Knee Replacement Surgery (knee + replacement_surgery)

Distribution by Scientific Domains


Selected Abstracts


Does Learning Matter for Knee Replacement Surgeries?

FINANCIAL ACCOUNTABILITY & MANAGEMENT, Issue 4 2003
Data Evidence from a German Hospital
In 2003, Germany will be the first country in the world to adopt a fully prospective payment system for the reimbursement of all inpatient hospital services. To face the increasing competition, hospitals can pursue either a specialization or a cost and quality leadership strategy. It stands to reason that organizational and individual learning will play an important role for both strategies. This paper raises the question, whether results from traditional learning curve theory can be applied to surgical procedures despite the latter's heterogeneity. We develop a theoretical model of surgical learning and test it using detailed operating room data from the first 601 total knee replacement surgeries of a small German hospital between 1994,2000. Our results suggest that classical learning curve theory can indeed be applied to this high cost high volume procedure. [source]


A bird can't fly on one wing: patient views on waiting for hip and knee replacement surgery

HEALTH EXPECTATIONS, Issue 2 2007
Barbara L. Conner-Spady PhD
Abstract Objectives, To obtain patients' perspectives on acceptable waiting times for hip or knee replacement surgery. Methods, A questionnaire with both open- and close-ended items was mailed to 432 consecutive patients who had hip or knee replacement surgery 3,12 months previously in Saskatchewan, Canada. A content analysis was used to analyse the text data from the open-ended questions. Results, The sample of 303 (response rate 70%) was 59% female with a mean age of 70 years (SD 11). The median waiting time from the decision date to surgery was 17 weeks. Individuals who rated their waiting time very acceptable (48%) had a median waiting time of 13 weeks compared with a median waiting time of 22 weeks for those who rated it unacceptable (23%). The two most common determinants of acceptability were patient expectations and pain and its impact on patient quality of life. The median maximum acceptable waiting time was 13 weeks and median ideal waiting time, 8.6 weeks. Seventy-nine per cent felt that those in greater need (higher severity) should go before them on the waiting list. Patient ratings of maximum acceptable waiting time were based on: pain and loss of mobility, time needed to prepare for surgery, and severity at the time of seeing the surgeon. In consideration of changing their surgeon to one with a shorter waiting list, 68% would not. Conclusions, Patient views on waiting times are not only related to quality of life issues, but also to prior expectations and notions of fairness and priority. Understanding patient views on waiting for surgery has implications for better management of waiting times and experiences for joint replacement. [source]


Major elective joint replacement surgery: socioeconomic variations in surgical risk, postoperative morbidity and length of stay

JOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 3 2010
Jennifer Hollowell PhD
Abstract Background, Patient deprivation is associated with greater need for total hip and knee replacement surgery (THR/TKR) and a higher prevalence of risk factors for surgical complications. Our aim was to examine associations between deprivation and aspects of the inpatient episode for patients undergoing these procedures. Methods, We analysed socioeconomic variations in preoperative surgical risk, postoperative morbidity and length of stay for 655 patients undergoing elective THR/TKR at a large metropolitan hospital. Surgical risk was assessed using the orthopaedic version of the POSSUM scoring system, postoperative morbidity was assessed using the postoperative morbidity survey, and socioeconomic status was measured using the Index of Multiple Deprivation. We adjusted for age, sex, surgical site and primary vs. revision surgery. Results, We found only a modest, clinically insignificant socioeconomic gradient in preoperative surgical risk and no socioeconomic gradient in postoperative morbidity. There was a strong socioeconomic gradient in length of stay, but only for patients undergoing TKR. This was due to deprived patients being more likely to remain in hospital without morbidity following TKR. Conclusions, Our findings suggest differential selection of healthier patients for surgery. Hospitals serving deprived communities may have excess, unfunded costs because of the increased length of stay of socioeconomically disadvantaged patients. [source]


Living with severe osteoarthritis while awaiting hip and knee joint replacement surgery

