The relation between total joint arthroplasty and risk for serious cardiovascular events in patients with moderate-severe osteoarthritis: propensity score matched landmark analysis

Evaluation of the Effectiveness of Canadian Cardiovascular Society Guidelines in Minimizing Cardiac Events After Total Hip Arthroplasty

BACKGROUND

The aim of the study was to analyze the Canadian Cardiovascular Society (CCS) guidelines for routine postoperative troponin testing after elective total hip arthroplasty (THA) to reduce the mortality rate resulting from myocardial injury. The purpose of this study was to assess the prognostic relevance of implementing these guidelines to minimize cardiac events in patients undergoing elective THA.

METHODS

Patients who underwent THA surgery in 2020 were included in the study. The inclusion criteria were elective THA patients aged ≥45 years, while emergency, revision, and simultaneous bilateral THA surgeries were excluded. The patients were categorized into 4 groups based on the CCS guidelines.

RESULTS

The study included 669 patients who had an average age of 67 years. There were 43 patients (6.4%), who experienced a rise in troponin levels ≥30 ng/L and developed myocardial injury after noncardiac surgery. Among these patients, 8 developed cardiac complications, and one experienced a serious cardiac event that resulted in death. Notably, there was a significant increase in the length of hospital stay for patients who received the postoperative screening protocol.

CONCLUSIONS

The implementation of the CCS guidelines for routine postoperative troponin testing in elective THA surgery did not significantly decrease the rate of cardiac events or mortality.

Prior Authorization Leads to Administrative Burden and Delays in Treatment in Primary Total Joint Arthroplasty Patients

BACKGROUND

The prior authorization (PA) process is often criticized by physicians due to increased administrative burden and unnecessary delays in treatment. The effects of PA policies on total hip arthroplasty (THA) and total knee arthroplasty (TKA) have not been well described. The purpose of this study was to analyze the use of PA in a high-volume orthopaedic practice across 4 states.

METHODS

We prospectively collected data on 28,725 primary THAs and TKAs performed at our institution between 2020 and 2023. Data collected included patient demographics, payer approval or denial, time to approval or denial, the number of initial denials, the number of peer-to-peer (P2P) or addenda, and the reasons for denial.

RESULTS

Seven thousand five hundred twenty eight (56.4%) patients undergoing THA and 8,283 (54%) patients undergoing TKA required PA, with a mean time to approval of 26.3 ± 34.6 and 33.7 ± 41.5 days, respectively. Addenda were requested in 608 of 7,528 (4.6%) THA patients and 737 of 8,283 (8.9%) TKA patients. From a total of 312 (4.1%) THA patients who had an initial denial, a P2P was requested for 50 (0.7%) patients, and only 27 (0.4%) were upheld after the PA process. From a total of 509 (6.1%) TKA patients who had an initial denial, a P2P was requested for 55 (0.7%) patients, and only 26 (0.3%) were upheld after the PA process. The mean time to denial in the THA group was 64.7 ± 83.5, and the most common reasons for denial were poor clinical documentation (25.9%) and lack of coverage (25.9%). The mean time to denial in the TKA group was 63.4 ± 103.9 days, and the most common reason for denial was not specified by the payer (46.1%).

CONCLUSIONS

The use of PA to approve elective THA and TKA led to increased surgical waiting times and a high administrative burden for surgeons and healthcare staff.

Head-to-head comparison of appropriate use criteria for knee arthroplasty: A multicenter cohort study

Objective

To determine, in a head-to-head comparison, which of two RAND-based knee replacement appropriateness criteria is optimal based on comparison to an externally validated method of judging good versus poor outcome.

Design

Longitudinal data from the Osteoarthritis Initiative (OAI) and the Multicenter Osteoarthritis Study (MOST) were combined to produce a dataset of 922 persons with knee arthroplasty, 602 of which had adequate data for RAND classification and had their surgery within one year prior to a study visit. Data were used to determine appropriateness classification (i.e., Appropriate, Inconclusive, Rarely Appropriate) using modified versions of the first-generation and second-generation Escobar system. Growth curve analyses and multivariable regression were used to compare the two systems.

Results

Neither system associated with the gold standard measure of good versus poor outcome. Distributions of appropriateness categories for the second-generation system were inconsistent with current evidence for knee arthroplasty outcome. For example, 16% of participants were classified as Appropriate and 64% as Rarely Appropriate for pain outcome. Distributions for the first-generation system aligned with current evidence.

Conclusion

The first-generation modified version of the Escobar appropriateness system is superior to the newer version but neither version associated with our gold standard growth curve analyses. Both systems only differentiate between patient classification groups preoperatively and up to ten months following surgery. Reliance on appropriateness criteria to inform long-term outcome is not warranted.

Life Expectancy of Patients Undergoing Total Knee Arthroplasty: Comparison With General Population

BACKGROUND

This study aimed to analyze the life expectancy and cause of death in osteoarthritis (OA) patients who underwent total knee arthroplasty (TKA) and to identify risk factors that affect long-term mortality rate after TKA.

METHODS

Among 601 patients, who underwent primary TKA due to OA by a single surgeon from July 2005 to December 2011, we identified patients who died after the operation using data obtained from the National Statistical Office of Korea. We calculated 5-, 10-, and 15-year survival rates of the patients and age-specific standardized mortality ratios (SMRs) compared to general population of South Korea according to the causes of death. We also identified risk factors for death.

RESULTS

The 5-year, 10-year, and 15-year survival rates were 94%, 84%, and 75%, respectively. The overall age-specific SMR of the TKA cohort was lower than that of the general population (0.69; P < 0.001). Cause-specific SMRs for circulatory diseases, neoplasms, and digestive diseases after TKA were significantly lower than those of the general population (0.65, 0.58, and 0.16, respectively; all P < 0.05). Male gender, older age, lower body mass index (BMI), anemia, and higher Charlson comorbidity index (CCI) were significant factors associated with higher mortality after TKA.

CONCLUSION

TKA is a worthwhile surgery that can improve life expectancy, especially from diseases of the circulatory system, neoplasms, and digestive system, in patients with OA compared to the general population. However, careful follow-up is needed for patients with male gender, older age, lower BMI, anemia, and higher CCI, as these factors may increase long-term mortality risk after TKA.

LEVEL OF EVIDENCE

III.

Hip and Knee Osteoarthritis, Not Nonsteroidal Anti-Inflammatory Drugs, are Linked to Cardiac Disease

BACKGROUND

In 2005, the Food and Drug Administration placed a black-box warning (the most stringent warning for drugs) on all nonaspirin nonsteroidal anti-inflammatory drugs (NSAIDs) stating that these agents may cause heart attacks and/or strokes. No level I evidence demonstrates that nonselective NSAIDs increase cardiovascular risk. An alternative hypothesis is that hip and knee osteoarthritis (OA) indirectly causes cardiovascular disease (CVD) through decreased activity and NSAIDs are correlated with CVD as an arthritis treatment.

METHODS

Systematic reviews were conducted to find observational studies evaluating the association of hip and/or knee OA, CVD, activity, walking, and step counts. The systematic review found studies correlating hip and/or knee OA and CVD morbidity incidence (n = 2); CVD morbidity prevalence (n = 6); odds ratios, relative risks, or hazard ratios of CVD morbidity (n = 11); relative risk, standardized mortality ratios, or hazard ratios of CVD mortality (n = 14); and all-cause mortality hazard ratios associated with NSAID use (n = 3).

RESULTS

Hip OA (5 studies), knee OA (9 studies), and hip and knee OA (6 studies) are linked to an increased risk of CVD morbidity and mortality. Cardiac risk increases with validated disability scores, use of walking aids, walking difficulties, longer follow-up times, younger ages of OA onset, numbers of joints involved, and OA severities. No study linked NSAID use to cardiac disease.

CONCLUSIONS

All studies with more than 10-year follow-up linked cardiac disease with hip and knee OA. No study linked nonselective NSAID use to CVD. The Food and Drug Administration should reconsider the black-box warnings on naproxen, ibuprofen, and celecoxib.

Effects of a Province-wide Triaging System for TIA: The ASPIRE Intervention

BACKGROUND AND OBJECTIVES

Urgent transient ischemic attack (TIA) management to reduce stroke recurrence is challenging, particularly in rural and remote areas. In Alberta, Canada, despite an organized stroke system, data from 1999 to 2000 suggested that stroke recurrence after TIA was as high as 9.5% at 90 days. Our objective was to determine whether a multifaceted population-based intervention resulted in a reduction in recurrent stroke after TIA.

