Does Image Derived Instrumentation Alter Revision Rates? An AOANJRR Analysis

Objectives: Image Derived Instrumentation (IDI) has been introduced into regular use in modern day total knee arthroplasty (TKA) with many potential benefits touted. Despite this, much of the research involving IDI has failed to prove any significant benefit in alignment, operative time, blood loss and cost. The purpose of this study, the first of its kind, was to compare IDI with non-IDI TKA with respect to rate of revision. Methods: The Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) was queried to analyse the survivorship of primary TKAs using IDI reported to the AOANJRR, between April 2009 to December 2014, compared with those without IDI instrumentation. Subgroup analysis was performed to determine the effect of polyethylene insert thickness upon IDI outcomes. The Kaplan-Meier method and proportional hazards models were used to determine the cumulative rates of revision and which prostheses or circumstances lead to an increased risk of revision. Results: In the period studied, there were 11197 primary TKAs performed utilising IDI. This was 4.8% of all primary TKAs during this period. The overall rate of revision/100 observed years was 1.07 in the PSI group, compared with, 0.82 in the standard group. This was equivalent to a hazard ratio (HR) of 1.15 (1.01,1.31; p=0.041). Posterior stabilised (PS) knees in particular showed an increased risk when compared with minimally stabilised knees when using IDI (HR=1.49; p=0.002) and non-IDI PS knees (HR=1.30; p=0.014). Subgroup analysis of the PSI (Zimmer); Signature (Vanguard) and Visionaire (Smith and Nephew) systems by polyethylene insert thickness found varied alteration in revision rates. Of the specific prosthetic combinations examined the NEXGEN CR FLEX/NEXGEN >11 mm poly (909 pts) HR 1.83 p=0.022 and GII Oxinium PS/GII <11 mm poly (868 pts) HR 1.45 p=0.049 were found to have significantly elevated risk of revision with the use of IDI. Conclusion: Using the AOANJRR we have shown that in primary TKAs, the use of IDI is associated with an increased overall revision rate. This is particularly prevalent in those knees using posterior stabilisation. The effect of polyethylene insert thickness varied dependent on manufacturer. The reasons for this cannot be determined from this analysis but suggest caution should be exercised in relation to this technology. Further study is warranted to better understand the reasons for increased revision rates.

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The Varus–Valgus Constrained Knee Implant: Survivorship and Outcomes

The Journal of Knee Surgery ◽

10.1055/s-0036-1593361 ◽

2016 ◽

Vol 30 (05) ◽

pp. 484-492 ◽

Cited By ~ 8

Author(s):

Marcelo Siqueira ◽

Paul Jacob ◽

John McLaughlin ◽

Alison Klika ◽

Robert Molloy ◽

...

Keyword(s):

Periprosthetic Fracture ◽

Proportional Hazards ◽

Revision Total Knee Arthroplasty ◽

Cox Proportional Hazards ◽

Modes Of Failure ◽

Kaplan Meier ◽

Cox Proportional Hazards Models ◽

Primary Tkas ◽

Total Knee ◽

Septic Revision

AbstractThe purpose of this study was to estimate the survivorship of the varus–valgus constrained (VVC) knee implants in primary, aseptic, and septic revision total knee arthroplasty (TKA); determine functional outcomes; main modes of failure; and variables associated with increased mechanical failures. In this study, 685 consecutive cases of primary (n = 247), aseptic (n = 315), and septic revision (n = 123) TKAs with VVC implants were performed between 1999 and 2008; 533 knees (78%) had a mean follow-up of 8.2 years (range, 2–15.1). Kaplan–Meier method was used to evaluate implant survival with mechanical failure as the end point. Clinical outcomes were measured with a modified Knee Society Score (mKSS) and modified Knee Function Score (mKFS) and modes of failure were determined. Cox proportional hazards models were performed to assess for factors associated with implant failure. Ten-year survival was 88.5% (95% confidence interval [CI]: 83.9–93.5%) for primary TKAs, 75.8% (95% CI: 70.4–81.7%) for aseptic, and 54.6% (95% CI: 43.7–68.2%) for septic revisions. Improvement in pre- to postoperative mKSS and mKFS were significant in all three groups (p < 0.05). The most common mode of failure overall was infection. Mechanical modes of failures included periprosthetic fracture (45%) for primary TKA and soft tissue instability (19%) for aseptic revisions. A longer period since the last surgery in affected knee was associated with lower mechanical failures (hazards ratio of 0.55 [95% CI: 0.31–0.95], p = 0.03). VVC implant showed reliable survivorship at 10 years although careful patient selection is warranted due to the risk of infection. The main mechanical modes of failure were instability and periprosthetic fracture.