MUSCULOSKELETAL CARE, Issue 2 2009
Cert HSM, Gail Elizabeth Parsons MSc
Abstract Objectives:,To explore the lived experiences of patients with severe osteoarthritis (OA) of the hip or knee joint while awaiting joint replacement surgery. Methods:,An exploratory qualitative approach using phenomenology was adopted for the purpose of the study. Unstructured interviews were carried out on a sample of six patients who had been referred to the National Health Service waiting list for a primary hip or knee replacement. The participants were invited to share their experiences and concerns relating to how they were coping with end-stage OA of their hip or knee joint. Interviews were digitally recorded and transcribed verbatim. Narrative data were analysed using Giorgi's (1985) procedural steps to reveal themes which recurred in the participants' stories. Results:,Six themes emerged from the data, central to the experience of living with severe OA. They were: coping and living with pain; not being able to walk; coping with everyday activities; body image; advice and support available; and the effect of their disease upon family, friends and helpers. There were also a number of sub-themes associated with each major theme. Conclusions:,This study suggests that there is an absence of generic support, guidance and information relating to the management of symptoms of OA for individuals awaiting hip and knee replacement surgery. Patients awaiting hip and knee joint replacement surgery often have difficulty in managing their symptoms. Support in general appears to be dependent on the availability of resources in the primary care setting. Potential patients who are fortunate to know or meet someone who has undergone a similar procedure learn from the experience of exchanging information between themselves, along with coping strategies in the management of their symptoms. Copyright 2008 John Wiley & Sons, Ltd. [source]


Latest news and product developments

PRESCRIBER, Issue 21 2008
Article first published online: 2 DEC 200
Osteoporosis guideline A new guideline on the management of osteoporosis in men over 50 and post-menopausal women has been published by the National Osteoporosis Guideline Group (www.shef.ac.uk/NOGG), a group of organisations representing health professionals and patients, with funding from several pharmaceutical companies. The guideline recommends using the FRAX tool (www.shef.ac.uk/FRAX) to assess the 10-year fracture risk in individuals with risk factors to facilitate targeting DXA scans to measure bone mineral density. Patients who have already sustained a fragility fracture should be treated without risk assessment. Treatment recommendations are similar to those published in draft NICE guidance on primary and secondary prevention, selecting alendronate as the drug of first choice for most patients. Efalizumab efficacy A multicentred postapproval trial has demonstrated long-term efficacy and a favourable safety profile for efalizumab (Raptiva) in moderate to severe chronic plaque psoriasis. The CONTROL II study, presented in September at the 17th EADV congress in Paris, was conducted at 170 sites in 18 European countries and involved 1255 patients who had failed to respond to traditional systemic therapies. In this non-blinded study, 68 per cent of participants achieved the primary efficacy end-point and showed improvement within the first 12 weeks; control was maintained in responding patients who continued treatment. Adverse effects were graded as mild or moderate and similar to those reported in earlier studies. There was no evidence of an increase in malignancies or infections. New oral anticoagulant Rivaroxaban (Xarelto), an oral factor Xa inhibitor, has been introduced for the prevention of venous thrombo-embolism in patients undergoing elective hip or knee replacement surgery. Compared with the low molecular weight heparin enoxaparin (Clexane), rivaroxaban has been shown to reduce the risk of venous thrombosis by 70 per cent after hip replacement and by 49 per cent after knee replacement; the risk of bleeding was similar. At the recommended dose of 10mg once daily, prophylaxis after hip surgery lasts five weeks and costs 157; prophylaxis after knee surgery lasts two weeks and costs 63. New products UCB Pharma has introduced lacosamide (Vimpat) as adjunctive treatment of partial-onset epilepsy with or without secondary generalisation in patients aged 16 and over. A month's treatment at the recommended maintenance dose of 100-200mg twice daily costs approximately 73-140. A new non-nucleoside reverse transcriptase inhibitor (NNRI) is available for the treatment of HIV-1 infection in combination with a boosted protease inhibitor (PI) and other antiretrovirals in treatment-experienced adults. Etravirine (Intelence) costs approximately 320 for one month's treatment at the recommended dose of 200mg twice daily. Voltarol Pain-Eze (diclofenac) 12.5mg tablets are now available without prescription; a pack of 18 tablets costs 5.99. Atypicals and EPS risk Atypical antipsychotics are not associated with a significantly lower risk of extra-pyramidal symptoms than first-generation agents such as perphenazine (Fentazin), a new analysis of the CATIE study has shown (Br J Psychiatry 2008;193:279,88). CATIE was a large trial comparing the efficacy and safety of antipsychotics in the treatment of schizophrenia in which perphenazine was a representative first-generation agent (Am J Psychiatry 2006;163:611,22). This analysis found no differences in the risk of parkinsonism, dystonia, akathisia or tardive dyskinesia between perphenazine and the newer antipsychotics; use of antiparkinsonian medication was higher with risperidone and lower with quetiapine (Seroquel). Mental health website A new website offering information about mental illnesses and drug treatment has been launched by the United Kingdom Psychiatric Pharmacy Group (UKPPG), the College of Mental Health Pharmacists (CMHP), the Pharmaceutical Schizo-phrenia Initiative (PSI) and the National Institute for Mental Health in England (NIMHE). www.choiceandmedication.org.uk includes information about 17 mental illnesses and a large number of drug treatments. It offers links to other sites offering information and downloadable leaflets, help to identify the local mental health trust and downloadable charts comparing treatments for each indication. [source]


