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

Comparison of current relative value unit-based prices and utility between common surgical procedures, including orthopedic surgeries, in South Korea

BACKGROUND

The medical pricing system strongly influences physicians' job satisfaction and patient health outcomes. This study aimed to investigate the current relative value unit (RVU)-based pricing and utility of patients in commonly performed surgical procedures in South Korea.

METHODS

Fifteen common surgical procedures were selected from OECD statistics, and three additional orthopedic procedures were examined. The current pricing of each surgical procedure was retrieved from the Korea National Health Insurance Service, and the corresponding utilities were obtained as quality-adjusted life year (QALY) gains from previous studies. The relationship between the current prices (RVUs) and the patients' utility (incremental QALY gains/year) was analyzed. Subgroup analysis was performed between fatal and non-fatal procedures and between orthopedic and non-orthopedic procedures.

RESULTS

A significant negative correlation (r = - 0.558, p < 0.001) was observed between RVU and incremental QALY among all 18 procedures. The fatal subgroup had a significantly higher RVU than the non-fatal subgroup (p < 0.05), while the former had a significantly lower incremental QALY than the latter (p < 0.001). Orthopedic procedures showed higher incremental QALY values than non-orthopedic procedures, but they did not show higher prices (RVU).

CONCLUSIONS

This paradoxical relationship between current prices and patient utility is attributed to the higher pricing of surgical procedures for fatal and urgent conditions. Orthopedic surgery has been found to be a cost-effective treatment strategy. These findings could contribute to a better understanding of the potential role of incremental QALY in pursuing value-based purchasing or reasonable modification of the current medical fee schedule.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

III.

Assessing the Mortality Rate After Primary Total Knee Arthroplasty: An Observational Study to Inform Future Economic Analysis

BACKGROUND

Previous research has focused on the perioperative or short-term (<1 year) mortality rate of total knee arthroplasty (TKA), leaving the long-term (>1 year) mortality rate unresolved. In this study, we calculated the mortality rate up to 15 years after primary TKA.

METHODS

Data from the New Zealand Joint Registry from April 1998 to December 2021 were analyzed. Patients aged 45 years or older who underwent TKA for osteoarthritis were included. Mortality data were linked with national records from births, deaths, and marriages. To determine the expected mortality rates in the general population, age-sex-specific life tables from statistics New Zealand were used. Mortality rate was presented as standardized mortality ratios (SMRs) - a comparison of relative mortality rate between the TKA and general populations. In total, 98,156 patients with a median follow-up of 7.25 years (range, 0.00 to 23.74) were included.

RESULTS

Over the entire follow-up period, 22,938 patients (23.4%) had died. The overall SMR for the TKA cohort was 1.08 (95% confidence interval (CI): 1.06 to 1.09), suggesting that TKA patients have an 8% higher mortality rate compared to the general population. However, a reduction in short-term mortality rate was observed for TKA patients up to 5 years post TKA (SMR 5 years post TKA; 0.59 95% CI: 0.57 to 0.60]). On the contrary, a significantly increased long-term mortality rate was observed in TKA patients with greater than 11 years of follow-up, particularly in men over the age of 75 years (SMR 11 to 15 years post TKA for males ≥ 75 years; 3.13 [95% CI: 2.95 to 3.31]).

CONCLUSION

The results suggest a reduction in short-term mortality rate for patients who undergo primary TKA. However, there is an increased long-term mortality rate particularly in men over the age of 75 years. Importantly, the mortality rates observed in this study cannot be causally attributed to TKA alone.

