Causes of death after total hip arthroplasty: a nationwide cohort study with 24,638 patients

Spinal surgery and the risk of reoperation after total hip arthroplasty: a cohort study based on Swedish spine and hip arthroplasty registers

BACKGROUND AND PURPOSE

Studies suggest increased revision risk of total hip arthroplasty (THA) in individuals with lumbar spinal fusion, but studies including non-fused individuals are lacking. We aimed to investigate whether individuals undergoing lumbar spinal stenosis surgery with or without fusion are at an increased risk of reoperation before or after THA.

PATIENTS AND METHODS

The Swedish Spine Register and the Swedish arthroplasty register were searched from 2000 through 2021. Chi-square, Kaplan-Meier and binary multivariate logistic regression were used to compare reoperation rates up to 10 years after THA surgery.

RESULTS

7,908 individuals had undergone lumbar spinal stenosis surgery (LSSS) (fusion n = 1,281) and THA. LSSS before THA compared with THA-only controls was associated with a higher risk of THA reoperations: 87 (2%) out of 3,892 vs. 123 (1%) out of 11,662 (P < 0.001). LSSS after THA compared with THA-only controls was not associated with a higher risk of reoperation, confirmed by Kaplan- Meier analyses and binary multivariate logistic regression. Mortality was lower in individuals undergoing both LSSS and THA, regardless of procedure order. There was no difference in THA reoperations in individuals who had undergone LSSS before THA without fusion or with fusion. The individuals who had undergone LSSS after THA with fusion had an increased risk of THA reoperation compared with those without fusion.

CONCLUSION

LSSS with or without fusion before THA is associated with an increased risk of THA reoperation. Spinal fusion increased the risk of reoperation of THA when performed after THA.

Site-specific cancer risk following cobalt exposure via orthopedic implants or in occupational settings: A systematic review and meta-analysis

In 2020, the European Commission up-classified metal cobalt as Class 1B Carcinogen (presumed to have carcinogenic potential) based primarily on data from rodent inhalation carcinogenicity studies. This up-classification requires an assessment under the Medical Device Regulations of cobalt cancer risk from medical devices. We performed a systematic review and meta-analysis to evaluate site-specific cancer risks with cobalt exposure from either total joint replacement (TJR) or occupational exposure (OC). Results were stratified by exposure type (OC or TJR), exposure level (metal-on-metal (MoM) or non-MoM), follow-up duration (latency period: <5, 5-10 or >10 years), and cancer incidence or mortality (detection bias assessment). From 30 studies (653,104 subjects, average 14.5 years follow-up), the association between TJR/OC and cancer risk was null for 22 of 27 cancer sites, negative for 3 sites, and positive for prostate cancer and myeloma. Significant heterogeneity and large estimate ranges were observed for many cancer sites. No significant increase in estimates was observed by exposure level or follow-up duration. The current evidence, including weak associations, heterogeneity across studies and no increased association with exposure level or follow-up duration, is insufficient to conclude that there exists an increased risk for people exposed to cobalt in TJR/OC of developing site-specific cancers.

Daily step counts and health-related quality of life before and after bilateral and unilateral total hip arthroplasty

Purpose: We examined and compared the daily step counts and health-related quality of life of patients before undergoing either bilateral or unilateral (with or without arthritis in the opposite joint) total hip arthroplasty (THA), and for 6 months afterwards.

Participants and Methods: Participants were patients who were living at home and were requested to wear accelerometers and log their daily step count preoperatively and again 6 months postoperatively. Additionally, they completed the Oxford Hip Score and EuroQol 5-Dimension questionnaires at both time points.

Results: Data from 40 patients were analyzed. Patients underwent bilateral total hip arthroplasty (n=13), unilateral total hip arthroplasty with arthritis in the opposite joint (n=13), and unilateral total hip arthroplasty without arthritis in the opposite joint (n=14). The Oxford Hip Score and EuroQol 5-Dimension score showed that the daily step counts of patients who underwent bilateral or unilateral total hip arthroplasty without arthritis in the opposite joint significantly increased postoperatively, but that of patients who received unilateral THA with arthritis in the opposite joint did not change significantly. The Oxford Hip Score indicated an improvement in hip joint function after surgery, but the EuroQol 5-Dimension score did not show a significant change postoperatively in patients who received bilateral total hip arthroplasty.

Conclusion: The pre- and postoperative comparisons of the participant’s daily step count after bilateral and unilateral operations without arthritis on the other side showed improvements in their amount of daily life activities. In all surgeries, Oxford Hip Score improvements were confirmed. The EuroQol 5-Dimension score of bilateral operations did not change. Bilateral operations and an understanding of unilateral postoperative qualitative support will be necessary in the future.