A pilot study of the effect of the Queen's Square external bladder stimulator on urinary retention after knee replacement surgery

ANAESTHESIA, Issue 6 2003
A. Butwick
Summary Postoperative urinary retention remains an important problem after major orthopaedic surgery and can increase morbidity. External vibration applied to the suprapubic region has improved bladder emptying and urinary symptoms in patients with neurogenic bladders. Forty-three patients undergoing elective major knee surgery were randomly assigned to receive either a Queen's Square bladder stimulator or placebo device for 24 h postoperatively. No statistically significant differences in rates of urinary retention could be demonstrated in the bladder stimulator group compared to the placebo group (41% and 33%, respectively). There were no differences between the two groups when analysed for prostatic symptoms, type and effectiveness of analgesia and fluid balance. We conclude that, while the Queen's Square external bladder stimulator may be effective in treating chronic urinary retention associated with a neurogenic bladder, it does not appear to be effective in preventing postoperative urinary retention. [source]


Increased friction coefficient and superficial zone protein expression in patients with advanced osteoarthritis

ARTHRITIS & RHEUMATISM, Issue 9 2010
C. P. Neu
Objective To quantify the concentration of superficial zone protein (SZP) in the articular cartilage and synovial fluid of patients with advanced osteoarthritis (OA) and to further correlate the SZP content with the friction coefficient, OA severity, and levels of proinflammatory cytokines. Methods Samples of articular cartilage and synovial fluid were obtained from patients undergoing elective total knee replacement surgery. Additional normal samples were obtained from donated body program and tissue bank sources. Regional SZP expression in cartilage obtained from the femoral condyles was quantified by enzyme-linked immunosorbent assay (ELISA) and visualized by immunohistochemistry. Friction coefficient measurements of cartilage plugs slid in the boundary lubrication system were obtained. OA severity was graded using histochemical analyses. The concentrations of SZP and proinflammatory cytokines in synovial fluid were determined by ELISA. Results A pattern of SZP localization in knee cartilage was identified, with load-bearing regions exhibiting high SZP expression. SZP expression patterns were correlated with friction coefficient and OA severity; however, SZP expression was observed in all samples at the articular surface, regardless of OA severity. SZP expression and aspirate volume of synovial fluid were higher in OA patients than in normal controls. Expression of cytokines was elevated in the synovial fluid of some patients. Conclusion Our findings indicate a mechanochemical coupling in which physical forces regulate OA severity and joint lubrication. The findings of this study also suggest that SZP may be ineffective in reducing joint friction in the boundary lubrication mode at an advanced stage of OA, where other mechanisms may dominate the observed tribological behavior. [source]


Aurothiomalate inhibits cyclooxygenase 2, matrix metalloproteinase 3, and interleukin-6 expression in chondrocytes by increasing MAPK phosphatase 1 expression and decreasing p38 phosphorylation: MAPK phosphatase 1 as a novel target for antirheumatic drugs

