Early death following primary total knee arthroplasty

Thirty-Day Mortality and Complication Rates in Total Joint Arthroplasty After a Recent COVID-19 Diagnosis: A Retrospective Cohort in the National COVID Cohort Collaborative (N3C)

BACKGROUND

The risk of postoperative complications in patients who had a positive COVID-19 test prior to a total joint arthroplasty (TJA) is unknown. The purpose of this investigation was to study the complications and mortality associated with a recent COVID-19 diagnosis prior to TJA.

METHODS

Patients undergoing primary and revision total hip arthroplasties (THAs) or total knee arthroplasties (TKAs) were identified using the National COVID Cohort Collaborative (N3C) Data Enclave. Patients were divided into a COVID-19-positive group (positive polymerase chain reaction [PCR] test, clinical diagnosis, or positive antibody test) and a COVID-19-negative group, and the time from diagnosis was noted. There was no differentiation between severity or acuity of illness available. The postoperative complications reviewed included venous thromboembolism, pneumonia, acute myocardial infarction, readmission rates, and 30-day mortality rates.

RESULTS

A total of 85,047 patients who underwent elective TJA were included in this study, and 3,516 patients (4.13%) had had a recent positive COVID-19 diagnosis. Patients diagnosed with COVID-19 at 2 weeks prior to TJA were at increased risk of pneumonia (odds ratio [OR], 2.46), acute myocardial infarction (OR, 2.90), sepsis within 90 days (OR, 2.63), and 30-day mortality (OR, 10.61).

CONCLUSIONS

Patients with a recent COVID-19 diagnosis prior to TJA are at greater risk of postoperative complications including 30-day mortality. Our analysis presents critical data that should be considered prior to TJA in patients recently diagnosed with COVID-19.

LEVEL OF EVIDENCE

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

Long-Term Nonoperative Management is Associated With Lower Mean 9-Year Follow-Up Survival Compared to Total Knee Arthroplasty in Knee Osteoarthritis Patients-Survival Analysis of a Nationwide South Korean Cohort

BACKGROUND

Total knee arthroplasty (TKA) and medications are both considered as a treatment for knee osteoarthritis. However, the impact of the TKA on long-term survival remains controversial. This study aimed to compare 9-year follow-up survival between a TKA group with a nonoperative medication group.

METHODS

From 2007 to 2009, knee osteoarthritis patients were divided into TKA (N = 2,228) and nonoperative medication (N = 76,430) groups, and followed for up to 9 years. The hazard ratio (HR) and subdistribution HR (SHR) were derived from Cox proportional hazards regressions and Fine and Gray analyses, respectively.

RESULTS

The TKA group had a significantly lower adjusted mortality rate (adjusted HR , 0.78, 95% confidence interval [CI], 0.68-0.9) than the nonoperative medication group. Dose-response relationship between medication possession ratio and mortalities for overall (adjusted HR , 1.02; 95% CI, 1.01-1.04) and cardiovascular (CV) death (adjusted SHR, 1.03; 95% CI, 1.01-1.05) was also found. Also, there were significant interactions that indicate stronger protective survival effects of the TKA in several covariates: age >75 years (P = .04 for overall; P = .009 for CV), hypertension (P = .006 for overall), and ischemic heart disease (P = .009 for CV).

CONCLUSIONS

This study suggests that TKA patients had better mean 9-year follow-up survival than the nonoperative medication group after adjusting for baseline differences. For overall death, including CV death, adjusted mortality rates were higher in the medication group and showed a dose-response relationship. Specifically, the protective effect of the TKA for overall or CV deaths was found to be higher for age >75, hypertension, or ischemic heart disease patients.

LEVEL OF EVIDENCE

III.

Increased early mortality after total knee arthroplasty using conventional instrumentation compared with technology-assisted surgery: an analysis of linked national registry data

OBJECTIVES

This study aims to compare early mortality after total knee arthroplasty (TKA) using conventional intramedullary instrumentation to TKA performed using technology-assisted (non-intramedullary) instrumentation.

DESIGN

Comparative observational study. Using data from a large national registry, the 30-day mortality after unilateral TKA performed for osteoarthritis was compared between procedures using conventional instrumentation and those using technology-assisted instrumentation. Firth logistic regression was used to calculate ORs, adjusting for age, sex, use of cement and procedure year for the whole period, and additionally adjusting for American Society of Anesthesiologists physical status classification system class and body mass index (BMI) for the period 2015 to 2019. This analysis was repeated for 7-day and 90-day mortality.

SETTING

National arthroplasty registry.

PARTICIPANTS

People undergoing unilateral, elective TKA for osteoarthritis from 2003 to 2019 inclusive.

INTERVENTIONS

TKA performed using conventional intramedullary instrumentation or technology-assisted instrumentation.

MAIN OUTCOME MEASURES

30-day mortality (primary), and 7-day and 90-day mortality.

RESULTS

A total of 581 818 unilateral TKA procedures performed for osteoarthritis were included, of which 602 (0.10%) died within 30 days of surgery. The OR of death within 30 days following TKA performed with conventional instrumentation compared with technology-assisted instrumentation, adjusted for age, sex, cement use, procedure year, American Society of Anesthesiologists and BMI was 1.72 (95% CI, 1.23 to 2.41, p=0.001). The corresponding ORs for 7-day and 90-day mortality were 2.21 (96% CI, 1.34 to 3.66, p=0.002) and 1.35 (95% CI, 1.07 to 1.69, p=0.010), respectively.

CONCLUSIONS

The use of conventional instrumentation during TKA is associated with higher odds of early postoperative death than when technology-assisted instrumentation is used. This difference may be explained by complications related to fat embolism secondary to intramedullary rods used in conventional instrumentation. Given the high number of TKA performed annually worldwide, increasing the use of technology-assisted instrumentation may reduce early post-operative mortality.

Increased Early Mortality in Bilateral Simultaneous TKA Using Conventional Instrumentation Compared with Technology-Assisted Surgery: A Study of 34,908 Procedures from a National Registry

BACKGROUND

Controversy exists regarding the safety of bilateral simultaneous total knee arthroplasty (BSTKA). When conventional instrumentation is used, the increased fat emboli that result from the insertion of intramedullary rods may increase the risk of perioperative complications. We hypothesized that the use of technology-assisted instrumentation (avoiding intramedullary involvement) would be associated with a lower rate of early postoperative death compared with the use of conventional instrumentation.

