90-day mortality after 409,096 total hip replacements for osteoarthritis, from the National Joint Registry for England and Wales: a retrospective analysis

Predictors of mortality following shoulder arthroplasty

Introduction

This study aims to determine 30-day, 90-day and 1 year mortality following shoulder arthroplasty and identify predictors of mortality.

Materials and methods

All shoulder arthroplasty cases performed at the host institution, between 2012 and 2018 were included. A review of patient records was completed to identify demographic data, Charlson comorbidity index, date of death and factors associated with mortality.Mortality analysis was undertaken using 1-Kaplan Meier estimates with 95% confidence intervals. Comparative analysis was performed for mortality following shoulder arthroplasty for elective vs. trauma and for primary vs. revision surgery. A multiple regression analysis was conducted to determine which factors were associated with increased mortality risk.

Results

640 shoulder arthroplasty cases were performed in 566 patients. There were 44 deaths, 1 occurred within 90 days and 13 within 1 year. Trauma procedures had a hazard ratio of 5.3 (95% CI 1.9 to 15.0) for mortality compared to elective procedures (5 year survival trauma 78.6% (95% CI 60.7 to 89.0); elective 91.8% (95% CI 88.1 to 94.4). 1-year mortality was predicted by presence of malignancy, liver failure, cardiac failure, peptic ulcer, trauma surgery, revision surgery, intra-operative complication, transfusion and increased length of stay.

Discussion

30-day, 90-day and 1-year mortality following shoulder arthroplasty were 0%, 0.16% and 2%; trauma procedures had a hazard ratio of 5.3 for 1-year mortality when compared to elective surgery. Malignancy, cardiac failure, liver failure, peptic ulcer and trauma surgery are associated with an increased risk of 1-year mortality.

General vs Spinal Anesthesia for Total Joint Arthroplasty: A Single-Institution Observational Review

BACKGROUND

Total joint arthroplasty (TJA) can be successfully carried out under general (GA) or spinal anesthesia (SA). The existing literature does not adequately illustrate which technique is optimal. The purpose of this study is to prospectively compare the effects of anesthesia technique on TJA outcomes.

METHODS

This 2-year, prospective, observational study was conducted at a single institution where patients receiving primary TJA were consecutively enrolled. Patients were contacted postoperatively to assess for any 90-day complications. The primary outcome of the study was the overall complication rate.

RESULTS

A total of 2242 patients underwent total hip arthroplasty (n = 656; 29.26%) or total knee arthroplasty (n = 1586; 70.74%) between 2015 and 2017. Of these procedures, 1325 (59.10%) were carried out under SA and 917 (40.90%) were carried out under GA. Patients in the GA cohort had higher mean Charlson Comorbidity Index scores (0.05 SA vs 0.09 GA; P < .05) and higher average body mass index (29.35 SA vs 30.24 GA; P < .05). On multivariate analysis, patients in the SA cohort had a significantly lower overall complication rate relative to their GA counterparts (7.02% vs 10.14%; odds ratio, 0.66; 95% confidence interval, 0.49-0.90; P < .05). In addition, length of stay in the GA cohort was significantly longer (2.43 [SD, 1.62] vs 2.18 [SD, 0.88] days; P < .01) and a larger percentage of GA patients were discharged to a nursing facility (32.28% vs 25.06%; odds ratio, 0.55; 95% confidence interval, 0.44-0.70; P < .05).

CONCLUSION

Our study demonstrates that SA for TJA is associated with a decrease in overall complications and healthcare resource utilization.

Preoperative behavioural intervention to reduce drinking before elective orthopaedic surgery: the PRE-OP BIRDS feasibility RCT

BACKGROUND

Heavy alcohol consumption is associated with an increased risk of postoperative complications and extended hospital stay. Alcohol consumption therefore represents a modifiable risk factor for surgical outcomes. Brief behavioural interventions have been shown to be effective in reducing alcohol consumption among increased risk and risky drinkers in other health-care settings and may offer a method of addressing preoperative alcohol consumption.

OBJECTIVES

To investigate the feasibility of introducing a screening process to assess adult preoperative drinking levels and to deliver a brief behavioural intervention adapted for the target population group. To conduct a two-arm (brief behavioural intervention plus standard preoperative care vs. standard preoperative care alone), multicentre, pilot randomised controlled trial to assess the feasibility of proceeding to a definitive trial. To conduct focus groups and a national web-based survey to establish current treatment as usual for alcohol screening and intervention in preoperative assessment.

DESIGN

A single-centre, qualitative, feasibility study was followed by a multicentre, two-arm (brief behavioural intervention vs. treatment as usual), individually randomised controlled pilot trial with an embedded qualitative process evaluation. Focus groups and a quantitative survey were employed to characterise treatment as usual in preoperative assessment.

SETTING

The feasibility study took place at a secondary care hospital in the north-east of England. The pilot trial was conducted at three large secondary care centres in the north-east of England.

PARTICIPANTS

Nine health-care professionals and 15 patients (mean age 70.5 years, 86.7% male) participated in the feasibility study. Eleven health-care professionals and 68 patients (mean age 66.2 years, 80.9% male) participated in the pilot randomised trial. An additional 19 health-care professionals were recruited to one of three focus groups, while 62 completed an electronic survey to characterise treatment as usual.

INTERVENTIONS

The brief behavioural intervention comprised two sessions. The first session, delivered face to face in the preoperative assessment clinic, involved 5 minutes of structured brief advice followed by 15-20 minutes of behaviour change counselling, including goal-setting, problem-solving and identifying sources of social support. The second session, an optional booster, took place approximately 1 week before surgery and offered the opportunity to assess progress and boost self-efficacy.

MAIN OUTCOME MEASURES

Feasibility was assessed using rates of eligibility, recruitment and retention. The progression criteria for a definitive trial were recruitment of ≥ 40% of eligible patients and retention of ≥ 70% at 6-month follow-up. Acceptability was assessed using themes identified in qualitative data.

RESULTS

The initial recruitment of eligible patients was low but improved with the optimisation of recruitment processes. The recruitment of eligible participants to the pilot trial (34%) fell short of the progression criteria but was mitigated by very high retention (96%) at the 6-month follow-up. Multimethod analyses identified the methods as acceptable to the patients and professionals involved and offers recommendations of ways to further improve recruitment.

CONCLUSIONS

The evidence supports the feasibility of a definitive trial to assess the effectiveness of brief behavioural intervention in reducing preoperative alcohol consumption and for secondary outcomes of surgical complications if recommendations for further improvements are adopted.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN36257982.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 12. See the National Institute for Health Research Journals Library website for further project information.

The Effect of Surgical Approach on Outcomes Following Total Hip Arthroplasty Performed for Displaced Intracapsular Hip Fractures: An Analysis from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

BACKGROUND

Studies have suggested that the anterolateral approach is preferable to the posterior approach when performing total hip arthroplasty (THA) for a displaced intracapsular hip fracture, because of a perceived reduced risk of reoperations and dislocations. However, this suggestion comes from small studies with short follow-up. We determined whether surgical approach in THAs performed for hip fracture affects revision-free hip survival, patient survival, and intraoperative complications.

METHODS

We retrospectively analyzed all stemmed primary THAs for hip fracture that were recorded in the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man that were performed between 2003 and 2015. The 2 surgical approach groups, posterior and anterolateral, were matched for patient and surgical confounding factors using propensity scores, with outcomes compared using regression modeling (with regression model ratios of <1 representing a reduced risk of the specified outcome in the posterior group). Outcomes were 5-year hip survival free from revision (all-cause revision, revision for dislocation and/or subluxation, and revision for periprosthetic fracture), patient survival (30 days, 1 year, and 5 years postoperatively), and intraoperative complications.

RESULTS

After matching, 14,536 THAs (7,268 per group) were studied. Five-year cumulative revision-free survival rates were similar (posterior group, 97.3%, and anterolateral group, 97.4%; subhazard ratio [SHR], 1.15 [95% confidence interval (CI), 0.93 to 1.42]). Five-year survival rates free from revision for dislocation (SHR, 1.28 [95% CI, 0.89 to 1.84]) and for periprosthetic fracture (SHR, 1.03 [95% CI, 0.68 to 1.56]) were also comparable between the 2 approach groups. Thirty-day patient survival was significantly higher following a posterior approach (99.5% compared with 98.8%; hazard ratio [HR], 0.44 [95% CI, 0.30 to 0.64]), which persisted at 1 year (HR, 0.73 [95% CI, 0.64 to 0.84]) and 5 years (HR, 0.87 [95% CI, 0.81 to 0.94]) postoperatively. The posterior approach was associated with a lower risk of intraoperative complications (odds ratio [OR], 0.59 [95% CI, 0.45 to 0.78]).

CONCLUSIONS

In THA for hip fracture, the posterior approach was associated with a similar risk of revision and a lower risk of both patient mortality and intraoperative complications compared with the anterolateral approach. We propose that the posterior approach is as safe as the anterolateral approach when performing THA for hip fracture and that either approach may be used according to surgeon preference.

LEVEL OF EVIDENCE

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

Simultaneous or Staged Bilateral Total Hip Arthroplasty? An Analysis of Complications in 14,460 Patients Using National Data

BACKGROUND

Simultaneous bilateral total hip arthroplasty (SimBTHA) is often performed in younger, fitter patients with bilateral hip disease. If patients are deemed not suitable for SimBTHA due to concurrent comorbidity, it may be more appropriate to perform staged bilateral total hip arthroplasties (StBTHAs) 3-6 months apart to minimize complications and morbidity. Complication rates following hip arthroplasty are low and large national datasets are helpful for assessing these rare events. We aimed at comparing SimBTHA vs StBTHA in order to determine any differences in morbidity and mortality.

METHODS

Hospital Episode Statistics data for all patients who underwent bilateral THAs in the English National Health Service between April 2005 and July 2014 were obtained. Patients were grouped into SimBTHAs (same day) or staged, with the second THA occurring between 3 and 6 months after the first. Medical and surgical complications were compared and total length of stay was assessed.

