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Total Hip Replacement (total + hip_replacement)
Kinds of Total Hip Replacement Selected AbstractsCeramic-On-Metal for Total Hip Replacement: Mixing and Matching Can Lead to High WearARTIFICIAL ORGANS, Issue 4 2010Saverio Affatato Abstract Ceramic-on-ceramic and metal-on-metal bearing surfaces are often employed for total hip replacement because of their resistance to wear. However, they have some limits: brittleness is a major concern for ceramic, and ion release is a drawback for metal. To reduce the effect of these limitations, a hybrid coupling of ceramic-on-metal has been proposed. The theoretical advantage of this new coupling might lead orthopedic surgeons to use it indiscriminately. We asked whether the wear rate of this innovative solution was comparable with that of ceramic-on-ceramic, which is considered to be the gold standard for wear resistance. In a hip simulator study, we tested the wear pattern of a hybrid ceramic-on-metal coupling supplied by the same distributor; in particular, three different configurations were tested for 5 million cycles: 36-mm ceramic-on-ceramic, 32-mm and 36-mm ceramic-on-metal. These combinations were gravimetrically and geometrically evaluated. After 5 million cycles, the volumetric loss for the metal acetabular cups (, 36-mm) was 20-fold greater than that of the ceramic cups of the same size (, 36-mm); a volumetric loss of 4.35 mm3 and 0.26 mm3 was observed, respectively, for ceramic-on-metal and ceramic-on-ceramic combinations. Significant statistical differences were observed between all 36-mm different combinations (P < 0.0001). The increased diameter of the 36-mm ceramic-on-metal configuration resulted in a lower volumetric loss compared with that of the 32-mm ceramic-on-metal configuration. Our findings showed an increase in wear for the proposed hybrid specimens with respect to that of the ceramic-on-ceramic ones. This confirms that even in the case of ceramic-on-metal bearings, mixing and matching could not prove effective wear behavior, not even comparable with that of the ceramic-on-ceramic gold standard. [source] Measuring fatigue in patients with Parkinson's disease , the Fatigue Severity ScaleEUROPEAN JOURNAL OF NEUROLOGY, Issue 6 2002K. Herlofson The objective was to compare the prevalence and severity of fatigue in patients with Parkinson's disease (PD) with that in two control groups, one consisting of randomly chosen control subjects of the same age and sex distribution and the other consisting of patients with coxarthrosis waiting to receive total hip replacement. We also explored the possible correlation of demographic and clinical data to the presence and severity of fatigue. Sixty-six patients with PD, 131 randomly chosen controls and 79 patients with coxarthrosis, waiting to receive total hip replacement, were evaluated for fatigue. Patients and controls with a depressive mood disorder or cognitive impairment had been excluded from the study. Fatigue was measured by the Fatigue Severity Scale (FSS). For the patients with PD the mean total FSS score was 4.1, compared with 2.7 amongst the randomly chosen control group and 2.9 in the group consisting of patients with coxarthrosis. Fifty per cent of the patients with PD had a mean total FSS score of 4 or higher, compared with 25% in both of the two control groups. There was no correlation between pain, presence of self-reported nocturnal sleep disorders or duration of PD and fatigue. The patients with fatigue did have a more advanced disease, measured both by Unified Parkinson's Disease Rating Scale score and Hoehn and Yahr stage. Although the univariate analyses indicated that more severe parkinsonism was correlated to the symptom, the multivariate analysis showed that none of the studied variables were significant explanatory factors for fatigue. Fatigue is a common symptom in patients with PD without depression or dementia. The study indicates that fatigue is an independent symptom of the disease without relation to other motor or non-motor symptoms. [source] Successful use of recombinant factor VIIa in a patient with inhibitor secondary to severe factor XI deficiencyHAEMOPHILIA, Issue 2 2002P. LAWLER Factor XI (FXI) inhibitors are a rare complication of inherited FXI deficiency. We report the successful use of recombinant factor VIIa (FVIIa) in a patient with a high-responding inhibitor undergoing cataract extraction. At the time of surgery there were limited available data on the optimal management of patients with FXI deficiency. A 62-year-old Ashkenazi Jewish woman had a lifelong history of excessive bleeding secondary to severe FXI deficiency (2 U dL,1), and received FXI concentrate (FXI:C) when she underwent a colposuspension procedure. She was subsequently diagnosed with a FXI inhibitor of 16 Bethesda units (BU) when she developed a poor response to FXI:C at the time of total hip replacement. Two months later she was admitted for cataract extraction. The FXI level was < 1 U dL,1 with an inhibitor titre of 48 BU. She received 90 ,g kg,1 of FVIIa immediately preoperatively followed by continuous infusion at a rate of 20 ,g kg,1 h,1 for 24 h. The cataract extraction was successful and there was no excess bleeding during surgery or in the postoperative period. Mutation analysis of the FXI gene showed that the patient was homozygous for the type II genotype [exon 5, Glu117,Ter]. The reason for the low prevalence of inhibitor formation in patients with FXI deficiency is unclear but may reflect a number of factors including reporting bias, the rarity of absent circulating FXI:C activity, and the infrequent use of FXI replacement therapy. [source] Health service costs in Europe: cost and reimbursement of primary hip replacement in nine countriesHEALTH ECONOMICS, Issue S1 2008Tom Stargardt Abstract This paper assesses variations in the cost of primary hip replacement between and within nine member states of the European Union (EU). It also compares the cost of service with public-payer reimbursements. To do so, data on cost and reimbursement were surveyed at the micro-level in 42 hospitals in Denmark, England, France, Germany, Hungary, Italy, The Netherlands, Poland, and Spain. The total cost of treatment ranged from ,1290 (Hungary) to ,8739 (The Netherlands), with a mean cost of ,5043 (STD±,2071). The main cost