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Fast-Track Programs in Total Hip and Knee Replacement at Swedish Hospitals—Influence on 2-Year Risk of Revision and Mortality

Journal of Clinical Medicine ◽

10.3390/jcm10081680 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1680

Author(s):

Urban Berg ◽

Annette W-Dahl ◽

Anna Nilsdotter ◽

Emma Nauclér ◽

Martin Sundberg ◽

...

Keyword(s):

Fast Track ◽

Cox Regression ◽

Cox Regression Analysis ◽

Total Hip ◽

Total Knee Replacements ◽

Risk Of Death ◽

Kaplan Meier ◽

Increased Risk ◽

Hip And Knee Arthroplasty ◽

Total Knee

Purpose: We aimed to study the influence of fast-track care programs in total hip and total knee replacements (THR and TKR) at Swedish hospitals on the risk of revision and mortality within 2 years after the operation. Methods: Data were collected from the Swedish Hip and Knee Arthroplasty Registers (SHAR and SKAR), including 67,913 THR and 59,268 TKR operations from 2011 to 2015 on patients with osteoarthritis. Operations from 2011 to 2015 Revision and mortality in the fast-track group were compared with non-fast-track using Kaplan–Meier survival analysis and Cox regression analysis with adjustments. Results: The hazard ratio (HR) for revision within 2 years after THR with fast-track was 1.19 (CI: 1.03–1.39), indicating increased risk, whereas no increased risk was found in TKR (HR 0.91; CI: 0.79–1.06). The risk of death within 2 years was estimated with a HR of 0.85 (CI: 0.74–0.97) for TKR and 0.96 (CI: 0.85–1.09) for THR in fast-track hospitals compared to non-fast-track. Conclusions: Fast-track programs at Swedish hospitals were associated with an increased risk of revision in THR but not in TKR, while we found the mortality to be lower (TKR) or similar (THR) as compared to non-fast track.

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Increased risk of periprosthetic joint infection after acute, traumatic wound dehiscence following primary total knee arthroplasty

The Bone & Joint Journal ◽

10.1302/0301-620x.103b6.bjj-2020-2425.r1 ◽

2021 ◽

Vol 103-B (6 Supple A) ◽

pp. 191-195

Author(s):

Elizabeth B. Gausden ◽

Matthew B. Shirley ◽

Matthew P. Abdel ◽

Rafael J. Sierra

Keyword(s):

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Periprosthetic Joint Infection ◽

Joint Infection ◽

Significant Risk ◽

Wound Dehiscence ◽

Increased Risk ◽

Primary Tkas ◽

Traumatic Wound ◽

Total Knee

Aims To describe the risk of periprosthetic joint infection (PJI) and reoperation in patients who have an acute, traumatic wound dehiscence following total knee arthroplasty (TKA). Methods From January 2002 to December 2018, 16,134 primary TKAs were performed at a single institution. A total of 26 patients (0.1%) had a traumatic wound dehiscence within the first 30 days. Mean age was 68 years (44 to 87), 38% (n = 10) were female, and mean BMI was 34 kg/m2 (23 to 48). Median time to dehiscence was 13 days (interquartile range (IQR) 4 to 15). The dehiscence resulted from a fall in 22 patients and sudden flexion after staple removal in four. The arthrotomy was also disrupted in 58% (n = 15), including a complete extensor mechanism disruption in four knees. An irrigation and debridement with component retention (IDCR) was performed within 48 hours in 19 of 26 knees and two-thirds were discharged on antibiotic therapy. The mean follow-up was six years (2 to 15). The association of wound dehiscence and the risk of developing a PJI was analyzed. Results Patients who sustained a traumatic wound dehiscence had a 6.5-fold increase in the risk of PJI (95% confidence interval (CI) 1.6 to 26.2; p = 0.008). With the small number of PJIs, no variables were found to be significant risk factors. However, there were no PJIs in any of the patients who were treated with IDCR and a course of antibiotics. Three knees required reoperation including one two-stage exchange for PJI, one repeat IDCR for PJI, and one revision for aseptic loosening of the tibial component. Conclusion Despite having a traumatic wound dehiscence, the risk of PJI was low, but much higher than experienced in all other TKAs during the same period. We recommend urgent IDCR and a course of postoperative antibiotics to decrease the risk of PJI. A traumatic wound dehiscence increases risk of PJI by 6.5-fold. Cite this article: Bone Joint J 2021;103-B(6 Supple A):191–195.