RESULTS

A total of 2507 underwent SimBTHAs and 9915 had StBTHAs. SimBTHA patients were significantly younger (60.6 vs 65.5 years, P < .001) and more likely to be male, but had similar Charlson comorbidity scores. Compared to StBTHAs, patients undergoing SimBTHAs had a greater risk of pulmonary embolism, myocardial infarction, renal failure, chest infection, and inhospital death. Patients undergoing SimBTHAs had a significantly shorter overall hospital stay (8.9 vs 10.4 days). Patients undergoing SimBTHA at high-volume units had a lower average Charlson score and subsequent complication rate than low-volume units.

CONCLUSION

These findings highlight the greater risks of SimBTHA in patients with Charlson score greater than 0 performed at lower-volume centers in England.

Perioperative multidisciplinary implementation enhancing recovery after hip arthroplasty in geriatrics with preoperative chronic hypoxaemia

We investigated risk factors for postoperative serious adverse events (SAEs) in elderly patients with preoperative chronic hypoxaemia undergone total hip arthroplasty (THA) or hemiarthroplasty and performed an implementation to modify and improve clinical outcome. A retrospective medical record review was performed to identify geriatric patients who receiving THA or hemiarthroplasty at a single university teaching hospital, Kunming, Yunnan, China between January 2009 and August 2017. Total of 450 elderly patients were included in the study. Data were collected on baseline characteristics, detailed treatments, and adverse events. Univariate and multivariate logistic regression analysis were used to identify risk factors for SAEs. In multivariate regression analysis, a higher occurrence of general anaesthesia and multiple episodes of hypotension were associated with higher risk of SAEs (general anesthesia: odds ratio [OR] 5.09, 95% confidence interval [CI] 1.96–13.24, P = 0.001; hypotension time: OR 4.29, 95% CI 1.66–11.10, P = 0.003). After the multidisciplinary implementation, the postoperative length of stay was decreased from 15 days to 10 days (P < 0.0001); incidence of SAEs was decreased from 21.1% to 7.0% (P = 0.002), and the all-cause mortality rate within 30 days decreased from 4.6% to 1.0% (P = 0.040). Our observational study demonstrated that an increasing application of general anaesthesia and longer time of hypotension were associated with an increased risk of postoperative SAEs in patients after THA or hemiarthroplasty. Additionally, optimizing stable haemodynamics under higher application of combined-spinal epidural anaesthesia was associated with improved outcome up to 30 days after THA or hemiarthroplasty.

Perioperative, short-, and long-term mortality related to fixation in primary total hip arthroplasty: a study on 79,557 patients in the -Norwegian Arthroplasty Register

Background and purpose - There are reports on perioperative deaths in cemented total hip arthroplasty (THA), and THA revisions are associated with increased mortality. We compared perioperative (intraoperatively or within 3 days of surgery), short-term and long-term mortality after all-cemented, all-uncemented, reverse hybrid (cemented cup and uncemented stem), and hybrid (uncemented cup and cemented stem) THAs.Patients and methods - We studied THA patients in the Norwegian Arthroplasty Register from 2005 to 2018, and performed Kaplan-Meier and Cox survival analyses with time of death as end-point. Mortality was calculated for all patients, and in 3 defined risk groups: high-risk patients (age ≥ 75 years and ASA > 2), intermediate-risk patients (age ≥ 75 years or ASA > 2), low-risk patients (age < 75 years and ASA ≤ 2). We also calculated mortality in patients with THA due to a hip fracture, and in patients with commonly used, contemporary, well-documented THAs. Adjustement was made for age, sex, ASA class, indication, and year of surgery.Results - Among the 79,557 included primary THA patients, 11,693 (15%) died after 5.8 (0-14) years' follow-up. Perioperative deaths were rare (30/10⁵) and found in all fixation groups. Perioperative mortality after THA was 4/10⁵ in low-risk patients, 34/10⁵ in intermediate-risk patients, and 190/10⁵ in high-risk patients. High-risk patients had 9 (CI 1.3-58) times adjusted risk of perioperative death compared with low-risk patients. All 4 modes of fixation had similar adjusted 3-day, 30-day, 90-day, 3-30 day, 30-90 day, 90-day-10-year, and 10-year mortality risk.Interpretation - Perioperative, short-term, and long-term mortality after primary THA were similar, regardless of fixation type. Perioperative deaths were rare and associated with age and comorbidity, and not type of fixation.

The effect of smoking on outcomes following primary total hip and knee arthroplasty: a population-based cohort study of 117,024 patients

Background and purpose - Smoking is a modifiable risk factor that may adversely affect postoperative outcomes. Healthcare providers are increasingly denying smokers access to total hip and knee arthroplasty (THA and TKA) until they stop smoking. Evidence supporting this is unclear. We assessed the effect of smoking on outcomes following arthroplasty.Patients and methods - We identified THAs and TKAs from the Clinical Practice Research Datalink, which were linked with datasets from Hospital Episode Statistics and the Office for National Statistics to identify outcomes. The effect of smoking on postoperative outcomes (complications, medications, revision, mortality, patient-reported outcome measures [PROMs]) was assessed using adjusted regression models.Results - We studied 60,812 THAs and 56,212 TKAs (11% smokers, 33% ex-smokers, 57% non-smokers). Following THA, smokers had an increased risk of lower respiratory tract infection (LRTI) and myocardial infarction compared with non-smokers and ex-smokers. Following TKA, smokers had an increased risk of LRTI compared with non-smokers. Compared with non-smokers (THA relative risk ratio [RRR] = 0.65; 95% CI = 0.61-0.69; TKA RRR = 0.82; CI = 0.78-0.86) and ex-smokers (THR RRR = 0.90; CI = 0.84-0.95), smokers had increased opioid usage 1-year postoperatively. Similar patterns were observed for weak opioids, paracetamol, and gabapentinoids. 1-year mortality rates were higher in smokers compared with non-smokers (THA hazard ratio [HR] = 0.37, CI = 0.29-0.49; TKA HR = 0.52, CI = 0.34-0.81) and ex-smokers (THA HR = 0.53, CI = 0.40-0.70). Long-term revision rates were not increased in smokers. Smokers had improvement in PROMs compared with preoperatively, with no clinically important difference in postoperative PROMs between smokers, non-smokers, and ex-smokers.Interpretation - Smoking is associated with more medical complications, higher analgesia usage, and increased mortality following arthroplasty. Most adverse outcomes were reduced in ex-smokers, therefore smoking cessation should be encouraged before arthroplasty.

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.

Preliminary report of clinical experience with metal-on-highly-crosslinked-polyethylene hip resurfacing

Objectives

Modern metal-on-metal (MoM) hip resurfacing arthroplasty (HRA), while achieving good results with well-orientated, well-designed components in ideal patients, is contraindicated in women, men with head size under 50 mm, or metal hypersensitivity. These patients currently have no access to the benefits of HRA. Highly crosslinked polyethylene (XLPE) has demonstrated clinical success in total hip arthroplasty (THA) and, when used in HRA, potentially reduces metal ion-related sequelae. We report the early performance of HRA using a direct-to-bone cementless mono-bloc XLPE component coupled with a cobalt-chrome femoral head, in the patient group for whom HRA is currently contraindicated.

Methods

This is a cross-sectional, observational assessment of 88 consecutive metal-on-XLPE HRAs performed in 84 patients between 2015 and 2018 in three centres (three surgeons, including the designer surgeon). Mean follow-up is 1.6 years (0.7 to 3.9). Mean age at operation was 56 years (sd 11; 21 to 82), and 73% of implantations were in female patients. All patients were individually counselled, and a detailed informed consent was obtained prior to operation. Primary resurfacing was carried out in 85 hips, and three cases involved revision of previous MoM HRA. Clinical, radiological, and Oxford Hip Score (OHS) assessments were studied, along with implant survival.

Results

There was no loss to follow-up and no actual or impending revision or reoperation. Median OHS increased from 24 (interquartile range (IQR) 20 to 28) preoperatively to 48 (IQR 46 to 48) at the latest follow-up (48 being the best possible score). Radiographs showed one patient had a head-neck junction lucency. No other radiolucency, osteolysis, component migration, or femoral neck thinning was noted.

Conclusion

The results in this small consecutive cohort suggest that metal-on-monobloc-XLPE HRA is successful in the short term and merits further investigation as a conservative alternative to the current accepted standard of stemmed THA. However, we would stress that survival data with longer-term follow-up are needed prior to widespread adoption.

Cite this article: R. B. C. Treacy, J. P. Holland, J. Daniel, H. Ziaee, D. J. W. McMinn. Preliminary report of clinical experience with metal-on-highly-crosslinked-polyethylene hip resurfacing. Bone Joint Res 2019;8:443–450. DOI: 10.1302/2046-3758.810.BJR-2019-0060.R1

In-hospital mortality after hip arthroplasty in China

Aims

There is an increasing demand for hip arthroplasty in China. We aimed to describe trends in in-hospital mortality after this procedure in China and to examine the potential risk factors.

Patients and Methods

We included 210 450 patients undergoing primary hip arthroplasty registered in the Hospital Quality Monitoring System in China between 2013 and 2016. In-hospital mortality after hip arthroplasty and its relation to potential risk factors were assessed using multivariable Poisson regression.

Results

During the study period, 626 inpatient deaths occurred within 30 days after hip arthroplasty. Mortality decreased from 2.9% in 2013 to 2.6% in 2016 (p for trend = 0.02). Compared with their counterparts, old age, male sex, and divorced or widowed patients had a higher rate of mortality (all p < 0.05). Risk ratio (RR) for mortality after arthroplasty for fracture was two-fold higher (RR 2.0, 95% confidence interval (CI) 1.5 to 2.6) than that for chronic disease. RRs for mortality were 3.3 (95% CI 2.7 to 3.9) and 8.2 (95% CI 6.5 to 10.4) for patients with Charlson Comorbidity Index (CCI) of 1 to 2 and CCI ≥ 3, respectively, compared with patients with CCI of 0. The rate of mortality varied according to geographical region, the lowest being in the East region (1.8%), followed by Beijing (2.1%), the North (2.9%), South-West (3.6%), South-Central (3.8%), North-East (4.1%), and North-West (5.2%) regions.