drivers were found to be implants (34% of total cost on average) and ward costs (20.9% of total cost on average). A one-way random effects analysis of variance model indicated that 74.0% of variation was between and only 26% of variation was within countries. In a two-level random-intercept regression model, purchasing-power parities explained 79.4% of the explainable between-country variation, while the percentage of uncemented implants used and the number of beds explained 12.1 and 1.6% of explainable within-country variation, respectively. The large differences in cost and reimbursement between Poland, Hungary, and the other EU member states shows that primary total hip replacement is a highly relevant case for cross-border care. Copyright © 2008 John Wiley & Sons, Ltd. [source] Bladder wall injury consequent to total hip replacement: Delayed presentationINTERNATIONAL JOURNAL OF UROLOGY, Issue 7 2006ULRICH KALDENBACH Abstract, Bladder injury, although rare, may be traumatic or iatrogenic. We report a patient with greatly delayed presentation of bladder injury after a total hip replacement. [source] The effect of surface treatments on the fretting behavior of Ti-6Al-4V alloyJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2008Matteo Dalmiglio Abstract Stem modularity in total hip replacement introduces an additional taper joint between Ti-6Al-4V stem components with the potential for fretting corrosion processes. One possible way to reduce the susceptibility of the Ti-6Al-4V/Ti-6Al-4V interface to fretting is the surface modification of the Ti-6Al-4V alloy. Among the tested, industrially available surface treatments, a combination of two deep anodic spark deposition treatments followed by barrel polishing resulted in a four times lower material release with respect to untreated, machined fretting pad surfaces. The fretting release has been quantified by means of radiotracers introduced in the alloy surface by proton irradiation. In a simple sphere on flat geometry, the semispherical fretting pads were pressed against flat, dog-bone shaped Ti-6Al-4V fatigue samples cyclically loaded at 4 Hz. In this way a cyclic displacement amplitude along the surfaces of 20 ,m has been achieved. A further simplification consisted in the use of deionized water as lubricant. A comparison of the radiotracer results with an electrochemical material characterization after selected treatments by potentiostatic tests of modular stems in 0.9% NaCl at 40°C for 10 days confirmed the benefit of deep anodic spark deposition and subsequent barrel polishing for improving the fretting behavior of Ti-6Al-4V. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008 [source] Quantitative evaluation of the prosthetic head damage induced by microscopic third-body particles in total hip replacementJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 4 2001Manuela Teresa Raimondi Abstract The increase of the femoral head roughness in artificial hip joints is strongly influenced by the presence of abrasive particulate entrapped between the articulating surfaces. The aim of the present study is to evaluate the dependence of such damage on the geometry of the particles entrapped in the joint, with reference to the UHMWPE/chrome-cobalt coupling. Five chrome-cobalt femoral heads and their coupled UHMWPE acetabular cups, retrieved at revision surgery after a short period of in situ functioning, have been investigated for the occurrence of third-body damage. This was found on all the prosthetic heads, where the peak-to-valley height of the scratches, as derived from profilometry evaluations, ranged from 0.3,1.3 ,m. The observed damage has been divided into four classes, related to the particle motion while being embedded into the polymer. Two kinds of particle morphology have been studied, spherical and prismatic, with size ranging from 5,50 ,m. In order to provide an estimation of the damage induced by such particles, a finite element model of the third-body interaction was set up. The peak-to-valley height of the impression due to the particle indentation on the chrome-cobalt surface is assumed as an index of the induced damage. The calculated values range from 0.1,0.5 ,m for spherical particles of size ranging from 10,40 ,m. In the case of prismatic particles, the peak-to-valley height can reach 1.3 ,m and depends both on the size and width of the particle's free corner, indenting the chrome-cobalt. As an example, a sharp-edged particle of size 30 ,m can induce on the chrome-cobalt an impression with peak-to-valley height of 0.75 ,m, when embedded into the polyethylene with a free edge of 5 ,m facing the metallic surface. Negligible damage is induced, if a free edge of 7.5 ,m is indenting the counterface. Our findings offer new support to the hypothesis that microscopic third-body particles are capable of causing increased roughening of the femoral head and provide a quantitative evaluation of the phenomenon. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 436,448, 2001 [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] Monitoring surgical performance: an application to total hip replacementJOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 3 2009David J. Biau MD Abstract Rationale, aims and objectives, Inadequate surgical implantation of a hip replacement may result in decreased patient satisfaction and reduced implant survival. The objective was to monitor surgical performance in hip replacement. Method, The study took place at a teaching centre. All primary total hip replacements were prospectively included in the series. For each hip replacement, intraoperative technical errors, cup and stem fixation and position, and postoperative complications were recorded. If all items rated were correct, the procedure was considered as correct. The Cumulative Sums (CUSUM) test was used to monitor the performance of the centre. A 90% proportion of successful procedures was considered as adequate performance and a 75% proportion of successful procedures was deemed as inadequate performance. Meetings were conducted to discuss the results of monitoring. Results, Eighty-three total hip replacements were monitored. Overall, 28 procedures (34%) were considered inadequate. The most potent reasons for inadequate performance were cup positioning and stem fixation. The CUSUM test signalled after the second