A prospective study on cancer risk after total hip replacements for 41,402 patients linked to the Cancer registry of Norway

BACKGROUND

Concerns have been raised that implants used in total hip replacements (THR) could lead to increased cancer risk. Several different materials, metals and fixation techniques are used in joint prostheses and different types of articulation can cause an increased invasion of particles or ions into the human body.

METHODS

Patients with THR registered in the Norwegian Arthroplasty Register during 1987-2009 were linked to the Cancer registry of Norway. Patients with THR due to osteoarthritis, under the age of 75 at time of surgery, were included. Standardized incidence ratios (SIR) were applied to compare cancer risk for THR patients to the general population. Types of THR were divided into cemented (both components), uncemented (both components), and hybrid (cemented femoral and uncemented acetabular components). To account for selection mechanisms, time dependent covariates were applied in Cox-regression, adjusting for cancer risk the first 10 years after surgery. The analyses were adjusted for age, gender and if the patient had additional THR-surgery in the same or the opposite hip. The study follows the STROBE guidelines.

RESULTS

Comparing patients with THR to the general population in Norway we found no differences in cancer risk. The overall SIR for the THR-patients after 10 years follow-up was 1.02 (95% CI: 0.97-1.07). For cemented THR, the SIR after 10 years follow-up was 0.99 (95% CI: 0.94-1.05), for uncemented, 1.16 (95% CI: 1.02-1.30), and for hybrid 1.12 (95% CI: 0.91-1.33). Adjusted Cox analyses showed that patients with uncemented THRs had an elevated risk for cancer (hazard ratio: HR = 1.24, 95% CI: 1.05-1.46, p = 0.009) when compared to patients with cemented THRs after 10 years follow-up. Stratified by gender the increased risk was only present for men. The risk for patients with hybrid THRs was not significantly increased (HR = 1.07, 95% CI: 0.85-1.35, p = 0.55) compared to patients with cemented THRs.

CONCLUSIONS

THR patients had no increased risk for cancer compared to the general population. We found, however, that receiving an uncemented THR was associated with a small increased risk for cancer compared to cemented THR in males, but that this may be prone to unmeasured confounding.

Geographical and ethnic differences of osteoarthritis-associated hip and knee replacement surgeries in New Zealand: a population-based cross-sectional study

OBJECTIVES

To (1) explore the regional and ethnic differences in rates of publicly funded osteoarthritis-associated hip and knee replacement surgeries and (2) investigate the mortality after surgery.

DESIGN

Population-based, retrospective, cross-sectional study.

SETTING

General population in New Zealand.

PARTICIPANTS

Patients with osteoarthritis who underwent publicly funded primary hip and knee replacement surgeries in 2005-2017. Patients aged 14-99 years were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

Age-standardised rate, standardised mortality ratio (SMR) and 30 days, 90 days and 1 year mortality.

RESULTS

We identified 53 439 primary hip replacements and 50 072 primary knee replacements with a diagnosis of osteoarthritis. The number and age-standardised rates of hip and knee replacements increased over time. Māori had the highest age-standardised rate of hip replacements, followed by European/others and Pacific, and Asian had the lowest rate. Pacific had the highest age-standardised rate of knee replacements, followed by Māori and European/others, and Asian had the lowest rate. The Northern Health Network had the lowest rate of hip surgeries, and the Southern Health Network had the lowest rate of knee surgeries. The SMRs of patients undergoing hip and knee replacements were lower than the general population: 0.92 (95% CI 0.89 to 0.95) for hip and 0.79 (95% CI 0.76 to 0.82) for knee. The SMRs were decreasing over time. The patterns of 30 days, 90 days and 1 year mortality were similar to the SMR.

CONCLUSIONS

The numbers of publicly funded osteoarthritis-associated primary hip and knee replacements are steadily increasing. Māori people had the highest age-standardised rate of hip replacements and Pacific people had the highest rate of knee replacements. The Northern Health Network had the lowest rate of hip surgeries, and the Southern Health Network had the lowest rate of knee surgeries. Compared with the general population, patients who had hip and knee replacements have a better life expectancy.

The Use of Aspirin for Prophylaxis Against Venous Thromboembolism Decreases Mortality Following Primary Total Joint Arthroplasty

BACKGROUND

The use of aspirin as prophylaxis against venous thromboembolism (VTE) following total joint arthroplasty (TJA) has increased in popularity; however, the potential cardioprotective effects of aspirin when administered as VTE prophylaxis remain unknown. The present study investigated the influence of VTE prophylaxis, including aspirin, on mortality following TJA.