METHODS

In this quasi-experimental health services research intervention study, we implemented a TIA management algorithm across the entire province, centered around a 24-hour physician's TIA hotline and public and health provider education on TIA. From administrative databases, we linked emergency department discharge abstracts to hospital discharge abstracts to identify incident TIAs and recurrent strokes at 90 days across a single payer system with validation of recurrent stroke events. The primary outcome was recurrent stroke; with a secondary composite outcome of recurrent stroke, acute coronary syndrome, and all-cause death. We used an interrupted time series regression analysis of age-adjusted and sex-adjusted stroke recurrence rates after TIA, incorporating a 2-year preimplementation period (2007-2009), a 15-month implementation period, and a 2-year postimplementation period (2010-2012). Logistic regression was used to examine outcomes that did not fit the time series model.

RESULTS

We assessed 6,715 patients preimplementation and 6,956 patients postimplementation. The 90-day stroke recurrence rate in the pre-Alberta Stroke Prevention in TIA and mild Strokes (ASPIRE) period was 4.5% compared with 5.3% during the post-ASPIRE period. There was neither a step change (estimate 0.38; p = 0.65) nor slope change (parameter estimate 0.30; p = 0.12) in recurrent stroke rates associated with the ASPIRE intervention implementation period. Adjusted all-cause mortality (odds ratio 0.71, 95% CI 0.56-0.89) was significantly lower after the ASPIRE intervention.

DISCUSSION

The ASPIRE TIA triaging and management interventions did not further reduce stroke recurrence in the context of an organized stroke system. The apparent lower mortality postintervention may be related to improved surveillance after events identified as TIAs, but secular trends cannot be excluded.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that a standardized population-wide algorithmic triage system for patients with TIA did not reduce recurrent stroke rate.

Effect of sodium bicarbonate on cardiovascular outcome and mortality in patients with advanced chronic kidney disease

Background: Metabolic acidosis is a common complication in patients with chronic kidney disease (CKD). Oral sodium bicarbonate is often used to treat metabolic acidosis and prevent CKD progression. However, there is limited information about the effect of sodium bicarbonate on major adverse cardiovascular events (MACE) and mortality in patients with pre-dialysis advanced CKD. Method: 25599 patients with CKD stage V between January 1, 2001 and December 31, 2019 were identified from the Chang Gung Research Database (CGRD), a multi-institutional electronic medical record database in Taiwan. The exposure was defined as receiving sodium bicarbonate or not. Baseline characteristics were balanced using propensity score weighting between two groups. Primary outcomes were dialysis initiation, all-cause mortality, and major adverse cardiovascular events (MACE) (myocardial infarction, heart failure, stroke). The risks of dialysis, MACE, and mortality were compared between two groups using Cox proportional hazards models. In addition, we performed analyzes using Fine and Gray sub-distribution hazard models that considered death as a competing risk. Result: Among 25599 patients with CKD stage V, 5084 patients (19.9%) were sodium bicarbonate users while 20515 (80.1%) were sodium bicarbonate non-users. The groups had similar risk of dialysis initiation (hazard ratio (HR): 0.98, 95% confidence interval (CI): 0.95-1.02, p < 0.379). However, taking sodium bicarbonate was associated with a significantly lower risks of MACE (HR: 0.95, 95% CI 0.92-0.98, p < 0.001) and hospitalizations for acute pulmonary edema (HR: 0.92, 95% CI 0.88-0.96, p < 0.001) compared with non-users. The mortality risks were significantly lower in sodium bicarbonate users compared with sodium bicarbonate non-users (HR: 0.75, 95% CI 0.74-0.77, p < 0.001). Conclusion: This cohort study revealed that in real world practice, use of sodium bicarbonate was associated with similar risk of dialysis compared with non-users among patients with advanced CKD stage V. Nonetheless, use of sodium bicarbonate was associated with significantly lower rate of MACE and mortality. Findings reinforce the benefits of sodium bicarbonate therapy in the expanding CKD population. Further prospective studies are needed to confirm these findings.

Effect of repeat catheter ablation vs. antiarrhythmic drug therapy among patients with recurrent atrial tachycardia/atrial fibrillation after atrial fibrillation catheter ablation: data from CHINA-AF registry

AIMS

Although several studies have proved that repeat catheter ablation is beneficial to recurrent atrial tachycardia (AT)/atrial fibrillation (AF) after AF catheter ablation, the hard endpoints of the effect of catheter ablation on recurrent AT/AF patients after AF catheter ablation remains unclear. Our study aims to compare the effect of catheter ablation and drug therapy on recurrent AT/AF patients after AF catheter ablation.

METHODS AND RESULTS

Four thousand nine hundred and thirteen consecutive patients with recurrent AT/AF after catheter ablation from the China-AF registry were enrolled. The patients were divided into two study groups: the repeat catheter ablation group and the medical therapy group. The primary endpoint is a composite of cardiovascular mortality or ischaemic stroke or major bleeding events. Secondary endpoints were each component of the primary endpoints and AF recurrence rate. Landmark analysis and Cox regression were used in the statistical analysis. We chose landmark 36 months as the primary landmark date. Over a median follow-up period of 40 ± 24 months, 4913 patients were divided into either the repeat ablation group or the medical therapy group. The cumulative incidence of the composite primary outcome was significantly lower in the repeat ablation group than the medical therapy group (adjusted hazard ratio = 0.56; 95% confidence interval: 0.35-0.89; P = 0.015) of landmark 36 months (2359 patients were included in medical therapy group and 704 patients were included in repeat ablation group at landmark 36 months). However, all secondary endpoints were not statistically different in the two groups, including cardiovascular mortality, ischaemic stroke, major bleeding events, and AF recurrence rate.

CONCLUSION

Based on this research, in recurrent AT/AF patients after a catheter ablation procedure, compared with medical therapy, repeat catheter ablation may significantly reduce the risk of the endpoint of composite cardiovascular mortality, ischaemic stroke, and major bleeding events.

The Regional Burden and Disability-Adjusted Life Years of Knee Osteoarthritis in Kazakhstan 2014-2020

A Global Burden of Disease (GBD) study reported that 9.6 million years lived with disability (YLDs) were lost due to hip and knee osteoarthritis (KOA) in 2017. Although the GBD study presents the disease burden at the global level, there is no information on any Central Asian country. This study aims to investigate the epidemiology of knee osteoarthritis in Kazakhstan. The data of 56,895 people with KOA between 2014-2020 was derived from the Unified National Electronic Health System of Kazakhstan and retrospectively analyzed. The majority of the cohort (76%) were women, of Kazakh ethnicity (66%), and older than 50 years of age (87%). The risk of gonarthrosis escalated for women after 50 years and peaked at 75 years with a rate of 3062 females admitted to hospital per 100,000 women in the population. This observation is approximately three times higher than for men of the same age group. A geographical analysis showed that the Jambyl oblast, West Kazakhstan, North Kazakhstan, and the Akmola oblast have the highest burden of disease. During the observation period, 127,077 age-adjusted YLDs were lost due to knee osteoarthritis. This is the first study in Kazakhstan to investigate the burden of knee osteoarthritis. This research recognizes age and sex-based differences, and regional disparities in the incidence of knee osteoarthritis. This knowledge can lead to the development of more specific diagnostic approaches and gender-personalized therapy protocols for patients.

Time for return to sport following total knee arthroplasty: a meta-analysis

INTRODUCTION

The frequency of total knee arthroplasty (TKA) is increasing, particularly in younger and more active patients. In these patients, there may be greater functional demands, with an expectation to return to sporting activities (RTS) following TKA. There is a paucity of data on the time to RTS following TKA and the aim of this meta-analysis is to determine the time to RTS following TKA.

METHODS

Using the PRISMA guidelines, an electronic search of PUBMED, MEDLINE, EMBASE, and the Cochrane Library for trails was performed on TKA and RTS in English language, published since the inception of the database to 31st October 2020. Data evaluating the time to RTS and functional outcomes were recorded by two authors independently that were included in the analysis. Pooled analysis using random effect model on overall proportions at the different time intervals and at the end of the follow-up was carried out for all studies.

RESULTS

In total, 1,611 studies were retrieved from literature search. Of these, nine studies met the inclusion criteria with 1,307 patients. Two studies with 148 patients demonstrated an overall pooled proportion of 18.7% (95% CI 8.2-32.3%) of patients RTS at 3 month post-TKA; Three studies reported RTS rate at 6 months 70.% (95% CI 48-88.4). Two studies with 123 patients demonstrated an overall pooled proportion of 84.0% (95% CI 77.1-89.9%) patients RTS at 12 months. 986 patients returned to sport from total of 1307, with an overall adjusted proportion return to sport of 87.9 (95% CI 80.5-93.8%) at the end of follow-up; mean 14 months (range 3-36 months).