METHODS

We compared the 30 and 90-day rates of mortality following BSTKA performed with conventional versus technology-assisted instrumentation from 2003 to 2019, with use of data from a large national registry. Firth logistic regression analysis was utilized, adjusting for age, sex, and procedure year for all BSTKAs performed during the study period. For procedures performed from 2015 to 2019, odds ratios were additionally adjusted for American Society of Anesthesiologists physical status classification and body mass index.

RESULTS

A total of 34,908 BSTKAs were identified. The proportion of cases utilizing technology-assisted instrumentation increased over the study period. The odds ratio of death within 30 days after technology-assisted BSTKA, adjusted for age, sex, and procedure year, was 0.26 (95% confidence interval [CI], 0.08 to 0.83; p = 0.02). The odds ratio, adjusted for age, sex, procedure year, American Society of Anesthesiologists classification, and body mass index, was 0.26 (95% CI, 0.09 to 0.74; p = 0.01). The corresponding odds ratios for 90-day mortality were 0.25 (95% CI, 0.09 to 0.72; p = 0.01) and 0.26 (95% CI, 0.10 to 0.67; p = 0.005), respectively.

CONCLUSIONS

Technology-assisted BSTKA was associated with a significant reduction in early mortality compared with the use of conventional instrumentation. This difference may be explained by the reduced fat emboli associated with technology-assisted BSTKA and is likely to be clinically important on a population scale.

LEVEL OF EVIDENCE

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

Primary and Revision Total Knee Arthroplasty in Patients With Pulmonary Hypertension: High Perioperative Mortality and Complications

BACKGROUND

Although perioperative medical management during total knee arthroplasty (TKA) has improved, there is limited literature characterizing outcomes of patients with pulmonary hypertension (HTN). This study examined mortality, medical complications, implant survivorship, and clinical outcomes in this medically complex cohort.

METHODS

We identified 887 patients with pulmonary HTN who underwent 881 primary TKAs and 228 revision TKAs from 2000 to 2016 at a tertiary care center. Patients were followed up at regular intervals until death, revision surgery, or last clinical follow-up. Perioperative medical complications were individually reviewed. The risk of death was examined by calculating standardized mortality ratios and Cox proportional hazards regression models. Cumulative incidence analysis was used for reporting mortality, revision, and reoperation with death as a competing risk.

RESULTS

The 90-day mortality was 0.7% and 4.8% for primary and revision TKAs, respectively. The risk of death was 2-fold higher compared to primary (hazard ratio 2.54, 95% confidence interval [CI] 2.12-3.05) and revision (hazard ratio 2.16, 95% CI 1.78-2.62) TKA patients without pulmonary HTN. Rate of medical complications within 90 days from surgery was 6.5% and 14% in primary and revision TKAs. The 10-year cumulative incidence of any revision was 5% and 16% in primaries and revisions, respectively.

CONCLUSION

Patients with pulmonary HTN undergoing primary and revision TKAs had excess risk of death and experience a high rate of medical complications within 90 days of surgery. Counseling of risks, medical optimization, and referral to tertiary centers should be considered.

LEVEL OF EVIDENCE

Level IV.

Incidence and risk factors analysis for mortality after total knee arthroplasty based on a large national database in Korea

This study aimed to analyze the rates and risk factors of postoperative mortality among 560,954 patients who underwent total knee arthroplasty (TKA) in Korea. The National Health Insurance Service-Health Screening database was used to analyze 560,954 patients who underwent TKA between 2005 and 2018. In-hospital, ninety-day, and one-year postoperative mortality, and their association with patient’s demographic factors and various comorbidities (ie., cerebrovascular disease, congestive heart failure, and myocardial infarction) were assessed. In-hospital, ninety-day and one-year mortality rates after TKA were similar from 2005 to 2018. The risk of in-hospital mortality increased with comorbidities like cerebrovascular disease (hazard ratio [HR] = 1.401; 95% confidence interval [CI] = 1.064–1.844), congestive heart failure (HR = 2.004; 95% CI = 1.394 to 2.881), myocardial infarction (HR = 2.111; 95% CI = 1.115 to 3.998), and renal disease (HR = 2.641; 95% CI = 1.348–5.173). These co-morbidities were also independent predictors of ninety-day and one-year mortality. Male sex and old age were independent predictors for ninety-day and one-year mortality. And malignancy was risk factor for one-year mortality. The common preoperative risk factors for mortality in all periods were male sex, old age, cerebrovascular disease, congestive heart failure, myocardial infarction, and renal disease. Malignancy was identified as risk factor for one-year mortality. Patients with these comorbidities should be provided better perioperative care.

Short-term mortality after primary and revision total joint arthroplasty: a single-center analysis of 103,560 patients

INTRODUCTION

The demand for total joint arthroplasty (TJA) is increasing worldwide with excellent long-term results. In general, TJA provides several benefits to the patients but also causes possible complications. The aim of our study was to describe trends in mortality after TJA in a high-volume arthroplasty center, and to examine the potential risk factors.

METHODS

From 1996 to 2018, a total of 103,560 patients (73,130 primary cases, 30,430 revision cases) underwent a TJA procedure in our institution. Anthropometric parameters, Charlson Comorbidity Index (CCI), pre- and postoperative hemoglobin (Hb), blood loss during surgery, postoperative complication (such as infection, deep vein thrombosis, pulmonary embolism, etc.) and cause of death from all patients who deceased during hospitalization were collected. The short-term mortality rate was analyzed between the primary and the revision groups.

RESULTS

The short-term mortality rate within our investigated groups was low with 0.041% in primary THA, 0.299% in revision THA, 0.045% in primary TKA, 0.205% in revision TKA, 0.214% in TSA/RSA, 0.15 % in primary TAA and 0% after TEA. Significant differences were found for preoperative Hb-values in patients undergoing septic revision (10.7 g/dl) compared to patients undergoing aseptic revision (12.8 g/dl) or primary arthroplasty (13.6 g/dl) (p < 0.001). Furthermore, we found significant differences regarding CCI between the groups. The comparison between causes of death (COD) showed a significantly higher number for pulmonary embolisms in the aseptic groups, while septic shock was the leading COD in the septic group and myocardial infarction as COD was found significantly more often after primary TJA.

CONCLUSION

This is the largest single-center study presenting the short-term mortality rate following TJA. Consequently, TJA is a safe procedure with a low short-term mortality rate. However, depending on the type of surgery, certain risk factors cannot be eliminated. In order to further reduce the mortality, procedures as such should continue to be performed at specialized centers under standardized conditions.