procedure that performance was inadequate. After the first meeting, despite an improvement was seen, the CUSUM test raised an alarm indicating inadequate performance. The study was stopped after the second meeting because of funding reasons before it could be demonstrated that performance had reached the desired level. Conclusion, This study has demonstrated that implementing a dedicated system to monitor surgical performance in a teaching hospital improves the quality of implantation of total hip replacements. Nonetheless, the target of ninety percent of adequate primary total hip replacement could not be reached and efforts should be continued. [source] Continuous lumbar epidural infusion of levobupivacaine: effects of small-or large-volume regimen of infusionACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 4 2009G. DANELLI Background: The question of whether the dose, concentration or volume of a local anesthetic solution is the relevant determinant of the spread and quality of post-operative epidural analgesia is still open. In this prospective, randomized, double-blind study, we compared the effects of a large volume,low concentration with a small-volume,high-concentration lumbar epidural infusion of levobupivacaine. Methods: Seventy patients scheduled for total hip replacement were enrolled. After surgery, patients were randomly allocated to receive a continuous epidural infusion of levobupivacaine (10.5 mg/h) using either 0.125% levobupivacaine infused at 8.4 ml/h (low concentration group, n=35) or 0.75% levobupivacaine infused at 1.4 ml/h (high concentration group, n=35). We blindly recorded the degree of pain relief at rest and during movement every 8 h for the first two post-operative days, as well as hip flexion, motor block, rescue analgesic consumption and adverse events. Results: No difference in pain relief was observed between groups as estimated with the areas under the curve of the verbal Numerical Rating Scale for pain over time, both at rest and during movement. Similarly, there was no difference between groups in hip flexion degree, motor blockade and hemodynamic stability. Conclusions: Continuous lumbar epidural infusion of 0.75% levobupivacaine was as effective as continuous lumbar epidural infusion of 0.125% levobupivacaine, when administered at the same hourly dose of 10.5 mg, in achieving adequate analgesia both at rest and during movement, without differences in the incidence of hypotension and motor blockade. [source] Mechanical properties of femoral cortical bone following cemented hip replacementJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 11 2007G.X. Ni Abstract Femoral bone remodeling following total hip replacement is a big concern and has never been examined mechanically. In this study, six goats underwent unilateral cemented hip hemiarthroplasty with polymethyl methacrylate (PMMA) bone cement. Nine months later animals were sacrificed, and the femoral cortical bone slices at different levels were analysed using microhardness testing and microcomputed tomography (micro-CT) scanning. Implanted femurs were compared to contralateral nonimplanted femurs. Extensive bone remodeling was demonstrated at both the proximal and middle levels, but not at the distal level. Compared with the nonimplanted side, significant decreases were found in the implanted femur in cortical bone area, bone mineral density, and cortical bone hardness at the proximal level, as well as in bone mineral density and bone hardness at the middle level. However, no significant difference was observed in either variable for the distal level. In addition, similar proximal-to-distal gradient changes were revealed both in cortical bone microhardness and bone mineral density. From the mechanical point of view, the results of the present study suggested that stress shielding is an important mechanical factor associated with bone adaptation following total hip replacement. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1408,1414, 2007 [source] Postoperative serum attenuates LPS-induced release of TNF-, in orthopaedic surgeryJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 10 2007Olav Reikerås Abstract Studies with ex vivo stimulation of whole blood samples from injured patients have revealed a diminished production capacity for a broad range of secretory products, including inflammatory cytokines. Recent interest has focused on the release of mediators in serum that depress the cell-mediated immune response following trauma. The involvement of the lipid mediator prostaglandin E2 (PGE2) has been assumed because it is a potent endogenous immunosuppressor. In the present study, we tested the hypothesis that inhibitory substances circulating in the patient's serum after a major musculoskeletal trauma might impair leukocyte function by evaluating the effect of such serum on cytokine release in a whole blood model. Six females and three males undergoing elective total hip replacement were included in the study. Ex vivo LPS-induced TNF-, and IL-10 were measured in whole blood sampled preoperatively and added serum taken before, at the end of operation, and at postoperative days 1 and 6 with saline as negative control. LPS induced significant releases of TNF-, and IL-10 in whole blood. Addition of preoperative, postoperative, and day-1 postoperative serum did not alter the LPS-induced release of TNF-, as compared to saline. In the presence of serum from postoperative day 6, however, the expression of TNF-, was significantly reduced as compared to saline and preoperative serum (p,=,0.021 and 0.008, respectively). Neither of the serum samples altered the release of IL-10. PGE2 was significantly (p,=,0.008) increased in serum at postoperative day 6 as compared to preoperative levels. In conclusion, these data show that at day 6 after major orthopaedic surgery, the patient serum contained activity that inhibited ex vivo LPS-induced TNF-, release. The potent TNF-, inhibitory activity found at day 6 after injury correlated with increased levels of PGE2 and indicates cell-mediated hyporesponsiveness to a second stimulus. © 2007 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:1395,1400, 2007 [source] Biofilm formation by bacteria isolated from retrieved failed prosthetic hip implants in an in vitro model of hip arthroplasty antibiotic prophylaxisJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2007M.M. Tunney Abstract Bacterial infection primarily with Staphylococcus spp. and Propionibacterium acnes remains a significant complication following total hip replacement. In this in vitro study, we investigated the efficacy of gentamicin loading of bone cement and pre- and postoperative administration of cefuroxime in the prevention of biofilm formation by clinical isolates. High and low initial inocula, representative of the number of bacteria that may be present at the operative site as a result of overt infection and skin contamination, respectively, were used. When a high initial inoculum was used, gentamicin loading of the cement did not prevent biofilm formation by the 10 Staphylococcus spp. and the 10 P. acnes isolates tested. Similarly, the use of cefuroxime in the fluid phase with gentamicin-loaded cement did not prevent biofilm formation by four Staphylococcus spp. and four P. acnes isolates tested. However, when a low bacterial inoculum was used, a combination of both gentamicin-loaded cement and cefuroxime prevented biofilm formation by these eight isolates. Our results indicate that this antibiotic combination may protect against infection after intra-operative challenge with bacteria present in low numbers as a result of contamination from the skin but would not protect against bacteria present in high numbers as a result of overt infection of an existing implant. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:2,10, 2007 [source] Use of volumetric computerized tomography as a primary outcome measure to evaluate drug efficacy in the prevention of peri-prosthetic osteolysis: A 1-year clinical pilot of etanercept vs. placeboJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 6 2003Edward M. Schwarz Although total hip replacement (THR) is amongst the most successful and beneficial medical procedures to date, long-term outcomes continue to suffer from aseptic loosening secondary to peri-prosthetic osteolysis. Extensive research over the last two decades has elucidated a central mechanism for osteolysis in which wear debris generated from the implant stimulates inflammatory cells to promote osteoclastogenesis and bone resorption. The cytokine tumor necrosis factor alpha (TNF,) has been demonstrated to be central to this process and is considered to be a leading target for intervention. Unfortunately, even though FDA approved TNF antagonists are available (etanercept), currently there are no reliable outcome measures that can be used to evaluate the efficacy of a drug to prevent peri-prosthetic osteolysis. To the end of developing an effective outcome measure, we evaluated the progression of lesion size in 20 patients with established peri-acetabular osteolysis (mean = 29.99 cm3, range = 2.9,92.7 cm3) of an uncemented primary THR over 1-year, using a novel volumetric computer tomography (3D-CT) technique. We also evaluated polyethylene wear, urine N-telopeptides and functional assessments (WOMAC, SF-36 and Harris Hip Score) for comparison. At the time of entry into the study baseline CT scans were obtained and the patients were randomized to etanercept (25 mg s.q., twice/week) and placebo in a double-blinded fashion. CT scans, urine and functional assessments were also obtained at 6 and 12 months. No serious adverse drug related events were reported, but one patient had to have revision surgery before completion of the study due to aseptic loosening. No remarkable differences between the groups were observed. However, the study was not powered to see significant drug effects. 3D-CT data from the 19 patients was used to determine the mean increase in lesion size over 48 weeks, which was 3.19 cm3 (p < 0.0013). Analysis of the urine N-telopeptides and functional assessment data failed to identify a significant correlation with wear or osteolysis. In conclusion, volumetric CT was able to measure progression of osteolysis over the course of a year, thus providing a technology that could be used in therapeutic trials. Using the data from this pilot we provide a model power calculation for such a trial. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Four-year study of cobalt and chromium blood levels in patients managed with two different metal-on-metal total hip replacementsJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 2 2003Christian Lhotka Abstract Background: Metal-on-metal total hip prostheses will produce a certain amount of wear debris. This results in increased whole-blood metal levels, which may cause adverse effects. It is not known to what extent the problem has been overcome by advances in alloy technology. Methods: In 259 patients who with total hip replacement, blood cobalt and chromium concentrations were measured with atomic absorption spectrophotometry over a period of four years after arthroplasty. Of the patients enrolled in the study, 131 had been managed with a METASUL® cobalt-chromium alloy metal-on-metal bearing combination, while 128 had been given a SIKOMET®-SM21® cobalt-chromium alloy metal-on-metal combination. The control group consisted of 31 age- and gender-matched subjects. Results: Compared with the controls, all the patients had higher cobalt and chromium levels. Cobalt concentrations were up to 50 times higher, while chromium concentrations were up to 100 times higher. Conclusions: Both systems showed evidence, in the whole-blood samples, of wear debris production by the implants. Therefore, patients managed with metal-on-metal bearing combinations should be carefully monitored in order to ensure that any local or systemic complications are detected early on. © 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Infection of a total hip prosthesis in a dog caused by Achromobacter(Alcaligenes) xylosoxidansJOURNAL OF SMALL ANIMAL PRACTICE, Issue 12 2006S. L. Girling A four-year-old male, neutered Labrador retriever was presented with progressive left hindlimb lameness 10 months following total hip replacement. Radiography revealed changes consistent with infection and culture of joint fluid from the left coxofemoral joint revealed Achromobacter (Alcaligenes) xylosoxidans. The prosthesis was removed. Culture of the acetabular cup confirmed Achromobacter xylosoxidans. Achromobacter xylosoxidans is an uncommon but serious cause of nosocomial epidemics in hospitals for human beings. To the