CONCLUSION

Patients undergoing TKA were found to successfully RTS, pooled proportion analysis showed an increasing rate of RTS with time, at a mean of 14 months following TKA, where 87.9% of patients had returned to sports. The findings of this study will enable more informed discussions and rehabilitation planning between patients and clinicians on RTS following TKA.

Total knee replacement in osteoarthritis patients on reducing the risk of major adverse cardiac events: a 18-year retrospective cohort study

OBJECTIVES

Osteoarthritis (OA) is a common degenerative joint disease, and total knee replacement (TKR) is a successful surgical intervention for knee OA treatment. However, the risks of mortality and major cardiovascular events (MACEs) in patients receiving TKR remain unclear. This study investigated the risks of mortality and MACEs in knee OA patients who received TKR.

METHODS

For this population-based cohort study, the Longitudinal Health Insurance Database 2000 was used. Two million individuals with knee OA defined by ICD-9-CM codes who received physical therapy between 1999 and 2017 were selected. For propensity score matching (PSM), we considered the year of knee OA diagnosis, demographics, comorbidities, co-medications, and knee OA-related hyaluronic acid or physical therapy at baseline. After PSM, regression analyses were performed to assess the association of mortality or MACEs with TKR and non-TKR individuals.

RESULTS

We identified patients (n = 189,708) with a new diagnosis of knee OA between 2000 and 2017. In total, 10,314 propensity-score-paired TKR and non-TKR individuals were selected. The PSM cohort algorithm revealed that the risk of mortality or MACEs was lower in the TKR group (adjusted hazard ratio: 0.791; 95% confidence interval: 0.755-0.830) than in the non-TKR group.

CONCLUSIONS

Patients with knee OA who received TKR had decreased risks of mortality and MACEs than those who did not receive TKR. Moreover, the TKR group received a reduced dosage of nonsteroidal anti-inflammatory drugs at the 1-year follow-up.

Prediction models for the risk of total knee replacement: development and validation using data from multicentre cohort studies

Background

Few prognostic prediction models for total knee replacement are available, and the role of radiographic findings in predicting its use remains unclear. We aimed to develop and validate predictive models for total knee replacement and to assess whether adding radiographic findings improves predictive performance.

Methods

We identified participants with recent knee pain (in the past 3 months) in the Multicenter Osteoarthritis Study (MOST) and the Osteoarthritis Initiative (OAI). The baseline visits of MOST were initiated in 2003 and of OAI were initiated in 2004. We developed two predictive models for the risk of total knee replacement within 60 months of follow-up by fitting Cox proportional hazard models among participants in MOST. The first model included sociodemographic and anthropometric factors, medical history, and clinical measures (referred to as the clinical model). The second model added radiographic findings into the predictive model (the radiographic model). We evaluated each model's discrimination and calibration performance and assessed the incremental value of radiographic findings using both category-free net reclassification improvement (NRI) and integrated discrimination improvement (IDI). We tuned the models and externally validated them among participants in OAI.

Findings

We included 2658 participants from MOST (mean age 62·4 years [SD 8·1], 1646 [61·9%] women) in the training dataset and 4060 participants from OAI (mean age 60·9 years [9·1], 2379 [58·6%] women) in the validation dataset. 290 (10·9%) participants in the training dataset and 174 (4·3%) in the validation dataset had total knee replacement. The retained predictive variables included in the clinical model were age, sex, race, history of knee arthroscopy, frequent knee pain, current use of analgesics, current use of glucosamine, body-mass index, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain score, and the most predictive factors were age, race, and WOMAC pain score. The retained predictive variables in the radiographic model were age, sex, race, frequent knee pain, current use of analgesics, WOMAC pain score, and Kellgren-Lawrence grade, and the most predictive factors were Kellgren-Lawrence grade, race, and age. The C-statistic was 0·79 (95% CI 0·76-0·81) for the clinical model and 0·87 (0·85-0·99) for the radiographic model in the training dataset. The calibration slope was 0·95 (95% CI 0·86-1·05) and 0·96 (0·87-1·04), respectively. Adding radiograph findings significantly improved predictive performance with an NRI of 0·43 (95% CI 0·38-0·50) and IDI of 0·14 (95% CI: 0·10-0·18). Both models, with tuned coefficients, showed a good predictive performance among participants in the validation dataset.

Interpretation

The risk of total knee replacement can be predicted based on common risk factors with good discrimination and calibration. Additionally, adding radiographic findings of knee osteoarthritis into the model substantially improves its predictive performance.

Funding

National Natural Science Foundation of China, National Key Research and Development Program, and Beijing Municipal Science & Technology Commission.

A Weighted Scoring System Based on Preoperative and Long-Term Patient-Reported Outcome Measures to Guide Timing of Knee Arthroplasty

BACKGROUND

There is currently no existing consensus regarding timing of knee arthroplasty. This study aimed to develop a weighted scoring system from patient-reported outcome measures (PROMs) to guide timing of knee arthroplasty based on preoperative severity and long-term effectiveness.

METHODS

Prospectively collected data of 766 total knee arthroplasties (TKAs) and 382 unicompartmental knee arthroplasties (UKAs) at a single institution were analyzed. PROMs were assessed preoperatively and at 10 years using the Knee Society Score (KSS), Oxford Knee Score (OKS), and Short Form-36 physical component score (SF-36 PCS). Receiver operating characteristic analysis identified thresholds where preoperative PROMs predicted 10-year clinically meaningful improvements (minimal clinically important difference [MCID]). Threshold weights were assigned to PROMs based on their ability to predict MCID in isolation or in combination.

RESULTS

Poorer baseline PROMs predicted 10-year MCID attainments. The threshold of 49.5 points for the KSS, 30.5 points for the OKS, and 40.7 points for the SF-36 PCS and 55.5 points for the KSS, 33.5 points for the OKS, and 40.5 points for the SF-36 PCS was weighted 1 point for predicting MCID in 1 PROM for TKA and UKA, respectively. The threshold of 33.4 and 33.9 points for the SF-36 PCS was weighted 2 points for predicting MCID in 2 PROMs, whereas 29.3 and 31.3 points for the SF-36 PCS were weighted 3 points for predicting MCID in 3 PROMs for TKA and UKA, respectively. The sum of weighted components from 0 (lowest) to 5 (highest) represented likelihood for long-term benefits at 10 years.

CONCLUSION

This scoring system is a useful clinical adjunct for deciding timing of knee arthroplasty and prioritizing patients in institutions with long waitlists.

LEVEL OF EVIDENCE

II.

Fast Return to Sports and High Level of Activity after Cementless Oxford Unicompartmental Knee Arthroplasty

Physical activity is essential for overall health. For patients undergoing knee arthroplasty, questions about the implant's suitability for sports arise. The general recommendations for physical activity with knee replacements are often based upon experts' opinions, with a lack of scientific data. This study was performed at an independent high-volume center and aimed to investigate what level of activity patients can achieve and how they perform with a well-functioning cementless unicompartmental knee replacement (UKR). Possible differences in outcome in regards to patients' body mass index (BMI) were also examined. A total of 228 knees treated with cementless Oxford UKR (OUKR) were followed up after a mean of 37.1 months. Tegner's and UCLA (University of California, Los Angeles) scores were obtained to assess the level of physical activity. The Schulthess Clinical Activity Questionnaire was assessed for detailed information on practiced sports, and the SF-36 questionnaire was evaluated to analyze patients' quality of life. The return to activity rate was 92.9%. In total, 64% of the physically active patients had already taken up sports within 3 months after surgery. Mean Tegner's score was at 3.5, and mean UCLA score was at 6.3. High impact sports were not performed very often after surgery. Higher BMI showed a negative correlation with the numbers of sports (r_sp = -0.289) as well as Tegner's (r_sp = -0.222) and UCLA (r_sp = -0.383) scores. The SF-36 scores were comparably good to those in an age-equivalent standard reference group. In conclusion, cementless OUKR allows a fast return to activity with a high level of physical exercise. Patients with increased BMI tend to practice less types of sports with decreased activity scores.

Outcomes After Intensive Rehabilitation for Mechanically Ventilated Patients: A Nationwide Retrospective Cohort Study

OBJECTIVE

To examine the effects of intensive rehabilitation on mortality and liberation from mechanical ventilation among patients with mechanical ventilation in intensive care units.

DESIGN

Retrospective cohort study using the Diagnosis Procedure Combination inpatient database.

SETTING

Patients discharged from acute care hospitals from April 2010 to March 2016.

PARTICIPANTS

Patients (N=46,438) aged 20 years and older who were admitted to intensive care units and who started rehabilitation within 3 days of starting mechanical ventilation.