Conclusion

While in-hospital mortality after hip arthroplasty in China appears low and declined during the study period, discrepancies in mortality after this procedure exist according to sociodemographic factors. Healthcare resources should be allocated more to underdeveloped regions to further reduce mortality. Cite this article: Bone Joint J 2019;101-B:1209–1217

Is single-anaesthetic bilateral total hip replacement using cemented stems safe and appropriate? A review of four decades of practice

BACKGROUND

Symptomatic bilateral hip osteoarthritis can be treated surgically with either staged or single-anaesthetic bilateral total hip replacement (BTHR). Today the typical candidate for BTHR is more likely to receive cementless implants. We present the experience of BTHR at our institution using cemented stems combined with cemented and uncemented sockets and, to our knowledge, the largest prospective single-centre series.

PATIENTS AND METHODS

This cohort study reviews all patients (319 patients: 638 hips) having BTHR at our institution between December 1977 and December 2015. No case was lost to follow-up. Data were collected prospectively but reviewed retrospectively. Length of stay and complication rates were included, and data were compared with Hospital Episode Statistics figures for operations carried out between March 2005 and June 2014 to confirm local database validity. Patient experience and Oxford Hip Scores were obtained for a subgroup of this cohort, comparing them with patients who underwent bilateral staged operations performed within 1 year.

RESULTS

The rates for mortality, deep vein thrombosis, non-fatal myocardial infarction within 6 months were each 0.3% (1 episode) and non-fatal pulmonary embolism 0.6% (2 episodes). There were no intraoperative periprosthetic fractures or readmissions within 30 days.

CONCLUSIONS

Our study shows a low risk of complications when using cemented and hybrid BTHRs for selected patients and the risk of complications compares favourably with published results. Available functional scores compared favourably to a comparison group of patients undergoing bilateral staged procedures, and a positive impression on treatment experience from a subgroup of interviewed BTHR patients was noticeable.

Road to Perioperative Medicine: A Perspective From China

With the development of anesthesiology, patient safety has been remarkably improved, but the postoperative mortality rate at 30 days is still as high as 0.56%-4%, and the morbidity is even higher. Three years ago, the Chinese Society of Anesthesiology proposed that the direction of the anesthesiology development should be changed to perioperative medicine in China. Anesthesiologists should pay more attention to the long-term outcome. In this article, we introduced what we have done, what the challenges are, and what we should do in the future with regard to the practice of perioperative medicine in China.

Descriptive epidemiology of hip and knee replacement in rheumatoid arthritis: An analysis of UK electronic medical records

OBJECTIVE

To provide descriptive data on rates of total hip replacement (THR) and total knee replacement (TKR) within a large RA cohort and describe variation in risk.

METHODS

Incident RA patients (1995 to 2014) were identified from the Clinical Practice Research Datalink (CPRD). First subsequent occurrence of THR and TKR were identified (analysed separately) and incidence rates calculated, stratified by sex, age, BMI, geographic region, and quintiles of the index of multiple deprivation (IMD) score.

RESULTS

There were 27,607 RA patients included, with a total of 1,028 THRs (mean age at surgery: 68.4 years) and 1,366 TKRs (mean age at surgery: 67.6 years), at an overall incidence rate per 1,000 person-years (PYs) [95% CI] of 6.38 [6.00-6.78] and 8.57 [8.12-9.04], respectively. TKR incidence was similar by gender but THR rates were higher in females than males. Rates of TKR but not THR rose according to BMI. An increasing trend was observed in rates of both outcomes according to age (although not ≥75) but of decreasing rates according to socio-economic deprivation. There was some evidence for regional variation in TKR. The 10-year cumulative incidence was 5.2% [4.9, 5.6] and 7.0% [6.6, 7.4] for THR and TKR, respectively.

CONCLUSION

We provide generalizable estimates of THR and TKR incidence in the UK RA patient population and note variation across several key variables. Increased BMI was associated with a large increase in TKR but not THR incidence. Increased deprivation was associated with a downward trend in rates of THR and TKR.

Gender Differences for Hip and Knee Arthroplasty: Complications and Healthcare Utilization

INTRODUCTION

The influence of patient gender on complications and healthcare utilization remains unexplored. The purpose of the present study was to determine if patient gender significantly affected outcomes following total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

Retrospective cohort study of THA and TKA patients was performed using the Nationwide Inpatient Sample from 2002 to 2011. Only patients who underwent elective procedures and those with complete perioperative data were included. Multivariate logistic regression was used to compare the rates of adverse events between male and female cohorts while controlling for baseline characteristics.

RESULTS

A total of 6,123,637 patients were included in the study (31.2% THA and 68.8% TKA). The cohort was 61.1% female. While males had a lower rate of any adverse event (odds ratio [OR] = 0.8, P < .001), urinary tract infection (OR = 0.4, P < .001), deep vein thrombosis/pulmonary embolism (OR = 0.9, P < .001), and blood transfusion (OR = 0.5, P < .001), male gender was associated with statistically significant increases in the rates of death (OR = 1.6, P < .001), acute kidney injury (OR = 1.6, P < .001), cardiac arrest (OR = 1.7, P < .001), myocardial infarction (OR = 1.6, P < .001), pneumonia (OR = 1.1, P < .001), sepsis (OR = 1.6, P < .001), surgical site infection (OR = 1.4, P < .001), and wound dehiscence (OR = 1.4, P < .001).

CONCLUSION

Males had increased rates of many individual adverse events. Females had higher rates of urinary tract infection, which translated to an overall higher rate of adverse events in females because of the rarity of the other individual adverse events.

No Threshold Exists for Recommending Revision Surgery in Metal-on-Metal Hip Arthroplasty Patients With Adverse Reactions to Metal Debris: A Retrospective Cohort Study of 346 Revisions

BACKGROUND

Surgeons currently have difficulty when managing metal-on-metal hip arthroplasty (MoMHA) patients with adverse reactions to metal debris (ARMD). This stems from a lack of evidence, which is emphasized by the variability in the recommendations proposed by different worldwide regulatory authorities for considering MoMHA revision surgery. We investigated predictors of poor outcomes following MoMHA revision surgery performed for ARMD to help inform the revision threshold and type of reconstruction.

METHODS

We retrospectively studied 346 MoMHA revisions for ARMD performed at 2 European centers. Preoperative (metal ions/imaging) and intraoperative (findings, components removed/implanted) factors were used to predict poor outcomes. Poor outcomes were postoperative complications (including re-revision), 90-day mortality, and poor Oxford Hip Score.

RESULTS

Poor outcomes occurred in 38.5%. Shorter time (under 4 years) to revision surgery was the only preoperative predictor of poor outcomes (odds ratio [OR] = 2.12, confidence interval [CI] = 1.00-4.46). Prerevision metal ions and imaging did not influence outcomes. Single-component revisions (vs all-component revisions) increased the risk of poor outcomes (OR = 2.99, CI = 1.50-5.97). Intraoperative modifiable factors reducing the risk of poor outcomes included the posterior approach (OR = 0.22, CI = 0.10-0.49), revision head sizes ≥36 mm (vs <36 mm: OR = 0.37, CI = 0.18-0.77), ceramic-on-polyethylene revision bearings (OR vs ceramic-on-ceramic = 0.30, CI = 0.14-0.66), and metal-on-polyethylene revision bearings (OR vs ceramic-on-ceramic = 0.37, CI = 0.17-0.83).

CONCLUSION

No threshold exists for recommending revision in MoMHA patients with ARMD. However postrevision outcomes were surgeon modifiable. Optimal outcomes may be achieved if surgeons use the posterior approach, revise all MoMHA components, and use ≥36 mm ceramic-on-polyethylene or metal-on-polyethylene articulations.

Cementing does not increase the immediate postoperative risk of death after total hip arthroplasty or hemiarthroplasty: a hospital-based study of 10,677 patients

Background and purpose - It has been suggested that cemented arthroplasty is associated with increased peri- and postoperative mortality due to bone cement implanting syndrome, especially in fracture surgery. We investigated such an association in elective total hip arthroplasty (THA) patients and hemiarthroplasty (HA) patients treated for femoral neck fracture. Patients and methods - All 10,677 patients receiving elective THA or HA for fracture in our hospital between 2004 and 2015 were identified. Mortality rates for cemented and uncemented THA and HA were compared at different times postoperatively using logistic regression analysis. Analysis was adjusted for age, sex, ASA class, and year of surgery. Results - Adjusted 10- and 30-day mortality after cemented THA was comparable to that of the uncemented THA (OR 1.7; 95% CI 0.3-8.7 and OR 1.6; CI 0.7-3.6, respectively). There was no statistically significant difference in the adjusted 2-day mortality in the cemented HA group when compared with the uncemented group. However, in a subgroup analyses of ASA-class IV HA patients there was a difference, statistically not significant, during the first 2 days postoperatively in the cemented HA group compared with the uncemented HA group (OR 2.1; CI 0.9-4.7). Interpretation - Cementing may still be a safe option in both elective and hip fracture arthroplasty. Excess mortality of cemented THA and HA in the longer term is comorbidity related, not due to bone cement implantation syndrome. However, in the most fragile HA patient group caution is needed at the moment of cementing.

Increased early mortality and morbidity after total hip arthroplasty in patients with socioeconomic disadvantage: a report from the Swedish Hip Arthroplasty Register

Background and purpose - Socioeconomic status is associated with the outcome of major surgery. We investigated the association of socioeconomic status with the risk of early mortality and readmissions after primary total hip arthroplasty (THA). Patients and methods - We obtained information on income, education, immigration, and cohabiting status as well as comorbidities of 166,076 patients who underwent primary THA due to primary osteoarthritis (OA) from the Swedish Hip Arthroplasty Register, the Swedish National Inpatient Register and Statistics Sweden. Multivariable Cox regression models were fitted to estimate the adjusted risk of mortality or readmissions within 90 days after index surgery. Results - Compared with patients on a low income, the adjusted risk of 30-day mortality was considerably lower in patients on a high income (hazard ratio [HR] 0.5, 95% confidence interval [CI] 0.3-0.7) and in those on a medium income (HR 0.7, CI 0.6-0.9). Similar risk reductions were found for the endpoint 90-day mortality. Patients with a high income had a lower adjusted risk of readmission for cardiovascular reasons than those with a low income (HR 0.7, CI 0.6-0.9), as had those with a higher level of education (adjusted HR 0.7, CI 0.6-0.9). Patients with higher socioeconomic status had a lower degree of comorbidities than socioeconomically disadvantaged patients. However, adjusting for socioeconomic confounders in multivariable models only marginally influenced the predictive ability of the models, as expressed by their area under the curve. Interpretation - Income and level of education are strongly associated with early mortality and readmissions after primary THA, and both parameters are closely connected to health status. Since adjustment for socioeconomic confounders only marginally improved the predictive ability of multivariable regression models our findings indicate that comorbidities may under certain circumstances serve as an acceptable proxy measure of socioeconomic background.