Multimodal thromboprophylaxis in low-risk patients undergoing lower limb arthroplasty: A retrospective observational cohort analysis of 1400 patients with ultrasound screening

PURPOSE

This study reports the results of a multimodal thromboprophylaxis protocol for lower limb arthroplasty involving risk stratification, intraoperative calf compression, aspirin prophylaxis and early (within 4 h) post-operative mobilisation facilitated by the use of local infiltration analgesia. The study also aimed to identify risk factors for venous thromboembolism (VTE) within a 3-month period following surgery for patients deemed not at elevated risk.

METHODS

Patients undergoing knee/hip arthroplasty or hip resurfacing were preoperatively screened for VTE risk factors, and those at standard risk were placed on a thromboprophylaxis protocol consisting of intraoperative intermittent calf compression during surgery, 300 mg/day aspirin for 6 weeks from surgery and early mobilisation. Patients were screened bilaterally for deep vein thrombosis (DVT) on post-operative days 10-14. If proximal DVT was detected, patients were anticoagulated and outcomes were recorded. Symptomatic VTE within 3 months of surgery were recorded separately. Patient notes were retrospectively collated and cross-validated against ultrasound reports.

RESULTS

At initial screening, the rate of proximal DVT was 0.54% (1.1% for knee and 0.27% for hip), and distal DVT was 6.63% (20.11% for knee and 2.31% for hip). One small, nonfatal pulmonary embolism (PE) was detected within 3 months of surgery (0.28% of total knee arthroplasty patients or 0.07% of total). All proximal DVTs were treated successfully with anticoagulants; however, one patient suffered a minor PE approximately 10 months post-operatively. Regression analysis identified knee implant and advanced age as independent risk factors for VTE in this cohort.

CONCLUSION

Although knee arthroplasty patients remained at higher risk than hip replacement/resurfacing patients, the incidence and outcomes of VTE remained positive compared with protocols involving extended immobilisation, and episodes of PE were extremely rare. Thus, we conclude that patients at standard preoperative risk of VTE may safely be taken through the post-operative recovery process with a combination of intraoperative mechanical prophylaxis, early mobilisation and post-operative aspirin, with closer attention required for older patients and those undergoing knee surgery.

Total knee arthroplasty reduces the risk of mortality in osteoarthritis patients up to 12 years: A Korean national cohort longitudinal follow-up study

INTRODUCTION

Mortality rates and causes of death after total knee arthroplasty (TKA) are of great interest to surgeons. However, there is a shortage of studies regarding those of the Asian population. The aim of this study was to compare the mortality rate and causes of death in patients after TKA to the general population.

METHODS

National sample cohort data from the Korean Health Insurance Review and Assessment Service were used. In this study, 1:4 matched patients after TKA (TKA group: 5072) and general participants (control group: 20,288) were selected as subjects. Their average follow-up duration was 57.2 months ranging from a year up to 12 years. The matches were processed for age, gender, income, region of residence, and past medical history. Mortality rates and causes of death were compared between groups. Regarding the mortality rates, we also performed subgroup analyses according to age.

RESULTS

Adjusted hazard ratio (HR) of the TKA group for mortality rate was less than 1 with significance (adjusted HR = 0.61 (95% confidence interval = 0.54-0.70, p < 0.001)). The ratios were less than 1 for both age groups (<70 and ≥70 years), respectively; however, for patients under 70, they were insignificant. Among the 11 major causes of death, the circulatory disease showed the most significantly reduced mortality rate for the TKA group compared to the control group. The neoplasm was the only other cause with a significantly reduced mortality rate for the TKA group.

CONCLUSION

The mortality rate in the TKA group was significantly lower than in the control group up to 12 years after the surgery in Korea. Among the major causes of death, circulatory disease and neoplasm showed a significant reduction in the mortality rate of the TKA group compared with the control group.

HIGHER RISK OF COMPLICATIONS AFTER TOTAL KNEE ARTHROPLASTY IN OCTOGENARIANS

OBJECTIVE

To evaluate the complication rate of total knee arthroplasty (TKA) in octogenarian patients and identify predictive factors.

METHODS

The study comprised 70 octogenarians and 70 non-octogenarian patients as control group, all submitted to TKA. We analyzed the medical records of these patients, seeking for complications during the first postoperative year. Regarding the risk factors, we evaluated: age, sex, race, American Society of Anesthesiologists score, body mass index, smoking, hypertension and diabetes mellitus.

RESULTS

In the control group, the incidence of complications was 7.1%. Whereas in the octogenarian group it was significantly higher, reaching 34.3% (OR 6.8; 95% CI 2.4-19.1). We found no association to sex, skin color, and comorbidities. Age is an independent risk factor for postoperative complications. Our data may help patients to acknowledge the risks of undergoing primary TKA and physicians to assess and adjust perioperative risk.

CONCLUSION

The incidence of postoperative complications is significantly higher in octogenarians. Level of Evidence III, Case-control study.

Declining early mortality after hip and knee arthroplasty

BACKGROUND

We aimed to measure the period effect (change over time) in 30-day mortality after total hip arthroplasty (THA) and total knee arthroplasty (TKA) using data from the Australian Orthopaedic Association National Joint Replacement Registry.

METHODS

We performed an observational study using national registry data from all hospitals performing THA and TKA in Australia including people undergoing primary elective conventional THA and TKA for osteoarthritis from 2003 to 2017, inclusive. Data from the Australian Orthopaedic Association National Joint Replacement Registry, the National Death Index and the Australian Bureau of Statistics were used to generate unadjusted 30-day mortality, the incident rate ratio for mortality adjusted for age and gender, and the standardized mortality ratio at 30 days for each year separately.

RESULTS

For the years 2003 and 2017, respectively, for THA, the unadjusted 30-day mortality was 0.23% and 0.06%, and the standardized mortality ratio was 1.11 (95% CI: 0.73, 1.49) and 0.38 (95% CI: 0.16, 0.59). The incident rate ratio was significantly higher than the reference year (2017) from 2003 to 2010, and for 2012, 2013 and 2016, decreasing over time. For the years 2003 and 2017, respectively, for TKA, the unadjusted 30-day mortality was 0.17% and 0.08%, and the standardized mortality ratio was 0.84 (95% CI: 0.55, 1.13) and 0.61 (95% CI: 0.38, 0.83). The incident rate ratio was significantly higher than the reference year (2017) from 2003 to 2009 inclusive, decreasing over time.

CONCLUSIONS

Thirty-day mortality after THA and TKA declined from 2003 to 2017. This may be due to improvements in intra-operative and post-operative patient management.