Increase in Postoperative Body Mass Index in Patients After Total Knee Arthroplasty

Objectives The aim of this is to investigate the changes in body mass index (BMI) following knee arthroplasty and to evaluate their impact on patient-reported outcomes and functional evaluations. Methods This observational study included 90 patients who underwent total knee arthroplasty (TKA) and were followed up for a median period of 2.6 years. BMI measurements were recorded before and after surgery, and patient-reported outcomes and functional evaluations were assessed using standardized scales and tests. Results Following TKA, BMI increased statistically significantly (Wilcoxon signed-rank test, p < 0.000). In addition, half of the patients experienced an increase in BMI, with 32% moving up in their BMI category. However, there were no clinically significant differences in patient-reported outcomes or functional evaluations between the group that gained BMI and the group that maintained or lost BMI. Conclusion This study reveals that patients tend to have increased BMI following TKA. However, these BMI changes do not significantly impact patient-reported outcomes or functional evaluations. It underscores the importance of patient education regarding healthy lifestyle habits, including diet and physical activity, to address postoperative weight gain effectively.

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

BACKGROUND

Perioperative medical management during total hip arthroplasty (THA) is continuously improving, allowing an increasing number of medically complex patients to undergo total joint arthroplasty. This study examined mortalities, medical complications, implant survivorships, and clinical outcomes of THA in patients who have pulmonary hypertension (HTN).

METHODS

We identified 638 patients who had pulmonary HTN and underwent 508 primary THAs and 191 revision THAs from 2000 to 2016 at a tertiary care center. Patients were followed up at regular intervals until death, revision surgery, or last clinical follow-up. Perioperative medical complications were individually reviewed. The risk of death was examined by calculating standardized mortality ratios and Cox proportional hazards regression models. Cumulative incidence analyses were used for reporting mortality, reoperation, and revision with death as a competing risk.

RESULTS

The 90-day mortality was 1.8% and 3.1% for primary and revision THAs, respectively. The risk of death was approximately two-fold higher compared to primary (hazard ratio 2.69) and revision (hazard ratio 2.04) THA patients who did not have pulmonary HTN. Rate of medical complications within 90 days from surgery were 6.2% and 13.1% in primary and revision THAs, respectively. The 10-year cumulative incidence of any revision was 9% and 14% following primaries and revisions, respectively.

CONCLUSION

Patients who had pulmonary HTN undergoing primary and revision THAs had an increased risk of death and experienced a high rate of medical complications within 90 days of surgery. Counseling of risks, medical optimization, and referral to medical centers expert at managing complex medical problems should be considered.

LEVEL OF EVIDENCE

Level IV.

Spinal versus general anaesthesia in contemporary primary total knee arthroplasties

Aims

Spinal anaesthesia has seen increased use in contemporary primary total knee arthroplasties (TKAs). However, controversy exists about the benefits of spinal in comparison to general anaesthesia in primary TKAs. This study aimed to investigate the pain control, length of stay (LOS), and complications associated with spinal versus general anaesthesia in primary TKAs from a single, high-volume academic centre.

Methods

We retrospectively identified 17,690 primary TKAs (13,297 patients) from 2001 to 2016 using our institutional total joint registry, where 52% had general anaesthesia and 48% had spinal anaesthesia. Baseline characteristics were similar between cohorts with a mean age of 68 years (SD 10), 58% female (n = 7,669), and mean BMI of 32 kg/m2 (SD 7). Pain was evaluated using oral morphine equivalents (OMEs) and numerical pain rating scale (NPRS) data. Complications including 30- and 90-day readmissions were studied. Data were analyzed using an inverse probability of treatment weighted model based on propensity score that included many patient and surgical factors. Mean follow-up was seven years (2 to 18).

Results

Patients treated with spinal anaesthesia required fewer postoperative OMEs (p < 0.001) and had lower NPRS scores (p < 0.001). Spinal anaesthesia also had fewer cases of altered mental status (AMS; odds ratio (OR) 1.3; p = 0.044), as well as 30-day (OR 1.4; p < 0.001) and 90-day readmissions (OR 1.5; p < 0.001). General anaesthesia was associated with increased risk of any revision (OR 1.2; p = 0.021) and any reoperation (1.3; p < 0.001).