METHODS

We retrospectively reviewed 31,133 patients who underwent primary TJA from 2000 to 2017. Patient demographics, body mass index, and comorbidities were obtained from an electronic chart query. Patients were allocated into 2 cohorts on the basis of the VTE prophylaxis administered: aspirin (25.9%, 8,061 patients) and non-aspirin (74.1%, 23,072 patients). Mortality was assessed with use of an institutional mortality database that is updated biannually. Univariate and multivariate regression analyses were performed.

RESULTS

The overall mortality rate was 0.2% and 0.6% at 30 days and 1 year after TJA, respectively. The use of aspirin was independently associated with lower risk of death at both 30 days (odds ratio [OR], 0.39; p = 0.020) and 1 year (OR, 0.51; p = 0.004). Patients in the non-aspirin cohort showed 3 times the risk of death at 30 days compared with the aspirin cohort (0.3% compared with 0.1%; p = 0.004), and twice the risk of death at 1 year (0.7% compared with 0.3%; p < 0.001). At 1 year, the primary cause of death in the non-aspirin group was cardiac-related (46 of 23,072, 0.20%). In the aspirin group, the rate of cardiac-related death was almost 5 times lower (3 of 8,061, 0.04%; p = 0.005). Risk factors for mortality at 1 year included higher age (p < 0.001), male sex (p = 0.020), history of congestive heart failure (p = 0.003), cerebrovascular disease (p < 0.001), malignancy (p < 0.001), and history of prior myocardial infarction (p < 0.001).

CONCLUSIONS

The present study demonstrates that the use of aspirin as prophylaxis against VTE following TJA may reduce the risk of mortality. Given the numerous options available and permitted by the current guidelines, orthopaedic surgeons should be aware of the potential added benefits of aspirin when selecting a VTE-prophylactic agent.

LEVEL OF EVIDENCE

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

Early death following revision total hip arthroplasty

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

CONTEXT

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

OBJECTIVE

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

DESIGN

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSION

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

Long-term Mortality After Revision THA

BACKGROUND

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

QUESTIONS/PURPOSES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

Level III, therapeutic study.

Cause-Specific Mortality Trends Following Total Hip and Knee Arthroplasty

BACKGROUND

While studies have demonstrated that mortality after total hip (THA) and total knee (TKA) arthroplasty is better than the general population, the causes of death are not well established. We evaluated cause-specific mortality after THA and TKA.

METHODS

The study included population-based cohorts of patients who underwent THA (N = 2019) and TKA (N = 2259) between 1969 and 2008. Causes of death were classified using the International Classification of Diseases 9th and 10th editions. Cause-specific standardized mortality ratios (SMR) and 95% confidence intervals (CI) were calculated by comparing observed and expected mortality. Expected mortality was derived from mortality rates in the United States white population of similar calendar year, age, and sex characteristics.

RESULTS

All-cause mortality was lower than expected following both THA and TKA. However, there was excess mortality due to mental diseases such as dementia following both THA (SMR 1.40, 95% CI 1.08, 1.80) and TKA (SMR 1.49, 95% CI 1.19, 1.85). There was also excess mortality from inflammatory musculoskeletal diseases in THA (SMR 3.50, 95% CI 2.11, 5.46) and TKA (SMR 4.85, 95% CI 3.29, 6.88). When the cohorts were restricted to patients with osteoarthritis as the surgical indication, the excess risk of death from mental diseases still persisted in THA (SMR 1.36, 95% CI 1.02, 1.78) and TKA (SMR 1.52, 95% CI 1.20, 1.91).

CONCLUSION

THA and TKA patients experience a higher risk of death from mental and inflammatory musculoskeletal diseases. These findings warrant further research to identify drivers of mortality and prevention strategies in arthroplasty patients.

In-Hospital Mortality in Patients With Periprosthetic Joint Infection

BACKGROUND

While periprosthetic joint infection (PJI) has a huge impact on patient function and health, only a few studies have investigated its impact on mortality. The purpose of this large-scale study was to (1) determine the rate and trends of in-hospital mortality for PJI and (2) compare the in-hospital mortality rate of patients with PJI and those undergoing revision arthroplasty for aseptic failure and patients undergoing other nonorthopedic major surgical procedures.

METHODS

Data from the Nationwide Inpatient Sample from 2002 to 2010 were analyzed to determine the risk of in-hospital mortality for PJI patients compared with aseptic revision arthroplasty. The Elixhauser comorbidity index was used to obtain patient comorbidities. Multiple logistic regression analyses were used to examine whether PJI and other patient-related factors were associated with mortality.

RESULTS

PJI was associated with an increased risk (odds ratio, 2.05; P < .0001) of in-hospital mortality (0.77%) compared with aseptic revisions (0.38%). The in-hospital mortality rate of revision total hip arthroplasties with PJI was higher than those for interventional coronary procedures (1.22%; 95% confidence interval [CI], 1.20-1.24), cholecystectomy (1.13%; 95% CI, 1.11-1.15), kidney transplant (0.70%; 95% CI, 0.61-0.79), and carotid surgery (0.89%; 95% CI, 0.86-0.93).