INTERVENTION

Intensive rehabilitation in intensive care unit in the first 5 days after admission. Amount of rehabilitation was defined as the average number of units per day in the first 5 days after admission and was dichotomized as intensive (≥1.0 unit/d) or nonintensive (<1.0 unit/d) rehabilitation.

MAIN OUTCOME MEASURES

The primary outcome was in-hospital mortality. The secondary outcome was liberation from mechanical ventilation.

RESULTS

We identified 29,982 eligible patients, including intensive (n=7745) and nonintensive (n=22,237) rehabilitation groups. In the propensity score-matched analysis, the intensive rehabilitation group had significantly lower in-hospital mortality (risk difference: -3.4%; 95% CI, -4.9% to -1.9%) and a higher proportion of liberation from mechanical ventilation (subdistribution hazard ratio, 1.08; 95% CI, 1.03-1.13) compared with the nonintensive rehabilitation group.

CONCLUSIONS

Patients receiving a higher amount of rehabilitation in intensive care units were less likely to die and more likely to be liberated from mechanical ventilation.

Examining Timeliness of Total Knee Replacement Among Patients with Knee Osteoarthritis in the U.S.: Results from the OAI and MOST Longitudinal Cohorts

BACKGROUND

Patients with knee osteoarthritis may undergo total knee replacement too early or may delay or underuse this procedure. We quantified these categories of total knee replacement utilization in 2 cohorts of participants with knee osteoarthritis and investigated factors associated with each category.

METHODS

Data were pooled from 2 multicenter cohort studies that collected demographic, patient-reported, radiographic, clinical examination, and total knee replacement utilization information longitudinally on 8,002 participants who had or were at risk for knee osteoarthritis and were followed for up to 8 years. Validated total knee replacement appropriateness criteria were longitudinally applied to classify participants as either potentially appropriate or likely inappropriate for total knee replacement. Participants were further classified on the basis of total knee replacement utilization into 3 categories: timely (indicating that the patient had total knee replacement within 2 years after the procedure had become potentially appropriate), potentially appropriate but knee not replaced (indicating that the knee had remained unreplaced for >2 years after the procedure had become potentially appropriate), and premature (indicating that the procedure was likely inappropriate but had been performed). Utilization rates were calculated, and factors associated with each category were identified.

RESULTS

Among 8,002 participants, 3,417 knees fulfilled our inclusion and exclusion criteria and were classified into 1 of 3 utilization categories as follows: 290 knees (8% of the total and 9% of the knees for which replacement was potentially appropriate) were classified as "timely", 2,833 knees (83% of the total and 91% of those for which replacement was potentially appropriate) were classified as "potentially appropriate but not replaced", and 294 knees (comprising 9% of the total and 26% of the 1,114 total knee replacements performed) were considered to be "likely inappropriate" yet underwent total knee replacement and were classified as "premature". Of the knees that were potentially appropriate but were not replaced, 1,204 (42.5%) had severe symptoms. Compared with the patients who underwent timely total knee replacement, the likelihood of being classified as potentially appropriate but not undergoing total knee replacement was greater for black participants and the likelihood of having premature total knee replacement was lower among participants with a body mass index of >25 kg/m and those with depression.

CONCLUSIONS

In 2 multicenter cohorts of patients with knee osteoarthritis, we observed substantial numbers of patients who had premature total knee replacement as well as of patients for whom total knee replacement was potentially appropriate but had not been performed >2 years after it had become potentially appropriate. Further understanding of these observations is needed, especially among the latter group.

CLINICAL RELEVANCE

Undergoing total knee replacement too early may result in little or no benefit while exposing the patient to the risks of a major operation, whereas waiting too long may cause limitations in physical activity that in turn increase the risk of additional disability and chronic disease; however, little is known about timing of this surgery. We quantified the extent of premature, timely, and delayed use, and found a high prevalence of both premature and delayed use.

How Does Mortality Risk Change Over Time After Hip and Knee Arthroplasty?

BACKGROUND

Mortality after THA and TKA is lower than expected for several years after surgery when compared with age- and sex-adjusted population data. With long-term followup (beyond approximately 10 years), some evidence has suggested that this trend reverses, such that postsurgical mortality is higher than expected as more time passes. However, the degree to which this may be the case has not been clearly established.

QUESTIONS/PURPOSES

In this large-registry study, we asked: What is the long-term mortality after THA and TKA compared with the expected mortality, adjusted for age, sex, and calendar year.

METHODS

Using data on 243,057 THAs and 363,355 TKAs performed for osteoarthritis from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) from 2003 to 2016, and life tables from the Australian Bureau of Statistics the Standardised Mortality Ratio (SMR), relative mortality and excess mortality (relative to the expected mortality for people of the same sex and age in the same country) was calculated separately for hips and knees. The AOANJRR contains near-complete (98%-100%) data from all hospitals in Australia performing arthroplasty but does not include followup data on people who have left the country. Followup was from the date of surgery to 13 years, mean 5.8 years.

RESULTS

We found a lower-than-expected mortality for THA and TKA in the early years after surgery. This association diminished over time and the mortality became higher than expected after 12 years for both THA and TKA. For THA, the excess mortality (per thousand people) increased from 11 fewer deaths (95% CI, 10-11 fewer) after 1 year to four more deaths (95% CI, 0-9 more) in the 13th year, and the SMR increased from 0.50 (95% CI, 0.48-0.52) after 1 year to 1.07 (95% CI, 0.99-1.14) in the 13th year. For TKA, the excess mortality (per thousand people) increased from 12 fewer deaths (95% CI, 12-13 fewer) after 1 year to five more deaths (95% CI 2-9 more) in the 13th year, and the SMR increased from 0.39 (95% CI, 0.37-0.40) after 1 year to 1.09 (95% CI, 1.03-1.15) in the 13th year.

CONCLUSIONS

Mortality after hip and knee arthroplasty is lower than expected (based on population norms) in the first 8 years to 9 years but gradually increases over time, becoming higher than expected after 12 years. The lower-than-expected mortality in the early years after surgery is likely the result of patient selection with patients undergoing primary arthroplasty having better health at the time of surgery than that of the age- and sex-matched population. The increasing mortality over time cannot be regression to the mean, as late mortality is higher than expected, moving beyond the mean. It is important to understand if there are modifiable factors associated with this increased mortality. The reasons for the change are uncertain. Factors to consider in future research include determining the effect of different patient factors on late mortality. Some of these included higher obesity rates for joint replacement patients and the association or causal impact of osteoarthritis and/or its treatment to increase late mortality in a similar manner to other forms of arthritis. There is also a possibility that the arthroplasty device itself may affect late mortality.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Optimizing Clinical Use of Biologics in Orthopaedic Surgery: Consensus Recommendations From the 2018 AAOS/NIH U-13 Conference

Concern that misinformation from direct-to-consumer marketing of largely unproven "biologic" treatments such as platelet-rich plasma and cell-based therapies may erode the public trust and the responsible investment needed to bring legitimate biological therapies to patients have resulted in calls to action from professional organizations and governing bodies. In response to substantial patient demand for biologic treatment of orthopaedic conditions, the American Academy of Orthopaedic Surgeons convened a collaborative symposium and established a consensus framework for improving and accelerating the clinical evaluation, use, and optimization of biologic therapies for musculoskeletal diseases. The economic and disease burden of musculoskeletal conditions is high. Of the various conditions discussed, knee osteoarthritis was identified as a "serious condition" associated with substantial and progressive morbidity and emerged as the condition with the most urgent need for clinical trial development. It was also recognized that stem cells have unique characteristics that are not met by minimally manipulated mixed cell preparations. The work group recommended that minimally manipulated cell products be referred to as cell therapy and that the untested and uncharacterized nature of these treatments be clearly communicated within the profession, to patients, and to the public. Minimum standards for product characterization and clinical research should also be followed. A framework for developing clinical trials related to knee OA was agreed upon. In addition to recommendations for development of high-quality multicenter clinical trials, another important recommendation was that physicians and institutions offering biologic therapies commit to establishing high-quality patient registries and biorepository-linked registries that can be used for postmarket surveillance and quality assessments.

The association of under-weight and obesity with mortality after hip arthroplasty

Background

although many studies have demonstrated the association between body mass index (BMI) and many diseases, there is little evidence of postoperative mortality after hip arthroplasty. The aim of this study was to evaluate the association between BMI and mortality after hip arthroplasty in the older population.

Methods

a total of 3,627 older patients who underwent hip arthroplasty from 2010 to 2013 were included. We used Cox regression analysis to evaluate the association between BMI and mortality after hip arthroplasty. The hazard ratios (HRs) was calculated from 30 days, 31-365 days, and from the first day of surgery to the day of death during the study.