Conclusion

In the largest single institutional report to date, we found that spinal anaesthesia was associated with significantly lower OME use, lower risk of AMS, and lower overall 30- and 90-day readmissions following primary TKAs. Additionally, spinal anaesthesia was associated with reduced risk of any revision and any reoperation after accounting for numerous patient and operative factors. When possible and safe, spinal anaesthesia should be considered in primary TKAs. Cite this article: Bone Joint J 2022;104-B(11):1209–1214.

Administrative Data Use in National Registry Efforts: Blessing or Curse?

"Big data" refers to a growing field of large database research. Administrative data, a subset of big data, includes information from insurance claims, electronic medical records, and registries that can be useful for investigating novel research questions. While its use provides salient advantages, potential researchers relying on big data would benefit from knowing about how these databases are coded, common errors they may encounter, and how to best use large data to address various research questions. In the first section of this paper, Dr. Nicholas A. Bedard addresses the four major pitfalls to avoid with diagnosis and procedure codes in administrative data. In the next section, Dr. Jeffrey N. Katz et al. focus on the strengths and limitations of administrative data, suggesting methods to mitigate these limitations. Lastly, Dr. Elena Losina et al. review the uses and misuses of large databases for cost-effectiveness research, detailing methods for careful economic evaluations.

Antimicrobial PMMA Bone Cement Containing Long Releasing Multi-Walled Carbon Nanotubes

Prosthetic joint infections (PJIs) ensued from total joint replacement (TJR) pose a severe threat to patients that involve poor health outcomes, severe pain, death (in severe cases), and negative influence patients' quality of life. Antibiotic-loaded bone cement (ALBC) is frequently used for the prevention and treatment of PJI. This work aims to study gentamicin release from carbon nanotubes (CNTs) incorporated in polymethyl methacrylate (PMMA) bone cement to prolong release over several weeks to provide prophylaxis from PJIs after surgery. Different CNT concentrations were tested with the presence of gentamicin as a powder or preloaded onto carboxyl functionalized CNTs. The different types of bone cement were tested for drug release, mechanical properties, water uptake, antimicrobial properties, and cytocompatibility with human osteoblast cells (MTT, LDH, alizarin red, and morphology). Results showed prolonged release of gentamicin from CNT-loaded bone cements over several weeks compared to gentamicin-containing bone cement. Additionally, the presence of CNT enhanced the percentage of gentamicin released without adversely affecting the nanocomposite mechanical and antimicrobial properties needed for performance. Cytotoxicity testing showed non-inferior performance of the CNT-containing bone cement to the equivalent powder containing cement. Therefore, the developed nanocomposites may serve as a novel PMMA bone cement to prevent PJIs.

In-Hospital Mortality Is Associated With Low-Volume Hip Revision Centers After Septic Revision Total Hip Arthroplasty

Revision total hip arthroplasty (rTHA) after septic failure is associated with higher morbidity and mortality compared with aseptic revisions. The goals of this study were to characterize (1) the in-hospital mortality rate for patients with septic rTHA, (2) the effect of hospital hip revision surgery volume (HRV) on mortality after septic rTHA, and (3) the independent risk factors associated with in-hospital mortality rates after rTHA with 2-year follow-up. The authors analyzed the Healthcare Cost and Utilization Project State Inpatient Databases of New York and Florida to identify cases of septic rTHA from 2007 to 2012 with International Classification of Diseases, Ninth Revision, codes. The authors included patients with (1) no history of THA for 2 years before the index admission and (2) 2 years of follow-up. Groups with primary THA and aseptic rTHA were identified as control groups. Logistic regression was used to evaluate independent associations. Of 3057 patients with septic rTHA, 5.2% (n=160) had in-hospital mortality vs 2.9% of those with primary THA (n=3525, P=.0001) and 2.1% of those with aseptic rTHA (n=252, P=.0001). Octogenarian status, medium-risk Elixhauser comorbidity score, and high-risk Elixhauser comorbidity score were independent risk factors for mortality (adjusted odds ratio [AOR]=1.587, 95% CI=1.103-2.282, P=.0128; AOR=2.439, 95% CI=1.680-3.541, P<.0001; and AOR=6.367, 95% CI=4.134-9.804, P<.0001, respectively). Undergoing rTHA in a high-HRV hospital was associated with lower odds of in-hospital mortality (AOR=0.539, 95% CI=0.332-0.877, P=.0127). Receiving care in a low-HRV hospital increased the risk of 2-year postoperative patient mortality. Similarly, older age and a higher comorbidity burden were independently associated with increased 2-year postoperative mortality. [Orthopedics. 2022;45(1):57-63.].