CONCLUSION

Patients undergoing treatment for PJI have a 2-fold increase in in-hospital mortality for each surgical admission compared to aseptic revisions. Considering that PJI cases often have multiple admissions and that this analysis is by surgical admission, the risk of mortality will accumulate for every additional surgery. Surgeons should be cognizant of the potentially fatal outcome of PJI and the importance of infection control to reduce the risk of mortality.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Early death following primary total hip arthroplasty

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

Mortality after total hip replacement surgery: A systematic review

Total hip replacement causes a short-term increase in the risk of mortality. It is important to quantify this and to identify modifiable risk factors so that the risk of post-operative mortality can be minimised. We performed a systematic review and critical evaluation of the current literature on the topic. We identified 32 studies published over the last 10 years which provide either 30-day or 90-day mortality data. We estimate the pooled incidence of mortality during the first 30 and 90 days following hip replacement to be 0.30% (95% CI 0.22 to 0.38) and 0.65% (95% CI 0.50 to 0.81), respectively. We found strong evidence of a temporal trend towards reducing mortality rates despite increasingly co-morbid patients. The risk factors for early mortality most commonly identified are increasing age, male gender and co-morbid conditions, particularly cardiovascular disease. Cardiovascular complications appear to have overtaken fatal pulmonary emboli as the leading cause of death after hip replacement.

Cite this article: Bone Joint Res 2014;3:175–82.

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

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

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

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

Risk factors for early mortality following modern total hip arthroplasty

The aim of this study was to evaluate the incidence of early mortality and identify risk factors for early death following modern uncemented THA. Between 2000 and 2006, we identified patients who died within 90days of THA. Demographics, comorbidities, laboratory studies, and complications were analyzed as risk factors for mortality. 38 of 8261 patients undergoing THA (0.46%) died within 90days postoperatively. Of these, 26% were due to myocardial infarction. Multivariate analysis revealed Charlson index >3, peripheral vascular disease, elevated postoperative glucose, and abnormal postoperative cardiac studies as independent predictors of early mortality following THA. Caution should be taken in patients with increased comorbidities, PVD, perioperative hyperglycemia, and impaired renal function in order to reduce mortality following THA.

Early death following primary total knee arthroplasty

BACKGROUND

Total knee arthroplasty carries major risks, including death. Conventional studies have compared the mortality rate following total knee arthroplasty with standardized mortality ratios or age and sex-matched populations. The purpose of the present study was to compare the mortality rate in a population of patients who were managed with total knee arthroplasty with that in patients who were awaiting surgery.

METHODS

All patients undergoing primary total knee arthroplasty from 2000 to 2007 at a single institution were recorded. In the same period, all patients who were added to the waiting list for total knee arthroplasty were recorded. The mortality rate and time to death were calculated, and death certificates were retrieved for those who died within thirty or ninety days after the index event.

RESULTS

Two thousand, six hundred and ninety-five patients undergoing primary total knee arthroplasty were used for the thirty-day mortality calculation, and 2527 were used for the ninety-day mortality calculation. These patients were compared with 5857 and 5689 patients who were added to the waiting list for the thirty-day and ninety-day mortality calculations, respectively. There was no difference between the populations in terms of age or sex (p > 0.05). The thirty-day mortality following surgery was significantly greater for the surgery group (0.371%; 95% confidence interval, 0.202% to 0.682%) than for the waiting list group (0.0683%; 95% confidence interval, 0.0266% to 0.1755%) (odds ratio, 5.45; 95% confidence interval, 1.81 to 16.43). The ninety-day mortality was also significantly greater for the surgery group (0.792%; 95% confidence interval, 0.513% to 1.219%) than for the waiting list group (0.387%; 95% confidence interval, 0.256% to 0.585%) (odds ratio, 2.05; 95% confidence interval, 1.13 to 3.74).

CONCLUSIONS

Primary total knee arthroplasty is associated with an increased risk of death at thirty and ninety days after the operation when compared with a population awaiting the same procedure. Increasing age was a risk factor for death following total knee arthroplasty.