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Association of pulse pressure with all-cause mortality in young adults

Postgraduate Medical Journal ◽

10.1136/postgradmedj-2019-137070 ◽

2019 ◽

Vol 96 (1138) ◽

pp. 461-466

Author(s):

Jie LI ◽

Jia-Yi Huang ◽

Kenneth Lo ◽

Bin Zhang ◽

Yu-Qing Huang ◽

...

Keyword(s):

Young Adults ◽

Pulse Pressure ◽

Subgroup Analysis ◽

Proportional Hazards ◽

Continuous Variable ◽

Cox Proportional Hazards ◽

Cox Proportional Hazards Models ◽

Increased Risk ◽

All Cause Mortality ◽

Cox Analysis

BackgroundPulse blood pressure was significantly associated with all-cause mortality in middle-aged and elderly populations, but less evidence was known in young adults.ObjectiveTo assess the association of pulse pressure (PP) with all-cause mortality in young adults.MethodsThis cohort from the 1999–2006 National Health and Nutrition Examination Survey included adults aged 18–40 years. All included participants were followed up until the date of death or 31 December 2015. PP was categorised into three groups: <50, 50~60, ≥60 mm Hg. Cox proportional hazards models and subgroup analysis were performed to estimate the adjusted HRs and 95% CIs for all-cause mortality.ResultsAfter applying the exclusion criteria, 8356 participants (median age 26.63±7.01 years, 4598 women (55.03%)) were included, of which 265 (3.17%) have died during a median follow-up duration of 152.96±30.45 months. When treating PP as a continuous variable, multivariate Cox analysis showed that PP was an independent risk factor for all-cause mortality (HR 1.94, 95% CI 1.02 to 3.69; p=0.0422). When using PP<50 mm Hg as referent, from the 50~60 mm Hg to the ≥60 mm Hg group, the risks of all-cause mortality for participants with PP ranging 50–60 mm Hg or ≥60 mm Hg were 0.93 (95% CI 0.42 to 2.04) and 1.15 (95% CI 0.32 to 4.07) (P for tend was 0.959). Subgroup analysis showed that PP (HR 2.00, 95% CI 1.05 to 3.82; p=0.0360) was associated with all-cause mortality among non-hypertensive participants.ConclusionAmong young adults, higher PP was significantly associated with an increased risk of all-cause mortality, particularly among those without hypertension.

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Early Hb Response to ESA Treatment May Be An Indicator of Better Survival Prognosis

Blood ◽

10.1182/blood.v112.11.4587.4587 ◽

2008 ◽

Vol 112 (11) ◽

pp. 4587-4587

Author(s):

Jesse A Berlin ◽

Peter Bowers ◽

Sudhakar Rao ◽

Suresh Aravind ◽

Steven Sun ◽

...

Keyword(s):

