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Purpose: To examine the applicability and process of change of Cognitive Functional Therapy (CFT) in the management of pain and disability in people with knee osteoarthritis who were offered knee replacement surgery and had risk factors for poor response to surgery., Methods: Single-case experimental design with a mixed-methods, repeated measures approach was used to investigate the process of change through CFT in four participants. Qualitative interviews investigated beliefs, behaviours and coping responses, and self-reported measures assessed pain, disability, psychological factors, and function at 25 timepoints. Study registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12619001491156)., Results: Qualitative data indicate that CFT promoted helpful changes in all participants, with two responses observed. One reflected a clear shift to a biopsychosocial conceptualisation of osteoarthritis, behavioural re-engagement and the view that a knee replacement was no longer necessary. The other response reflected a mixed conceptualisation with dissonant beliefs about osteoarthritis and its management. Psychological and social factors were identified as potential treatment barriers. Overall, quantitative measures supported the qualitative findings., Conclusion: The process of change varies between and within individuals over time. Psychological and social barriers to treatment have implications for future intervention studies for the management of knee osteoarthritis.IMPLICATIONS FOR REHABILITATIONCognitive Functional Therapy is applicable in the management of knee osteoarthritis.Reconceptualisation of osteoarthritis reflected a helpful change.Psychological and social factors emerged as barriers to recovery.

Background: Patient-reported outcome measure (PROM) questionnaires in national arthroplasty registries often have low response rates leading to questions about data reliability. In Australia, the SMART (St. Vincent's Melbourne Arthroplasty Outcomes) registry captures all elective total hip (THA) and total knee (TKA) arthroplasty patients with an approximate 98% response rate for preoperative and 12-month PROM scores. This high response rate is due to dedicated registry staff following up patients who do not initially respond (subsequent responders). This study compared initial responders to subsequent responders to find differences in 12-month PROM outcomes for THA and TKA., Methods: All elective THA and TKA patients for osteoarthritis from 2012 to 2021 captured by the SMART registry were included. In total, 1,333 THA and 1,340 TKA patients were included. The PROM scores were assessed using the Veterans-RAND 12 (VR12) and Western Ontario and McMasters Universities Arthritis Index (WOMAC) questionnaires. The primary outcome was differences in mean 12-month PROM scores between initial and subsequent responders., Results: Baseline characteristics and PROM scores were similar between initial and subsequent responders. However, 12-month PROM scores varied significantly. The adjusted mean difference showed that for the WOMAC pain score, subsequent responders scored 3.4 points higher in the THA cohort and 7.4 points higher in the TKA cohort compared to initial responders. Significant differences were also found in other WOMAC and VR12 scores for both THA and TKA cohorts at the 12-month timepoint., Conclusion: This study found that significant differences in PROM outcomes postsurgery occurred in THA and TKA patients based on response to PROM questionnaires, suggesting that loss to follow-up in PROM outcomes should not be treated as missing completely at random (MCAR)., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Previous research has focused on the perioperative or short-term (<1 year) mortality rate of total knee arthroplasty (TKA), leaving the long-term (>1 year) mortality rate unresolved. In this study, we calculated the mortality rate up to 15 years after primary TKA., Methods: Data from the New Zealand Joint Registry from April 1998 to December 2021 were analyzed. Patients aged 45 years or older who underwent TKA for osteoarthritis were included. Mortality data were linked with national records from births, deaths, and marriages. To determine the expected mortality rates in the general population, age-sex-specific life tables from statistics New Zealand were used. Mortality rate was presented as standardized mortality ratios (SMRs) - a comparison of relative mortality rate between the TKA and general populations. In total, 98,156 patients with a median follow-up of 7.25 years (range, 0.00 to 23.74) were included., Results: Over the entire follow-up period, 22,938 patients (23.4%) had died. The overall SMR for the TKA cohort was 1.08 (95% confidence interval (CI): 1.06 to 1.09), suggesting that TKA patients have an 8% higher mortality rate compared to the general population. However, a reduction in short-term mortality rate was observed for TKA patients up to 5 years post TKA (SMR 5 years post TKA; 0.59 95% CI: 0.57 to 0.60]). On the contrary, a significantly increased long-term mortality rate was observed in TKA patients with greater than 11 years of follow-up, particularly in men over the age of 75 years (SMR 11 to 15 years post TKA for males ≥ 75 years; 3.13 [95% CI: 2.95 to 3.31])., Conclusion: The results suggest a reduction in short-term mortality rate for patients who undergo primary TKA. However, there is an increased long-term mortality rate particularly in men over the age of 75 years. Importantly, the mortality rates observed in this study cannot be causally attributed to TKA alone., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Current predictive tools for TKA focus on clinicians rather than patients as the intended user. The purpose of this study was to develop a patient-focused model to predict health-related quality of life outcomes at 1-year post-TKA., Methods: Patients who underwent primary TKA for osteoarthritis from a tertiary institutional registry after January 2006 were analysed. The primary outcome was improvement after TKA defined by the minimal clinically important difference in utility score at 1-year post-surgery. Potential predictors included demographic information, comorbidities, lifestyle factors, and patient-reported outcome measures. Four models were developed, including both conventional statistics and machine learning (artificial intelligence) methods: logistic regression, classification tree, extreme gradient boosted trees, and random forest models. Models were evaluated using discrimination and calibration metrics., Results: A total of 3755 patients were included in the study. The logistic regression model performed the best with respect to both discrimination (AUC = 0.712) and calibration (intercept = -0.083, slope = 1.123, Brier score = 0.202). Less than 2% (n = 52) of the data were missing and therefore removed for complete case analysis. The final model used age (categorical), sex, baseline utility score, and baseline Veterans-RAND 12 responses as predictors., Conclusion: The logistic regression model performed better than machine learning algorithms with respect to AUC and calibration plot. The logistic regression model was well calibrated enough to stratify patients into risk deciles based on their likelihood of improvement after surgery. Further research is required to evaluate the performance of predictive tools through pragmatic clinical trials., Level of Evidence: Level II, decision analysis., (© 2023 The Authors. ANZ Journal of Surgery published by John Wiley & Sons Australia, Ltd on behalf of Royal Australasian College of Surgeons.)