ARTHRITIS & RHEUMATISM, Issue 6 2010
Riina Nieminen
Objective Aurothiomalate is a disease-modifying antirheumatic drug that suppresses inflammation and retards cartilage degradation and bone erosion in arthritis. The molecular mechanisms of action of aurothiomalate are not known in detail. MAPK pathways are major signaling pathways in inflammation that regulate the production of many inflammatory and destructive factors in arthritis. The purpose of the present study was to investigate the effects of aurothiomalate on the activity of p38 MAPK and on the expression of MAPK phosphatase 1 (MKP-1), cyclooxygenase 2 (COX-2), matrix metalloproteinase 3 (MMP-3), and interleukin-6 (IL-6) in immortalized murine H4 chondrocytes and in intact human and murine cartilage. Methods Protein expression was examined by Western blotting or by enzyme-linked immunosorbent assay, and messenger RNA (mRNA) expression was examined by real-time reverse transcription,polymerase chain reaction analysis. The mediator role of MKP-1 was investigated by using small interfering RNA (siRNA) methods to down-regulated MKP-1 expression in chondrocytes in culture and by comparing the responses in intact cartilage from MKP-1,deficient and wild-type mice. The effects of aurothiomalate were also confirmed in human rheumatoid cartilage by using tissue samples obtained at the time of total knee replacement surgery. Results Aurothiomalate inhibited IL-1,,induced COX-2 expression and prostaglandin E2 production by destabilizing COX-2 mRNA, as did the p38 MAPK inhibitor SB203580. Interestingly, aurothiomalate also increased the expression of MKP-1 and reduced the IL-1,,induced phosphorylation of p38 MAPK. Knockdown of MKP-1 by siRNA significantly impaired the ability of aurothiomalate to inhibit the phosphorylation of p38 MAPK and the expression of COX-2, MMP-3, and IL-6. Likewise, aurothiomalate reduced COX-2, MMP-3, and IL-6 expression in articular cartilage from patients with rheumatoid arthritis, as well as in articular cartilage from wild-type mice but not from MKP-1,/, mice. Conclusion Our findings indicate a novel mechanism for the antiinflammatory and antierosive actions of aurothiomalate, through increased expression of MKP-1, which leads to reduced activation of p38 MAPK and suppressed expression of COX-2, MMP-3, and IL-6. The results suggest that manipulation of MKP-1 levels is a promising new mechanism to be directed in the search and development of novel antiinflammatory and antierosive compounds that have the good efficacy of gold compounds but not their toxicity. [source]


Nonsteroidal antiinflammatory drugs and prostaglandin E2 modulate the synthesis of osteoprotegerin and RANKL in the cartilage of patients with severe knee osteoarthritis

ARTHRITIS & RHEUMATISM, Issue 2 2010
Juan Moreno-Rubio
Objective Although the osteoprotegerin (OPG)/RANK/RANKL system is the main modulator of bone remodeling, it remains unclear whether it is regulated in cartilage during osteoarthritis (OA). The aim of this study was to examine whether nonsteroidal antiinflammatory drug (NSAID) treatment modulates the synthesis of OPG and RANKL in the cartilage of patients with OA, and to investigate whether prostaglandin E2 (PGE2) modifies this system in human OA chondrocytes in culture. Methods A 3-month clinical trial was carried out in 20 patients with severe knee OA, all of whom were scheduled to undergo knee replacement surgery. Ten of these patients were treated with celecoxib, and the other 10 patients, who did not want to be treated, served as the control group. After surgery, cartilage was processed for molecular biology studies. We also used human OA chondrocytes to examine the effects of PGE2 on OPG/RANKL synthesis, examining which surface receptors were affected by PGE2. Results In patients with OA, celecoxib decreased RANKL synthesis in the cartilage, thereby increasing the OPG:RANKL ratio. In human OA chondrocytes in culture, PGE2 elicited a dose- and time-dependent increase in the synthesis of RANKL, the extent of which was greater than that of OPG. Confocal microscopy revealed that PGE2 induced RANKL transport to the cell membrane. Only EP2/EP4 agonists reproduced the effects of PGE2 on OPG and RANKL induction. Conclusion Long-term NSAID treatment inhibited the resorptive signal synthesized by chondrocytes. In vitro, PGE2 regulated the expression and release of these key mediators of bone metabolism by articular chondrocytes. The role of OPG/RANK/RANKL in OA cartilage metabolism is still unknown, although the synthesis of these proteins would enable the cartilage to control the activity of subchondral bone cells. [source]