Long-term mortality rates and associated risk factors following primary and revision knee arthroplasty : 107,121 patients from the Scottish Arthroplasty Project

AIMS

The aim of this study was to determine the long-term mortality rate, and to identify factors associated with this, following primary and revision knee arthroplasty (KA).

METHODS

Data from the Scottish Arthroplasty Project (1998 to 2019) were retrospectively analyzed. Patient mortality data were linked from the National Records of Scotland. Analyses were performed separately for the primary and revised KA cohorts. The standardized mortality ratio (SMR) with 95% confidence intervals (CIs) was calculated for the population at risk. Multivariable Cox proportional hazards were used to identify predictors and estimate relative mortality risks.

RESULTS

At a median 7.4 years (interquartile range (IQR) 4.0 to 11.6) follow-up, 27.8% of primary (n = 27,474/98,778) and 31.3% of revision (n = 2,611/8,343) KA patients had died. Both primary and revision cohorts had lower mortality rates than the general population (SMR 0.74 (95% CI 0.73 to 0.74); p < 0.001; SMR 0.83 (95% CI 0.80 to 0.86); p < 0.001, respectively), which persisted for 12 and eighteight years after surgery, respectively. Factors associated with increased risk of mortality after primary KA included male sex (hazard ratio (HR) 1.40 (95% CI 1.36 to 1.45)), increasing socioeconomic deprivation (HR 1.43 (95% CI 1.36 to 1.50)), inflammatory polyarthropathy (HR 1.79 (95% CI 1.68 to 1.90)), greater number of comorbidities (HR 1.59 (95% CI 1.51 to 1.68)), and periprosthetic joint infection (PJI) requiring revision (HR 1.92 (95% CI 1.57 to 2.36)) when adjusting for age. Similarly, male sex (HR 1.36 (95% CI 1.24 to 1.49)), increasing socioeconomic deprivation (HR 1.31 (95% CI 1.12 to 1.52)), inflammatory polyarthropathy (HR 1.24 (95% CI 1.12 to 1.37)), greater number of comorbidities (HR 1.64 (95% CI 1.33 to 2.01)), and revision for PJI (HR 1.35 (95% 1.18 to 1.55)) were independently associated with an increased risk of mortality following revision KA when adjusting for age.

CONCLUSION

The SMR of patients undergoing primary and revision KA was lower than that of the general population and remained so for several years post-surgery. However, approximately one in four patients undergoing primary and one in three patients undergoing revision KA died within tenten years of surgery. Several patient and surgical factors, including PJI, were associated with the risk of mortality within ten years of primary and revision surgery. Cite this article: Bone Joint J 2022;104-B(1):45-52.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

LEVEL OF EVIDENCE

Level IV.

Mortality After Revision Total Hip Arthroplasty

BACKGROUND

In counseling patients about the complications of revision total hip arthroplasty (revTHA), it is imperative that mortality be considered. The actual mortality rate by indication of revision is ill-defined. The purpose of this study is to determine the mortality rate after revTHA.

METHODS

An institutional database identified 596 patients who had undergone revTHA between 2012 and 2018. Medical records, national, state, and local death indexes were queried for mortality status and indication for revTHA. For survivors, the last clinical visit date was used for censoring in the mortality analysis. Mortality rates were calculated for all clinical patients and then by specific indication for revision.