Background: Approximately 1 in 5 patients feel unsatisfied after total knee arthroplasty (TKA). Prognostic tools may aid in the patient selection process and reduce the proportion of patients who experience unsatisfactory surgery. This study uses the prognostic tool SMART Choice (Patient Prognostic Tool for Total Knee Arthroplasty) to predict patient improvement after TKA. The tool aims to be used by the patient without clinician input and does not require clinical data such as X-ray findings or blood results. The objective of this study is to evaluate the SMART Choice tool on patient decision making, particularly willingness for surgery. We hypothesise that the use of the SMART Choice tool will influence willingness to undergo surgery, especially when used earlier in the patient TKA journey., Methods: This is a multicentred, pragmatic, randomised controlled trial conducted in Melbourne, Australia. Participants will be recruited from the St. Vincent's Hospital, Melbourne (SVHM) Orthopaedic Clinic, and the client base of HCF, Australia (private health insurance company). Patients over 45 years of age who have been diagnosed with knee osteoarthritis and considering TKA are eligible for participation. Participants will be randomised to either use the SMART Choice tool or treatment as usual. The SMART Choice tool provides users with a prediction for improvement or deterioration / no change after surgery based on utility score change calculated from the Veterans-RAND 12 (VR-12) survey. The primary outcome of the study is patient willingness for TKA surgery. The secondary outcomes include evaluating the optimal timing for tool use and using decision quality questionnaires to understand the patient experience when using the tool. Participants will be followed up for 6 months from the time of recruitment., Discussion: The SMART Choice tool has the potential to improve patient decision making for TKA. Although many prognostic tools have been developed for other areas of surgery, most are confined within academic bodies of work. This study will be one of the first to evaluate the impact of a prognostic tool on patient decision making using a prospective clinical trial, an important step in transitioning the tool for use in clinical practice., Trial Registration: Australia and New Zealand Clinical Trials Registry (ANZCTR) - ACTRN12622000072718 . Prospectively registered - 21 January 2022., (© 2022. The Author(s).)

Introduction: Fifty per cent of patients consent for total knee replacement (TKR) with unrealistic expectations about what it involves and can achieve. A framework is needed to help surgeons identify key knowledge gaps and misconceptions that can be targeted during the informed consent process. In this qualitative study, we explored knowledge gaps and misconceptions by asking patients to reflect on their expectations along the TKR journey., Methods: Eligible adults were ≥18 years, 12-month post-TKR and had completed a validated expectations questionnaire pre-TKR as part of a joint replacement registry. To capture a variety of perspectives, people with a range of pre-TKR expectation scores were invited. In interviews, participants reflected on anticipated and actual experiences and unexpected experiences they had along the way. Transcripts were analysed through inductive thematic analysis. Recruitment ceased when thematic saturation was reached., Ethics Approval: Ethical approval for this study was granted by the St Vincent's Hospital Melbourne Ethics Committee (LRR 077/18)., Results: In the final sample (n = 20; 50% female; median age = 72 years; contralateral TKR = 11), all participants described instances where their anticipated and actual experiences diverged, including high expectations of improvements in pain/function (pre-surgical optimism), lacking awareness about anaesthetic procedures (perioperative misunderstandings), feeling unprepared for the length of the recovery period (post-operative misestimations) and trying to make sense of ongoing functional limitations (long-term misattributions)., Discussion and Conclusion: These findings are captured in a preliminary framework of therapeutic misconception. Although future research is needed to test this framework prospectively in larger, more generalisable samples, surgeons can consider these key knowledge gaps and misconceptions when consenting for TKR., (© 2020 John Wiley & Sons, Ltd.)