Perioperative management of diabetes and hyperglycemia in patients undergoing orthopaedic surgery

Persons with diabetes undergo more surgical procedures, have a higher perioperative risk of complications, and have longer hospital stays than do persons who do not have diabetes. Persons with diabetes are frequently overweight, have a high prevalence of cardiovascular risk factors, and are more likely to suffer from chronic musculoskeletal conditions and traumatic injuries that require orthopaedic attention. Surgery frequently disrupts usual diabetes management, requiring adjustments to the treatment regimen. Suboptimal perioperative glucose control may contribute to increased morbidity, and it aggravates concomitant illnesses. Many patients undergoing elective or urgent orthopaedic surgery may have unrecognized diabetes or may develop stress-related hyperglycemia in the hospital. The challenge is to minimize the effects of metabolic derangements on surgical outcomes, reduce glycemic excursions, and prevent hypoglycemia. Recent guidelines advocate evidence-based glucose targets in the inpatient setting, and regimens for intravenous and subcutaneous insulin are gaining in popularity. Individualized treatment should be based on the ambient level of glycemic control, outpatient treatment regimen, presence of complications, nature of the surgical procedure, and type of anesthesia administered. Management by a multidisciplinary team and attention to discharge planning are key aspects of care during and after orthopaedic surgery.

A retrospective comparative study of mortality and causes of death among patients with metal-on-metal and metal-on-polyethylene total hip prostheses in primary osteoarthritis after a long-term follow-up

Background

All patients with total hip arthroplasty (THA), especially those with metal-on-metal (MM) THA, are exposed to metallic particles and ions, which may cause total or site-specific mortality. We analyzed the causes of total and site-specific mortality among a cohort of patients with MM and with metal-on-polyethylene (MP) THA after a long follow-up time.

Methods

Standardized mortality ratios (SMR) of total and site-specific causes of death were calculated for 579 patients with MM (McKee-Farrar) and 1585 patients with MP (Brunswik, Lubinus) THA for primary osteoarthritis.

Results

Mean follow-up time was 17.9 years for patients with MM and 16.7 years for patients with MP. Overall SMR was 0.95 for the MM cohort and 0.90 for the MP cohort, as compared to the normal population. Both cohorts showed significantly decreased mortality for the first decade postoperatively, equal mortality over the next 10 years, and significantly increased mortality after 20 years. Patients with MM THA had higher cancer mortality (SMR 1.01) than those with MP THA (SMR 0.66) during the first 20 years postoperatively, but not thereafter.

Conclusion

Both MM and MP prostheses are safe based on total and site-specific mortality of recipients during the first 20 postoperative years in comparison with the general population.

VKORC1 variant genotypes influence warfarin response in patients undergoing total joint arthroplasty: a pilot study

Warfarin dosing algorithms do not account for genetic mutations that can affect anticoagulation response. We retrospectively assessed to what extent the VKORC1 variant genotype would alter the likelihood of being a hyperresponder or hyporesponder to warfarin in patients undergoing total joint arthroplasty. We used the international normalized ratio (INR) on the third postoperative day of 3.0 or greater to define warfarin hyperresponders and 1.07 or less to define hyporesponders. A control group of normal responders was identified. From a cohort of 1125 patients receiving warfarin thromboprophylaxis, we identified 30 free of predisposing factors that could affect warfarin response: 10 hyperresponders, eight hyporesponders, and 12 normal responders. Homozygous carriers of the VKORC1 mutant AA genotype were more likely (compared with carriers of GA or GG genotypes) to be hyperresponders (odds ratio, 7.5; 95% confidence interval, 1.04-54.1). Homozygous carriers of the GG (normal) genotype were more likely (compared with carriers of AA or GA genotypes) to be hyporesponders (odds ratio, 9; 95% confidence interval, 1.14-71). Preoperative screening for the VKORC-1 genotype could identify patients with a greater potential for being a hyperresponder or hyporesponder to warfarin. This may allow an adjusted pharmacogenetic-based warfarin dose to optimize anticoagulation, reducing postoperative risks of bleeding and thrombosis or embolism.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Early mortality after modern total hip arthroplasty

Because of improvements in surgical technique, anesthesia, and rehabilitation, mortality after hip arthroplasty may be on the decline. The purpose of this study was to determine the 90-day mortality rate after uncemented total hip arthroplasty (THA) performed under regional anesthesia. We retrospectively reviewed 7478 consecutive patients undergoing cementless primary or revision THA between January 2000 and July 2006. Patient survivorship was established and causes of death were obtained by accessing the Social Security Death Index, Centers for Disease Control and Prevention National Death Index, and State Departments of Vital Statistics. There were two intraoperative deaths from cardiac arrest. The overall 30- and 90-day mortality rates were 0.24% (18 of 7478) and 0.55% (41 of 7478), respectively. Thirty-day mortality after primary THA was low at 0.13% (eight of 6272). The most common cause of death was cardiovascular-related. Mortality after modern THA seems to have remained very low despite the availability of this procedure to patients of all ages and comorbidities.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Life expectancy after lumbar spine surgery: one- to eleven-year follow-up of 1015 patients

STUDY DESIGN

Retrospective study.