authors' knowledge, this is the first report of total hip prosthetic infection with Achromobacter xylosoxidans. Little is reported about its pathogenicity in human beings and the authors failed to retrieve any reports of its clinical significance in animals. [source] Association between asymptomatic deep vein thrombosis detected by venography and symptomatic venous thromboembolism in patients undergoing elective hip or knee surgeryJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 7 2007D. J. QUINLAN Summary.,Background:,Venography is commonly used to compare the efficacy of different thromboprophylaxis strategies for preventing deep vein thrombosis (DVT) in patients undergoing total hip replacement (THR) or total knee replacement (TKR). Methods:,We explored the relation between asymptomatic DVT and symptomatic venous thromboembolism (VTE) in patients undergoing THR or TKR treated with standard doses of enoxaparin (30 mg b.i.d. or 40 mg o.d.) by comparing the incidence of asymptomatic DVT in venographic studies with the incidence of symptomatic VTE in studies where venography was not performed. Results:,In 10 venographic studies involving 5796 patients, the incidence of asymptomatic DVT after THR was 13.2% [95% CI, 12.2,14.2%] and after TKR was 38.1% (95% CI, 35.5,40.8%). In two studies involving 3500 patients who did not undergo venography, the 90-day incidence of symptomatic VTE after THR was 2.7% (95% CI, 2.1,3.4%) and after TKR was 1.8% (95% CI, 0.9,2.7%). For every symptomatic VTE in THR studies where venography was not performed there were five asymptomatic DVTs in the venographic studies; for TKR, the ratio was 1:21. The incidence of asymptomatic DVT and the symptomatic VTE/asymptomatic DVT ratio was influenced by the venogram reading committee (Gothenburg vs. Hamilton: total DVT after THR, 19.5% vs. 8.7%, P < 0.0001; for TKR, 42.7% vs. 27.2%, P < 0.0001). Conclusions:,Comparisons across trials show a consistent relation between asymptomatic venographic DVT in patients undergoing elective THR or TKR surgery and symptomatic VTE in patients not undergoing venography. Differences exist in the strength of the relation depending on the type of surgery and the venogram reading committee. [source] Oral, direct Factor Xa inhibition with BAY 59-7939 for the prevention of venous thromboembolism after total hip replacementJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 1 2006B. I. ERIKSSON Summary.,Background:,Joint replacement surgery is an appropriate model for dose-ranging studies investigating new anticoagulants. Objectives:,To assess the efficacy and safety of a novel, oral, direct factor Xa (FXa) inhibitor , BAY 59-7939 , relative to enoxaparin in patients undergoing elective total hip replacement. Methods:,In this double-blind, double-dummy, dose-ranging study, patients were randomized to oral BAY 59-7939 (2.5, 5, 10, 20, or 30 mg b.i.d.), starting 6,8 h after surgery, or s.c. enoxaparin 40 mg once daily, starting on the evening before surgery. Treatment was continued until mandatory bilateral venography was performed 5,9 days after surgery. Results:,Of 706 patients treated, 548 were eligible for the primary efficacy analysis. The primary efficacy endpoint was the incidence of any deep vein thrombosis, non-fatal pulmonary embolism, and all-cause mortality; rates were 15%, 14%, 12%, 18%, and 7% for BAY 59-7939 2.5, 5, 10, 20, and 30 mg b.i.d., respectively, compared with 17% for enoxaparin. The primary efficacy analysis did not demonstrate any significant trend in dose,response relationship for BAY 59-7939. The primary safety endpoint was major, postoperative bleeding; there was a significant increase in the frequency of events with increasing doses of BAY 59-7939 (P = 0.045), but no significant differences between individual BAY 59-7939 doses and enoxaparin. Conclusions:,When efficacy and safety were considered together, the oral, direct FXa inhibitor BAY 59-7939, at 2.5,10 mg b.i.d., compared favorably with enoxaparin for the prevention of venous thromboembolism in patients undergoing elective total hip replacement. [source] Transesophageal monitoring of aortic blood flow during nonemergent canine surgeriesJOURNAL OF VETERINARY EMERGENCY AND CRITICAL CARE, Issue 1 2002Piper L. Wall Abstract Objective: To establish baseline values for descending thoracic aortic blood flow parameters as determined with a transesophageal combined M-mode and pulsed Doppler ultrasound-based monitoring method. Design: Preliminary observational study. Setting: University small animal teaching hospital. Animals: The study population consisted of anesthetized canine patients undergoing nonemergent surgeries. Prospectively set criteria for inclusion were adequate body size for placement of the esophageal probe and a nonemergent reason for surgery. The criterion for exclusion was recent trauma. Interventions: Placement of the transesophageal probe. Measurements and main results: Data was collected during 15 surgeries. Data from three dogs was excluded from data analysis (two recently hit by motor vehicles, one recently having undergone a total hip replacement). Each parameter was stable across time within each individual dog. The ranges of the descending thoracic aortic parameters across the 12 nonemergent cases were as follows: blood flow, 0.038,0.085 L min,1 kg,1; blood flow per beat, 0.31,0.84 mL kg,1; blood acceleration, 6,29 m s2,1; blood peak velocity, 38,105 m s,1; left ventricular ejection time interval 331,492 ms; and diameter, 0.30,0.93 mm kg,1. Conclusions: The range of descending thoracic aortic blood flow parameters encountered in this small group of dogs during nonemergent surgeries was broad; however, each parameter was quite stable across time with little change occurring in any dog during monitoring. [source] Incidence of heterotopic bone formation after major hip surgeryANZ JOURNAL OF SURGERY, Issue 11 2002Bruce Neal Background: Heterotopic bone formation is a well-established complication of major hip surgery, but traditional reviews of the published literature may have underestimated its frequency. Methods: A systematic overview of all the relevant studies was performed to determine reliably the incidence of any heterotopic bone formation and the incidence of each Brooker equivalent grade. Separate estimates were made for patients with total hip replacement and patients