Purpose: As patient-reported outcome measures (PROMs) are increasingly integrated into clinical practice, there is a need to translate collected data into valuable information to guide and improve the quality and value of patient care. The purpose of this study was to investigate health-related quality-of-life (QoL) trajectories in the 5 years following total knee replacement (TKR) and the patient characteristics associated with these trajectories. The feasibility of translating QoL trajectories into valuable information for guiding patient-centered care was also explored., Methods: Data on patients who underwent TKR between 2006 and 2011 from a single-institution registry were extracted including patient-reported QoL (captured using the Short Form Survey (SF-12) instrument) up to 5 years post-surgery. QoL trajectories were modelled using latent class growth analysis. Quality-adjusted life-years (QALYs) were calculated to illustrate longer term health benefit. Multinomial logistic regression analyses were performed to examine the association between trajectory groups and baseline patient characteristics., Results: After exclusions, 1553 patients out of 1892 were included in the analysis. Six unique QoL trajectories were identified; with differing levels at baseline and improvement patterns post-surgery. Only 18.4% of patients were identified to be in the most positive QoL trajectory (low baseline, large sustainable improvement after surgery) associated with the greatest gain in QALY. These patients were likely to be younger, have no co-morbidities and report greater pain at pre-surgery than most in other QoL trajectories., Conclusions: Our findings demonstrate the importance of underlying heterogeneity in QoL trajectories, resulting in variable QALY gains. There is scope in translating routinely collected PROMs to improve shared decision-making allowing for more patient engagement. However, further research is required to identify suitable approaches of its implementation into practice to guide clinical care and maximize patient outcomes.

Osteoarthritis is a debilitating condition as well as a growing global health problem, and total knee arthroplasty (TKA) is an effective treatment for advanced disease. Unplanned 30-day hospital readmission is an indicator of complications, which is a significant financial burden on healthcare systems. We reviewed the literature to better understand the patient-related factors associated with unplanned 30-day readmission following TKA. MEDLINE and EMBASE were searched for studies reporting on patient-related risk factors for unplanned 30-day readmission following primary or revision TKA for any indication. The impact of specific medical comorbidities on increasing the risk of 30-day readmission following TKA is quite well established. The following comorbidities are strongly associated with readmission: bleeding disorder, diabetes, chronic kidney disease and dialysis, chronic immunosuppressant use and history of cancer. Other significant comorbidities include: dementia; depression; haematological (coagulopathy and anaemia), cardiovascular (atrial fibrillation, cardiovascular disease, coronary artery disease and congestive heart failure), respiratory (chronic obstructive pulmonary disease) and liver diseases; and cerebrovascular accident/transient ischaemic attack (but only in revision TKA patients). The influence of variation in sex, age and body mass index each demonstrate a more complex pattern. A systematic review and meta-analysis is required to quantify the impact of the various patient-related factors on 30-day readmission following TKA. Clinicians can use this information in preoperative decision-making., (© 2020 Royal Australasian College of Surgeons.)

Background . There is growing evidence that quality of life (QoL) has a strong association with mortality. However, incorporation of QoL is uncommon in standard survival modeling. Methods . Using data extracted from a registry of patients undergoing total knee replacement (TKR), the impact of incorporating QoL in survival modeling was explored using 4 parametric survival models. QoL was incorporated and tested in 2 forms, which are baseline and change in QoL due to intervention. Life expectancy and quality-adjusted life years (QALYs) were calculated and comparisons made to a reference model (no QoL) to translate the findings in the context of modeled economic evaluations. Results . A total of 2858 TKR cases (2309 patients) who had TKR between 2006 and 2015 were included in this analysis. Increases in baseline and change in QoL were associated with a reduction in mortality. Compared to the reference model, differences of up to 0.32 life years and 0.53 QALYs were observed, and these translated into a 9.5% change in incremental effectiveness. These differences were much larger as the strength of the association between QoL and mortality increased. Conclusions . This work has demonstrated that the inclusion of QoL measures (at baseline and change from baseline) when extrapolating survival does matter. It can influence health outcomes such as life expectancy and QALYs, which are relevant in cost-effectiveness analysis. This is important because neglecting the correlation between QoL and mortality can lead to imprecise extrapolations and thus risk misleading results affecting subsequent decisions made by policy makers.

Background: Osteoarthritis is a debilitating condition as well as a growing global health problem, and total knee arthroplasty is an effective treatment for advanced stages of disease. Unplanned 30-day hospital readmission is an indicator of complications, which is a significant financial burden on healthcare systems. The objective is to perform a systematic review of patient-related factors associated with unplanned 30-day readmission following total knee arthroplasty. This information will inform future strategies to improve health outcomes after knee arthroplasty surgery., Methods: MEDLINE and EMBASE will be systematically searched using a comprehensive search strategy. Studies of higher quality than case series will be included, in order to optimise the quality of the findings of this review. We will include studies reporting on patient-related risk factors for unplanned 30-day readmission following primary or revision total knee arthroplasty for any indication. Case series will be excluded, as will studies reporting exclusively on intraoperative, clinician, hospital, and health system risk factors. The reference lists of selected papers will then be screened for any additional literature. Two reviewers will independently apply stringent eligibility criteria to titles, abstracts, and full texts of studies identified in the literature search. They will then extract data from the final list of selected papers according to an agreed-upon taxonomy and vocabulary of the data to be extracted. Assessment of risk of bias and quality of evidence will then take place. Finally, the effect size of each identified risk factor will be determined; meta-analysis will be performed where adequate data is available., Discussion: The findings of this review and subsequent meta-analysis will aid clinicians as they seek to understand the risk factors for 30-day readmission following total knee arthroplasty. Clinicians and patients will be able to use this information to align expectations of the postoperative course, which will enhance the recovery process, and aid in the development of strategies to mitigate identified risks. Another purpose of this review is to assist policy-makers in developing quality indicators for care and provide insights into the drivers of health costs., Systematic Review Registration: PROSPERO CRD42019118154.