OBJECTIVES

To investigate the 10-year survival of a large number of elderly patients who underwent spine surgery for lumbar spinal stenosis, and to identify significant risk factors and compare them with age- and gender-matched controls from the general population.

SUMMARY OF BACKGROUND DATA

There have been many studies on treatment options and surgical outcomes for lumbar spinal stenosis. However, survival outcomes after lumbar spinal stenosis surgery have not previously been studied. Because these operations are usually performed for elderly patients, we consider patient survival or life expectancy to be a significant outcome measure.

METHODS

Between January 1997 and June 2006, patients underwent spine surgery for lumbar spinal stenosis. The date of death was verified using records from the National Health Insurance Corporation. Cumulative 10-year survival was calculated using the Kaplan-Meier method, and the survival of patients who had undergone spine surgery was compared to that of age- and sex-matched members of the general population. A Cox multivariate regression analysis was used in order to compare the survival rates for different covariates.

RESULTS

Using Kaplan-Meier curves, the overall 10-year survival was 87.8% in patients 60 to 70 years old at surgery, and 83.8% in patients 70 to 85 years old at surgery. The 10-year survival rate of female patients and patients who underwent fusion surgery were higher than those of male patients and patients with nonfusion surgery. Compared to the adjusted corresponding portion in general population, the standardized mortality ratios were 0.21, 0.53, and 0.45 in patients aged 50 to 59, 60 to 69, and 70 to 85, respectively.

CONCLUSION

Elderly patients who underwent spine surgery for spinal stenosis had reduced mortality compared to the corresponding portion of the general population. Therefore, surgery for spinal stenosis is a justifiable procedure even in elderly patients.

The impact of diabetes on perioperative patient outcomes after total hip and total knee arthroplasty in the United States

The purpose of this study was to determine whether patients with diabetes mellitus (DM) have a higher likelihood of immediate, inpatient complications following primary and revision total hip (THA) and total knee arthroplasty (TKA) than patients without DM. From 1988 to 2003, the Nationwide Inpatient Sample identified 751340 primary or revision THA or TKA patients. 64262 (8.55%) had DM. Comparisons of specific outcome measures between diabetic and nondiabetic cohorts were performed using bivariate and multivariate analyses with logistic regression modeling. Diabetic patients had fewer routine discharges and higher inflation-adjusted hospital charges for all procedures. Although complications were not uniformly increased, diabetic patients had significantly increased odds of pneumonia, stroke, and transfusion (P < .001) after primary arthroplasty. This analysis of a large patient database indicates clinically relevant information for patients and surgeons, suggesting that patients undergoing THA and TKA demonstrate more complications and utilize more resources if they have the comorbidity of DM level II evidence.

Ten-year life expectancy after primary total hip replacement

We determined the ten-year life expectancy of 5831 patients who had undergone 6653 elective primary total hip replacements at a regional orthopaedic centre between April 1993 and October 2004. Using hospital, general practitioner and the local health authority records, we recorded the dates of death for those who died following surgery. The mean age at operation was 67 years (13 to 96) with a male:female ratio of 2:3. Of 1154 patients with a ten-year follow-up 340 (29.5%) had died a mean of 5.6 years (0 to 10) after surgery. Using Kaplan-Meier curves, the ten-year survival was 89% in patients under 65 years at surgery, 75% in patients aged between 65 and 74 years, and 51% in patients over 75. The standardised mortality rates were considerably higher for patients under 45 years, 20% higher for those between 45 and 64 years, and steadily reduced in patients aged 65 and over. The survival of cemented hip replacement derived from the Swedish Hip Arthroplasty Register Annual Report 2004 exceeds the life expectancy of patients over the age of 60 in our area, suggesting that cemented hip replacement is the procedure of choice in this population.

The 2007 Otto Aufranc Award. Ceramic-on-metal hip arthroplasties: a comparative in vitro and in vivo study

The performance of novel ceramic-on-metal bearing couples has been compared with metal-on-metal and ceramic-on-ceramic bearing couples in laboratory and short-term clinical studies. Laboratory studies compared ceramic-on-metal with metal-on-metal and ceramic-on-ceramic bearings with diameters of 28 and 36 mm under standard conditions and under adverse conditions with head loading on the rim of the cup. Clinical studies compared metal ion levels in ceramic-on-metal with metal-on-metal, ceramic-on-ceramic, and ceramic-on-polyethylene bearings in a randomized prospective study. In the laboratory studies, friction, wear, and ion levels were lower in ceramic-on-metal bearings compared with metal-on-metal, with results similar to ceramic-on-ceramic couples. Under adverse conditions and rim loading, all bearings showed increased wear with lower wear and absence of stripe wear in ceramic-on-metal compared with metal-on-metal bearings. Short-term studies in 31 patients at 6 months revealed lower metal ion levels (cobalt and chromium) in those with ceramic-on-metal compared with metal-on-metal bearings.