with acetabular fracture repair. Results: A computer-based search identified 218 studies with data on the incidence of heterotopic bone formation after either hip replacement or acetabular fracture repair. These studies included data from an estimated 59 121 operated hips among patients that received total hip replacement and an estimated 998 hips among patients that underwent acetabular fracture repair. In these studies, the incidence of any heterotopic bone formation was 43% after total hip replacement and 51% after acetabular fracture repair. The incidence of severe heterotopic bone formation was 9% and 19%, respectively. Conclusions: These results suggest that heterotopic bone formation occurs more frequently after total hip replacement than is generally believed. It is possible that heterotopic bone formation is a more important cause of postoperative disability than has previously been recognized and that effective prophylactic regimens might improve outcome in substantial numbers of patients. [source] Involvement of different risk factors in clinically severe large joint osteoarthritis according to the presence of hand interphalangeal nodesARTHRITIS & RHEUMATISM, Issue 9 2010Ana M. Valdes Objective To quantify the differences in risk factors influencing total hip replacement (THR) and total knee replacement (TKR) based on the presence versus absence of multiple interphalangeal nodes in 2 or more rays of the fingers of each hand in patients with large joint osteoarthritis (OA). Methods A group of 3,800 patients with large joint OA who underwent total joint replacement (1,201 of whom had the nodal phenotype) and 1,906 control subjects from 2 case,control studies and a population-based cohort in the UK were studied. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for the risk of total joint replacement in association with age, sex, body mass index (BMI), height, and prevalence of the T allele in the GDF5 rs143383 polymorphism. ORs for total joint replacement were compared between cases of nodal OA and cases of non-nodal OA and between patients who underwent TKR and those who underwent THR. Results Age, sex, and BMI had significantly higher ORs for an association with total joint replacement in nodal OA cases than in non-nodal OA cases. The GDF5 polymorphism was significantly associated with THR in cases of nodal OA, but not in cases of non-nodal OA, and increased height was a risk factor for THR in non-nodal OA cases only. Female sex was a protective risk factor for TKR in non-nodal OA cases (OR 0.60, 95% CI 0.52,0.70) but was predisposing for TKR in the nodal form of OA (OR 1.83, 95% CI 1.49,2.26). The nodal phenotype was associated with a significantly higher risk of undergoing both THR and TKR (OR 1.46, 95% CI 1.09,1.94) and also a significantly higher risk of bilateral TKR (OR 1.70, 95% CI 1.37,2.11), but, paradoxically, was associated with a lower risk of bilateral THR (OR 0.72, 95% CI 0.56,0.91). Conclusion Nodal and non-nodal forms of large joint OA have significantly different risk factors and outcomes, indicating a different etiology for the 2 forms of OA. With regard to the likelihood of undergoing THR, this appears to be, at least in part, genetically determined. [source] Genetic variation in the SMAD3 gene is associated with hip and knee osteoarthritisARTHRITIS & RHEUMATISM, Issue 8 2010Ana M. Valdes Objective Smad3 (or, MADH3) is a key intracellular messenger in the transforming growth factor , signaling pathway. In mice, Smad3 deficiency accelerates growth plate chondrocyte maturation and leads to an osteoarthritis (OA),like disease. We undertook this study to investigate the role of genetic variation in SMAD3 in the risk of large-joint OA in humans. Methods Ten tag single-nucleotide polymorphisms (SNPs) in the SMAD3 gene region were tested in a discovery set: 313 patients who had undergone total knee replacement, 214 patients who had undergone total hip replacement, and 520 controls from the UK. The SNP associated with both hip and knee OA was subsequently genotyped in 1,221 controls and 1,074 cases from 2 cohorts of patients with hip OA and 2,537 controls and 1,575 cases from 4 cohorts of patients with knee OA. Results A SNP (rs12901499) mapping to intron 1 of SMAD3 was associated with both knee and hip OA (P < 0.0022 and P < 0.021, respectively) in the discovery set. In all study cohorts, the major allele (G) was increased among OA patients relative to controls. A meta-analysis for knee OA yielded an odds ratio (OR) of 1.22 (95% confidence interval [95% CI] 1.12,1.34), P < 7.5 × 10,6. For hip OA, the OR was 1.22 (95% CI 1.09,1.36), P < 4.0 × 10,4. No evidence for heterogeneity was found (I2 = 0%). Conclusion Our data indicate that genetic variation in the SMAD3 gene is involved in the risk of both hip OA and knee OA in European populations, confirming the results from animal models on the potential importance of this molecule in the pathogenesis of OA. [source] Defining incident radiographic hip osteoarthritis for epidemiologic studies in womenARTHRITIS & RHEUMATISM, Issue 4 2009Nigel K. Arden Objective To evaluate definitions of radiographic hip osteoarthritis (RHOA) for use in longitudinal epidemiologic studies of disease incidence in women. Methods We studied 5,839 women from the Study of Osteoporotic Fractures who had had serial pelvic radiographs obtained (mean of 8.3 years apart) and who were followed up (mean followup 7.1 years from the time of the second radiograph) for evaluation of clinical outcomes. Definitions of RHOA were assessed for construct validity (association with symptoms and signs at the time of the second radiograph) and predictive validity (association with total hip replacement [THR] and signs and symptoms a mean of 7.1 years later). Odds ratios (ORs) and 95% confidence intervals were calculated to assess the strength of association using logistic regression. Results The cumulative incidence of RHOA ranged from 2.2% to 11.7%. All definitions displayed significant construct validity; the most consistent was found for composite definitions that required the concurrent presence of 2 or more individual radiographic features and definitions based on stringent criteria for joint space narrowing. All definitions except minimum joint space ,2.5 mm displayed consistent predictive validity. Composite definitions had the strongest