Aims: As the population ages, there is projected to be an increase in the level of demand for total knee arthroplasty (TKA) in octogenarians. We aimed to explore whether those aged ≥ 80 years achieved similar improvements in physical function to younger patients while also comparing the rates of length of stay (LOS), discharge to rehabilitation, postoperative complications, and mortality following TKA in older and younger patients., Patients and Methods: Patients from one institution who underwent primary elective TKA between 1 January 2006 and 31 December 2014 were dichotomized into those ≥ 80 years old (n = 359) and those < 80 years old (n = 2479) for comparison. Multivariable regression was used to compare the physical status component of the 12-Item Short-Form Health Survey (SF-12), LOS, discharge to rehabilitation, complications, and mortality between the two groups., Results: Both age groups demonstrated a clinically meaningful improvement in their self-reported physical health relative to their baseline with no clinically relevant difference noted between them. Being ≥ 80 years old was associated with a 0.58-day increase in LOS and older patients were more likely to be discharged to rehabilitation (odds ratio (OR) 3.06, p < 0.001). Medical complications and mortality were higher in elderly patients (OR 1.92 for complications, p < 0.001; hazard ratio 3.40 for death, p < 0.001). There was no statistically significant association between age group and experiencing a postoperative surgical or wound-related complication., Conclusion: Those aged over 80 years achieved a statistically significant lower median SF-12 physical score than the younger group, after adjusting for the preoperative score, but this difference of 4.46 was not considered to be clinically meaningful. However, clinicians should be aware that the elderly are at a higher risk of experiencing longer hospital stays, postoperative medical complications, and mortality. Cite this article: Bone Joint J 2018;100-B:1463-70.