Ultrasound-guided lumbar selective nerve root block plus T12 paravertebral and sacral plexus block for hip and knee arthroplasty: Three case reports

RATIONALE

For hip or knee arthroplasty, it is essential to develop a satisfied peripheral nerve block method that will benefit elderly patients or patients who are contraindicated to neuraxial anesthesia.

PATIENTS CONCERNS

Patient in Case 1 suffered from the right intertrochanteric fracture, combined with chronic obstructive pulmonary disease; Patient in Case 2 suffered from hip osteoarthritis; combined with ankylosing spondylitis; Patient in Case 3 suffered from rheumatoid arthritis, combined with ischemic encephalopathy.

DIAGNOSIS

Case 1: Right intertrochanteric fracture, chronic obstructive pulmonary disease. Case 2: hip osteoarthritis. Case 3: rheumatoid arthritis.

INTERVENTIONS

Ultrasound-guided lumbar selective nerve root block (SNRB) plus T12 paravertebral and sacral plexus block were performed in 2 patients who received hip arthroplasty and 1 patient who received knee arthroplasty.

OUTCOMES

All patients successfully received surgeries with this peripheral nerve block method and no postoperative complication was reported.

LESSONS

Ultrasound-guided lumbar SNRB plus T12 paravertebral and sacral plexus block not only satisfied the analgesia requirement of surgery, but also reduced the consumption of local anesthetic.

Risk factors associated with revision for prosthetic joint infection following knee replacement: an observational cohort study from England and Wales

Background

Prosthetic joint infection is a devastating complication of knee replacement. The risk of developing a prosthetic joint infection is affected by patient, surgical, and health-care system factors. Existing evidence is limited by heterogeneity in populations studied, short follow-up, inadequate power, and does not differentiate early prosthetic joint infection, most likely related to the intervention, from late infection, more likely to occur due to haematogenous bacterial spread. We aimed to assess the overall and time-specific associations of these factors with the risk of revision due to prosthetic joint infection following primary knee replacement.

Methods

In this cohort study, we analysed primary knee replacements done between 2003 and 2013 in England and Wales and the procedures subsequently revised for prosthetic joint infection between 2003 and 2014. Data were obtained from the National Joint Registry linked to the Hospital Episode Statistics data in England and the Patient Episode Database for Wales. Each primary replacement was followed for a minimum of 12 months until the end of the observation period (Dec 31, 2014) or until the date of revision for prosthetic joint infection, revision for another indication, or death (whichever occurred first). We analysed the data using Poisson and piecewise exponential multilevel models to assess the associations between patient, surgical, and health-care system factors and risk of revision for prosthetic joint infection.

Findings

Of 679 010 primary knee replacements done between 2003 and 2013 in England and Wales, 3659 were subsequently revised for an indication of prosthetic joint infection between 2003 and 2014, after a median follow-up of 4·6 years (IQR 2·6–6·9). Male sex (rate ratio [RR] for male vs female patients 1·8 [95% CI 1·7–2·0]), younger age (RR for age ≥80 years vs <60 years 0·5 [0·4–0·6]), higher American Society of Anaesthesiologists [ASA] grade (RR for ASA grade 3–5 vs 1, 1·8 [1·6–2·1]), elevated body-mass index (BMI; RR for BMI ≥30 kg/m²vs <25 kg/m² 1·5 [1·3–1·6]), chronic pulmonary disease (RR 1·2 [1·1–1·3]), diabetes (RR 1·4 [1·2–1·5]), liver disease (RR 2·2 [1·6–2·9]), connective tissue and rheumatic diseases (RR 1·5 [1·3–1·7]), peripheral vascular disease (RR 1·4 [1·1–1·7]), surgery for trauma (RR 1·9 [1·4–2·6]), previous septic arthritis (RR 4·9 [2·7–7·6]) or inflammatory arthropathy (RR 1·4 [1·2–1·7]), operation under general anaesthesia (RR 1·1 [1·0–1·2]), requirement for tibial bone graft (RR 2·0 [1·3–2·7]), use of posterior stabilised fixed bearing prostheses (RR for posterior stabilised fixed bearing prostheses vs unconstrained fixed bearing prostheses 1·4 [1·3–1·5]) or constrained condylar prostheses (3·5 [2·5–4·7]) were associated with a higher risk of revision for prosthetic joint infection. However, uncemented total, patellofemoral, or unicondylar knee replacement (RR for uncemented vs cemented total knee replacement 0·7 [95% CI 0·6–0·8], RR for patellofemoral vs cemented total knee replacement 0·3 [0·2–0·5], and RR for unicondylar vs cemented total knee replacement 0·5 [0·5–0·6]) were associated with lower risk of revision for prosthetic joint infection. Most of these factors had time-specific effects, depending on the time period post-surgery.

Interpretation

We have identified several risk factors for revision for prosthetic joint infection following knee replacement. Some of these factors are modifiable, and the use of targeted interventions or strategies could lead to a reduced risk of revision for prosthetic joint infection. Non-modifiable factors and the time-specific nature of the effects we have observed will allow clinicians to appropriately counsel patients preoperatively and tailor follow-up regimens.

Funding

National Institute for Health Research.

Choice of Prosthetic Implant Combinations in Total Hip Replacement: Cost-Effectiveness Analysis Using UK and Swedish Hip Joint Registries Data

BACKGROUND

Prosthetic implants used in total hip replacements (THR) have a range of bearing surface combinations (metal-on-polyethylene, ceramic-on-polyethylene, ceramic-on-ceramic, and metal-on-metal), head sizes (small [<36 mm in diameter] and large [≥36 mm in diameter]), and fixation techniques (cemented, uncemented, hybrid, and reverse hybrid). These can influence prosthesis survival, patients' quality of life, and healthcare costs.

OBJECTIVES

To compare the lifetime cost-effectiveness of implants for patients of different age and sex profiles.

METHODS

We developed a Markov model to compare the cost-effectiveness of various implants against small-head cemented metal-on-polyethylene implants. The probability that patients required 1 or more revision surgeries was estimated from analyses of more than 1 million patients in the UK and Swedish hip joint registries, for men and women younger than 55, 55 to 64, 65 to 74, 75 to 84, and 85 years and older. Implant and healthcare costs were estimated from local procurement prices, national tariffs, and the literature. Quality-adjusted life-years were calculated using published utility estimates for patients undergoing THR in the United Kingdom.

RESULTS

Small-head cemented metal-on-polyethylene implants were the most cost-effective for men and women older than 65 years. These findings were robust to sensitivity analyses. Small-head cemented ceramic-on-polyethylene implants were most cost-effective in men and women younger than 65 years, but these results were more uncertain.

CONCLUSIONS

The older the patient group, the more likely that the cheapest implants, small-head cemented metal-on-polyethylene implants, were cost-effective. We found no evidence that uncemented, hybrid, or reverse hybrid implants were the most cost-effective option for any patient group. Our findings can influence clinical practice and procurement decisions for healthcare payers worldwide.

Long-Term Mortality Trends After Revision Total Knee Arthroplasty

BACKGROUND

Long-term mortality following primary total knee arthroplasty (TKA) is lower than the general population. However, it is unknown whether this is true in the setting of revision TKA. We examined long-term mortality trends following revision TKA.

METHODS

This retrospective study included 4907 patients who underwent 1 or more revision TKA between 1985 and 2015. Patients were grouped by surgical indications and followed until death or October 2017. The observed number of deaths was compared to the expected number of deaths using standardized mortality ratios (SMR) and Poisson regression models.

RESULTS

Compared to the general population, patients who underwent revision TKA for infection (SMR, 1.45; 95% confidence interval [CI], 1.33-1.57; P < .0001) and fracture (SMR, 1.16; 95% CI, 1.00-1.34; P = .04) experienced a significantly higher mortality risk. Patients who underwent revision TKA for infection and fracture experienced excess mortality soon after surgery which became more pronounced over time. In contrast, the mortality risk among patients who underwent revision TKA for loosening and/or bearing wear was similar to the general population (SMR, 0.95; 95% CI, 0.89-1.02; P = .16). Aseptic loosening and/or wear and instability patients had improved mortality initially; however, there was a shift to excess mortality beyond 5 years among instability patients, and beyond 10 years among aseptic loosening and/or wear patients.

CONCLUSION

Mortality is elevated soon after revision TKA for infection and fracture. Mortality is lower than the general population after revision TKA for loosening and/or bearing wear but gets worse than the general population beyond the first postoperative decade.

Serious adverse events and lifetime risk of reoperation after elective shoulder replacement: population based cohort study using hospital episode statistics for England

OBJECTIVES

To provide accurate risk estimates of serious adverse events after elective shoulder replacement surgery for arthritis, including age and sex specific estimates of the lifetime risk of revision surgery.

DESIGN

Population based cohort study.

SETTING

Hospital episode statistics for NHS England, including civil registration mortality data.

PARTICIPANTS

58 054 elective shoulder replacements in 51 895 adults (aged ≥50 years) between April 1998 and April 2017.

MAIN OUTCOME MEASURES

The lifetime risk of revision surgery, calculated using an actuarial life table approach and the cumulative probability method. Rates of serious adverse events at 30 and 90 days post-surgery: pulmonary embolism, myocardial infarction, lower respiratory tract infection, acute kidney injury, urinary tract infection, cerebrovascular events, and all cause death. Secondary outcome measures were the number of surgeries performed each year and Kaplan-Meier estimates of revision risk at 3, 5, 10, and 15 years.