Early death following revision total knee arthroplasty

All patients from our institution who underwent revision total knee arthroplasty (TKA) or were added to the waiting list for revision TKA between 2003 and 2013 were analysed to describe the timing and degree of excess early surgical mortality. We measured the excess surgical mortality at 90-days for the revision TKA group compared to the waiting list group as 0.37% (95% CI 0.10%-0.65%, p = 0.075). A larger sample size will be required to give a more accurate measurement and thus we encourage other authors with access to larger cohorts to use our methods to quantify excess mortality after revision TKA.

Impact of Atrial Fibrillation on Postoperative Adverse Outcomes of Surgical Patients With Knee Endoprosthetic Surgery

BACKGROUND

Atrial fibrillation/flutter (AF) is associated with increased mortality, thromboembolism, heart failure, and adverse perioperative outcomes. We aimed to investigate the impact of AF on adverse in-hospital outcomes of hospitalized patients who underwent knee endoprosthetic surgery (KES).

METHODS

The nationwide German inpatient sample of the years 2005-2015 was used for this analysis. Patients who underwent KES were identified based on the surgical and interventional procedural codes (surgery and procedure code [Operationen-und Prozedurenschlüssel] 5-822), and patients were further stratified by AF (International Classification of Diseases and Related Health Problems code I48). We compared patients with and without AF who underwent KES as well as survivors vs nonsurvivors among patients with AF. Logistic regression models were used to investigate the impact of AF as a predictor for adverse in-hospital outcomes.

RESULTS

Overall, 1,642,875 hospitalized surgical patients (65.4% females, 49.5% aged >70 years) were included in the analysis. Of these, 93,748 patients (5.7%) were diagnosed with AF. Overall, 0.1% of the patients who underwent KES and 0.6% of the patients who underwent KES with additional AF died during in-hospital stay. All-cause death (risk ratio 5.97 [95% confidence interval {CI} 5.41-6.58], P < .001) and adverse in-hospital events (risk ratio 2.62 [95% CI 2.50-2.74], P < .001) occurred both more often in patients with AF compared to those without. AF was an important predictor for in-hospital death (odds ratio 2.09 [95% CI 1.88-2.32], P < .001) and adverse in-hospital events (odds ratio 1.76 [95% CI 1.68-1.85], P < .001) in patients who underwent KES independent of age, sex, and comorbidities.

CONCLUSION

In patients who underwent KES, AF is associated with increased in-hospital mortality and adverse in-hospital outcomes. Pneumonia, pulmonary embolism, shock, myocardial infarction, intracerebral bleeding, and stroke were the key complications promoting in-hospital death.

Early death following revision total hip arthroplasty

INTRODUCTION

The frequency of primary total hip arthroplasty procedures is increasing, with a subsequent rise in revision procedures. This study aims to describe timing and surgical mortality associated with revision total hip arthroplasty (THA) compared to those on the waiting list.

METHODS

All patients from a single institution who underwent revision total hip arthroplasty or were added to the waiting list for the same procedure between 2003 and 2013 were recorded. Mortality rates were calculated at 30 and 90 days following surgery or addition to the waiting list.

RESULTS

561 patients were available for the survivorship analysis in the surgical group. Following exclusion, 901 and 484 patients were available for the 30 and the 90-day analysis in the revision THA waiting list group. 30- and 90-day mortality rates were significantly greater for the revision THA group compared to the waiting list group (excess surgical mortality at 30 days = 0.357%, p = 0.037; odds ratio of 5.22, excess surgical mortality at 90 days = 0.863%, p = 0.045).

CONCLUSIONS

Revision total hip arthroplasty is associated with a significant excess surgical mortality rate until 90 days post-operation when compared to the waiting list population. We would encourage other authors with access to larger samples to use our method to quantify excess mortality after both primary and revision arthroplasty procedures.

Mortality After Total Knee Arthroplasty: A Systematic Review of Incidence, Temporal Trends, and Risk Factors

BACKGROUND

The capacity for total knee arthroplasty to improve pain, quality of life, and functional outcomes is widely recognized. Postoperative mortality is rare but of paramount importance, and needs to be accurately quantified and conveyed to patients in order to support decision-making prior to surgery. The purpose of this study was to determine a contemporary estimate of the risk of mortality following total knee arthroplasty, including the identification of temporal trends, common causes, and modifiable and nonmodifiable risk factors.

METHODS

We performed a systematic review with searches of MEDLINE, AMED, CAB Abstracts, and Embase. Studies in any language published from 2006 to 2016 reporting 30 or 90-day mortality following total knee arthroplasty were included, supplemented by contact with authors. Meta-analysis and meta-regression were performed for quantitative data.

RESULTS

Thirty-seven studies with mortality data from 15 different countries following over 1.75 million total knee arthroplasties formed the basis of this review. The pooled Poisson-normal random-effects meta-analysis estimates of 30 and 90-day mortality were 0.20% (95% confidence interval [CI], 0.17% to 0.24%) and 0.39% (95% CI, 0.32% to 0.49%). Both estimates have fallen over the 10-year study period (p < 0.001). Meta-regression using the median year of surgery as a moderator showed that 30 and 90-day mortality following total knee arthroplasty fell to 0.10% (95% CI, 0.07% to 0.14%) and 0.19% (95% CI, 0.15% to 0.23%), respectively, in 2015. The leading cause of death was cardiovascular disease.

CONCLUSIONS

There is an ongoing worldwide temporal decline in mortality following total knee arthroplasty. Improved patient selection and perioperative care and a healthy-population effect may account for this observation. Efforts to further reduce mortality should be targeted primarily at reducing cardiovascular events following total knee arthroplasty.

LEVEL OF EVIDENCE

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

The Effect of Age, Sex, Area Deprivation, and Living Arrangements on Total Knee Replacement Outcomes: A Study Involving the United Kingdom National Joint Registry Dataset

Background:

Total knee replacement (TKR) is a common procedure for the treatment of osteoarthritis that provides a substantial reduction of knee pain and improved function in most patients. We investigated whether sociodemographic factors could explain variations in the benefit resulting from TKR.

Methods:

Data were collected from 3 sources: the National Joint Registry for England, Wales, Northern Ireland, and the Isle of Man; National Health Service (NHS) England Patient Reported Outcome Measures; and Hospital Episode Statistics. These 3 sources were linked for analysis. Pain and function of the knee were measured with use of the Oxford Knee Score (OKS). The risk factors of interest were age group, sex, deprivation, and social support. The outcomes of interest were sociodemographic differences in preoperative scores, 6-month postoperative scores, and change in scores.