Background: Gait biomechanics, sex, and obesity can contribute to suboptimal outcomes from primary total knee arthroplasty. The aims of this study were to i) determine if sex and/or obesity influence the amount of change in gait biomechanics from pre-surgery to six months post-surgery and; ii) assess if gait returns to normal in men and women., Methods: Three-dimensional gait analysis was performed on 43 patients undergoing primary total knee arthroplasty for knee osteoarthritis (pre- and six months post-operative) and 40 asymptomatic controls. Mixed linear regression models were fit to assess which factors influenced change in gait biomechanics within the arthroplasty cohort, and interaction terms were included to assess if biomechanics returned to normal following surgery., Findings: Male peak knee adduction moment (p < 0.001) and impulse (p < 0.001) decreased six months following arthroplasty, whilst gait in women remained unchanged after surgery. Obesity did not influence gait changes in men or women. Gait of female arthroplasty participants did not differ from female controls after surgery except for sagittal plane knee range of motion (p = 0.003), whilst men differed from controls for peak knee adduction moment (p = 0.011), knee range of motion (p < 0.001), and peak knee flexion moment (p < 0.001)., Interpretation: Sex, but not obesity, influenced changes in gait biomechanics after arthroplasty. Men retained abnormal gait patterns after surgery, whilst women did not. Further research should determine the long-term implications of gait abnormalities seen in men after arthroplasty., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objectives: The demand for total knee arthroplasty (TKA) is increasing. Differentiating who will derive a clinically meaningful improvement from TKA from others is a key challenge for orthopaedic surgeons. Decision aids can help surgeons select appropriate candidates for surgery, but their uptake has been low. The aim of this study was to explore the barriers and facilitators to decision aid uptake among orthopaedic surgeons., Design: A qualitative study involving face-to-face interviews. Questions were constructed on the Theoretical Domains Framework to systematically explore barriers and facilitators., Setting: One tertiary hospital in Australia., Participants: Twenty orthopaedic surgeons performing TKA., Outcome Measures: Beliefs underlying similar interview responses were identified and grouped together as themes describing relevant barriers and facilitators to uptake of decision aids., Results: While prioritising their clinical acumen, surgeons believed a decision aid could enhance communication and patient informed consent. Barriers identified included the perception that one's patient outcomes were already optimal; a perceived lack of non-operative alternatives for the management of end-stage osteoarthritis, concerns about mandatory cut-offs for patient-centred care and concerns about the medicolegal implications of using a decision aid., Conclusions: Multifaceted implementation interventions are required to ensure that orthopaedic surgeons are ready, willing and able to use a TKA decision aid. Audit/feedback to address current decision-making biases such as overconfidence may enhance readiness to uptake. Policy changes and/or incentives may enhance willingness to uptake. Finally, the design/implementation of effective non-operative treatments may enhance ability to uptake by ensuring that surgeons have the resources they need to carry out decisions., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Objective: Preoperative pain and function is viewed as an important predictor of total knee arthroplasty (TKA) outcomes. We examined whether variations in pain and function outcomes existed at 12 months between two centres in Sweden and Australia, and whether this was explained by variations in patient presentation for TKA., Methods: This was a retrospective analysis of prospectively collected data. Patients from one centre in Australia (St. Vincent's Hospital (SVH), N = 516) and in Sweden (Trelleborg (TBG), N = 899) who underwent primary TKA between 2012 and 2013. The Western Ontario and McMaster Universities Arthritis Index (WOMAC) was analysed pre- and 12 months' post TKA from which non-response to surgery was determined using the OMERACT-OARSI criteria. Multiple linear regression analysis was used to examine the relationship between change in pain and function and surgery centre, adjusting for preoperative patient characteristics and surgical technique., Results: Despite worse preoperative outcomes in all subscales of the WOMAC for the SVH cohort, there were no clinically meaningful differences in 12-month WOMAC subscales nor change in WOMAC subscales between SVH and TBG. Almost identical proportions of patients were considered OMERACT-OARSI responders, 85.7% (SVH) and 85.9% (TBG), however for the SVH cohort 25 (4.9%) were moderate and 417 (80.8%) were high responders, compared to the TBG cohort of which 225 (25%) were moderate and 547 (60.9%) were high responders., Conclusion: Despite differences in preoperative presentation between 2 countries, improvements in pain and function and the proportion of individual who responded to TKA surgery at 1 year were similar. Factors related to poor response to TKA surgery require further elucidation., (Copyright © 2016 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Background: A patient- and surgeon-Delphi-derived Outcome Measures in Rheumatology (OMERACT) draft core domain set for total joint arthroplasty (TJR) trials was recently developed. Our objective was to obtain further patient stakeholder endorsement of draft core domain set for TJR clinical trials., Methods: We surveyed two patient groups: (1) OMERACT patient partners; and (2) patients who had undergone hip or knee TJR. Patients received an introductory email with explanations about the core domain set and instructions to rate the core domains, i.e., important aspects, of OMERACT TJR clinical trial draft core domain set. Rating was on a nominal scale, where 1-3 indicated a domain of limited importance, 4-6 an important, but not critical domain, and 7-9 a critical domain. We used Mann-Whitney test (a non-parametric test) to compare the distribution of ratings between the two groups., Results: Thirty one survey participants from the OMERACT patient partner group and 118 knee/hip TJR patients responded with response rates of 66 and 80%, respectively. Majority of the survey respondents were female, 87 vs. 53%, and were 55 years or older, 57 vs. 94%. Median (interquartile range [IQR]) scores for six core domains by OMERACT and knee/hip TJR patient groups were, respectively: pain, 8 [8, 9] and 9 [8, 9]; function, 9 [8, 9] and 9 [8, 9]; patient satisfaction, 8 [8, 9] and 8 [7, 9]; revision surgery, 7 [7, 8] and 7 [5, 9]; adverse events, 8 [7, 9] and 8 [6, 9]; and death, 9 [6, 9] and 9 [4, 9]. No statistically significant differences in rating were noted for any of the six core domains between the two groups (p ≥ 0.31). Among the additional domains, ratings for patient participation did not differ by group (p = 0.98), but ratings for cost were significantly different (p = 0.005). Patients provided qualitative feedback regarding core domains, and did not propose any modifications to the draft core domain set., Conclusions: Two separate patient stakeholder groups endorsed the OMERACT TJR draft core domain set for TJR trials.

Objective: To characterize groups of subjects according to their trajectory of knee pain and function over 1 to 5 years post total knee arthroplasty (TKA)., Methods: Patients from one centre who underwent primary TKA (N = 689) between 2006 and 2008. The Knee Society Score (KSS) was collected pre-operatively and annually post-operatively. Latent Class Growth Analysis (LCGA) was used to classify groups of subjects according to their trajectory of knee pain and function over 1-5 years post-surgery., Results: LCGA identified a class of patients with persistent moderate knee pain (22.0%). Predictors (OR, 95% CI) of moderate pain trajectory class membership were pre-surgery SF12 mental component summary (MCS) per 10 points (0.65, 0.54-0.79) and physical component summary (PCS) per 10 points (0.50, 0.33-0.76), Charlson Comorbidity Index (CCI) one (1.70, 1.07-2.69) and ≥two (2.82, 1.59-4.81) and the absence of computer-navigation (2.26, 1.09-4.68). LCGA also identified a class of patients with poor function (23.0%). Predictors of low function trajectory class membership were, female sex (3.31, 1.95-5.63), advancing age per 10 years (2.27, 1.69-3.02), pre-surgery PCS per 10 points (0.50, 0.33-0.74), obesity (1.69, 1.05-2.72), morbid obesity (3.12, 1.55-6.27) and CCI ≥two (2.50, 1.41-4.42)., Conclusions: Modifiable predictors of poor response to TKA included baseline co-morbidity, physical and mental well-being and obesity. This provides useful information for clinicians in terms of informing patients of the expected course of longer term outcomes of TKA and for developing prediction algorithms that identify patients in whom there is a high likelihood of poor surgical response., (Copyright © 2015. Published by Elsevier Ltd.)