Results

under-weight (BMI under 18.5 kg/m2) is significantly associated with increased mortality (HR:1.423; 95% Confidence Interval (CI): 1.023-1.981) after hip arthroplasty compared to the normal range. However, in the short-term mortality within 30 days after surgery, both under-weight (HR: 2.368; 95%CI: 1.130-4.960) and obesity (25-29.9 kg/m2, HR: 2.023; 95%CI: 1.008-4.059) are associated with increased mortality.

Conclusion

our study suggested that under-weight is associated with increased risk of mortality after hip arthroplasty. Further, in a short-term outcome, obesity appear to be associated with increased mortality after hip arthroplasty within 30 days.

Pharmacologic Hemostatic Agents in Total Joint Arthroplasty-A Cost-Effectiveness Analysis

BACKGROUND

Total knee and hip arthroplasties can be associated with substantial blood loss, affecting morbidity and even mortality. Two pharmacological antifibrinolytics, ε-aminocaproic acid (EACA) and tranexamic acid (TXA) have been used to minimize perioperative blood loss, but both have associated morbidity. Given the added cost of these medications and the risks associated with then, a cost-effectiveness analysis was undertaken to ascertain the best strategy.

METHODS

A cost-effectiveness model was constructed using the payoffs of cost (in United States dollars) and effectiveness (quality-adjusted life expectancy, in days). The medical literature was used to ascertain various complications, their probabilities, utility values, and direct medical costs associated with various health states. A time horizon of 10 years and a willingness to pay threshold of $100,000 was used.

RESULTS

The total cost and effectiveness (quality-adjusted life expectancy, in days) was $459.77, $951.22, and $1174.87 and 3411.19, 3248.02, and 3342.69 for TXA, no pharmacologic hemostatic agent, and EACA, respectively. Because TXA is less expensive and more effective than the competing alternatives, it was the favored strategy. One-way sensitivity analyses for probability of transfusion and myocardial infarction for all 3 strategies revealed that TXA remains the dominant strategy across all clinically plausible values.

CONCLUSION

TXA, when compared with no pharmacologic hemostatic agent and with EACA, is the most cost-effective strategy to minimize intraoperative blood loss in hip and knee total joint arthroplasties. These findings are robust to sensitivity analyses using clinically plausible probabilities.

Participation in Regular Physical Activity After Total Knee or Hip Arthroplasty for Osteoarthritis: Prevalence, Associated Factors, and Type

OBJECTIVE

To describe the rates of participation in regular physical activity presurgery and at 3 years follow-up after knee or hip arthroplasty, and to describe factors associated with participation postsurgery and types of activity undertaken.

METHODS

A previously acquired multicenter, prospective cohort of knee or hip arthroplasty recipients was followed up for 3 years postsurgery. Regular participation in physical activity was defined as participation in physical activity ≥1 time/week, excluding incidental activities. Participants were interviewed about current participation as well as participation in the year presurgery. Joint-specific and health-related quality-of-life scores and information on experience of major complications were obtained. Information about comorbidity and body weight were updated. Factors associated with 3-year physical activity participation were determined using multivariable logistic regression modeling.

RESULTS

In total, 73.4% of the eligible cohort (1,289 of 1,757) were followed up (718 patients with total knee arthroplasty, and 571 patients with total hip arthroplasty). Participation profiles were similar regardless of the joint replaced. Participation in physical activity increased postsurgery in the combined cohort (from 45.2% to 63.5%; P < 0.001). Participation at 3 years was associated with participation presurgery (P < 0.0001), better 3-year quality of life (P < 0.001), younger age (P = 0.002), better 3-year joint scores (P = 0.01), >1 lifetime arthroplasty (P = 0.02), and higher education level (P = 0.04). Low-impact and nonambulatory activities significantly increased postsurgery with no change in high-impact activities.

CONCLUSION

Participation rates increased postsurgery when recovery was stable, but approximately one-third of arthroplasty recipients did not engage in physical activity at least once per week. Because participation is associated with habitual activity presurgery, a potential role for behavior change interventions is suggested. The increase in nonambulatory activities indicates that current devices measuring ambulatory activity alone are inadequate for capturing physical activity.

Alternative Design and Analytical Techniques for Longitudinal Rheumatology Studies: Improved Understanding of Outcomes

Longitudinal cohort designs (with three or more measurement occasions) are invaluable to investigate between- and within-individual variation in outcomes. However, traditional longitudinal designs require a lengthy implementation and data collection period and impose a substantial burden on participants and investigators. We discuss alternative longitudinal designs, including planned missing data designs and retrospective cohort studies with secondary data, which require a shorter period for data accrual and reduce participant burden while maintaining statistical power. We also discuss analysis strategies to maximize data use and produce unbiased estimates of treatment effectiveness, including models for recurrent or multistate events and time-varying covariates.

Long-term Mortality After Revision THA

BACKGROUND

Long-term mortality after primary THA is lower than in the general population, but it is unknown whether this is also true after revision THA.

QUESTIONS/PURPOSES

We examined (1) long-term mortality according to reasons for revision after revision THA, and (2) relative mortality trends by age at surgery, years since surgery, and calendar year of surgery.

METHODS

This retrospective study included 5417 revision THAs performed in 4532 patients at a tertiary center between 1969 and 2011. Revision THAs were grouped by surgical indication in three categories: periprosthetic joint infections (938; 17%); fractures (646; 12%); and loosening, bearing wear, or dislocation (3833; 71%). Patients were followed up until death or December 31, 2016. The observed number of deaths in the revision THA cohort was compared with the expected number of deaths using standardized mortality ratios (SMRs) and Poisson regression models. The expected number of deaths was calculated assuming that the study cohort had the same calendar year, age, and sex-specific mortality rates as the United States general population.

RESULTS

The overall age- and sex-adjusted mortality was slightly higher than the general population mortality (SMR, 1.09; 95% CI, 1.05-1.13; p < 0.001). There were significant differences across the three surgical indication subgroups. Compared with the general population mortality, patients who underwent revision THA for infection (SMR, 1.35; 95% CI, 1.24-1.48; p < 0.001) and fractures (SMR, 1.23; 95% CI, 1.11-1.37; p < 0.001) had significantly increased risk of death. Patients who underwent revision THA for aseptic loosening, wear, or dislocation had a mortality risk similar to that of the general population (SMR, 1.01; 95% CI, 0.96-1.06; p = 0.647). The relative mortality risk was highest in younger patients and declined with increasing age at surgery. Although the relative mortality risk among patients with aseptic indications was lower than that of the general population during the first year of surgery, the risk increased with time and got worse than that of the general population after approximately 8 to 10 years after surgery. Relative mortality risk improved with time after revision THA for aseptic loosening, wear, or dislocation.

CONCLUSIONS

Shifting mortality patterns several years after surgery and the excess mortality after revision THA for periprosthetic joint infections and fractures reinforce the need for long-term followup, not only for implant survival but overall health of patients having THA.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Thirty-day mortality following total knee arthroplasty over 7 years at a tertiary referral centre of orthopaedic excellence

Total Knee Arthroplasty (TKA) is one of the most successful orthopaedic procedures. Around 100,000 TKAs are performed yearly in the United Kingdom. The aim of this study was to report the mortality rate within 30 days after a TKA in an Orthopaedic Centre of Excellence. We reviewed prospectively collected data of 7067 TKAs performed between April 2009-November 2016. All mortalities within 30 days of a TKA were recorded. Data such as age, sex, ASA, comorbidities and cause of death was recorded. There were 14 (0.198%) deaths within 30 days of TKA. There were eight male patients and six female patients who died. No statistical difference was demonstrated between gender. (p = 0.37). The mean age was 77.9 years (66-94 years). Means days to death from post-op were 9.6 days (2-30 days). One patient was ASA 1, six patients were ASA 2, six patients were ASA 3 and one patient did not have an ASA recorded. There was no statistical difference between the difference ASA groups. (p = 0.27). Cause of death documented was as follow: acute left ventricular failure-3; myocardial infarction-2; pneumonia-2; pulmonary oedema-1; gastrointestinal bleed-1 and multiorgan failure-1. Four patients did not have their cause of death recorded. The 30-day mortality rate after TKA in our institute is low and is comparable to other institutes. This emphasizes that primary TKA is a safe procedure. The predominant cause of perioperative mortality is cardiopulmonary disease.

Association of Overlapping Surgery With Increased Risk for Complications Following Hip Surgery: A Population-Based, Matched Cohort Study

IMPORTANCE

Overlapping surgery, also known as double-booking, refers to a controversial practice in which a single attending surgeon supervises 2 or more operations, in different operating rooms, at the same time.

OBJECTIVE

To determine if overlapping surgery is associated with greater risk for complications following surgical treatment for hip fracture and arthritis.