Results:

Ninety-one thousand nine hundred and thirty-six adults underwent primary TKR for the treatment of osteoarthritis in an NHS England unit from 2009 to 2012. Sixty-six thousand seven hundred and sixty-nine of those patients had complete knee score data and were included in the analyses for the present study. The preoperative knee scores were worst in female patients, younger patients, and patients from deprived areas. At 6 months postoperatively, the mean knee score had improved by 15.2 points. There were small sociodemographic differences in the benefit of surgery, with greater area deprivation (−0.71 per quintile of increase in deprivation; 95% confidence interval [CI], −0.76 to −0.66; p < 0.001) and younger age group (−3.51 for ≤50 years compared with 66 to 75 years; 95% CI, −4.00 to −3.02; p < 0.001) associated with less benefit. Cumulatively, sociodemographic factors explained <1% of the total variability in improvement.

Conclusions:

Sociodemographic factors have a small influence on the benefit resulting from TKR. However, as they are associated with the clinical threshold at which the procedure is performed, they do affect the eventual outcomes of TKR.

Level of Evidence:

Prognostic Level IV. See Instructions for Authors for a complete description of evidence.

Mortality After Total Knee and Total Hip Arthroplasty in a Large Integrated Health Care System

CONTEXT

The number of excess deaths associated with elective total joint arthroplasty in the US is not well understood.

OBJECTIVE

To evaluate one-year postoperative mortality among patients with elective primary and revision arthroplasty procedures of the hip and knee.

DESIGN

A retrospective analysis was conducted of hip and knee arthroplasties performed in 2010. Procedure type, procedure volume, patient age and sex, and mortality were obtained from an institutional total joint replacement registry. An integrated health care system population was the sampling frame for the study subjects and was the reference group for the study.

MAIN OUTCOME MEASURES

Standardized 1-year mortality ratios (SMRs) and 95% confidence intervals (CIs) were calculated.

RESULTS

A total of 10,163 primary total knee arthroplasties (TKAs), 4963 primary total hip arthroplasties (THAs), 606 revision TKAs, and 496 revision THAs were evaluated. Patients undergoing primary THA (SMR = 0.6, 95% CI = 0.4-0.7) and TKA (SMR = 0.4, 95% CI = 0.3-0.5) had lower odds of mortality than expected. Patients with revision TKA had higher-than-expected mortality odds (SMR = 1.8, 95% CI = 1.1-2.5), whereas patients with revision THA (SMR = 0.9, 95% CI = 0.4-1.5) did not have higher-than-expected odds of mortality.

CONCLUSION

Understanding excess mortality after joint surgery allows clinicians to evaluate current practices and to determine whether certain groups are at higher-than-expected mortality risk after surgery.

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.

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.

Primary Total Knee Arthroplasty After Solid Organ Transplant: Survivorship and Complications

BACKGROUND

Clinical outcomes remain largely unknown beyond perioperative and short-term follow-up of solid organ transplant (SOT) patients undergoing total knee arthroplasty (TKA).

METHODS

Patient mortality, implant survivorship, and complications of 96 TKAs (76 patients) after SOT were retrospectively reviewed through an internal joint registry. Mean age at index arthroplasty was 66 years, and mean follow-up was 4 years.

RESULTS

Overall mortality rates at 1 year, 2 years, and 5 years from TKA were 2.6%, 7.9%, and 13.2%, respectively, and combined SOT patient survivorship was 92% at 2 years and 82% at 5 years. Implant survivorship free of any component revision or implant removal was 98% at 2 years and 93% at 5 years. There was a high rate of perioperative complications (12.5%), including periprosthetic fractures (5.2%) and deep periprosthetic infection (3.2%).

CONCLUSION

TKA does not appear to have any effect on SOT patient survivorship following the procedure. However, SOT patients may have a higher risk of perioperative complications and a lower implant survivorship than the general population of TKA patients at midterm follow-up.

Inpatient mortality after elective primary total hip and knee joint arthroplasty in Botswana

PURPOSE

Total hip and knee joint arthroplasty (TJA) rank among the most successful orthopaedic operations. Several developing countries in Africa have started to perform these procedures that are routine in developed countries. The aims of this study were to measure the incidence and assess the determinants of in-hospital mortality after elective primary TJA in our unit and compare it with published data.

METHODS

This was a retrospective study of the first consecutive cohort of patients who underwent elective primary TJA in Princess Marina Hospital, Botswana between March 2009 and October 2015 (6.5 years).

RESULTS

346 elective joint replacements were performed comprising 153 total hip arthroplasties (THA) and 193 total knee arthroplasties (TKA); 36 % of the THA were in female patients and 82 % of TKA were in females. The mean age was 64.5 years (range 26-86). Three patients died giving an inpatient mortality rate of 0.86 %. These three mortalities represent 1.55 % (three out of 193) of all the TKA. There were no deaths after THA. The cause of mortality in two patients was an adverse cardiac event while the third mortality was due to pulmonary embolism.

CONCLUSION

The inpatient mortality rate of 0.86 % following TJA is higher than the reported rates in the developed countries but comparable with data from other developing countries. The inpatient mortality rate following TKA was higher than that following THA and cardiovascular events proved to be the main cause of death. We recommend formal cardiology assessment and close peri-operative monitoring of all patients with a history of cardiovascular disease undergoing TJA.

Adverse cardiac events in 56,000 orthopaedic trauma patients: Does anatomic area make a difference?

PURPOSE

Postoperative cardiac events in orthopaedic trauma patients constitute severe morbidity and mortality. It is therefore increasingly important to determine patient risk factors that are predictive of postoperative myocardial infarctions and cardiac arrests. This study sought to assess if there is an association between anatomic area and cardiac complications in the orthopaedic trauma patient.

PATIENTS AND METHODS

From 2006-2013, a total of 361,402 orthopaedic patients were identified in the NSQIP database using Current Procedural Terminology (CPT) codes. Of these, 56,336 (15.6%) patients were identified as orthopaedic trauma patients broken down by anatomic region: 11,905 (21.1%) upper extremity patients (UE), 29,009 (51.5%) hip/pelvis patients (HP), and 15,422 (27.4%) lower extremity patients (LE) using CPT codes. Patients were defined as having adverse cardiac events if they developed myocardial infarctions or cardiac arrests within 30days after surgery. Chi-squared analysis was used to determine if there was an association between anatomic area and rates of cardiac events. Multivariate logistical analysis was used with over 40 patient characteristics including age, gender, history of cardiac disease, and anatomic region as independent predictors to determine whether anatomic area significantly predicted the development of cardiac complications.