RESULTS

The overall 2-year mortality rate following revTHA was 19.5 deaths per 1000 or 1 in 51 patients. Patients presenting with a periprosthetic fracture had a significantly higher 2-year mortality rate of 74.5 deaths per 1000 or 1 in 13 patients (P < .001), while an indication of dislocation or instability had a slightly higher 2-year mortality rate of 50.3 per 1000 (1 in 20) but this difference was not significant (P = .531). Other indications such as mechanical loosening or infection did not have a significantly different mortality rate.

CONCLUSION

The overall 2-year mortality rate following revTHA was 19.5 deaths per 1000 which was largely attributed to patients with a periprosthetic fracture (74.5 per 1000) with other indications not significantly impacting mortality. Mortality rates and specific rates by indication for revision should be considered when counseling patients prior to revTHA.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

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

BACKGROUND

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

QUESTIONS/PURPOSES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

Level III, therapeutic study.

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.

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.

LbL-assembled gentamicin delivery system for PMMA bone cements to prolong antimicrobial activity

INTRODUCTION

Antibiotic-loaded poly(methyl methacrylate) bone cements (ALBCs) are widely used in total joint replacement (TJR), for local delivery of antibiotics to provide prophylaxis against prosthetic joint infections (PJI). One of the shortcomings of the current generation of ALBCs is that the antibiotic release profile is characterized by a burst over the first few hours followed by a sharp decrease in rate for the following several days (often below minimum inhibitory concentration (MIC)), and, finally, exhaustion (after, typically, ~ 20 d). This profile means that the ALBCs provide only short-term antimicrobial action against bacterial strains involved PJI.

RATIONALE

The purpose of the present study was to develop an improved antibiotic delivery system for an ALBC. This system involved using a layer-by-layer technique to load the antibiotic (gentamicin sulphate) (GEN) on silica nanoparticles, which are then blended with the powder of the cement. Then, the powder was mixed with the liquid of the cement (NP-GEN cement). For controls, two GEN-loaded brands were used (Cemex Genta and Palacos R+G). Gentamicin release and a host of other relevant properties were determined for all the cements studied.

RESULTS

Compared to control cement specimens, improved GEN release, longer antimicrobial activity (against clinically-relevant bacterial strains), and comparable setting time, cytocompatibility, compressive strength (both prior to and after aging in PBS at 37 oC for 30 d), 4-point bend strength and modulus, fracture toughness, and PBS uptake.

CONCLUSIONS

NP-GEN cement may have a role in preventing or treating PJI.

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.

Total knee and hip arthroplasty: the reality of assistance in Brazilian public health care

Objective

To analyze the number of hospital permits for total knee arthroplasty (TKA) and total hip arthroplasty (THA) in Brazil between 2008 and 2015, and correlate them with regional, national, and international demographic and epidemiological aspects.

Methods

Data on demographics, economic level, and TKA and THA were obtained from the website of the Ministry of Health/DATASUS, Brazilian Institute of Geography and Statistics, and the National Health Agency to assess the assistance provided by the Public Health Care System in arthroplasties for elderly Brazilian population without private health care.

Results

The South and Southeast had the best care, with 8.07 and 6.07 TKAs/100,000 inhabitants, one TKA per 1811 and 2624 seniors, 17.3 and 10.99 THAs/100,000 inhabitants, and one THA per 923 and 1427 seniors, respectively. The worst rates were found in the North and Northeast, with 0.88 and 0.98 TKAs/100,000, one TKA per 6930 and 10,411 seniors, 0.96 and 3.25 THAs/100,000, and one THA per 6849 and 2634 seniors, respectively. The national average was 4.00 TKAs/100,000, one TKA per 3249 seniors, 8.01 THAs/100,000, and one THA per 1586 seniors. The international average was 142.8 TKAs/100,000 and 191.8 THAs/100,000.

Conclusion

The results expressed unsatisfactory results for TKA and THA in Brazil, with greater relevance in the North and Northeast.