RESULTS

The number of shoulder replacements performed each year increased 5.6-fold between 1998 and 2017. Lifetime risks of revision surgery ranged from 1 in 37 (2.7%, 95% confidence interval 2.6% to 2.8%) in women aged 85 years and older to 1 in 4 (23.6%, 23.2% to 24.0%) in men aged 55-59 years. The risks of revision were highest during the first five years after surgery. The risk of any serious adverse event at 30 days post-surgery was 1 in 28 (3.5%, 3.4% to 3.7%), and at 90 days post-surgery was 1 in 22 (4.6%, 4.4% to 4.8%). At 30 days, the relative risk of pulmonary embolism compared with baseline population risk was 61 (95% confidence interval 50 to 73) for women aged 50-64. Serious adverse events were associated with increasing age, comorbidity, and male sex. 1 in 5 (21.2%, 17.9% to 25.1%) men aged 85 years and older experienced at least one serious adverse event within 90 days.

CONCLUSIONS

Younger patients, particularly men, need to be aware of a higher likelihood of early failure of shoulder replacement and the need for further and more complex revision replacement surgery. All patients should be counselled about the risks of serious adverse events. These risks are higher than previously considered, and for some could outweigh any potential benefits. Our findings caution against unchecked expansion of shoulder replacement surgery in both younger and older patients. The more accurate age and sex specific estimates of risk from this study are long overdue and should improve shared decision making between patients and clinicians.

STUDY REGISTRATION

ClinicalTrials.gov NCT03573765.

Early postoperative mortality similar between cemented and uncemented hip arthroplasty: a register study based on Finnish national data

Background and purpose - Implant survival of cemented total hip arthroplasty (THA) in elderly patients is higher than that of uncemented THA. However, a higher mortality rate in patients undergoing cemented THA compared with uncemented or hybrid THA has been reported. We assessed whether cemented fixation increases peri- or early postoperative mortality compared with uncemented and hybrid THA. Patients and methods - Patients with osteoarthritis who received a primary THA in Finland between 1998 and 2013 were identified from the PERFECT database of the National Institute for Health and Welfare in Finland. Definitive data on fixation method and comorbidities were available for 62,221 THAs. Mortality adjusted for fixation method, sex, age group, and comorbidities among the cemented, uncemented, and hybrid THA was examined using logistic regression analysis. Reasons for cardiovascular death within 90 days since the index procedure were extracted from the national Causes of Death Statistics and assessed separately. Results - 1- to 2-day adjusted mortality after cemented THA was comparable to that of the uncemented THA group (OR 1.2; 95% CI 0.24-6.5). 3- to 10-day mortality in the cemented THA group was comparable to that in the uncemented THA group (OR 0.54; CI 0.26-1.1), and in the hybrid THA group (OR 0.64, CI 0.25-1.6). Pulmonary embolism or cardiovascular reasons as a cause of death were not over-represented in the cemented THA group. Interpretation - Early peri- and postoperative mortality in the cemented THA group was similar compared with that of the hybrid and uncemented groups.

The Role of Total Hip Arthroplasty Through the Direct Anterior Approach in Femoral Neck Fracture and Factors Affecting the Outcome

BACKGROUND

Femoral neck fractures (FNFs) are a significant cause of mortality and disability among the elderly population. Total hip arthroplasty (THA) is the preferred treating method in active, cognitively intact patients. The direct anterior approach (DAA) has suggested a lower dislocation risk and a significant reduction in postoperative pain and recovery time in elective THA. This study aimed to compare clinical outcomes, perioperative complications, and mortality of THA through the DAA between FNF and elective cases.

METHODS

Patients with displaced FNF (n = 150) who received THA through the DAA were matched for gender, age, body mass index, and American Society for Anesthesiologists score with electively treated patients (n = 150). The perioperative complications, clinical and radiologic outcomes, as well as mortality were compared between groups, retrospectively.

RESULTS

FNF patients had an increased blood loss, operation duration, hospital stay, and mortality but similar surgery-related complication rates compared to their elective counterparts. The mortality was, however, lower than that reported in the literature. Age, American Society for Anesthesiologists score, and time-to-operation affected the duration of hospital stay and mortality. Less experienced surgeons did not have increased surgery-related complications, but longer operation time and higher blood loss compared to experienced surgeons.

CONCLUSION

THA through the DAA might be a credible and safe option for patients presenting an FNF, with excellent functional outcomes, less surgery-related complications, and lower short-term and long-term mortality than those reported in the literature. Early intervention and perioperative stabilization of the patients with FNF could potentially increase the survival rate.

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.

The Association of Body Mass Index with Risk of Long-Term Revision and 90-Day Mortality Following Primary Total Hip Replacement: Findings from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

BACKGROUND

The influence of obesity on outcomes following total hip replacement is unclear. Restriction of total hip replacement on the basis of body mass index (BMI) has been suggested. The purpose of this study was to assess the influence of BMI on the risk of revision and 90-day mortality.

METHODS

This was a population-based, longitudinal cohort study of the National Joint Registry (NJR) for England, Wales, Northern Ireland and the Isle of Man. Using data recorded from April 2003 to December 2015, linked to Office for National Statistics data, we ascertained revision and 90-day mortality rates following primary total hip replacement by BMI category. The probability of revision was estimated using Kaplan-Meier methods. Associations of BMI with revision and mortality were explored using adjusted Cox proportional hazards regression models.

RESULTS

We investigated revision and 90-day mortality among 415,598 and 413,741 primary total hip replacements, respectively. Each data set accounts for approximately 52% of the total number of recorded operations in the NJR. Thirty-eight percent of the patients were classified as obese. At 10 years, class-III obese patients had the highest cumulative probability of revision (6.7% [95% confidence interval (CI), 5.5% to 8.2%]), twice that of the underweight group (3.3% [95% CI, 2.2% to 4.9%]). When the analysis was adjusted for age, sex, American Society of Anesthesiologists [ASA] grade, year of operation, indication, and fixation type, compared with patients with normal BMI, significantly elevated hazard ratios (HRs) for revision were observed for patients in the BMI categories of class-I obese (≥30 to <35 kg/m) (HR, 1.14 [95% CI, 1.07 to 1.22]), class-II obese (≥35 to <40 kg/m) (HR, 1.30 [95% CI, 1.19 to 1.40]), and class-III obese (≥40 to ≤60 kg/m) (HR, 1.43 [95% CI, 1.27 to 1.61]) (p < 0.0005 for all). Underweight patients had a substantially higher cumulative probability of 90-day mortality (1.17%; 95% CI, 0.86% to 1.58%) compared with patients with normal BMI (0.43%; 95% CI, 0.39% to 0.48%). The risk of 90-day mortality was significantly higher for the underweight group (HR, 2.09 [95% CI, 1.51 to 2.89]; p < 0.0005) and significantly lower for patients who were categorized as overweight (HR, 0.70; 95% CI, 0.61 to 0.81; p < 0.0005), class-I obese (HR, 0.69 [95% CI, 0.59 to 0.81]; p < 0.0005), and class-II obese (HR, 0.79 [95% CI, 0.63 to 0.98]; p = 0.049) compared with patients with normal BMI.

CONCLUSIONS

Although long-term revision rates following total hip replacement were higher among obese patients, we believe that the rates remained acceptable by contemporary standards and were balanced by a lower risk of 90-day mortality.

LEVEL OF EVIDENCE

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

Risk factors for infection, revision, death, blood transfusion and longer hospital stay 3 months and 1 year after primary total hip or knee arthroplasty

BACKGROUND

Total joint replacement (TJR) is increasingly performed in older patients with more comorbidities, who are considered at higher risk for postoperative complications. We aimed to identify and calculate the odds ratio of the risk factors for infection, revision and death 3 months and 1 year after TJR as well as for postoperative blood transfusion and longer hospital stay.

METHODS

We analyzed all primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) cases in Nova Scotia between Apr. 1, 2000, and Mar. 31, 2014, as identified from the Discharge Abstract Database. We used the Charlson Comorbidity Index as a surrogate measure of comorbidities. We used hospital and physician billings data and Nova Scotia Vital Statistics data to identify the postoperative events in this cohort.

RESULTS

A total of 10 123 primary THA and 17 243 primary TKA procedures were performed during the study period. The mean patient age was 66.1 (standard deviation 11.7) years and 67.1 (standard deviation 9.3) years, respectively. With THA, the risk of infection was higher in patients with heart failure and those with diabetes. For TKA, liver disease and blood transfusion were associated with a higher risk of infection. Revision rates were higher among patients with hypertension and those with paraparesis/hemiparesis for THA, and among patients with metastatic disease for TKA. Significant risk factors for death included metastatic disease, older age, heart failure, myocardial infarction, dementia, rheumatologic disease, renal disease, blood transfusion and cancer. Multiple medical comorbidities and older age were associated with higher rates of blood transfusion and longer hospital stay.

CONCLUSION

We have identified the risk factors associated with higher rates of postoperative complications and longer hospital stay after TJR. The results enable individualized risk stratification during the preoperative consultation.

Adverse outcomes after arthroscopic partial meniscectomy: a study of 700 000 procedures in the national Hospital Episode Statistics database for England

BACKGROUND

Arthroscopic partial meniscectomy is one of the most common orthopaedic procedures worldwide. Clinical trial evidence published in the past 6 years, however, has raised questions about the effectiveness of the procedure in some patient groups. In view of concerns about potential overuse, we aimed to establish the true risk of serious complications after arthroscopic partial meniscectomy.

METHODS

We analysed national Hospital Episode Statistics data for all arthroscopic partial meniscectomies done in England between April 1, 1997, and March 31, 2017. Simultaneous or staged (within 6 months) bilateral cases were excluded. We identified complications occurring in the 90 days after the index procedure. The primary outcome was the occurrence of at least one serious complication within 90 days, which was defined as either myocardial infarction, stroke, pulmonary embolism, infection requiring surgery, fasciotomy, neurovascular injury, or death. Logistic regression modelling was used to identify factors associated with complications and, when possible, risk was compared with general population data.