RESULTS

There were significant differences in baseline demographics among the three groups: HP patients had the greatest average age (77.6 years) compared to 54.8 years for UE patients and 54.1 years in LE patients (p<0.001). HP patients also had the highest average ASA score (3.0) (p<0.001). There was a significant difference in adverse cardiac events based on anatomic area: 0.27% (32/11,905) UE patients developed cardiac complications compared to 2.15% (623/29,009) HP patients and 0.61% (94/15,422) LE patients. After multivariate analysis, HP patients were significantly more likely to develop cardiac complications compared to both UE patients (OR: 6.377, p=0.014) and LE patients (OR: 2.766, p=0.009).

CONCLUSION

There is a significant difference in adverse cardiac events following orthopaedic trauma based on anatomic region. Hip/Pelvis surgery appeared to be a significant risk factor in developing an adverse cardiac event. Further studies should investigate why hip/pelvic patients are at a higher risk of adverse cardiac events.

Improving patients’ experience and outcome of total joint replacement: the RESTORE programme

Background

Total hip replacements (THRs) and total knee replacements (TKRs) are common elective procedures. In the REsearch STudies into the ORthopaedic Experience (RESTORE) programme, we explored the care and experiences of patients with osteoarthritis after being listed for THR and TKR up to the time when an optimal outcome should be expected.

Objective

To undertake a programme of research studies to work towards improving patient outcomes after THR and TKR.

Methods

We used methodologies appropriate to research questions: systematic reviews, qualitative studies, randomised controlled trials (RCTs), feasibility studies, cohort studies and a survey. Research was supported by patient and public involvement.

Results

Systematic review of longitudinal studies showed that moderate to severe long-term pain affects about 7–23% of patients after THR and 10–34% after TKR. In our cohort study, 10% of patients with hip replacement and 30% with knee replacement showed no clinically or statistically significant functional improvement. In our review of pain assessment few research studies used measures to capture the incidence, character and impact of long-term pain. Qualitative studies highlighted the importance of support by health and social professionals for patients at different stages of the joint replacement pathway. Our review of longitudinal studies suggested that patients with poorer psychological health, physical function or pain before surgery had poorer long-term outcomes and may benefit from pre-surgical interventions. However, uptake of a pre-operative pain management intervention was low. Although evidence relating to patient outcomes was limited, comorbidities are common and may lead to an increased risk of adverse events, suggesting the possible value of optimising pre-operative management. The evidence base on clinical effectiveness of pre-surgical interventions, occupational therapy and physiotherapy-based rehabilitation relied on small RCTs but suggested short-term benefit. Our feasibility studies showed that definitive trials of occupational therapy before surgery and post-discharge group-based physiotherapy exercise are feasible and acceptable to patients. Randomised trial results and systematic review suggest that patients with THR should receive local anaesthetic infiltration for the management of long-term pain, but in patients receiving TKR it may not provide additional benefit to femoral nerve block. From a NHS and Personal Social Services perspective, local anaesthetic infiltration was a cost-effective treatment in primary THR. In qualitative interviews, patients and health-care professionals recognised the importance of participating in the RCTs. To support future interventions and their evaluation, we conducted a study comparing outcome measures and analysed the RCTs as cohort studies. Analyses highlighted the importance of different methods in treating and assessing hip and knee osteoarthritis. There was an inverse association between radiographic severity of osteoarthritis and pain and function in patients waiting for TKR but no association in THR. Different pain characteristics predicted long-term pain in THR and TKR. Outcomes after joint replacement should be assessed with a patient-reported outcome and a functional test.

Conclusions

The RESTORE programme provides important information to guide the development of interventions to improve long-term outcomes for patients with osteoarthritis receiving THR and TKR. Issues relating to their evaluation and the assessment of patient outcomes are highlighted. Potential interventions at key times in the patient pathway were identified and deserve further study, ultimately in the context of a complex intervention.

Study registration

Current Controlled Trials ISRCTN52305381.

Funding

This project was funded by the NIHR Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 4, No. 12. See the NIHR Journals Library website for further project information.

Is Total Knee Arthroplasty a Viable Treatment Option in Octogenarians with Advanced Osteoarthritis?

Purpose

This study directly compared clinical assessment scores and short-term systemic complications after total knee arthroplasty (TKA) between a group of patients aged 80 or older (141 patients) and another group of patients aged between 65 and 70 years (616 patients) with advanced osteoarthritis.

Materials and Methods

We retrospectively investigated 757 osteoarthritic patients who underwent primary TKA from January 2007 to January 2011 with a follow-up of 1 year. The surgery was performed using an extramedullary alignment guide instrument without invasion of the intramedullary canal to decrease embolic load and blood loss.

Results

At 1 year after surgery, the mean Knee Society knee score was improved in both groups (from 63.6 to 83.2 in octogenarians and from 68.3 to 89.0 in the younger group) and the level of satisfaction was excellent in both groups (8 in octogenarians and 8.3 in the younger group), even though there was no notable change in function score in the octogenarians (from 61.0 to 61.9 in the octogenarians and from 62.3 to 73.6 in the younger group). The total incidence of systemic complications (3.4% vs. 1.2%, p=0.400) and surgical complications (2.1% vs. 0.5%, p=0.229) showed no significant difference between groups.

Conclusions

TKA yielded favorable clinical outcomes with a comparatively low postoperative complication rate in octogenarians despite the negligible functional improvement.

45-day mortality after 467,779 knee replacements for osteoarthritis from the National Joint Registry for England and Wales: an observational study

BACKGROUND

Understanding the risk factors for early death after knee replacement could help to reduce the risk of mortality after this procedure. We assessed secular trends in death within 45 days of knee replacement for osteoarthritis in England and Wales, with the aim of investigating whether any change that we recorded could be explained by alterations in modifiable perioperative factors.

METHODS

We took data for knee replacements done for osteoarthritis in England and Wales between April 1, 2003, and Dec 31, 2011, from the National Joint Registry for England and Wales. Patient identifiers were used to link these data to the national mortality database and the Hospital Episode Statistics database to obtain details of death, sociodemographics, and comorbidity. We assessed mortality within 45 days by Kaplan-Meier analysis and assessed the role of patient and treatment factors by Cox proportional hazards models.

FINDINGS

467,779 primary knee replacements were done to treat osteoarthritis during 9 years. 1183 patients died within 45 days of surgery, with a substantial secular decrease in mortality from 0·37% in 2003 to 0·20% in 2011, even after adjustment for age, sex, and comorbidity. The use of unicompartmental knee replacement was associated with substantially lower mortality than was total knee replacement (hazard ratio [HR] 0·32, 95% CI 0·19–0·54, p<0·0005). Several comorbidities were associated with increased mortality: myocardial infarction (HR 3·46, 95% CI 2·81–4·14, p<0·0005), cerebrovascular disease (3·35, 2·7–4·14, p<0·0005), moderate/severe liver disease (7·2, 3·93–13·21, p<0·0005), and renal disease (2·18, 1·76–2·69, p<0·0005). Modifiable perioperative risk factors, including surgical approach and thromboprophylaxis were not associated with mortality.