Objective: Total joint arthroplasty (TJA) places a significant economic burden on health care resources. This cohort study examines the costs associated with arthroplasty in 827 patients undergoing hip and knee TJA from January 2011 to June 2012 at a single center in Melbourne, Australia., Methods: Data included total inpatient, outpatient, and readmissions costs in the 30 days following TJA. Factors associated with cost were modeled using negative binomial regression and extrapolated to the Australian population., Results: The base cost (i.e., the cost for a patient with no modifying factors) over the first 30 days following TJA was $13,060 Australian (AU) (interquartile range $12,126-14,067 AU). The median length of stay was 4 days (range 2-33 days) and 35 patients (4%) were readmitted in the first 30 days following index TJA, the majority of whom had a surgical site infection (SSI) (74%). The following factors were independently associated with increased costs: SSI, preoperative warfarin therapy, American Society of Anesthesiologists score of 3 or 4, hip TJA, increasing operation time, increasing postoperative blood transfusion requirements, other nosocomial infections, postoperative venous thromboembolism (VTE), pressure ulcers, postoperative confusion, and acute urinary retention. Based on data from the present study, the cost of TJA in Australia is estimated to exceed $1 billion AU per year. Preventable postoperative complications were major cost drivers: SSI and VTE added a further $97 million AU and $66 million AU, respectively, to arthroplasty costs in the first 30 days following surgery., Conclusion: This unique study has identified important factors influencing TJA costs and providing guidance for future research and resource allocation., (© 2015, American College of Rheumatology.)

Background: Knee arthroplasty (KA) is recognized as an effective treatment of knee joint osteoarthritis and up to 90% of patients experience substantial pain relief. There has been no systematic review synthesizing the longitudinal changes in gait following KA. The aims of this systematic review were to determine the effects of KA on (i) frontal plane and (ii) sagittal plane kinematic and kinetic parameters during the stance phase of gait., Methods: MEDLINE (PubMed), CINAHL, SPORTdiscus (EBSCO), and Cochrane Library (Wiley) were searched until April 10th, 2014. 1,765 articles were identified, of which 19 studies describing 3-dimensional gait analysis pre- and post-KA were included. Study quality was evaluated by two reviewers independently using the Downs and Black checklist., Findings: Following KA, in the frontal plane, the maximum knee adduction angle and external knee adduction moment (KAM) tended to decrease. In the sagittal plane, findings suggest that the maximum knee flexion moment is increased. From the ten studies that included a healthy reference group, it was unclear whether gait variables returned to normal following KA., Interpretation: Overall, it appears that KA results in a decreased peak KAM and maximum knee adduction angles, an increased peak knee flexion moment and inconsistent changes in the peak knee flexion angle. Knowledge gaps remain due to methodological inconsistencies across studies, limited statistical analysis, and largely heterogeneous sample populations. More research is needed to determine whether KA restores gait patterns to normal, or if additional rehabilitation may be needed to optimize gait following surgery for osteoarthritis., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Introduction: Wound complications following arthroplasty are associated with significant impact on the patient and healthcare system. Skin cleansing prior to surgical incision is a simple and effective method to prevent wound complications however, the question of which agent is superior for surgical skin antisepsis is unresolved., Methods and Analysis: This cluster randomised controlled trial aims to compare the incidence of superficial wound complications in patients undergoing elective prosthetic hip or knee replacement surgery receiving surgical skin antisepsis with either: 0.5% chlorhexidine gluconate (CHG) in 70% alcohol or 10% povidone in 70% alcohol. The trial will be conducted at an Australian tertiary, university affiliated hospital over a 3-year period involving 750 participants. Participants will be drawn from the surgical waiting list. Consent for this study will be 'opt-out' consent. On a given day, all eligible participants will have skin preparation either with 0.5% chlorhexidine in 70% alcohol or 10% povidone iodine in 70% alcohol. The primary outcome is superficial wound complications (comprised of superficial incisional surgical site infections (SSI) and/or prolonged wound ooze) in the first 30 days following prosthetic joint replacement surgery. Secondary outcomes will include the incidence of wound complications according to the joint replaced, assessment of the causative agents of SSI and cost-effectiveness analysis. The primary analysis is an intention-to-treat analysis including all participants who undergo randomisation and will be performed at the individual level taking into account the clustering effect., Ethics and Dissemination: The study design and protocol was reviewed and approved by the St Vincent's Hospital Human Research Ethics Committee (HREC-A 016/14 10/3/2014). Study findings will be disseminated in the printed media, and learned forums. A written lay summary will be available to study participants on request., Trial Registration Number: The trial has been registered with the Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12614000177651., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Superficial wound complications have been consistently implicated in the development of prosthetic joint infection. This cohort study aimed to determine perioperative risk factors associated with superficial wound complications. The study was performed over an 18-month period (January 2011 to June 2012) and included 964 patients undergoing prosthetic hip or knee replacement surgery. The factors associated with superficial wound complication differed according to arthroplasty site. In the combined cohort the following factors were associated with superficial wound complications: the use of 0.5% chlorhexidine in 70% alcohol for surgical skin preparation compared with 1% iodine in 70% alcohol (odds ratio (OR) 4.75; 95% confidence interval (CI) 1.42, 15.92; p = 0.012); increasing age (OR, 1.13; 95% CI, 1.06,1.19; p 0.18); increasing body mass index (BMI) (OR, 1.08; 95% CI, 1.05,1.12; p < 0.001); rheumatoid arthritis (OR, 2.56; 95% CI, 1.17, 5.58; p 0.018); and increasing blood transfusions (OR, 1.26; 95% CI, 1.06,1.49; p 0.008). In the hip arthroplasty cohort, the use of 0.5% chlorhexidine in 70% alcohol for surgical skin preparation (OR, 13.35; 95% CI, 2.11, 84.29; p 0.006), increasing BMI (OR, 1.13; 95% CI, 1.06, 1.19; p < 0.001) and increasing blood transfusions (OR, 1.26; 95% CI, 1.06, 1.49; p 0.008) were associated with superficial wound complications. In the knee arthroplasty cohort rheumatoid arthritis (OR, 2.75; 95% CI, 1.03, 7.33; p 0.043) and increasing tourniquet time (OR, 1.01; 95% CI, 1.00, 1.02; p = 0.029) were independent predictors of superficial wound complications. Further research is warranted to assess the impact of modification of these factors on the subsequent development of wound complications and prosthetic joint infection., (© 2013 The Authors Clinical Microbiology and Infection ©2013 European Society of Clinical Microbiology and Infectious Diseases.)

