. The carriage rate of the FRZB 200Trp allele was 14.2% in subjects with osteolysis versus 21.0% in controls (p,=,0.041). The carriage rate of this allele was 21.7% in subjects with HO (n,=,299) versus 12.0% in those without HO (p,=,0.063). The odds ratio for osteolysis with carriage of FRZB 200Trp was 0.62 (95% CI 0.38 to 0.99; p,=,0.049) and for HO was 1.64 (1.05 to 2.54; p,=,0.028), after adjustment for the effects of other risk factors associated with the development of osteolysis or HO. Variants in the FRZB 324 locus alone were not associated with osteolysis or HO. However, the most frequent haplotype (FRZB 200Arg:324Arg) was associated with osteolysis (OR 1.50, 95% CI 1.09 to 2.07; p,=,0.014). Our data suggest that the FRZB Arg200Trp locus may be a marker for pro-osteoblastic activity after THA. Carriage of the FRZB 200Trp allele is associated with a "positive" bone balance phenotype (osteolysis ,: HO+). © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1665,1670, 2007 [source] Avoiding misclassification bias with the traditional Charnley classification: Rationale for a fourth Charnley class BBJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 9 2006C. Röder Abstract Long-term follow up of patients with total hip arthroplasty (THA) revealed a marked deterioration of walking capacities in Charnley class B after postoperative year 4. We hypothesized that a specific group of patients, namely those with unilateral hip arthroplasty and an untreated but affected contralateral hip was responsible for this observation. Therefore, we conducted a study taking into consideration the two subclasses that make up Charnley class B: patients with unilateral THA and contralateral hip disease and patients with bilateral THA. A sample of 15,160 patients with 35,773 follow ups that were prospectively collected over 10 years was evaluated. The sample was categorized into four classes according to a new modified Charnley classification. Annual analyses of the proportion of patients with ambulation longer than 60 min were conducted. The traditionally labeled Charnley class B consists of two very different patient groups with respect to their walking capacities. Those with unilateral THA and contralateral hip disease have underaverage walking capacities and a deterioration of ambulation beginning 3 to 4 years after surgery. Those with bilateral THA have stable overaverage walking capacities similar to Charnley class A. An extension of the traditional Charnley classification is proposed, taking into account the two different patient groups in Charnley class B. The new fourth Charnley class consists of patients with bilateral THA and was labeled BB in order to express the presence of two artificial hip joints and to preserve the traditional classification A through C. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source] Precooling of the femoral canal enhances shear strength at the cement,prosthesis interface and reduces the polymerization temperatureJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 9 2006Pang-Hsin Hsieh Abstract Preheating of the femoral stem in total hip arthroplasty improves the cement,prosthesis bond by decreasing the interfacial porosity. The main concern, however, is the potential thermal osteonecrosis because of an increased polymerization temperature. In this study, the effects of femoral canal precooling on the characteristics of the cement,stem interface were evaluated in an experimental model for three test conditions: precooling of the femoral canal, preheating of the stem (44°C), and a control in which stems were inserted at room temperature without thermal manipulation of the implant, cement, or bone. Compared to the control group, precooling of the femoral canal and preheating of the stem had similar effects on the cement,stem interface, with greater interfacial shear strength and a reduced porosity. Femoral canal precooling also produced a lower temperature at the cement,bone interface. No difference was found in the ultimate compressive strength of bone cement for the three preparation conditions. Based on this laboratory model, precooling of the femoral canal could improve shear strength and porosity at the stem,cement interface, minimize thermal injury, and maintain the mechanical strength of the cement. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res [source] Alendronate prevents femoral periprosthetic bone loss following total hip arthroplasty: Prospective randomized double-blind studyJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 7 2006Mohammad Arabmotlagh Abstract Following total hip arthroplasty (THA), femoral periprosthetic bone undergoes a remodeling process that results in bone loss in its proximal regions that may compromise the long-term outcome of THA. Periprosthetic bone loss mainly occurs during the first postoperative months. The question is whether a postoperative treatment with alendronate is effective in reducing periprosthetic bone loss and which doses and duration of treatment are required. In a 12-month prospective, randomized double-blind study, 51 patients undergoing cementless THA were treated postoperatively either with a daily dose of 20 mg alendronate for 2 months and 10 mg for 2 months thereafter (group I), with 20 mg of alendronate for 2 months and 10 mg for 4 months thereafter (group II), or treated with placebo (group III). Proximal femoral bone mineral density (BMD) was measured with dual-energy X-ray absorptiometry (DEXA) and serum biochemical markers of bone turnover bone specific alkaline phosphatase, osteocalcin, and C-terminal telopeptides (CTX-I) were assayed. Six months of alendronate treatment significantly reduced (p,<,0.001) bone loss in proximal medial region (,10%) compared with placebo (,26%). All biochemical markers of bone turnover were suppressed by alendronate. These data suggest that alendronate administered for the first 6 postoperative months following THA was effective in preventing early periprosthetic bone loss. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:1336,1341, 2006 [source] Influence of polyethylene creep behavior on wear in total hip arthroplastyJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2006Janaki R. Penmetsa Abstract After total hip arthroplasty (THA), polyethylene acetabular liner creep occurs quickly and serves to increases head,liner contact area and decrease contact pressures. What effect these early changes in contact mechanics will have on the wear behavior of the articulation remains unclear, and hence, selection or modification of polyethylene materials for optimal creep and wear performance is impossible. The objective of this study was to determine the influence of polyethylene creep behavior on volumetric wear and linear creep and wear penetration during simulated gait loading conditions. A finite element model of THA articulation was developed, and simultaneous numerical creep and wear simulation was performed to 10 million gait cycles with three levels of polyethylene creep behavior. Long-term volumetric wear and penetration were surprisingly unaffected by the polyethylene creep behavior due to the competing decrease in contact pressures coupled with increased contact area. In addition, variation in contact mechanics with the creep levels studied was only noteworthy in the initial postoperative period; after 1 million gait cycles, peak contact pressures and areas were within 13% regardless of the creep material behavior selected. Femoral head size had considerable impact on wear and penetration, while liner thickness primarily affected only early penetration. These results suggest that polyethylene creep behavior plays a major role in early penetration, but has little influence on the more important long-term volumetric wear. © 2005 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 24:422,427, 2006 [source] Why would cement porosity reduction be clinically irrelevant, while experimental data show the contraryJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2005D. Janssen Abstract Laboratory bench tests have shown that porosity reduction increases the fatigue life of bone cement specimens. Clinically, however, the effect porosity reduction is subject to debate. We hypothesized that the discrepancy between clinical and experimental findings is related to differences in the stress distribution, which is typically uniform in experimental test specimens, while stress concentrations exist in cement around hip implants. We simulated fatigue failure of cement in a finite element model of an experimental test specimen and of a transverse slice of a total hip arthroplasty with a sharp-cornered stem. Four levels of porosity were introduced. In the fatigue test specimen model, the fatigue life clearly was dependent on the level of porosity, while in the transverse slice model, the level of porosity had virtually no effect on failure of the cement mantle. The results of the simulations confirmed our hypothesis. In simulations of laboratory tests, pores clearly acted as crack initiators, while in the simulation of a real total hip reconstruction, crack formation was governed by local stress singularities. This explains why the beneficial effect of cement porosity reduction on the lifetime of total hip reconstructions may be hard to detect clinically. © 2005 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] Effect of pamidronate on bone turnover and implant migration after total hip arthroplasty: A randomized trialJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2005J. Mark Wilkinson Abstract In this trial we studied the effect of pamidronate on periprosthetic bone turnover and pelvic implant migration over 2 years after hybrid total hip arthroplasty (THA). Twenty-two patients received 90 mg of pamidronate and 22 received placebo at randomization 5 days after surgery. Rapid periprosthetic bone loss occurred in the placebo group over the first 6 months and was accompanied by transient increases in biochemical markers of bone turnover. Partial recovery in bone mass occurred in most region after this period. No recovery of bone mass occurred at the femoral calcar or the medical wall of the acetabulum. Femoral calcar bone loss at 2 years was strongly predicted by acute biomarker changes at week 6. Pamidronate therapy reduced femoral bone loss in the region of the femoral calcar (P=0.01), but did not affect pelvic bone loss. Pamidronate therapy also inhibited the transient rise in biochemical markers of bone turnover during this period. Pamidronate therapy did not affect acetabular cup migration. Cup migration was inversely related to subject age, but unrelated to initial post-operative bone mineral density, or subsequent bone loss. In summary, early periprosthetic bone loss is associated with a transient expansion of the bone remodeling space. Bisphosphonate therapy reduces femoral calcar bone loss and bone turnover after THA, but did not influence cup migration in this study. Acute changes in biochemical markers predict femoral periprosthetic bone loss. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] Creep dominates tensile fatigue damage of the cement,bone interfaceJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2004Do-Gyoon Kim Abstract Fatigue damage from activities of daily living has been considered to be a major cause of aseptic loosening in cemented total hip arthroplasty. The cement,bone interface is one region where loosening could occur, but to date the fatigue response of the interface has not been examined. Cement,bone specimens were prepared from fresh frozen human cadaver tissue using simulated in vivo conditions. Tensile fatigue tests to failure were performed in an environmental chamber. Loss of specimen stiffness (stiffness damage) and permanent displacement after unloading (creep damage) were found in all specimens. At failure, creep damage accounted for the majority (79.9 ± 10.6%) of the total strain damage accumulation at failure (apparent strain, , = 0.0114 ± 0.00488). A power law relationship between strain-damage rate and time-to-failure showed that the strain-damage rate was an excellent predictor of the fatigue life of the cement,bone interface. The S,N response of the interface was obtained as a function of the applied stress ratio and the initial apparent strain. The total motion between cement and bone (72.2 ± 29.8 ,m) prior to incipient failure due to both stiffness and creep fatigue damage may be sufficient to result in fibrous tissue formation and contribute to eventual clinical loosening. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] THA loading arising from increased femoral anteversion and offset may lead to critical cement stressesJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2003Ralf U. Kleemann Abstract Aseptic loosening of artificial hip joints is believed to be influenced by the design and orientation of the implant. It is hypothesised that variations in implant anteversion and offset lead to changes in the loading of the proximal femur, causing critical conditions to both the bone and cement. The goal of this study was therefore to analyse the role of these parameters on loading, bone strains and cement stresses in total hip arthroplasty (THA). A validated musculo-skeletal model was used for the analysis of muscle and joint contact forces during walking and stair climbing. Two different anteversion angles (4° vs. 24°) and prostheses offsets (standard vs. long) were analysed. The loads for each case were applied to a cemented THA finite element model. Generally, stair climbing caused higher bone strains and cement stresses (max. +25%) than walking. Variations in anteversion and offset caused changes in the loading environment, bone strain distribution and cement stresses. Compared to the standard THA configuration, cement stresses were raised by increasing anteversion (max. +52%), offset (max. +5%) and their combination (max. +67%). Femoral anteversion, offset and their combination may therefore lead to an increased risk of implant loosening. Analyses of implant survival should consider this as a limiting factor in THA longevity. In clinical practice, implant orientation, especially in regard to pre- and post-operative anteversion, should be considered to be more critical. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Effect of age on the incidence of venous thromboembolism after major surgeryJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 8 2004R. H. White Summary.,Background:,Most guidelines for administration of thromboprophylaxis after major surgery use age as a major predictor of postoperative venous thromboembolism (VTE). We sought to quantify the effect of age on the risk of symptomatic VTE after a spectrum of surgical procedures. Methods:,Using the California Patient Discharge Data Set and specific ICD-9-CM surgical procedure codes, we retrospectively determined the incidence of VTE diagnosed within 91 days after 40 different urgent or elective surgeries performed in the hospital between 1992 and 1996. Logistic regression was used to quantify the effect of age on the incidence of postoperative VTE and to adjust for other risk factors. Results:,1 464 452 cases underwent one of 40 different procedures (mean cases per procedure = 35 718, range 4500,145 500). There was a significant interaction between age and the type of surgery performed (P<0.0001). Qualitative analysis of the effect of age on the incidence of VTE stratified by the presence or absence of malignancy revealed three general patterns: a steady increase in the incidence of VTE with age, exemplified by appendectomy or cholecystectomy; an increase in VTE up to approximately age 65 with no increase thereafter, exemplified by total hip arthroplasty; and no effect of age on the incidence of VTE, exemplified by vascular surgery. Conclusions:,The relationship between age and the risk of VTE after surgery is complex and depends on the nature of the surgery and the underlying pathologic process. Advancing age was a significant predictor for VTE following surgeries performed for conditions not inherently associated with significant comorbidity. Conversely, advancing age was not associated with a higher incidence of VTE after surgeries performed for conditions strongly associated with serious underlying comorbidity, such as a malignancy or severe peripheral vascular disease. [source] The safety and outcome of joint replacement surgery in liver transplant recipientsLIVER TRANSPLANTATION, Issue 4 2003Josh Levitsky A small group of patients may require total hip arthroplasty, total knee arthroplasty, or other joint replacement surgery after OLT for osteoporotic fractures, osteonecrosis, and osteoarthritis. Although arthroplasty is safe in the general population, its safety in liver transplant recipients is unclear. The aim of the study was to determine the safety and outcome of joint replacement surgery in our liver transplant recipients. A retrospective analysis was performed on all liver transplant recipients who had total joint arthroplasty at a single teaching institution between 1986 and 2002. Data regarding major intraoperative and postoperative complications was obtained from the medical charts and a hospital-based computer system. Of over 1,200 liver transplant recipients, we identified 7 patients who underwent 12 total arthroplasties (8 knee, 3 hip, 1 ankle). Joint replacements were performed electively for osteonecrosis (5 of 12) and osteoarthritis (5 of 12), whereas two hip arthroplasties were performed emergently for fractures. All patients with osteonecrosis or hip fracture had been treated with prolonged corticosteroids. There were no deaths or major complications in the intraoperative and postoperative periods. On long-term follow-up, no patients have had pain, dislocation, or infection in the postsurgical joint. No joint revision surgery has been required. In conclusion, a small number of stable liver transplant recipients at our institution underwent joint replacement surgery without major short-term or long-term complications. Our study suggests that joint replacement surgery may be safely and successfully performed in this population, although larger, randomized, prospective trials are needed to confirm our findings. [source] | ||||||||||||||||||||||||||||