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective population-based cohort study in Ontario, Canada (population, 13.6 million), for the years 2009 to 2014. There was 1 year of follow-up. This study encompassed 2 large cohorts. The "hip fracture" cohort captured all persons older than 60 years who underwent surgery for a hip fracture during the study period. The "total hip arthroplasty" (THA) cohort captured all primary elective THA recipients for arthritis during the study period. We matched overlapping and nonoverlapping hip fractures by patient age, patient sex, surgical procedure (for the hip fracture cohort), primary surgeon, and hospital.

EXPOSURES

Procedures were identified as overlapping if they overlapped with another surgical procedure performed by the same primary attending surgeon by more than 30 minutes.

MAIN OUTCOMES AND MEASURES

Complication (infection, revision, dislocation) within 1 year.

RESULTS

There were 38 008 hip fractures, and of those, 960 (2.5%) were overlapping (mean age of patients, 66 years [interquartile range, 57-74 years]; 503 [52.4%] were female). There were 52 869 THAs and of those, 1560 (3.0%) overlapping (mean age, 84 years [interquartile range, 77-89 years]; 1293 [82.9%] were female). After matching, overlapping hip fracture procedures had a greater risk for a complication (hazard ratio [HR], 1.85; 95% CI, 1.27-2.71; P = .001), as did overlapping THA procedures (HR, 1.79; 95% CI, 1.02-3.14; P = .04). Among overlapping hip fracture operations, increasing duration of operative overlap was associated with increasing risk for complications (adjusted odds ratio, 1.07 per 10-minute increase in overlap; P = .009).

CONCLUSIONS AND RELEVANCE

Overlapping surgery was relatively rare but was associated with an increased risk for surgical complications. Furthermore, increasing duration of operative overlap was associated with an increasing risk for complications. These findings support the notion that overlapping provision of surgery should be part of the informed consent process.

K, Agarwal AK. Is simultaneous bilateral total knee arthroplasty safe in geriatric population? A retrospective cohort study with upto 9 years follow up

INTRODUCTION

Considering the old age, uncertain life expectancy, co-morbidities and fear of postoperative complications, elderly patients often hesitate to undergo simultaneous bilateral total knee arthroplasty (SBTKA).

MATERIALS & METHODS

A retrospective study of SBTKA in 46 patients (92 knees) of age >70 years done between 2003 and 2012. Mean age was 80.13 ± 5.24 years (range -70-93 years).

RESULTS

74 percent had 1 or more major medical problems. There was a significant improvement of KSS at six months (p value = 0.00).

CONCLUSION

With expected benefits of surgery, SBTKA seems a safe, efficient, and viable procedure for carefully selected elderly patients.

The impact of musculoskeletal diseases on mortality-comparison with internal diseases: A 15-year longitudinal study

BACKGROUND

Aging is associated with an increased incidence of diabetes (DM), hypertension (HT), hyperlipidemia (HL), as well as musculoskeletal disorders, such as osteoarthritis (OA) and osteoporosis (OP). However, the impact of musculoskeletal disorders on mortality remains unclear. This study investigated the risk of mortality if having knee OA or OP.

METHODS

601 participants (mean age 67.8 ± 5.3 years) who underwent musculoskeletal check-ups in Yakumo town were enrolled in this study, 248 were males and 353 were females. The following parameters were assessed: age, sex, body mass index, smoking habit, alcohol drinking habit, physical exercise habit, knee OA, OP, HT, DM and HL. Kaplan-Meier survival curves for smoking, drinking and physical exercise habits, knee OA, OP, HT, DM and HL were prepared, and the log-rank test was performed. Furthermore, the Cox hazard model was used for multivariate analysis of all variables.

RESULTS

Knee OA, OP, HT, and DM were associated with a significantly higher mortality rate. Cox regression analysis results showed a hazard ratio of 1.972 for OA (95%CI: 1.356-2.867), 1.965 for DM (1.146-3.368), 1.706 for smoking habits (1.141-2.552), and 1.614 for OP (1.126-2.313). Cardiovascular diseases were the most common causes of death.

CONCLUSIONS

Smoking, knee OA, OP and DM were all associated with increased risk of mortality. Knee OA had a high hazard ratio, comparable to that of DM. These findings suggest that interventions against smoking, knee OA, OP and DM may reduce the risk of mortality.

The longitudinal relationship between hand, hip and knee osteoarthritis and cardiovascular events: a population-based cohort study

OBJECTIVE

In this population-based cohort study, we examined the association between the presence of symptomatic osteoarthritis (OA) and risk for cardiovascular (CV) events.

METHOD

A cohort aged ≥55 years recruited from 1996 to 98 was followed through provincial health administrative data to 2014. Demographics, joint complaints and functional limitations were collected. Hip, knee and hand OA were defined using a validated definition. Using Cox-regressions, the relationship between OA and a composite CV outcome (myocardial infarction (MI), stroke, angina, heart failure, revascularization) was assessed controlling for age, body mass index (BMI), sex, pre-existing metabolic factors, comorbidities, income status, primary care exposure and functional limitations.

RESULTS

18,490 participants were included: median age was 68 years, 60.3% were female; 24.4% met criteria for OA (10.0% hip, 15.3% knee, 16.0% hand), 16.3% self-reported limitation in grip and 25.4% in walking. Over a median 13.4 years, 31.9% experienced a CV event. Controlling for all but walking limitation, a dose-response relationship was observed between number of joints affected by knee/hip OA and CV risk (HR 2 hips/knees vs none: 1.13, 95% CI 1.03-1.23; 3+ hips/knees: 1.22, 95% CI 1.09-1.36). This relationship became non-significant additionally controlling for difficulty walking. Self-reported difficulty walking was associated with a 30% increased hazard for CV events. The effect of hand OA was not significant.

CONCLUSION

In a large population cohort, a greater burden of hip/knee OA was associated with higher CV risk; the relationship was explained by OA-related difficulty walking. Increased attention to management of OA with a view to improving mobility has potential to reduce CV events.

Cost-effectiveness of timely versus delayed primary total hip replacement in Germany: A social health insurance perspective

Without clinical guideline on the optimal timing for primary total hip replacement (THR), patients often receive the operation with delay. Delaying THR may negatively affect long-term health-related quality of life, but its economic effects are unclear. We evaluated the costs and health benefits of timely primary THR for functionally independent adult patients with end-stage osteoarthritis (OA) compared to non-surgical therapy followed by THR after progression to functional dependence (delayed THR), and non-surgical therapy alone (Medical Therapy), from a German Social Health Insurance (SHI) perspective. Data from hip arthroplasty registers and a systematic review of the published literature were used to populate a tunnel-state modified Markov lifetime model of OA treatment in Germany. A 5% annual discount rate was applied to costs (2013 prices) and health outcomes (Quality Adjusted Life Years, QALY). The expected future average cost of timely THR, delayed THR and medical therapy in women at age 55 were €27,474, €27,083 and €28,263, and QALYs were 20.7, 16.7, and 10.3, respectively. QALY differences were entirely due to health-related quality of life differences. The discounted cost per QALY gained by timely over delayed (median delay of 11 years) THR was €1270 and €1338 in women treated at age 55 and age 65, respectively, and slightly higher than this for men. Timely THR is cost-effective, generating large quality of life benefits for patients at low additional cost to the SHI. With declining healthcare budgets, research is needed to identify the characteristics of those able to benefit the most from timely THR.

The Main Cause of Death Following Primary Total Hip and Knee Replacement for Osteoarthritis: A Cohort Study of 26,766 Deaths Following 332,734 Hip Replacements and 29,802 Deaths Following 384,291 Knee Replacements

BACKGROUND

Patients undergoing primary total joint replacement are selected for surgery and thus (other than having a transiently increased mortality rate postoperatively) have a lower mortality rate than age and sex-matched individuals do. Understanding the causes of death following joint replacement would allow targeted strategies to reduce the risk of death and optimize outcome. We aimed to determine the rates and causes of mortality for patients undergoing primary total hip or knee replacement compared with individuals in the general population who were matched for age and sex.

METHODS

We compared causes and rates of mortality between age and sex-matched individuals in the general population (National Joint Registry for England, Wales and Northern Ireland; Hospital Episode Statistics; and Office for National Statistics) and a linked cohort of 332,734 patients managed with total hip replacement (26,766 of whom died before the censoring date) and 384,291 patients managed with primary total knee replacement (29,802 of whom died before the censoring date) from 2003 through 2012.