FINDINGS

During the study period 1 088 782 arthroscopic partial meniscectomies were done, 699 965 of which were eligible for analysis. Within 90 days, serious complications occurred in 2218 (0·317% [95% CI 0·304-0·330]) cases, including 546 pulmonary embolisms (0·078% [95% CI 0·072-0·085]) and 944 infections necessitating further surgery (0·135% [95% CI 0·126-0·144]). Increasing age (adjusted odds ratio [OR] 1·247 per decade [95% CI 1·208-1·288) and modified Charlson comorbidity index (adjusted OR 1·860 per 10 units [95% CI 1·708-2·042]) were associated with an increased risk of serious complications. Female sex was associated with a reduced risk of serious complications (adjusted OR 0·640 [95% CI 0·580-0·705). The risk of mortality fell over time (adjusted OR 0·965 per year [95% CI 0·937-0·994]). Mortality, myocardial infarction, and stroke occurred less frequently in the study cohort than in the general population. The risks of infection and pulmonary embolism did not change during the study, and were significantly higher in the study cohort than in the general population. For every 1390 (95% CI 1272-1532) fewer knee arthroscopies done, one pulmonary embolism could be prevented. For every 749 (95% CI 704-801) fewer procedures done, one native knee joint infection could be prevented.

INTERPRETATION

Overall, the risk associated with undergoing arthroscopic partial meniscectomy was low. However, some rare but serious complications (including pulmonary embolism and infection) are associated with the procedure, and the risks have not fallen with time. In view of uncertainty about the effectiveness of arthroscopic partial meniscectomy, an appreciation of relative risks is crucial for patients and clinicians. Our data provide a basis for decision making and consent.

FUNDING

UK National Institute for Health Research.

Fourteen-year experience with short cemented stems in total hip replacement

PURPOSE

The age of the population requiring total hip replacement (THR) is increasing and this may lead to a return of cemented stems. Advantages of a short cemented femoral device include preservation of metaphyseal bone, easier insertion, and easier cement removal in case of revision. The purpose of this study is to describe the rationale and assess midterm results of unique innovative short cemented double-tapered polished stem applied with contemporary cementing techniques.

METHODS

Our experience with this short cemented stem includes two different groups of elderly patients. Group 1 (prototype version of the short stem) from January 2005 to January 2008 counts 43 THR. Group 2 (final commercial version of the short stem) from January 2013 to January 2015 counts 54 THR. The average age in groups 1 and 2 was 79 and 75 respectively. Patients underwent clinical follow-up with the Harris Hip Score (HHS) and completed radiographic evaluation.

RESULTS

Thirty-one patients of group 1 had died for reasons unrelated to their THR. The surviving 9 hips have a follow-up of 11.2 years. In group 2, eight  patients died for reasons unrelated to their THR. Follow-up for the surviving 40 patients is 4.6 years. HHS improved in both groups. In 34/43 hips of group 1 and in 41/54 of group 2 we observed a Barrack grade A cement mantle. Survival with revision of the stem for aseptic loosening as the endpoint was 100%.

CONCLUSIONS

This study confirms the effectiveness of a short, polished, collarless, tapered cemented stem implanted with contemporary cementing techniques which appears as successful as the standard sized components.

Red Cell Distribution Width: An Unacknowledged Predictor of Mortality and Adverse Outcomes Following Revision Arthroplasty

BACKGROUND

Revision total joint arthroplasties (TJAs) have been empirically associated with significant postoperative morbidity and mortality. Red blood cell distribution width (RDW), a frequently measured hematological parameter, has been shown to predict mortality in hip fracture patients. However, its utility in risk-stratifying patients before revision TJA remains unknown. The aim of this study was to investigate the possible relationship between preoperative RDW levels and outcome of revision arthroplasty in terms of mortality, adverse outcomes, and length of hospital stay.

METHODS

A single-institution retrospective study was conducted on 4633 patients who underwent revision TJA (3289 hips and 1344 knees) between 2000 and September 2016. Of those, 656 (14.1%) surgeries were performed due to periprosthetic joint infection, and 3977 (85.9%) were aseptic revisions. The association between preoperative RDW and various outcomes, including 1-year mortality, in-hospital medical complications, length of hospital stay, and 90-day all-cause readmission, was examined.

RESULTS

The average age of patients in the cohort was 65.4 ± 12.9 years. The average Charlson comorbidity index was 0.6 (standard deviation = 1.0), with 691 patients (14.9%) having 2 or more comorbidities. Mean preoperative RDW level was 14.4% (standard deviation = 1.8). After adjusting for covariates, higher RDW levels were statistically significantly associated with mortality (adjusted odds ratio [OR], 1.25; 95% confidence interval [CI], 1.13-1.39; P < .001), any in-hospital medical complications (adjusted OR, 1.12; 95% CI, 1.07-1.18; P < .001), and readmission (adjusted OR, 1.07; 95% CI, 1.02-1.13; P < .001).

CONCLUSION

Higher levels of preoperative RDW appeared to be associated with less optimal outcomes after revision TJA. Adult reconstruction orthopedic surgeons should be aware of this predictive factor and exercise caution with TJA revision patients with high values of preoperative RDW. RDW could be included in the routine perioperative workup and used to counsel patients on their postoperative risk.

Is single-anaesthetic bilateral primary total hip replacement still safe? A 16-year cohort study from the New Zealand Joint Registry

BACKGROUND

The surgical management options for bilateral hip osteoarthritis comprise staged or single-anaesthetic bilateral total hip replacements (THRs). The key issue of contention in performing the latter remains safety. We compared unilateral, staged bilateral and single-anaesthetic bilateral THR with the hypothesis that there would be no difference between these three practices using mortality risk, functional outcome and revision rate as the primary outcome measures.

METHODS

We performed a retrospective cohort analysis of the New Zealand Joint Registry identifying all primary THRs performed between 1 January 1999 and 31 December 2015. We report this study in accordance with STROBE and RECORD guidelines. We identified all unilateral THRs, all single-anaesthetic bilateral THRs and all staged bilateral THRs and compared the mortality risk, all-cause revision risk with Kaplan-Meier survival analysis and reasons for revision and functional outcome using the Oxford 12 scores. Analysis was adjusted for age, gender, American Society of Anesthesiologists rating score and body mass index.

RESULTS

The mortality risk for single-anaesthetic bilateral THR within 3 months was 0.26% and for unilateral THR 0.75% (hazard ratio 0.35 (95% confidence interval (CI) 0.30-0.41, P < 0.001). The risk of revision in the single-anaesthetic bilateral THR group was 0.69/100 component years (95% CI 0.59-0.79/100 component years) versus 0.74/100 component years (95% CI 0.72-0.77/100 component years) in unilateral THR. Mean Oxford 12 scores at 6 months post-arthroplasty was 41.7 (95% CI 41.2-42.2) in the single-anaesthetic bilateral THR group. The best results in the staged bilateral THR group were obtained if the second procedure was delayed by at least 90 days from the first THR.

CONCLUSIONS

Single anaesthetic bilateral THR is at least as safe as unilateral THR or staged bilateral THR in appropriately selected cases. Experienced surgeons can expect predictable survival rates and functional scores.

Using long term mortality to determine which perioperative risk factors of mortality following hip and knee replacement may be causal

Observational studies have identified surgical factors that are associated with a reduced risk of mortality after joint replacement. It is not clear whether these are causal or reflect patient selection. Data on the first primary hip (n = 424,156) and knee replacements (n = 469,989) performed for osteoarthritis in the National Joint Registry were analysed. Flexible parametric survival modelling was used to determine if risk factors for mortality in the perioperative period persisted. To explore selection bias, standardised mortality ratios were calculated for all-cause, respiratory and smoking related cancer mortality using population rates. Selection was apparent for hip resurfacing, combined spinal and general anaesthetic and unicondylar knee implants; reduced mortality was observed for many years for both all and other causes of mortality with a waning effect. Mechanical thromboprophylaxis was also suggestive of selection although patients receiving aspirin had sustained reduced mortality, possibly due to to a cardioprotective effect. Posterior approach for hips was ambiguous with a possible causal component. Spinal anaesthesia was suggestive of a causal effect. We are reliant on observational data when it is not feasible to undertake randomised trials. Our approach of looking at long term mortality risks for perioperative interventions provides further insights to differentiate causal interventions from selection. We recommend the use of aspirin chemothromboprophylaxis, the posterior approach and spinal anaesthetic in total hip replacement due to the apparent causal effect on reduced mortality.

Preoperative Behavioural Intervention versus standard care to Reduce Drinking before elective orthopaedic Surgery (PRE-OP BIRDS): protocol for a multicentre pilot randomised controlled trial

Background

Evidence suggests that increased preoperative alcohol consumption increases the risk of postoperative complications; therefore, a reduction or cessation in alcohol intake before surgery may reduce perioperative risk. Preoperative assessment presents an opportunity to intervene to optimise patients for surgery. This multicentre, two-arm, parallel group, individually randomised controlled trial will investigate whether a definitive trial of a brief behavioural intervention aimed at reducing preoperative alcohol consumption is feasible and acceptable to healthcare professionals responsible for its delivery and the preoperative elective orthopaedic patient population.

Methods

Screening will be conducted by trained healthcare professionals at three hospitals in the North East of England. Eligible patients (those aged 18 or over, listed for elective hip or knee arthroplasty surgery and scoring 5 or more or reporting consumption of six or more units on a single occasion at least weekly on the alcohol screening tool) who enrol in the trial will be randomised on a one-to-one non-blinded basis to either treatment as usual or brief behavioural intervention delivered in the pre-assessment clinic. Patients will be followed up 1–2 days pre-surgery, 1–5 days post-surgery (as an in-patient), 6 weeks post-surgery, and 6 months post intervention. Feasibility will be assessed through rates of screening, eligibility, recruitment, and retention to 6-month follow-up. An embedded qualitative study will explore the acceptability of study methods to patients and staff.