Role of p53 in human chondrocyte apoptosis in response to shear strain

ARTHRITIS & RHEUMATISM, Issue 8 2009
Shingo Hashimoto
Objective Chondrocyte apoptosis plays an important role in cartilage degeneration in osteoarthritis (OA), and mechanical injury to cartilage induces chondrocyte apoptosis. In response to DNA damage, p53 expression is up-regulated, transcription activity is increased, and apoptosis signals are initiated. The p53-regulated apoptosis-inducing protein 1 (p53AIP-1) is one of the p53-regulated genes, and is activated in response to DNA damage. This study was undertaken to analyze p53 function after induction of apoptosis by shear strain in chondrocytes. Methods OA cartilage samples were obtained from subjects undergoing total knee replacement surgery, and normal cartilage samples were obtained from subjects undergoing surgery for femoral neck fracture. Chondrocytes were isolated from human cartilage and cultured. Expression of p53 and p53AIP in chondrocytes was detected by reverse transcriptase,polymerase chain reaction and Western blotting. Shear strain was introduced in normal human knee chondrocytes. To explore p53 function, normal human knee chondrocytes were pretreated with pifithrin-, or p53 small interfering RNA (siRNA) before induction of shear strain. Chondrocyte apoptosis was detected by expression of cleaved caspase 9 with Western blotting and TUNEL staining. Expression of p53 and p53AIP-1 was analyzed by Western blotting. Results OA and normal chondrocytes expressed p53. OA chondrocytes showed much higher expression of p53 and p53AIP-1 than did normal chondrocytes. TUNEL-positive cells and expression of p53, p53AIP-1, and cleaved caspase 9 were increased by shear strain, but chondrocyte apoptosis was suppressed after pretreatment with pifithrin-, or p53 siRNA. Conclusion Our findings indicate that p53 and p53AIP-1 play important roles in human chondrocyte apoptosis. Down-regulation of p53 expression prevents cartilage from undergoing apoptosis introduced by shear strain. [source]


Increased expression of the Akt/PKB inhibitor TRB3 in osteoarthritic chondrocytes inhibits insulin-like growth factor 1,mediated cell survival and proteoglycan synthesis

ARTHRITIS & RHEUMATISM, Issue 2 2009
John D. Cravero
Objective The chondrocyte response to insulin-like growth factor 1 (IGF-1) is reduced with aging and in osteoarthritis (OA). IGF-1 signals through the phosphatidylinositol 3-kinase/Akt pathway. TRB3, a tribbles homolog, has been shown to inhibit IGF-1,mediated activation of Akt in HEK 293 cells. This study was undertaken to determine if TRB3 is expressed in chondrocytes, and whether the chondrocyte response to IGF-1 is reduced by TRB3. Methods Human articular cartilage was obtained from normal tissue donors and from patients with OA at the time of knee replacement surgery. TRB3 was assessed in the tissue samples by reverse transcription,polymerase chain reaction, immunoblotting, and immunohistochemistry. Overexpression of TRB3 was induced by transient transfection to determine the effects of TRB3 on cell survival and proteoglycan synthesis. Results TRB3 messenger RNA was detected in normal human chondrocytes. TRB3 protein levels were low in cells from normal cartilage but significantly increased in cells from OA cartilage. Incubation with 2 agents that induce endoplasmic reticulum stress, tunicamycin and thapsigargin, increased TRB3 levels in normal cells. Overexpression of TRB3 inhibited Akt phosphorylation and reduced chondrocyte survival and proteoglycan synthesis. Conclusion These results are the first to demonstrate that TRB3 is present in human chondrocytes, and that the level of TRB3 is increased in OA cartilage and in isolated OA chondrocytes. Because it is an inhibitor of Akt activation, elevated TRB3 production could play a role in the increased cell death and reduced response to IGF-1 observed in OA cartilage. [source]