RESULTS

The main causes of death were malignant neoplasms (33.8% [9,037] of 26,766 deaths in patients with total hip replacement and 33.3% [9,917] of 29,802 deaths in patients with total knee replacement), circulatory system disorders (32.8% [8,784] of the deaths in patients with total hip replacement and 33.3% [9,932] of the deaths in patients with total knee replacement), respiratory system disorders (10.9% [2,928] of the deaths in patients with total hip replacement and 9.8% [2,932] of the deaths in patients with total knee replacement), and digestive system diseases (5.5% [1,465] of the deaths in patients with total hip replacement and 5.3% [1,572] of the deaths in patients with total knee replacement). There was a relative reduction in mortality (39%) compared with the individuals in the general population that equalized to the rate in the general population by 7 years for hips (overall standardized mortality ratio [SMR], 0.61; 95% confidence interval [CI], 0.60 to 0.62); for knees, the relative reduction (43%) partially attenuated by 7 years but still had not equalized to the rate in the general population (overall SMR, 0.57; 95% CI, 0.56 to 0.57). Ischemic heart disease was the most common cause of death within 90 days (29% [431] of the deaths in patients with primary hip replacement and 31% [436] of the deaths in patients with primary knee replacement). There was an elevated risk of death from circulatory, respiratory, and (most markedly) digestive system-related causes within 90 days postoperatively compared with 91 days to 1 year postoperatively.

CONCLUSIONS

Ischemic heart disease is the leading cause of death in the 90 days following total joint replacement, and there is an increase in postoperative deaths associated with digestive system-related disease following joint replacement. Interventions targeted at reducing these diseases may have the largest effect on mortality in total joint replacement patients.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

SOCS1 Regulates Apoptosis and Inflammation by Inhibiting IL-4 Signaling in IL-1β-Stimulated Human Osteoarthritic Chondrocytes

Recently, Suppressor of Cytokine Signaling 1 (SOCS1) was identified as a potential therapeutic target for osteoarthritis (OA) treatment. However, the mechanisms and signaling pathways of SOCS1 in the regulation of OA development are unclear. The purpose of the current study was to investigate whether interleukin- (IL-) 4 was involved in regulatory mechanism of SOCS1 in human osteoarthritic chondrocytes. First, IL-1β was used to stimulate human osteoarthritic chondrocytes isolated from the articular cartilage of OA patients undergoing total knee replacement. The protein and mRNA expression levels of SOCS1 were upregulated in IL-1β-stimulated human osteoarthritic chondrocytes compared with control cells. The knockdown of SOCS1 increased cell viability and inhibited cell apoptosis. It was also found that IL-4 expression was increased by SOCS1 silencing. Additionally, knockdown of IL-4 reduced cell viability and increased cell apoptosis of osteoarthritic chondrocytes transfected with SOCS1 siRNA. Moreover, the decreased expression of inflammatory factors induced by SOCS1 was enhanced by IL-4 knockdown. In conclusion, IL-4 signaling plays a crucial role in the regulatory functions of SOCS1 in apoptosis and inflammation in human osteoarthritic chondrocytes. These findings provide a potential therapeutic target for the clinical treatment of OA.

Osteoarthritis-related difficulty walking and risk for diabetes complications

OBJECTIVES

To examine the effect of Osteoarthritis (OA)-related difficulty walking on risk for diabetes complications in persons with diabetes and OA.

DESIGN

A population cohort aged 55+ years with symptomatic hip and knee OA was recruited 1996-98 and followed through provincial administrative data to 2015 (n = 2,225). In those with confirmed OA (examination and radiographs) and self-reported diabetes at baseline (n = 359), multivariate Cox regression modeling was used to examine the relationship between baseline difficulty walking (Health Assessment Questionnaire (HAQ) difficulty walking score; use of walking aid) and time to first diabetes-specific complication (hospitalization for hypo- or hyperglycemia, infection, amputation, retinopathy, or initiation of chronic renal dialysis) and cardiovascular (CV) events.

RESULTS

Participants' mean baseline age was 71.4 years; 66.9% were female, 77.7% had hypertension, 54.0% had pre-existing CV disease, 42.9% were obese and 15.3% were smokers. Median HAQ difficulty walking score was 2/3 indicating moderate to severe walking disability; 54.9% used a walking aid. Over a median 6.1 years, 184 (51.3%) experienced one or more diabetes-specific complications; 191 (53.2%) experienced a CV event over a median 5.7 years. Greater baseline difficulty walking was associated with shorter time to the first diabetes-specific complication (adjusted HR per unit increase in HAQ walking 1.24, 95% CI 1.04-1.47, P = 0.02) and CV event (adjusted HR for those using a walking aid 1.35, 95% CI 1.00-1.83, P = 0.04).

CONCLUSIONS

In a population cohort with OA and diabetes, OA-related difficulty walking was a significant - and potentially modifiable - risk factor for diabetes complications.

Locomotive syndrome is associated with large blood pressure variability in elderly hypertensives: the Japan Ambulatory Blood Pressure Prospective (JAMP) substudy

Chronic pain, represented by locomotive syndrome (LS), and psychosocial factors are possible factors of blood pressure (BP) variability (BPV). The authors tested the hypothesis that there are links among LS, depression, and BPV. In 85 Japanese elderly hypertensive patients with normal daily activities, the authors performed ambulatory BP monitoring, determined the LS scale (LSS), and administered the Self-Rating Questionnaire for Depression (SRQD). The LSS score but not the SRQD score was associated with the standard deviation (SD) and coefficient of variation (CV) of daytime systolic BP (SBP) and SD of nighttime SBP (all P<.05). Higher LSS score (in quartiles) was associated with a higher SD of daytime SBP (P=.041), even after adjusting for covariates. Regarding the components of the LSS score, movement-related difficulty and usual care difficulty were associated with the SD and CV of daytime SBP. In elderly hypertensive patients, the LSS score was associated with exaggerated systolic BPV. The LS state could be an important determinant of systolic BPV.

Comparison of Statistical Approaches for Dealing With Immortal Time Bias in Drug Effectiveness Studies

In time-to-event analyses of observational studies of drug effectiveness, incorrect handling of the period between cohort entry and first treatment exposure during follow-up may result in immortal time bias. This bias can be eliminated by acknowledging a change in treatment exposure status with time-dependent analyses, such as fitting a time-dependent Cox model. The prescription time-distribution matching (PTDM) method has been proposed as a simpler approach for controlling immortal time bias. Using simulation studies and theoretical quantification of bias, we compared the performance of the PTDM approach with that of the time-dependent Cox model in the presence of immortal time. Both assessments revealed that the PTDM approach did not adequately address immortal time bias. Based on our simulation results, another recently proposed observational data analysis technique, the sequential Cox approach, was found to be more useful than the PTDM approach (Cox: bias = -0.002, mean squared error = 0.025; PTDM: bias = -1.411, mean squared error = 2.011). We applied these approaches to investigate the association of β-interferon treatment with delaying disability progression in a multiple sclerosis cohort in British Columbia, Canada (Long-Term Benefits and Adverse Effects of Beta-Interferon for Multiple Sclerosis (BeAMS) Study, 1995-2008).

Notochordal cell conditioned medium (NCCM) regenerates end-stage human osteoarthritic articular chondrocytes and promotes a healthy phenotype

Background

Notochordal cell conditioned medium (NCCM) derived from non-chondrodystrophic dogs has pro-anabolic and anti-catabolic effects upon nucleus pulposus (NP) cells. Here, for the first time, we assessed the ability of NCCM to influence the production of extracellular matrix and inflammatory proteins by healthy and osteoarthritic human chondrocytes within engineered cartilage tissues. We hypothesized that, similar to its action on NP cells, NCCM exerts metabolic and anti-catabolic effects on human articular chondrocytes and has the potential to significantly counteract inflammatory mediators.

Methods

Chondrocytes from nine non-osteoarthritic patients and from six osteoarthritic (OA) donors at the time of total knee arthroplasty were chondro-differentiated in pellets for 2 weeks. Non-OA pellets were exposed for 72 hours to IL-1β/TNF-α and then cultured up to 14 days in 2 % FBS-supplemented NCCM or 2 % FBS-supplemented medium (control (ctr)). OA pellets were cultured in NCCM or ctr medium without pro-inflammatory treatment. Tissues after each culture phase were analyzed biochemically (GAG/DNA), (immuno-) histologically (collagen I, II and GAG) and by Western blotting. Supernatants were analyzed by ELISA.

Results

Response to NCCM was age and disease dependent with healthy chondrocyte pellets (from donors >55 years of age) recovering their glycosaminoglycan (GAG) contents to baseline levels only with NCCM. OA pellets treated with NCCM significantly increased GAG content (1.8-fold) and levels of hyaluronic acid link protein (HAPLN), fibromodulin and SOX-9. The catabolic proteins (matrix metalloproteinase (MMP)-3 and MMP-13) and pro-inflammatory enzyme levels (cyclooxygenase-2 (COX-2)) were markedly reduced and there was significantly reduced secretion of pro-inflammatory chemokines (IL-6 and IL-8).