Objective: To assess the influence of pre-operative X-ray changes on the response to total knee joint replacement (TKR)., Methods: We included patients from one centre who underwent primary TKR (n = 478) for osteoarthritis in 2006 and 2007. The International Knee Society score (IKSS) and short form health survey were collected pre-operatively and at 1 and 2 years after surgery. Pre-operative radiographs were read to assess Kellgren and Lawrence (K-L) grading, individual radiographic features using the OARSI atlas, and subchondral bone attrition using the Ahlbach method. The main independent variable was a modified (K-L) grade. The outcome variables were the IKSS pain and function scores. Covariates included demographic features, co-morbidities, baseline pain and function, prosthesis type, and the use of patella resurfacing. Multivariable linear regression models were created to assess the relationships between pre-operative X-ray findings and pain and function outcomes., Results: On average, pain and function improved greatly following surgery. However, pain relief was unsatisfactory in about 30%, and functional improvement suboptimal in about 50%. OR (95% CI) for ongoing moderate-severe pain at 12 months for modified K-L grades; <3: 5.39 (1.23-15.69), 3a: 2.62 (1.21-5.67), 3b: 1.81 (1.00-3.26), 4a: 2.06 (1.05-4.05) when compared to 4b. OR (95% CI) for poor function at 12 months were; 3a: 2.81 (1.23-6.39) and 4a: 2.45 (1.22-4.91), when compared to 4b., Conclusions: Patients with more severe radiographic knee damage at the time of surgery are most likely to have substantial gains in terms of both pain relief and improved function as a result of a TKR., (Copyright © 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Prosthetic joint infection is a devastating complication of arthroplasty. Previous epidemiological studies have assessed factors associated with arthroplasty infections but have not assessed the impact of comorbidity on infection at different arthroplasty locations. We used a case-control design to investigate risk factors for prosthetic joint infection with reference to the anatomical site. During an eight-year period at a single hospital, 63 patients developed a prosthetic joint infection (36 hips, 27 knees). Cases of prosthetic hip or knee joint infection were matched 1:2 to controls. The results suggest that factors associated with arthroplasty infections differ with anatomical location. Following knee arthroplasty, wound discharge was associated with an increased risk of prosthetic joint infection whereas the presence of a drain tube reduced the risk. By contrast, increased body mass index, increased drain tube loss and superficial incisional surgical site infections (SSIs) were associated with prosthetic hip infection. When analysed as a combined cohort, systemic steroid use, increased SSI drain tube losses, wound discharge, and superficial incisional SSIs were predictors of infection., (Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.)

The role of computer-assisted surgery in maintaining the level of the joint in primary knee joint replacement (TKR) has not been well defined. We undertook a blinded randomised controlled trial comparing joint-line maintenance, functional outcomes, and quality-of-life outcomes between patients undergoing computer-assisted and conventional TKR. A total of 115 patients were randomised (computer-assisted, n = 55; conventional, n = 60). Two years post-operatively no significant correlation was found between computer-assisted and conventional surgery in terms of maintaining the joint line. Those TKRs where the joint line was depressed post-operatively improved the least in terms of functional scores. No difference was detected in terms of quality-of-life outcomes. Change in joint line was found to be related to change in alignment. Change in alignment significantly affects change in joint line and functional scores.