Discussion

This pilot randomised controlled trial will establish the feasibility and acceptability of trial procedures reducing uncertainties ahead of a definitive randomised controlled trial to establish the effectiveness of brief behavioural intervention to reduce alcohol consumption in the preoperative period and the potential impact on perioperative complications.

Trial registration

Reference number ISRCTN36257982

Risk of further surgery on the same or opposite side and mortality after primary total hip arthroplasty: A multi-state analysis of 133,654 patients from the Swedish Hip Arthroplasty Register

Background and purpose - The hip-related timeline of patients following a total hip arthroplasty (THA) can vary. Ideally patients will live their life without need for further surgery; however, some will undergo replacement on the contralateral hip and/or reoperations. We analyzed the probability of mortality and further hip-related surgery on the same or contralateral hip. Patients and methods - We performed a multi-state survival analysis on a prospectively followed cohort of 133,654 Swedish patients undergoing an elective THA between 1999 and 2012. The study used longitudinally collected information from the Swedish Hip Arthroplasty Register and administrative databases. The analysis considered the patients' sex, age, prosthesis type, surgical approach, diagnosis, comorbidities, education, and civil status. Results - During the study period patients were twice as likely to have their contralateral hip replaced than to die. However, with passing time, probabilities converged and for a patient who only had 1 non-revised THA at 10 years, there was an equal chance of receiving a second THA and dying (24%). It was 8 times more likely that the second hip would become operated with a primary THA than that the first hip would be revised. Multivariable regression analysis reinforced the influence of age at operation, sex, diagnosis, comorbidity, and socioeconomic status influencing state transition. Interpretation - Multi-state analysis can provide a comprehensive model of further states and transition probabilities after an elective THA. Information regarding the lifetime risk for bilateral surgery, revision, and death can be of value when discussing the future possible outcomes with patients, in healthcare planning, and for the healthcare economy.

Risk factors associated with revision for prosthetic joint infection after hip replacement: a prospective observational cohort study

Background

The risk of prosthetic joint infection (PJI) is influenced by patient, surgical, and health-care factors. Existing evidence is based on short-term follow-up. It does not differentiate between factors associated with early onset caused by the primary intervention from those associated with later onset more likely to result from haematogenous spread. We aimed to assess the overall and time-specific associations of these factors with the risk of revision due to PJI after primary total hip replacement.

Methods

We did a prospective observational cohort study analysing 623 253 primary hip procedures performed between April 1, 2003, and Dec 31, 2013, in England and Wales and recorded the number of procedures revised because of PJI. We investigated the associations between risk factors and risk of revision for PJI across the overall follow-up period using Poisson multilevel models. We reinvestigated the associations by post-operative time periods (0–3 months, 3–6 months, 6–12 months, 12–24 months, >24 months) using piece-wise exponential multilevel models with period-specific effects. Data were obtained from the National Joint Registry linked to the Hospital Episode Statistics data.

Findings

2705 primary procedures were subsequently revised for an indication of PJI between 2003 and 2014, after a median (IQR) follow up of 4·6 years (2·6–7·0). Among the factors associated with an increased revision due to PJI there were male sex (1462 [1·2‰] of 1 237 170 male-years vs 1243 [0·7‰] of 1 849 691 female-years; rate ratio [RR] 1·7 [95% CI 1·6–1·8]), younger age (739 [1·1‰] of 688 000 person-years <60 years vs 242 [0·6‰] of 387 049 person-years ≥80 years; 0·7 [0·6–0·8]), elevated body-mass index (BMI; 941 [1·8‰] 517 278 person-years with a BMI ≥30 kg/m²vs 272 [0·9‰] of 297 686 person-years with a BMI <25 kg/m²; 1·9 [1·7–2·2]), diabetes (245 [1·4‰] 178 381 person-years with diabetes vs 2120 [1·0‰] of 2 209 507 person-years without diabetes; 1·4 [1·2–1·5]), dementia (5 [10·1‰] of 497 person-years with dementia at 3 months vs 311 [2·6‰] of 120 850 person-years without dementia; 3·8 [1·2–7·8]), previous septic arthritis (22 [7·2‰] of 3055 person-years with previous infection vs 2683 [0·9‰] of 3 083 806 person-years without previous infection; 6·7 [4·2–9·8]), fractured neck of femur (66 [1·5‰] of 43 378 person-years operated for a fractured neck of femur vs 2639 [0·9‰] of 3 043 483 person-years without a fractured neck of femur; 1·8 [1·4–2·3]); and use of the lateral surgical approach (1334 [1·0‰] of 1 399 287 person-years for lateral vs 1242 [0·8 ‰] of 1 565 913 person-years for posterior; 1·3 [1·2–1·4]). Use of ceramic rather than metal bearings was associated with a decreased risk of revision for PJI (94 [0·4‰] of 239 512 person-years with ceramic-on-ceramic bearings vs 602 [0·5‰] of 1 114 239 peron-years with metal-on-polyethylene bearings at ≥24 months; RR 0·6 [0·4–0·7]; and 82 [0·4‰] of 190 884 person-years with ceramic-on-polyethyene bearings vs metal-on-polyethylene bearings at ≥24 months; 0·7 [0·5–0·9]). Most of these factors had time-specific effects. The risk of revision for PJI was marginally or not influenced by the grade of the operating surgeon, the absence of a consultant surgeon during surgey, and the volume of procedures performed by hospital or surgeon.

Interpretation

Several modifiable and non-modifiable factors are associated with the risk of revision for PJI after primary hip replacement. Identification of modifiable factors, use of targeted interventions, and beneficial modulation of some of these factors could be effective in reducing the incidence of PJI. It is important for clinicians to consider non-modifiable factors and factors that exhibit time-specific effects on the risk of PJI to counsel patients appropriately preoperatively.

Funding

National Institute for Health Research.

Impact of comorbid conditions on outcomes of hip and knee replacement surgery: a systematic review and meta-analysis

OBJECTIVE

To systematically perform a meta-analysis of the association between different comorbid conditions on safety (short-term outcomes) and effectiveness (long-term outcomes) in patients undergoing hip and knee replacement surgery.

DESIGN

Systematic review and meta-analysis.

METHODS

Medline, Embase and CINAHL Plus were searched up to May 2017. We included all studies that reported data to allow the calculation of a pooled OR for the impact of 11 comorbid conditions on 10 outcomes (including surgical complications, readmissions, mortality, function, health-related quality of life, pain and revision surgery). The quality of included studies was assessed using a modified Newcastle-Ottawa Scale. Continuous outcomes were converted to ORs using the Hasselblad and Hedges approach. Results were combined using a random-effects meta-analysis.

OUTCOMES

The primary outcome was the adjusted OR for the impact of each 11 comorbid condition on each of the 10 outcomes compared with patients without the comorbid condition. Where the adjusted OR was not available the secondary outcome was the crude OR.

RESULTS

70 studies were included with 16 (23%) reporting on at least 100 000 patients and 9 (13%) were of high quality. We found that comorbidities increased the short-term risk of hospital readmissions (8 of 11 conditions) and mortality (8 of 11 conditions). The impact on surgical complications was inconsistent across comorbid conditions. In the long term, comorbid conditions increased the risk of revision surgery (6 of 11 conditions) and long-term mortality (7 of 11 conditions). The long-term impact on function, quality of life and pain varied across comorbid conditions.

CONCLUSIONS

This systematic review shows that comorbidities predominantly have an impact on the safety of hip and knee replacement surgery but little impact on its effectiveness. There is a need for high-quality studies also considering the severity of comorbid conditions.

General and Abdominal Obesity as Risk Factors for Late-Life Mobility Limitation After Total Knee or Hip Replacement for Osteoarthritis Among Women

OBJECTIVE

To investigate associations of body mass index (BMI), waist circumference (WC), and waist/hip ratio (WHR) with survival to age 85 years with mobility limitation or death before age 85 years among older women with total knee replacement (TKR) or total hip replacement (THR) for osteoarthritis (OA).

METHODS

This was a prospective study of women (ages 65-79 years at baseline) from the Women's Health Initiative, recruited during 1993-1998 and followed through 2012. Women's Health Initiative data were linked to Medicare claims data to determine TKR (n = 1,867) and THR (n = 944) for OA. Women were followed for up to 18 years after undergoing THR or TKR to determine mobility status at age 85 years.

RESULTS

Compared with normal-weight women, overweight, obese I, and obese II women with THR had significantly increased risk of survival to age 85 years with mobility limitation (P < 0.001 for linear trend), with the strongest risk among obese II women (odds ratio [OR] 4.37 [95% confidence interval (95% CI) 1.96-9.74]). Obese II women with THR also had increased risk of death before age 85 years. Women with THR and WC >88 cm relative to ≤88 cm had increased risk of survival to age 85 years with mobility limitation (OR 1.65 [95% CI 1.17-2.33]) but not death before age 85 years. High BMI, WC, and WHR were associated with significantly increased risk of late-life mobility limitation and death among women with TKR for OA.

CONCLUSION

Among older women who underwent THR or TKR for OA, baseline general and abdominal obesity were associated with increased risk of late-life mobility limitation.

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.

CT pulmonary angiography in lower limb arthroplasty

Aims

The aims of this study were to determine the indications and frequency of ordering a CT pulmonary angiography (CTPA) following primary arthroplasty of the hip and knee, and to determine the number of positive scans in these patients, the location of emboli and the outcome for patients undergoing CTPA.

Patients and Methods

We analyzed the use of CTPA, as an inpatient and up to 90 days as an outpatient, in a cohort of patients and reviewed the medical records and imaging for each patient undergoing CTPA.

Results

Out of 11 249 patients, scans were requested in 229 (2.04%) and 86 (38%) were positive. No patient undergoing CTPA died within 90 days. The rate of mortality from pulmonary embolism (PE) overall was 0.08%. CTPA was performed twice as often following total knee arthroplasty (TKA) compared with total hip arthroplasty (THA), and when performed was twice as likely to be positive. Hypoxia was the main indication for a scan, being the indication in 149 scans (65%); and in 23% (11 of 47), the PE was peripheral and unilateral. Three patients suffered complications resulting from therapeutic anticoagulation for possible PE, two of whom had a negative CTPA.