associations with THR (OR 10.5,18.5) and hip pain (OR 2.6,2.9). The hips identified as having OA by each definition varied, with especially small overlap between findings using definitions based on osteophytes and those using definitions based on joint space narrowing alone. Conclusion Most definitions of incident RHOA display good construct and predictive validity. Composite definitions have the best overall performance, and definitions requiring the presence of both osteophytes (in particular, femoral osteophytes) and joint space narrowing would be recommended for most epidemiologic and genetic studies. [source] Varus foot alignment and hip conditions in older adultsARTHRITIS & RHEUMATISM, Issue 9 2007K. Douglas Gross Objective Mechanical strain on the hip can result from varus malalignment of the foot. This study was undertaken to explore the cross-sectional relationship between varus foot alignment and hip conditions in a population of older adults. Methods The Framingham Osteoarthritis Study cohort consists of a population-based sample of older adults. Within this sample, we measured forefoot and rearfoot frontal plane alignment using photographs of a non,weight-bearing view of both feet of 385 men and women (mean age 63.1 years). Each foot segment was categorized according to the distribution of forefoot and rearfoot alignment among cases of ipsilateral hip pain, trochanter tenderness, hip pain or tenderness, and total hip replacement (THR). The relationship of foot alignment to these conditions was examined using logistic regression and generalized estimating equations, adjusting for age, body mass index, sex, and physical activity. Results The mean ± SD rearfoot varus alignment was 0.7 ± 5.5 degrees, and the mean ± SD forefoot varus alignment was 9.9 ± 9.9 degrees. Subjects in the highest category of forefoot varus alignment had 1.8 times the odds of having ipsilateral hip pain (P for trend = 0.06), 1.9 times the odds of having hip pain or tenderness (P for trend < 0.01), and 5.1 times the odds of having undergone THR (P for trend = 0.04) compared with those in the lowest category. No significant associations were found between rearfoot varus alignment and any hip conditions. Conclusion Forefoot varus malalignment may be associated with ipsilateral hip pain or tenderness and THR in older adults. These findings have implications for treatment, since this risk factor is potentially modifiable with foot orthoses. [source] Ceramic-On-Metal for Total Hip Replacement: Mixing and Matching Can Lead to High WearARTIFICIAL ORGANS, Issue 4 2010Saverio Affatato Abstract Ceramic-on-ceramic and metal-on-metal bearing surfaces are often employed for total hip replacement because of their resistance to wear. However, they have some limits: brittleness is a major concern for ceramic, and ion release is a drawback for metal. To reduce the effect of these limitations, a hybrid coupling of ceramic-on-metal has been proposed. The theoretical advantage of this new coupling might lead orthopedic surgeons to use it indiscriminately. We asked whether the wear rate of this innovative solution was comparable with that of ceramic-on-ceramic, which is considered to be the gold standard for wear resistance. In a hip simulator study, we tested the wear pattern of a hybrid ceramic-on-metal coupling supplied by the same distributor; in particular, three different configurations were tested for 5 million cycles: 36-mm ceramic-on-ceramic, 32-mm and 36-mm ceramic-on-metal. These combinations were gravimetrically and geometrically evaluated. After 5 million cycles, the volumetric loss for the metal acetabular cups (, 36-mm) was 20-fold greater than that of the ceramic cups of the same size (, 36-mm); a volumetric loss of 4.35 mm3 and 0.26 mm3 was observed, respectively, for ceramic-on-metal and ceramic-on-ceramic combinations. Significant statistical differences were observed between all 36-mm different combinations (P < 0.0001). The increased diameter of the 36-mm ceramic-on-metal configuration resulted in a lower volumetric loss compared with that of the 32-mm ceramic-on-metal configuration. Our findings showed an increase in wear for the proposed hybrid specimens with respect to that of the ceramic-on-ceramic ones. This confirms that even in the case of ceramic-on-metal bearings, mixing and matching could not prove effective wear behavior, not even comparable with that of the ceramic-on-ceramic gold standard. [source] Effects of Screw Eccentricity on the Initial Stability of the Acetabular Cup in Artificial Foam Bone of Different QualitiesARTIFICIAL ORGANS, Issue 1 2010Jui-Ting Hsu Abstract Acetabular cup loosening is one of the major failure models of total hip replacement (THR), which is mostly due to insufficient initial stability of the cup. Previous studies have demonstrated that cup stability is affected by the quality of the host bone and the surgical skill when inserting screws. The purpose of this study was to determine the effects on the initial stability of the acetabular cup of eccentric screws in bone of different qualities. In this study, hemispherical cups were fixed into bone specimens constructed from artificial foam with three elastic moduli using one to three screws. The effects of two types of screw eccentricity (offset and angular) on the stability of the acetabular cup were also evaluated. The experimental results indicate that in the presence of ideal screwing, the cup was stable in bone specimens constructed from foam with the highest elastic modulus. In addition, increasing the number of ideal screws enhanced the cup stability, especially in bone specimens constructed from soft foam. Moreover, the cup stability was most affected by offset eccentric screw(s) in the hard-foam bone specimens and by angular eccentric screw(s) in the soft-foam bone specimens. The reported results indicate that the presence of screw eccentricity affects the initial stability of the acetabular cup. Surgeons should keep this in mind when performing screw insertions in THR. However, care is necessary when translating these results to the intraoperative situation due to the experiments being conducted under laboratory conditions, and hence, future studies should attempt to replicate the results reported here in vivo. [source] Assessment of Five Interleukins in Human Synovial Fluid as Possible Markers