Background: Infection after primary knee arthroplasty is devastating. The aim of this study was to determine the significance of sentinel infective events prior to the development of haematogenous prosthetic knee infection., Methods: A retrospective single-centre case control study of 1641 primary knee arthroplasties was conducted between 1998 and 2006. Seventeen haematogenous prosthesis infections were identified and were matched with 51 controls. Perioperative data were collected prospectively, and co-morbidities, infection parameters and sentinel events were collected from patient files and questionnaires. Analysis was performed between controls and the 17 haematogenous infections., Results: The overall prosthetic infection rate was 2.2%. Acute infections accounted for 1.2% with late haematogenous accounting for 1%. The mean time to infection in the haematogenous infection group was 2.3 years (range 3 months to 11 years), and the mean follow-up was 3.8 years (range 7 months to 11 years). Significant risk factors included the number of co-morbidities (relative risk 3.4) and a sentinel event of cellulitis (relative risk 2.7). Fifteen of 17 cases described a sentinel event prior to infection compared with 31 of 51 controls (P= 0.041). The commonest preceding event was skin or soft tissue infection in nine (53%) cases. The most common infecting organism was Staphylococcus aureus in 12 patients (four methicillin-resistant Staphylococcus aureus, eight methicillin-sensitive Staphylococcus aureus)., Conclusions: Fifteen of 17 (88%) patients who developed late haematogenous infection had a preceding sentinel event with the commonest source being skin and soft tissue infection. Haematogenous infections are more likely to occur in patients with multiple co-morbidities., (© 2010 The Authors. ANZ Journal of Surgery © 2010 Royal Australasian College of Surgeons.)

We carried out a prospective, continuous study on 529 patients who underwent primary total knee replacement between January 2006 and December 2007 at a major teaching hospital. The aim was to investigate weight change and the functional and clinical outcome in non-obese and obese groups at 12 months post-operatively. The patients were grouped according to their pre-operative body mass index (BMI) as follows: non-obese (BMI < 30 kg/m(2)), obese (BMI (3) 30 to 39 kg/m(2)) and morbidly obese (BMI > 40 kg/m(2)). The clinical outcome data were available for all patients and functional outcome data for 521 (98.5%). Overall, 318 (60.1%) of the patients were obese or morbidly obese. At 12 months, a clinically significant weight loss of > or =5% had occurred in 40 (12.6%) of the obese patients, but 107 (21%) gained weight. The change in the International Knee Society score was less in obese and morbidly obese compared with non-obese patients (p = 0.016). Adverse events occurred in 30 (14.2%) of the non-obese, 59 (22.6%) of the obese and 20 (35.1%) of the morbidly obese patients (p = 0.001).

Purpose: To compare the radiological and functional outcomes of patients who underwent either computer-assisted or conventional total knee arthroplasty (TKA)., Methods: Two groups of 50 patients each underwent either computer-assisted or conventional TKA were retrospectively studied. Patients were matched according to body mass index (BMI), gender, and age. Three senior orthopaedic surgeons with comparable experience performed all surgeries, using 3 different prostheses. The surgical approach and peri- and postoperative regimens were the same. The mechanical axis and the tibial and femoral angles were measured using standardised long-leg weight-bearing radiographs. Overall function was assessed using the Short Form-12 (SF-12) and International Knee Society (IKS) scores., Results: No intra-operative technical difficulties were encountered in either group. The computer-assisted group resulted in more consistent and accurate alignments in both the coronal and sagittal planes and better SF-12 and IKS scores. In obese patients (BMI=30 kg/m2 or more), computer-assisted TKA provided better alignment than the conventional technique., Conclusion: Computer-assisted TKA improves implant positioning, limb alignment, and overall functional outcome. It may be particularly advantageous for obese patients.

Objective: To ascertain the effectiveness of clinical pathways for improving patient outcomes and decreasing lengths of stay after hip and knee arthroplasty., Design and Setting: Twelve-month randomised prospective trial comparing patients treated through a clinical pathway with those treated by an established standard of care at a single tertiary referral university hospital., Participants: 163 patients (56 men and 107 women; mean age, 66 years) undergoing primary hip or knee arthroplasty, and randomly allocated to the clinical pathway (92 patients) and the control group (71 patients)., Main Outcome Measures: Time to sitting out of bed and walking; rates of complications and readmissions; match to planned discharge destination; and length of hospital stay., Results: Clinical pathway patients had a shorter mean length of stay (P = 0.011), earlier ambulation (P = 0.001), a lower readmission rate (P = 0.06) and closer matching of discharge destination. There were beneficial effects of attending patient seminars and preadmission clinics for both pathway and control patients., Conclusion: Clinical pathway is an effective method of improving patient outcomes and decreasing length of stay following hip and knee arthroplasty.