Proportional Hazards ◽

Proportional Hazards Model ◽

Performance Status ◽

Epoetin Alfa ◽

Survival Prognosis ◽

Risk Of Death ◽

Hazards Model ◽

Kaplan Meier ◽

Increased Risk ◽

Baseline Covariates

Abstract Chemotherapy induced anemia patients who respond to ESA treatment have hemoglobin increases within 4–8 weeks. Patients with inadequate Hb response after several weeks treatment often have their ESA dose escalated.. We conducted an exploratory analysis to test the hypothesis that safety outcomes in randomized studies of epoetin alfa might differ depending on the Hb response after 4–8 weeks of treatment. Methods: The analysis compared the survival across subsets of epoetin-alfa treated patients. Specifically, a landmark analysis was used, which defines a hemoglobin responder at a pre-specified point in time (in this case 4 & 8 weeks post treatment), and then examines survival subsequent to that point in time.Patients were categorized as “Hb responder” when their Hb increased by >0.5 g/dL; “Hb stable” when Hb change within ≤ 0.5g/dL; “Hb non-responder” when the Hb decreased >0.5 g/dL, compared to the value prior to epoetin-alfa treatment. Survival was estimated using the Kaplan-Meier method and comparisons were made between the responders and non-responders versus the stable group. Cox’s proportional hazards model was used to adjust for the following baseline covariates: hemoglobin prior to treatment, baseline performance status, and advanced disease at baseline. All analyses were stratified by study to account for any differences in the study populations and study conduct. Results: These exploratory findings suggest the possibility that patients identified as non-responders to ESAs after 4 or 8 weeks of ESA treatment may be at increased risk of death, and that this effect is most pronounced in the studies that treated patients beyond the correction of anemia. Although these analyses were adjusted for several key baseline covariates, it is unclear whether these effects result from treatment, or whether patients who fail to respond to epoetin alfa are inherently at increased risk of death (e.g., due underlying malignancy), regardless of their treatment status.

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Socioeconomically Disadvantaged Neighborhoods Face Increased Persistence of SARS-CoV-2 Clusters

Frontiers in Public Health ◽

10.3389/fpubh.2020.626090 ◽

2021 ◽

Vol 8 ◽

Cited By ~ 1

Author(s):

David De Ridder ◽

José Sandoval ◽

Nicolas Vuilleumier ◽

Andrew S. Azman ◽

Silvia Stringhini ◽

...

Keyword(s):

Proportional Hazards ◽

Detection Algorithm ◽

Spatial Cluster ◽

Cox Proportional Hazards ◽

Socioeconomic Deprivation ◽

Deprivation Index ◽

Socioeconomically Disadvantaged ◽

Disadvantaged Neighborhoods ◽

Kaplan Meier ◽

Increased Risk

Objective: To investigate the association between socioeconomic deprivation and the persistence of SARS-CoV-2 clusters.Methods: We analyzed 3,355 SARS-CoV-2 positive test results in the state of Geneva (Switzerland) from February 26 to April 30, 2020. We used a spatiotemporal cluster detection algorithm to monitor SARS-CoV-2 transmission dynamics and defined spatial cluster persistence as the time in days from emergence to disappearance. Using spatial cluster persistence measured outcome and a deprivation index based on neighborhood-level census socioeconomic data, stratified survival functions were estimated using the Kaplan-Meier estimator. Population density adjusted Cox proportional hazards (PH) regression models were then used to examine the association between neighborhood socioeconomic deprivation and persistence of SARS-CoV-2 clusters.Results: SARS-CoV-2 clusters persisted significantly longer in socioeconomically disadvantaged neighborhoods. In the Cox PH model, the standardized deprivation index was associated with an increased spatial cluster persistence (hazard ratio [HR], 1.43 [95% CI, 1.28–1.59]). The adjusted tercile-specific deprivation index HR was 1.82 [95% CI, 1.56–2.17].Conclusions: The increased risk of infection of disadvantaged individuals may also be due to the persistence of community transmission. These findings further highlight the need for interventions mitigating inequalities in the risk of SARS-CoV-2 infection and thus, of serious illness and mortality.

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Abstract P353: Survival after Acute Coronary Syndrome in the Community

Circulation ◽

10.1161/circ.127.suppl_12.ap353 ◽

2013 ◽

Vol 127 (suppl_12) ◽

Author(s):

Sheila M McNallan ◽

Yariv Gerber ◽

Susan A Weston ◽

Jill Killian ◽

Shannon M Dunlay ◽

...