for Aseptic Loosening of Hip ArthroplastyARTIFICIAL ORGANS, Issue 7 2009Alina Beraudi Abstract One of the most important factors that seems to be involved in total hip replacement is periprosthetic osteolysis. As it is well documented that several interleukins (ILs) are triggered in periprosthetic osteolysis, this article investigates the role of five ILs in primary and replacement total hip arthroplasty, understanding if one of them can also predict hip implant loosening, secondary surgery, and prosthesis breakage. The levels of IL-1,, 1,, 6, 8, and 10 in synovial fluid were examined, using a high sensitivity enzyme-linked immunosorbent assay (ELISA) test kit (Pierce Biotechnology, Inc., Rockford, IL, USA) to determine whether these cytokines could be used as markers of enhanced periprosthetic osteolysis, leading to aseptic loosening of total/partial hip arthroplasty or revision surgery. Synovial fluid was harvested from 23 patients undergoing primary total hip arthroplasty and 35 patients undergoing total/partial hip revision due to aseptic loosening. In the revision group, four cases had suffered a prosthesis fracture and five were second revisions. ILs 6 and 8 were significantly higher in the revisions (305 and 817 pg/mL) compared with the primary arthroplasties (151 and 151 pg/mL), including cases with prosthesis fracture and those requiring a second revision. IL-10 levels were lower (not significantly) in second revision samples compared with those of revision samples. IL-1, levels were significantly higher in prosthesis fracture samples compared with those of all the other revision samples. No statistically significant differences in IL levels were found between osteoarthritis samples and those of other diseases. These results are a step forward to elucidating the complex network of events that are involved in loosening of hip implants. [source] Femoral component failure in canine cemented total hip replacement: a report of two casesAUSTRALIAN VETERINARY JOURNAL, Issue 6 2010GD Yates Femoral stem fracture is reported as an uncommon late complication of cemented total hip replacement in two dogs. In each case surgical salvage was achieved by extirpation of the proximal unstable component of the femoral stem, resulting in acceptable limb function. To the authors' knowledge, intramedullary femoral stem failure has not been previously reported after cemented total hip replacement in the dog. Factors believed to have contributed to implant failure in these dogs are discussed and compared with the same complication in humans. [source] Monitoring surgical performance: an application to total hip replacementJOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 3 2009David J. Biau MD Abstract Rationale, aims and objectives, Inadequate surgical implantation of a hip replacement may result in decreased patient satisfaction and reduced implant survival. The objective was to monitor surgical performance in hip replacement. Method, The study took place at a teaching centre. All primary total hip replacements were prospectively included in the series. For each hip replacement, intraoperative technical errors, cup and stem fixation and position, and postoperative complications were recorded. If all items rated were correct, the procedure was considered as correct. The Cumulative Sums (CUSUM) test was used to monitor the performance of the centre. A 90% proportion of successful procedures was considered as adequate performance and a 75% proportion of successful procedures was deemed as inadequate performance. Meetings were conducted to discuss the results of monitoring. Results, Eighty-three total hip replacements were monitored. Overall, 28 procedures (34%) were considered inadequate. The most potent reasons for inadequate performance were cup positioning and stem fixation. The CUSUM test signalled after the second procedure that performance was inadequate. After the first meeting, despite an improvement was seen, the CUSUM test raised an alarm indicating inadequate performance. The study was stopped after the second meeting because of funding reasons before it could be demonstrated that performance had reached the desired level. Conclusion, This study has demonstrated that implementing a dedicated system to monitor surgical performance in a teaching hospital improves the quality of implantation of total hip replacements. Nonetheless, the target of ninety percent of adequate primary total hip replacement could not be reached and efforts should be continued. [source] Mechanical characteristics of the bone,graft,cement interface after impaction allograftingJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 1 2005Hanspeter Frei Impaction allografting is an attractive procedure for the treatment of failed total hip replacements. The graft,cement,host bone interface after impaction allografting has not been characterized, although it is a potential site of subsidence for this type of revision total hip reconstruction. In six human cadaveric femurs, the cancellous bone was removed proximally and local diaphyseal lytic defects were simulated. After the impaction grafting procedure, the specimens were sectioned in 6 mm transverse sections and pushout tests were performed. From the adjacent sections the percentage cement contact of the PMMA cement with the endosteal bone surface was determined. The host bone interface mechanical properties varied significantly along the femur largely due to different interface morphologies. The apparent host bone interface shear strength was highest around the lesser trochanter and lowest around the tip of the stem. A significant positive correlation was found between the percentage cement contact and the apparent host bone interface shear strength (r2 = 0.52). The sections failed in 69% of the cases through a pure host bone interface failure without cement or allograft failure, 19% failed with local cement failure, and 12% with a local allograft failure. The apparent host bone interface strength was on average 89% lower than values reported for primary total hip replacements and were similar to cemented revisions proximally and lower distally. This study showed that cement penetration to the endosteal surface enhanced the host bone,graft interface. © 2004 Orthopaedic Research Society. Published by Elsevier Ltd. All rights reserved. [source] | ||||||||||