Conclusions

NCCM restores cartilage matrix production of end-stage human OA chondrocytes towards a healthy phenotype and suppresses the production of inflammatory mediators. Harnessing the necessary and sufficient factors within NCCM that confers chondroprotection and regenerative effects could lead to a minimally invasive agent for treatment of degenerative and inflammatory joint diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-1026-x) contains supplementary material, which is available to authorized users.

Long-Term Mortality Trends After Total Hip and Knee Arthroplasties: A Population-Based Study

BACKGROUND

Mortality after total hip and knee arthroplasty is lower than that in the general population, but it is unknown whether there are differences by surgery type, demographics, and calendar year. Our objective was to evaluate trends and determinants of long-term mortality among patients with total hip and knee arthroplasties.

METHODS

Using a historical cohort study design, we passively followed up population-based cohorts of total hip and total knee arthroplasty patients with degenerative arthritis who underwent surgery between January 1, 1969 and December 31, 2008. Patients were followed up until death or August 31, 2014. Observed and expected survival was compared using standardized mortality ratios (SMRs). Poisson regression models were used to examine relative mortality patterns by surgery type, age, sex, calendar year, and time since surgery.

RESULTS

The overall age- and sex-adjusted mortality was significantly lower than that in the general population after both total hip (SMR: 0.82, 95% CI: 0.76-0.88) and total knee (SMR = 0.80, 95% CI: 0.75-0.86) arthroplasties. Despite the low relative mortality within the first 8 years of surgery, we observed a worsening of relative mortality beyond 15 years after total knee arthroplasty surgery. Both short- and long-term mortality improved over calendar time, and the improvement occurred about a decade earlier in total knee arthroplasty than in total hip arthroplasty.

CONCLUSION

Survival after total hip and total knee arthroplasties is better than that in the general population for about 8 years after surgery. Secular trends are encouraging and suggest that survival after both procedures has been improving even further in recent years.

Return to Sports and Physical Activity After Total and Unicondylar Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

People today are living longer and want to remain active. While obesity is becoming an epidemic, the number of patients suffering from osteoarthritis (OA) is expected to grow exponentially in the coming decades. Patients with OA of the knee are progressively being restricted in their activities. Since a knee arthroplasty (KA) is a well accepted, cost-effective intervention to relieve pain, restore function and improve health-related quality of life, indications are expanding to younger and more active patients. However, evidence concerning return to sports (RTS) and physical activity (PA) after KA is sparse.

OBJECTIVES

Our aim was to systematically summarise the available literature concerning the extent to which patients can RTS and be physically active after total (TKA) and unicondylar knee arthroplasty (UKA), as well as the time it takes.

METHODS

PRISMA guidelines were followed and our study protocol was published online at PROSPERO under registration number CRD42014009370. Based on the keywords (and synonyms of) 'arthroplasty', 'sports' and 'recovery of function', the databases MEDLINE, Embase and SPORTDiscus up to January 5, 2015 were searched. Articles concerning TKA or UKA patients who recovered their sporting capacity, or intended to, were included and were rated by outcomes of our interest. Methodological quality was assessed using Quality in Prognosis Studies (QUIPS) and data extraction was performed using a standardised extraction form, both conducted by two independent investigators.

RESULTS

Out of 1115 hits, 18 original studies were included. According to QUIPS, three studies had a low risk of bias. Overall RTS varied from 36 to 89% after TKA and from 75 to >100% after UKA. The meta-analysis revealed that participation in sports seems more likely after UKA than after TKA, with mean numbers of sports per patient postoperatively of 1.1-4.6 after UKA and 0.2-1.0 after TKA. PA level was higher after UKA than after TKA, but a trend towards lower-impact sports was shown after both TKA and UKA. Mean time to RTS after TKA and UKA was 13 and 12 weeks, respectively, concerning low-impact types of sports in more than 90 % of cases.

CONCLUSIONS

Low- and higher-impact sports after both TKA and UKA are possible, but it is clear that more patients RTS (including higher-impact types of sports) after UKA than after TKA. However, the overall quality of included studies was limited, mainly because confounding factors were inadequately taken into account in most studies.

Total joint arthroplasty and the risk of myocardial infarction: a general population, propensity score-matched cohort study

OBJECTIVE

To replicate recent findings indicating that total knee arthroplasty (TKA) or total hip arthroplasty (THA) surgery will substantially reduce the risk of serious cardiovascular events among patients with osteoarthritis.

METHODS

A time-stratified, propensity score-matched cohort study was conducted to assess the incidence of myocardial infarction (MI) in a UK general population. The study population included individuals ages ≥50 years who had a UK National Health Service READ code diagnosis of knee osteoarthritis (to evaluate TKA) or hip osteoarthritis (to evaluate THA) between January 2000 and December 2012.

RESULTS

Among the patients who underwent TKA and their matched non-TKA control subjects (each n = 13,849), 306 patients and 286 control subjects developed MI during the followup. During the first postoperative month, the risk of MI was substantially increased among the TKA group compared with the non-TKA group (hazard ratio [HR] 8.75, 95% confidence interval [95% CI] 3.11-24.62), and then gradually declined during the subsequent followup. The HR for the risk of MI over the entire followup was 0.98 (95% CI 0.82-1.18). The corresponding HRs for the risk of MI in those who had undergone THA compared with the non-THA group (each n = 6,063) were 4.33 (95% CI 1.24-15.21) in the first postoperative month and 0.87 (95% CI 0.66-1.15) overall. In analyses using venous thromboembolism as a positive control outcome, both the first month and overall HRs for the risk of venous thromboembolism were substantially increased in both the TKA and THA groups.

CONCLUSION

These findings provide the first general population-based evidence to indicate that TKA and THA among osteoarthritis patients are associated with a substantially increased risk of MI during the immediate postoperative period. However, the overall long-term impact of these surgeries was null, unlike the risk of venous thromboembolism, which remained elevated years after patients had undergone the procedure.

Patients with knee osteoarthritis undergoing total knee arthroplasty have a lower risk of subsequent severe cardiovascular events: propensity score and instrumental variable analysis

Objective

This population-based study investigated the subsequent cardiovascular risk of patients with knee osteoarthritis underwent total knee arthroplasty in Taiwan.

Materials and methods

This was a population-based follow-up study of 22931 patients diagnosed with knee osteoarthritis between 2008 and 2011. Each patient was followed for 3 years or until death. Treatment was dichotomized into conservative treatment and TKA. The association between TKA and cardiovascular disease (CVD) events was analyzed using propensity score analysis and instrumental variable analysis and two-stage least-squares regression model.

Results

Patients with knee osteoarthritis who underwent TKA had a lower 3-year cumulative risk of stroke and acute myocardial infarction (AMI). After adjusting for measured risk and confounding factors, propensity score showed a 0.56 fold (adjusted OR = 0.56; 95% CI, 0.51–0.61; p<0.001) risk for CVD in those with TKA. Use of instrumental variable analysis for adjusting measured and unmeasured factors and two-stage least squares regression model revealed that the average treatment effect of TKA was statistically associated with a decreased 7% risk of CVD events (95% CI, 0.2%–13.6%).

Conclusion

Our study revealed that patients with knee osteoarthritis who underwent TKA had a lower risk of suffering from a future severe cardiovascular event. This benefit may be attributed to an improvement in physical activity, reduction of psychosocial stress, and/or a decreased use of NSAIDs as a result of having undergone TKA.

Cardiovascular disease and osteoarthritis: common pathways and patient outcomes

BACKGROUND

Osteoarthritis (OA) and cardiovascular disease (CVD) are the two most prevalent conditions in the population aged over 70 in developed countries. Both conditions share common risk factors, in particular age and body mass index. However, the very high level of co-occurrence of both diseases cannot be accounted by common risk factors alone.

MATERIALS AND METHODS

We reviewed the recent literature published in English in PubMed for articles relating to osteoarthritis and cardiovascular disease.

RESULTS

On the one hand, the disability caused by OA increases the risk of CVD and in particular of ischemic events and mortality beyond what can be explained by known common risk factors, such as ageing and obesity. Moreover, the presence of OA has a synergistic effect on CVD symptoms considerably worsening them. On the other hand, at least in women, there appears to be a common pathogenic mechanism underlying atherosclerosis (but not hypertension) and actual joint damage.

CONCLUSION

There are some possible molecular mechanisms underlying both diseases, in particular relating to low grade inflammation and female hormones. However, the data available to date also indicate that OA may be considered as an indirect cause of CVD by increasing walking disability and the use of analgesic medication such as NSAIDs. We discuss future directions that need to be taken to address these highly prevalent, costly and disabling morbidities.