Increased long-term mortality in patients less than 55 years old who have undergone knee replacement for osteoarthritis: results from the Swedish Knee Arthroplasty Register

Patients with osteoarthritis undergoing knee replacement have been reported to have an overall reduced mortality compared with that of the general population. This has been attributed to the selection of healthier patients for surgery. However, previous studies have had a maximum follow-up time of ten years. We have used information from the Swedish Knee Arthroplasty Register to study the mortality of a large national series of patients with total knee replacement for up to 28 years after surgery and compared their mortality with that of the normal population. In addition, for a subgroup of patients operated on between 1980 and 2002 we analysed their registered causes of death to determine if they differed from those expected. We found a reduced overall mortality during the first 12 post-operative years after which it increased and became significantly higher than that of the general population. Age-specific analysis indicated an inverse correlation between age and mortality, where the younger the patients were, the higher their mortality. The shift at 12 years was caused by a relative over-representation of younger patients with a longer follow-up. Analysis of specific causes of death showed a higher mortality for cardiovascular, gastrointestinal and urogenital diseases. The observation that early onset of osteoarthritis of the knee which has been treated by total knee replacement is linked to an increased mortality should be a reason for increased general awareness of health problems in these patients.

Total joint arthroplasties: current concepts of patient outcomes after surgery

Total hip and knee arthroplasties are effective surgical interventions for relieving hip pain and improving physical function caused by arthritis. Although the majority of patients substantially improve, not all report gains or are satisfied after receiving total joint arthroplasty. This article reviews the literature on patient outcomes after total hip and knee arthroplasties for osteoarthritis, and the evidence pertaining to factors that affect these patient-centered outcomes. Mounting evidence suggests that no single patient-related or perioperative factor clearly predicts the amount of pain relief or functional improvement that will occur following total hip or knee arthroplasty.

The effect of co-morbidities on health-related quality of life in patients placed on the waiting list for total joint replacement

Background

Co-morbidity is a powerful predictor of health care outcomes and costs, as well as an important cofounder in epidemiologic studies. The effect of co-morbidities is generally related to mortality or complications. This study evaluated the association between co-morbidity and health-related quality of life (HRQoL) in patients awaiting total joint replacement.

Methods

A total of 893 patients were recruited to the study between August 2002 and November 2003 in four Finnish hospitals. The effect of co-morbidity on HRQoL was measured by the generic 15D instrument and by a Visual Analog Scale (VAS). Comparative variance analysis of socio-demographic and clinical characteristics was described by using either an independent samples t-test or the Chi-square test. The differences in each of the 15D dimensions and the overall 15D single index score for patients were calculated. Two-sided p-values were calculated with the Levene Test for Equality of Variances.

Results

Patients with co-morbidity totaled 649; the incidence of co-morbidity was 73%. The mean number of co-morbidities among the patients was two. At baseline the 15D score in patients with and without co-morbidity was 0.778 vs 0.816, respectively. The difference of the score (0.038) was clinically and statistically significant (P < 0.001). The patients' scores with and without co-morbidity on the different 15D dimensions related to osteoarthritis-moving, sleeping, usual activities, discomfort and symptoms, vitality and sexual activity–were low in both groups. Patients with co-morbidity scored lower on the dimensions of moving, vitality and sexual activity compared to the patients without co-morbidity. Co-morbidity was significantly associated with a reduced HRQoL. Patients without co-morbidity had poorer VAS, arthritis had strong effect to their quality of life compared to the patients with co-morbidity.

Conclusion

Assessing co-morbidity in patients placed on the waiting list for joint replacement may be useful method to prioritization in medical decision-making for healthcare delivery. The assessment of co-morbidities during waiting time is important as well as evaluating how the co-morbidity may affect the final outcomes of the total joint replacement.

Ninety-day mortality after bilateral hip arthroplasty

Despite lack of any studies, to our knowledge, bilateral total hip arthroplasty (THA) is believed to carry higher perioperative mortality. The purpose of this study is to investigate the incidence of mortality within 90 days of bilateral THA in a major urban medical center. The incidence of 90-day mortality after 1-stage bilateral THA performed in 707 patients between 1995 and 2004 was evaluated. A detailed analysis of our database was performed to determine which bilateral THA patients died within 90 days of surgery. Every living patient who had undergone bilateral hip arthroplasty was contacted. One patient (0.14%, 1/707) died within 90 days of 1-stage bilateral THA. The patient developed spontaneous retroperitoneal hematoma requiring massive transfusion. The patient died of multisystem failure 35 days after undergoing bilateral THA. One-stage bilateral uncemented THA performed in a select group of healthy and young patients carries an acceptable risk.