INTERPRETATION

Postoperative mortality after knee replacement has fallen substantially between 2003 and 2011. Efforts to further reduce mortality should concentrate more on older patients, those who are male and those with specific comorbidities, such as myocardial infarction, cerebrovascular disease, liver disease, and renal disease.

FUNDING

National Joint Registry for England and Wales.

A nationwide analysis of risk factors for in-hospital myocardial infarction after total joint arthroplasty

PURPOSE

Despite acute myocardial infarction (AMI) being a feared medical complication and currently a major cause of death after total hip and knee arthroplasty (THA/TKA), little is known about its peri-operative associated factors.

METHODS

Data for this retrospective cohort study were extracted from the Nationwide Inpatient Sample for 2008-2011. Multivariate logistic regression modeling was performed to determine peri-operative factors associated with the development of inpatient AMI following THA/TKA.

RESULTS

An estimated 3,096,791 procedures were identified. Perioperative AMI rates were 0.25 % for THA and 0.18 % for TKA. Patients with AMI had significantly greater comorbidity burden, higher peri-operative mortality rates, longer length of hospital stay and increased complication rates. Independent risk factors for the development of AMI comprised advance age, male gender [odds ratio (OR) 1.4, 95 % confidence interval (CI) 1.4-1.5], THA surgery (OR 1.3, 95 % CI 1.3-1.4), low household income (OR 1.3, 95 % CI 1.2-1.4), history of cardiac disease (coronary artery disease: OR 4.9, 95 % CI 4.6-5.2; congestive heart failure: OR 2.6, 95 % CI 2.4-2.8; valvular disease: OR 1.2, 95 % CI 1.1-1.3), diabetes (OR 1.1, 95 % CI 1.1-1.2), pulmonary circulation disorders (OR 1.4, 95 % CI 1.2-1.6), cerebrovascular disease (OR 2.3, 95 % CI 2.0-2.6), peripheral vascular disorders (OR 1.5, 95 % CI 1.4-1.7), coagulopathy (OR 1.4, 95 % CI 1.2-1.5), AIDS/HIV infection (OR 7.9, 95 % CI 4.5-13.9), deficiency anaemia (OR 1.4, 95 % CI 1.3-1.5), fluid and electrolyte disorders (OR 1.9, 95 % CI 1.8-2.0) and the occurrence of concomitant postoperative complications.

CONCLUSION

Our findings can be used to better identify patients at high risk of AMI and to develop strategies aimed at diminishing its incidence, which could in turn translate to improved hospital efficiency and quality of care.

Early death following primary total hip arthroplasty

This study aims to describe the timing, cause of death, and excess surgical mortality associated with primary total hip arthroplasty when compared to a population awaiting primary total hip arthroplasty. Mortality rates were calculated at cutoffs of 30 and 90 days post-operation or following the addition to the waiting list. Cause of death was recorded from the death certificate. An excess surgical mortality of 0.256% at 30 days (P = 0.002) and 0.025% at 90 days post-operation (P = 0.892), unaffected by age or gender, was seen with myocardial infarction and pneumonia the cause of death in the majority of cases. By using a more appropriate control population, an excess surgical mortality at 30 days post-operation is demonstrated; the effect diminishes at 90 days post-operation.

Mortality following revision total knee arthroplasty: a matched cohort study of septic versus aseptic revisions

We report the medium-term mortality after septic versus aseptic revision total knee arthroplasty (TKA) and factors that can contribute to mortality in revision TKA. Mortality rates of 88 patients undergoing septic revision (septic group) were compared with age- and year of surgery-matched 88 patients of aseptic revision (aseptic group). The overall mortality after revision TKA was 10.7% at a median of 4 years of follow-up (range, 2-7 years). However, the mortality after septic revision (18%, 16/88) was six times higher than that of aseptic revision (3%, 3/88) (P = 0.003). Infections with Staphylococcus aureus and/or methicillin resistance was not associated with higher mortality rates. Multivariate analysis indicated that increased age (P < 0.001), higher ASA class (P = 0.002), and septic revision (P < 0.001) were identified as independent predictors of increased mortality after revision TKA.

Thirty-day postoperative complications and mortality following total knee arthroplasty: incidence and risk factors among a national sample of 15,321 patients

BACKGROUND

The purpose of this investigation was to determine the incidence rates of, and identify risk factors for, thirty-day postoperative mortality and complications among more than 15,000 patients who underwent a primary unilateral total knee arthroplasty as documented in the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP).

METHODS

The NSQIP database was queried to identify patients who had undergone primary unilateral total knee arthroplasty between 2006 and 2010. Patient demographics, medical history, and surgical characteristics were recorded, as were thirty-day postoperative complications, mortality, and length of hospital stay. Complications were divided into categories, which included major systemic complications (complications requiring complex medical intervention) and major local complications (including deep wound infection and peripheral nerve injury). Univariate testing and multivariate logistic regression analysis were used to identify significant independent predictors of the outcome measures.

RESULTS

A total of 15,321 individuals underwent primary unilateral total knee arthroplasty. The mean age (and standard deviation) of the patients was 67.3 ± 10.2 years. Obesity (a body mass index [BMI] of ≥30 kg/m²) was documented in 61.2% of cases, 18.2% of patients had diabetes, and 50% were graded as Class 3 or higher on the basis of the American Society of Anesthesiologists (ASA) classification system. The thirty-day mortality rate was 0.18%, and 5.6% of the patients experienced complications. Patient age (odds ratio [OR] = 1.12; 95% confidence interval [CI] = 1.06 to 1.17) and diabetes (OR = 2.99; 95% CI = 1.35 to 6.62) were independent predictors of mortality. A BMI of ≥40 kg/m² was an independent predictor of postoperative complications (OR = 1.47; 95% CI = 1.09 to 1.98). Patient age of eighty years or older, an ASA classification of ≥3, and an operative time of >135 minutes influenced the development of any postoperative complication as well as major and minor systemic complications. Cardiac disease (OR = 4.32; 95% CI = 1.01 to 18.45) and a BMI of ≥40 kg/m² (OR = 2.01; 95% CI = 1.02 to 3.97) were associated with minor local complications.