Keyword(s):

Acute Coronary Syndrome ◽

Proportional Hazards ◽

Cox Proportional Hazards ◽

Survival Estimate ◽

Risk Of Death ◽

Coronary Syndrome ◽

Kaplan Meier ◽

Increased Risk ◽

Over Time

Background: Contemporary data on survival after incident acute coronary syndrome (ACS), including both myocardial infarction (MI) and unstable angina (UA), are limited. Objective: To describe survival after incident ACS, to determine if it differs by ACS type (MI or UA) and to determine whether it has improved over time. Methods: Olmsted County, MN residents hospitalized between 1/1/2005-12/31/2010 were screened for incident ACS. ACS was defined as either MI validated by standard epidemiological criteria or UA validated by the Braunwald classification. Patients were followed for death from any cause. Cox proportional hazards regression was used to determine whether survival differed by ACS type, while adjusting for year of diagnosis, age, sex and comorbidities. Results: Among 1,160 incident ACS cases (mean±SD age 66.9±14.8, 60% male), 35% were UA and 65% were MI. After a mean (SD) follow up of 3.7 (2.1) years, 274 deaths occurred. The 3-year Kaplan-Meier survival estimate for MI was 79.6% (95% CI: 76.7%-82.6%) and for UA was 84.9% (95% CI: 81.3%-88.6%) (log-rank p=0.011). The association of ACS type with survival differed by age (p=0.056). After adjustment for year of diagnosis, sex and comorbidities, no difference in survival was observed between ACS types among those aged <60 (HR for MI vs. UA: 0.64, 95% 0.29-1.42). By contrast, among patients aged 60-79, those with an MI had 2 times the risk of death compared to those with UA (HR: 2.04, 95% CI: 1.24-3.37). Patients aged 80 or older who had an MI had a 40% increased risk of death compared to patients of the same age who had UA (HR: 1.42, 95% CI: 1.02-1.98). There was no difference in survival over time (HR for 2010 vs. 2005: 0.91, 95% CI: 0.61-1.36). Conclusions: Survival did not differ between UA and MI patients younger than 60, however among patients 60 or older, survival was worse among those with an MI. Survival after ACS did not change over the study period.

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Maternal Hypothyroidism during Pregnancy and the Risk for Infectious Morbidity of the Offspring

American Journal of Perinatology ◽

10.1055/s-0039-3400980 ◽

2019 ◽

Vol 37 (03) ◽

pp. 291-295 ◽

Cited By ~ 2

Author(s):

Ofer Beharier ◽

Asnat Walfisch ◽

Tamar Wainstock ◽

Irit Szaingurten-Solodkin ◽

Daniela Landau ◽

...

Keyword(s):

Animal Studies ◽

Proportional Hazards ◽

Proportional Hazards Model ◽

Cox Proportional Hazards ◽

Cox Proportional Hazards Model ◽

Infectious Morbidity ◽

Hazards Model ◽

Kaplan Meier ◽

Increased Risk

Abstract Objective Animal studies indicate a possible intrauterine immunological imprinting in pregnancies complicated by hypothyroidism. We aimed to evaluate whether exposure to maternal hypothyroidism during pregnancy increases the risk of long-term infectious morbidity of the offspring. Study Design A retrospective cohort study compared the long-term risk of hospitalization associated with infectious morbidity in children exposed and unexposed in utero to maternal hypothyroidism. Outcome measures included infectious diagnoses obtained during any hospitalization of the offspring (up to the age of 18 years). Results The study included 224,950 deliveries. Of them, 1.1% (n = 2,481) were diagnosed with maternal hypothyroidism. Children exposed to maternal hypothyroidism had a significantly higher rate of hospitalizations related to infectious morbidity (13.2 vs. 11.2% for control; odds ratio: 1.2; 95% confidence interval: 1.08–1.36; p = 0.002). Specifically, incidences of ear, nose, and throat; respiratory; and ophthalmic infections were significantly higher among the exposed group. The Kaplan–Meier curve indicated that children exposed to maternal hypothyroidism had higher cumulative rates of long-term infectious morbidity. In the Cox proportional hazards model, maternal hypothyroidism remained independently associated with an increased risk of infectious morbidity in the offspring while adjusting for confounders. Conclusion Maternal hypothyroidism during pregnancy is associated with significant pediatric infectious morbidity of the offspring.