Conclusion

CTPA is more likely to be performed following TKA compared with THA. Hypoxia was the main presenting feature of PE. A quarter of PEs which were diagnosed were unilateral and peripheral. Further study may indicate which patients who have a PE after lower limb arthroplasty require treatment, and which can avoid the complications associated with anticoagulation. Cite this article: Bone Joint J 2018;100-B:938–44.

The impact of rheumatoid arthritis on the risk of adverse events following joint replacement: a real-world cohort study

Purpose

To assess whether rheumatoid arthritis (RA) is associated with a greater risk of adverse events following total knee replacement (TKR) and total hip replacement (THR) than osteoarthritis (OA).

Patients and methods

Individuals with a diagnosis of RA or OA were identified using primary care records. TKR and THR following diagnosis were identified using linked hospital records. Myocardial infarction (MI), prosthetic joint infection (PJI), venous thromboembolism (VTE), and death were identified within 90 days following surgery, and revision procedures over 10 years following surgery. The impact of RA compared to OA on the risk for these adverse events was assessed using Cox proportional hazard models. Univariable models, with diagnosis as the only explanatory variable, and multivariable models, with age, gender, and year of surgery first added and then a measure of other comorbidities also included, were estimated.

Results

In all 20,763 individuals, with 10,260 TKR and 10,961 THR, were included in the analysis. Compared to those with OA, individuals with a diagnosis of RA had a greater incidence of MI over 90 days following TKR (OA: 0.28%, RA: 0.75%) and revision over 10 years following THR (OA: 5.55%, RA: 8.68%). Both of these differences were statistically significant with, for example, hazard ratios of 3.54 (1.44 to 8.73) for MI and 1.61 (1.06 to 2.46) for revision after controlling for age, gender, year of surgery, and other comorbidities.

Conclusion

These findings suggest that, compared to individuals with OA, those with RA have an increased short-term risk of MI following TKR. While risk of MI remains below 1%, this does underline the importance of the management of cardiovascular risk factors for those with RA. RA was also associated with an increased long-term risk of revision following THR, which strengthens the argument for investing in therapies which may prevent the need for joint replacement.

Body Mass Index Is Associated With All-cause Mortality After THA and TKA

BACKGROUND

Both obesity and underweight are associated with a higher risk of mortality in adulthood, but the association between mortality after arthroplasty and extreme ranges of body mass index (BMI) have not been evaluated beyond the first year.

QUESTIONS/PURPOSES

The purpose of this study was to investigate the association between BMI and all-cause mortality after TKA and THA.

METHODS

Data from two arthroplasty registries, the St Vincent's Melbourne Arthroplasty (SMART) Registry from Australia and the Kaiser Permanente Total Joint Replacement Registry (KPTJRR) from the United States, were used to identify patients aged ≥ 18 years undergoing elective TKAs and THAs between January 1, 2002, and December 31, 2013. Same-day bilateral THA and hemiarthroplasties were excluded. All-cause mortality was recorded from the day of surgery to the end of the study (December 31, 2013). Data capture was complete for the SMART Registry. No patients were lost to followup in the KPTJRR cohort and 2959 (5%) THAs and 5251 (5%) TKAs had missing data. Cox proportional hazard regression was used to estimate the all-cause mortality associated with six BMI categories: underweight (< 18.5 kg/m), normal weight (18.5-24.9 kg/m), overweight (25.0-29.9 kg/m), obese class I (30.0-34.9 kg/m), obese class II (35.0-39.9 kg/m), and obese class III (> 40 kg/m). For TKA, the SMART cohort had a median followup of 5 years (range, 0-12 years) and the KPTJRR cohort had a median followup of 4 years (range, 0-12 years). For THA, the SMART cohort had a median followup of 5 years (range, 0-12 years) and the KPTJRR cohort had a median followup of 4 years (range, 0-12 years).

RESULTS

In both the Australian and US cohorts, being underweight (Australia: hazard ratio [HR], 3.72; 95% confidence interval [CI], 1.94-7.08; p < 0.001 and United States: HR, 1.88; 95% CI, 1.33-2.64; p < 0.001) was associated with higher all-cause mortality after TKA, whereas obese class I (Australia: HR, 0.66; 95% CI, 0.47-0.92; p = 0.015; United States: HR, 0.71; 95% CI, 0.66-0.78; p < 0.001) or obese class II (Australia: HR, 0.54; 95% CI, 0.35-0.82; p = 0.004; United States: HR, 0.73; 95% CI, 0.66-0.81; p < 0.001) was associated with lower mortality when compared with normal-weight patients. In the US cohort, being overweight was also associated with a lower risk of mortality (HR, 0.76; 95% CI, 0.71-0.82; p < 0.001). In the US cohort, being underweight had a higher risk of mortality after THA (HR, 2.09; 95% CI, 1.65-2.64; p < 0.001), whereas those overweight (HR, 0.73; 95% CI, 0.67-0.80; p < 0.001), obese class I (HR, 0.68; 95% CI, 0.62-0.75; p < 0.001), or obese class II (HR, 0.71; 95% CI, 0.62-0.81; p < 0.001) were at a lower risk of mortality after THA when compared with normal-weight patients. In patients undergoing THA in the Australian cohort, we observed no association between BMI and risk of death.

CONCLUSIONS

We found that even severe obesity is not associated with a higher risk of death after arthroplasty. Patients should be informed of this when considering surgery. Clinicians should be cautious when considering total joint arthroplasty in underweight patients without first considering their nutritional status.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Moderate to Severe Renal Insufficiency Is Associated With High Mortality After Hip and Knee Replacement

BACKGROUND

In patients having elective hip or knee replacements, many comorbid conditions, including diabetes, cardiovascular disease, and congestive heart failure, are associated with postoperative mortality. Renal failure and a history of renal transplantation also increase mortality. However, the effect of different stages of chronic kidney disease on patients' prognoses is unclear.

QUESTIONS/PURPOSES

(1) What is the risk of postoperative mortality in different stages of chronic kidney disease after elective hip or knee replacement and does the risk increase with mild renal insufficiency? (2) How severe is the risk of death in patients with chronic kidney disease compared with other major medical comorbidities such as diabetes, cardiovascular disease, and congestive heart failure? (3) Are there risk factor combinations associated with especially poor survival?

METHODS

Using longitudinally maintained databases, the records of 18,575 patients (median age 69 years, 63% female, median body mass index 29 kg/m) undergoing elective hip and knee replacements from a single center between 2002 and 2011 were analyzed in this retrospective study. A total of 6519 (35%) patients had Stage I, 9917 (53%) Stage II, 2023 (11%) Stage III, 81 (0.4%) Stage IV, and 35 (0.2%) Stage V chronic kidney disease. Kaplan-Meier analysis was used to analyze mortality at different stages of the disease. Cox regression analysis was performed to compare the risk of death associated with the comorbid conditions of interest. Comorbid conditions with greatest risk for death (diabetes, coronary artery disease, and congestive heart failure) were combined separately with chronic kidney disease using logistic regression. According to data from the Finnish Population Register Centre, a total of 4055 deaths occurred in our patient cohort during the followup period. The median followup was 7.8 years (range, 0-14 years; interquartile range, 5.8-10.0 years).

RESULTS

The mean survival time was 13 years (95% confidence interval [CI], 12.5-12.7 years) in Stage I, 11 years (95% CI, 11.3-11.5 years) in Stage II, 9 years (95% CI, 9.2-9.7 years) in Stage III, 7 years (95% CI, 5.6-7.5 years) in Stage IV, and 6 years (95% CI, 4.9-8.0 years) in Stage V (p < 0.001). Compared with Stage I chronic kidney disease, the risk of death increased with every step of the disease (adjusted hazard ratio [HR], 1.9 [95% CI, 1.76-2.10]; HR, 3.8 [95% CI, 3.39-4.19]; and HR, 8.1 [95% CI, 6.33-10.31] in Stages II, III, and IV-V, respectively). Compared with congestive heart failure (HR, 2.11 [95% CI, 1.81-2.45], p < 0.001), coronary disease (HR, 1.54 [95% CI, 1.40-1.69], p < 0.001), diabetes (HR, 1.71 [95% CI, 1.54-1.90], p < 0.001), and hypertension (HR, 1.35 [95% CI, 1.26-1.45], p < 0.001), Stage III and Stage IV to V chronic kidney disease are associated with poorer survival. The combination of chronic kidney disease and diabetes (odds ratio [OR], 8.15 [95% CI, 4.9-13.51]) had a synergistic effect on the risk of death compared with chronic kidney disease (OR, 2.36 [95% CI, 1.70-3.28]) or diabetes alone (OR, 1.19 [95% CI, 0.70-2.03]) during the first postoperative year.

CONCLUSIONS

All stages of chronic kidney disease have a harmful effect on long-term life expectancy in joint replacement recipients. The risk becomes clinically meaningful in the most severe forms of the disease, but also in moderate chronic kidney disease when it is accompanied by diabetes, coronary disease, or congestive heart failure. It should be recognized that these patients achieve fewer quality-adjusted life-years even if clinical outcomes were similar. The effect of chronic kidney disease on cost-effectiveness of hip and knee replacements should be investigated in future studies.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Prevention of Dislocation After Total Hip Arthroplasty

BACKGROUND

Prevention of dislocation after primary total hip arthroplasty (THA) begins with patient preoperative assessment and planning.

METHODS

We performed a literature search to assess historical perspectives and current strategies to prevent dislocation after primary THA. The search yielded 3458 articles, and 154 articles are presented.

RESULTS

Extremes of age, body mass index >30 kg/m², lumbosacral pathology, surgeon experience, and femoral head size influence dislocation rates after THA. There is mixed evidence regarding the effect of neuromuscular disease, sequelae of pediatric hip conditions, and surgical approach on THA instability. Sex, simultaneous bilateral THA, and restrictive postoperative precautions do not influence the dislocation rates of THA. Navigation, robotics, lipped liners, and dual-mobility acetabular components may improve dislocation rates.

CONCLUSIONS

Risks for dislocation should be identified, and measures should be taken to mitigate the risk. Reliance on safe zones of acetabular component positioning is historical. We are in an era of bespoke THA surgery.