CONCLUSIONS

Patient age and diabetes increased the risk of mortality after primary total unilateral knee arthroplasty. Predictive factors impacting the development of postoperative complications included an ASA classification of ≥3, increased operative time, increased age, and greater body mass.

Mortality, cost, and downstream disease of total hip arthroplasty patients in the medicare population

The purpose of this study is to compare the differences in downstream cost and health outcomes between Medicare hip OA patients who undergo total hip arthroplasty (THA) and those who do not. All OA patients in the Medicare 5% sample (1998-2009) were separated into non-THA and THA groups. Differences in costs and risk ratios for mortality and new disease diagnoses were adjusted using logistic regression for age, sex, race, socioeconomic status, region, and Charlson score. Mortality, heart failure, depression, and diabetes were all reduced in the THA group, though there was an increased risk for atherosclerosis in the short term. The potential for selection bias was investigated with two separate propensity score analyses. This study demonstrates the potential benefit of THA in reducing mortality and improving aspects of overall health in OA patients.

Mortality after septic versus aseptic revision total hip arthroplasty: a matched-cohort study

Mortality rates after revision total hip arthroplasty (THA) for periprosthetic sepsis were investigated in 93 patients and compared to 93 patients, matched for age, gender, year of surgery, who underwent revision for aseptic failures. The mortality rate was 33% (31/93) in the septic group and 22% (20/93) in the aseptic group at 5 and 6 year follow-up, respectively (P=0.10). Patients in the septic group died on average 6 years earlier (74 versus 80 yrs; P<0.05) than those in the aseptic group. Charlson Comorbidity Index (CCI) was an independent predictor of mortality among the both groups (P<0.05), while age (P<0.01) was a predictor of mortality only in the aseptic group. While revision THA for sepsis alone did not predict increased mortality, a 33% mortality rate at five years in patients with an average age of 66 years and earlier death by 6 years compared to aseptic revisions is alarming.

Simultaneous bilateral total knee arthroplasty. A multicenter feasibility study

INTRODUCTION

The value and risk of simultaneous total knee arthroplasty (TKA) in patients with bilateral knee arthritis is a subject of debate.

HYPOTHESES

The risk of complications following simultaneous bilateral TKA will be increased compared to the rates published in the literature for unilateral TKA, and the clinical and functional outcomes will be poorer in this particular group.

MATERIALS AND METHODS

One hundred and twenty-three patients who underwent simultaneous bilateral TKA between 2005 and 2011 in five specialized, high volume centers were evaluated. The files were analyzed retrospectively after a mean 33 months of follow-up.

RESULTS

The mean hospital stay was 11 days. Mean blood loss was 4.1g/dL. A postoperative transfusion was performed in 68 patients (55%), with a mean 3.1 units of blood. The mean global IKS score increased from 90 to 150 points. Eighty patients would agree to undergo simultaneous bilateral TKA again (65%), and 70 would recommend this procedure to others (57%).

DISCUSSION

The hypothesis was not confirmed: the risk of complications was not increased compared to the generally accepted risk of a unilateral procedure. The risk of complications in this study was very similar to that published in the literature for the same therapeutic strategy. Therefore, there is no solid medical evidence to prevent recommending this strategy. The results of the participating centers suggest that this therapeutic approach should be continued in selected indications.

LEVEL OF EVIDENCE

IV, retrospective study.

Mortality, cost, and health outcomes of total knee arthroplasty in Medicare patients

There are little data that quantify the long term costs, mortality, and downstream disease after Total Knee Arthroplasty (TKA). The purpose of this study is to compare differences in cost and health outcomes between Medicare patients with OA who undergo TKA and those who avoid the procedure. The Medicare 5% sample was used to identify patients diagnosed with OA during 1997-2009. All OA patients were separated into non-arthroplasty and arthroplasty groups. Differences in costs, mortality, and new disease diagnoses were adjusted using logistic regression for age, sex, race, buy-in status, region, and Charlson score. The 7-year cumulative average Medicare payments for all treatments were $63,940 for the non-TKA group and $83,783 for the TKA group. The risk adjusted mortality hazard ratio (HR) of the TKA group ranged from 0.48 to 0.54 through seven years (all P<0.001). The risk of heart failure in the TKA group was 40.9% at 7years (HR=0.93, P<0.001). The results demonstrate the patients in the TKA cohort as having a lower probability of heart failure and mortality, at a total incremental cost of $19,843.

Accuracy and clinical utility of a peri-operative risk calculator for total knee arthroplasty

Utilizing the Medicare Provider Analysis and Review dataset, a, peri-operative total knee arthroplasty (TKA) risk calculator was created based on select preoperative comorbidities. We retrospectively identified and reviewed 2284 primary TKAs at a single institution from 2000-2008. A numerical, predicted complication risk was established for each patient. Actual complications occurring within the first 14 post-operative days were recorded. Statistical analysis was performed using the C-statistic and ANOVA test. Patients with higher predicted probability of a complication did show higher complication rates. The corresponding C-statistic was 0.609. (95% Confidence Interval: 0.542-0.677). When the patients were divided into 4 groups based on their calculated complication risk (0-5%, 5-10%, 10-25%, >25%) the statistical significance of the associated ANOVA was P < .001, showing that patients with higher predicted risk experienced more complications, and those with lower predicted risk experienced fewer complications. Based on our results, the calculator has predictive value and is clinically relevant.

Predictors of mortality after total knee replacement

We report the general mortality rate after total knee replacement and identify independent predictors of survival. We studied 2428 patients: there were 1127 men (46%) and 1301 (54%) women with a mean age of 69.3 years (28 to 94). Patients were allocated a predicted life expectancy based on their age and gender.

There were 223 deaths during the study period. This represented an overall survivorship of 99% (95% confidence interval (CI) 98 to 99) at one year, 90% (95% CI 89 to 92) at five years, and 84% (95% CI 82 to 86) at ten years. There was no difference in survival by gender. A greater mortality rate was associated with increasing age (p < 0.001), American Society of Anesthesiologists (ASA) grade (p < 0.001), smoking (p < 0.001), body mass index (BMI) <  20 kg/m2 (p < 0.001) and rheumatoid arthritis (p < 0.001). Multivariate modelling confirmed the independent effect of age, ASA grade, BMI, and rheumatoid disease on mortality. Based on the predicted average mortality, 114 patients were predicted to have died, whereas 217 actually died. This resulted in an overall excess standardised mortality ratio of 1.90. Patient mortality after TKR is predicted by their demographics: these could be used to assign an individual mortality risk after surgery.