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Racial Disparities in Delivery Gestational Age among Twin Pregnancies

American Journal of Perinatology ◽

10.1055/s-0037-1603764 ◽

2017 ◽

Vol 34 (11) ◽

pp. 1065-1071

Author(s):

Catherine Vladutiu ◽

Tracy Manuck ◽

Jacqueline Grant

Keyword(s):

Gestational Age ◽

Proportional Hazards ◽

Secondary Analysis ◽

Neonatal Morbidity ◽

Cox Proportional Hazards ◽

Kaplan Meier ◽

Cox Proportional Hazards Models ◽

Hazard Ratios ◽

Increased Risk ◽

Hydroxyprogesterone Caproate

Objective This study aims to estimate the association between maternal race and delivery gestational age among women with twin gestations. Study Design Secondary analysis of a prospective, randomized control trial of 17-α hydroxyprogesterone caproate versus placebo for preterm birth (PTB) prevention in twin gestations. Non-Hispanic (NH) black and whites were included. Demographic and antenatal characteristics were compared. The primary outcome was delivery gestational age. Secondary outcomes included a composite of major neonatal morbidity. Kaplan–Meier curves estimated survival probabilities for delivery gestational age by race. Cox proportional hazards models estimated hazard ratios (HR) and 95% confidence intervals (CI). Results A total of 535 women with twin gestations were included; 150 were NH black. NH blacks delivered earlier than NH whites (33.6 ± 4.8 weeks vs. 35.1 ± 3.5 weeks, p < 0.001). Differences in delivery gestational age between NH blacks and whites were consistent across gestation. In adjusted analyses, NH black race (HR: 1.24, 95% CI: 1.02–1.51), prior PTB (HR: 1.59, 95% CI: 1.15–2.19), and cerclage (HR: 3.90, 95% CI: 2.00–7.60) were associated with an increased risk of earlier delivery. Major neonatal morbidity was higher for NH blacks compared with NH whites (12.7 vs. 7.0%, p = 0.036). Conclusion NH blacks with twin gestations have an increased risk of early delivery and neonatal morbidity compared with NH whites.

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Outcomes of Constrained Prostheses in Primary and Revision TKR

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967117s00160 ◽

2017 ◽

Vol 5 (5_suppl5) ◽

pp. 2325967117S0016

Author(s):

Ben Parkinson ◽

Michelle Lorimer ◽

Peter Lewis

Keyword(s):

Proportional Hazards ◽

Proportional Hazards Model ◽

Survival Rates ◽

Cox Proportional Hazards ◽

Cox Proportional Hazards Model ◽

Knee Prostheses ◽

Hazards Model ◽

Kaplan Meier ◽

Hazard Ratios ◽

Total Knee

Introduction: The decision to use varus/valgus constrained or hinge knee prostheses in complex Total Knee Replacement (TKR) cases is difficult. There are few publications that compare survival rates, to aid this decision-making. This study compares the survival rates of unlinked fully constrained and hinge constrained prostheses in the primary and revision settings. Methods: Data from the AOANJRR to 31st of December 2013 was analysed to determine the survival rate of unlinked and hinge constrained TKR in the primary and revision settings (excluding the diagnosis of tumour and infection). Only first-time revisions of a known primary TKR were included in the revision analysis. Kaplan-Meier estimates of survivorship were calculated for the two categories of constraint and were matched for age and diagnosis in both primary and revision TKR situations. Hazard ratios using the Cox proportional-hazards model were used. The survivorship of individual prosthesis models was determined. Results: There were 3237 prostheses implanted during the study period that met the inclusion criteria. Of these, 1896 were for primary TKR and 1341 for revision TKR. There were 1349 unlinked fully constrained and 547 hinge prostheses for primary TKR and 991 unlinked fully constrained and 350 hinge prostheses for revision TKR. In both the primary and revision settings when matched by age, there was no difference in rates of revision for either level of constraint. When matched by indication in the primary setting, there was no difference in the rates of revision for either level of constraint. The rate of revision for both categories of constrained prosthesis was significantly higher in younger patients <55 years of age (p < 0.05). There were no differences in survival rates of individual models of constrained TKR. Conclusions: The survival rates of unlinked constrained and hinge knee prostheses are similar when matched by age or diagnosis. In complex TKR instability cases, surgeons should feel confident in choosing the appropriate prosthesis to gain a stable knee and need not be concerned that a hinge prosthesis may carry a higher revision rate.

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