Ninety-day mortality after hip arthroplasty: a comparison between unilateral and simultaneous bilateral procedures

This study compares the 90-day mortality of unilateral total hip arthroplasty (THA) with simultaneous bilateral THA. Patient demographics, cause of death, and risk factors for mortality after THA were investigated. A total of 6258 patients (6791 hips) received primary THA using uncemented prostheses from 1995 to 2002. There were 5725 (91%) patients who received unilateral THA, whereas 533 (9%) patients underwent simultaneous bilateral THA. Of 6258 patients, 10 (0.16%) died within 90 days of THA, none of whom underwent simultaneous bilateral THA (0%, 0/533). Simultaneous bilateral uncemented THA performed in a select group of patients carries no greater perioperative mortality rate than unilateral THA.

Pain and overall health status in older people with hip and knee replacement: a population perspective

OBJECTIVE

To investigate the health-related quality of life and presence of hip or knee pain according to whether or not people had had previous hip or knee arthroplasty.

STUDY DESIGN AND SETTING

Cross-sectional survey representing randomly selected sample of 5500 elderly (65+) people. Pain prevalence rates obtained from standard screening questions. Standard pain severity ratings obtained for each hip and knee.

RESULTS

People with a past arthroplasty had worse health status compared to other people (p < 0.001 for all but two SF-36 dimensions). Hip or knee pain was more prevalent amongst people with past hip or knee replacement than amongst those without (62.5% versus 36.5% respectively; following adjustment for age and sex: Mantel-Haenszel combined odds ratio = 2.90, 95% CI 2.30-3.68, p < 0.001). More replaced knee joints were symptomatic than replaced hip joints (OR = 1.62, p = 0.022).

CONCLUSIONS

Elderly people with a past hip or knee arthroplasty have significantly greater health and social care needs than other people--especially those related to pain and mobility. This may reflect the generalised nature of the underlying disease process.

Cancer incidence and causes of death among total hip replacement patients: A review based on Nordic cohorts with a special emphasis on metal-on-metal bearings

All patients with total hip arthroplasty (THA) are exposed to soluble or particulate forms of Co and Cr. Adverse effects of these wear products are not known. Data from Nordic registries is used to estimate adverse effects on a large scale, based mostly on metal-on-polyethylene bearings. Cancer incidence was in line with the general population when the patients were operated on for all indications and significantly decreased when the indication was primary osteoarthritis. Stomach cancer and colorectal cancers were significantly reduced and prostate cancer and skin melanoma significantly increased. There was no significant excess of cancer in target organs, i.e. liver, kidney, or haematopoietic cancers. THA patients had reduced mortality and extended life expectancy compared with standard Nordic populations.

All-site cancer incidence of the first-generation metal-on-metal McKee-Farrar patients operated on for primary osteoarthritis was in line with the general population after follow-up for up to 28 years. General mortality of these patients was also reduced and they also had an extended life expectancy.

Temporary increases in haematopoietic cancers at different follow-up periods were seen in some cohorts. This malignancy deserves a special record linkage monitoring while large numbers of young patients are provided with the second generation of metal-on-metal prostheses.

Total Joint Arthroplasties: Current Concepts of Patient Outcomes after Surgery

Total hip and knee arthroplasties are effective surgical interventions for relieving pain and improving physical function caused by arthritis. Although the majority of patients substantially improve, not all reports gains or are satisfied after receiving a total joint arthroplasty. This article reviews the literature on patient outcomes after total hip and knee arthroplasties for osteoarthritis and the evidence pertaining to factors that affect these patient-centered outcomes. Mounting evidence suggests that no one patient-related or peri-operative factor clearly predicts the amount of pain relief or functional improvement that will occur following total hip or knee arthroplasty.

Arthroplasty in the octogenarian: quantifying the risks

The objective of this study was to determine the risk of complications after primary total hip and knee arthroplasties in octogenarians. Using administrative data, we compared the rate of complications for octogenarians vs patients aged 65 to 79 years who underwent total hip or knee arthroplasty in Ontario between 1993 and 1997. Octogenarians were 3.4 times more likely to die, 2.7 times more likely to sustain a myocardial infarction, and 3.5 times more likely to develop pneumonia. Postoperative confusion and urinary tract infections were also significantly more common in octogenarians. Octogenarians are at higher risk for death and serious complications after primary joint arthroplasty. However, the overall event rate remains low and total joint arthroplasty surgery should continue to be offered to these individuals provided that the complication rates are acceptable to the patients and their families.