Do Patients Live Longer After THA and Is the Relative Survival Diagnosis-specific?

BACKGROUND

Hip replacements are successful in restoring mobility, reducing pain, and improving quality of life. However, the association between THA and the potential for increased life expectancy (as expressed by mortality rate) is less clear, and any such association could well be influenced by diagnosis and patient-related, socioeconomic, and surgical factors, which have not been well studied.

QUESTIONS/PURPOSES

(1) After controlling for birth year and sex, are Swedish patients who underwent THA likely to survive longer than individuals in the general population? (2) After controlling for relevant patient-related, socioeconomic/demographic factors and surgical factors, does relative survival differ across the various diagnoses for which THAs were performed in Sweden?

METHODS

Data from the Swedish Hip Arthroplasty Register, linked to administrative health databases, were used for this study. We identified 131,808 patients who underwent THA between January 1, 1999, and December 31, 2012. Of these, 21,755 had died by the end of followup. Patient- and surgery-specific data in combination with socioeconomic data were available for analysis. We compared patient survival (relative survival) with age- and sex-matched survival data in the entire Swedish population according to Statistics Sweden. We used multivariable modeling proceeded with a Cox proportional hazards model in transformed time.

RESULTS

Patients undergoing elective THA had a slightly improved survival rate compared with the general population for approximately 10 years after surgery. At 1 year after surgery, the survival in patients undergoing THA was 1% better than the expected survival (r = 1.01; 95% confidence interval [CI], 1.01-1.02; p < 0.001); at 5 years, this increased to 3% (r = 1.03; 95% CI, 1.03-1.03; p < 0.001); at 10 years, the difference was 2% (r = 1.02; 95% CI, 1.02-1.03; p < 0.001); and by 12 years, there was no difference between patients undergoing THA and the general population (r = 1.01; 95% CI, 0.99-1.02; p = 0.13). Using the diagnosis of primary osteoarthritis as a reference, hip arthroplasties performed for sequelae of childhood hip diseases had a similar survival rate (hazard ratio [HR], 1.02; 95% CI, 0.88-1.18; p = 0.77). Patients undergoing surgery for osteonecrosis of the femoral head (HR, 1.69; 95% CI, 1.60-1.79; p < 0.001), inflammatory arthritis (HR, 1.49; 95% CI, 1.38-1.61; p < 0.001), and secondary osteoarthritis (HR, 2.46; 95% CI, 2.03-2.99; p < 0.001) all had poorer relative survival. Comorbidities and the Elixhauser comorbidity index had a negative association with relative survival. Level of achieved education (middle level of education: HR, 0.90, 95% CI, 0.87-0.93, p < 0.001; high level: 0.76, 95% CI, 0.73-0.80, p < 0.001) and marital status (single status: HR, 1.33; 95% CI, 1.28-1.38; p < 0.001) were also negatively associated with survival.

CONCLUSIONS

Whereas it has been known that in most patients, THA improves quality of life, this study demonstrates that it also is associated with a slightly increased life expectancy that lasts for approximately 10 years after surgery, especially among patients whose diagnosis was primary osteoarthritis. This adds further proof of a health-economic value for this surgical intervention. The reasons for the increase in relative survival are unknown but are probably multifactorial.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Long-term Mortality After Revision THA

BACKGROUND

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

QUESTIONS/PURPOSES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

LEVEL OF EVIDENCE

Level III, therapeutic study.

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

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

Reduced survival for uncemented compared to cemented total hip arthroplasty after operatively treated acetabular fractures

BACKGROUND

Post traumatic arthritis and avascular necrosis of the femoral head are common complications after operatively treated acetabular fractures. This may cause severe disabilities for the patient, necessitating a total hip arthroplasty. Even though an arthroplasty may provide good symptomatic relief, the long-term results are more uncertain and no consensus exists according to preferred prosthetic designs. With this cohort study, we aimed to investigate the medium to long term arthroplasty survival and clinical results of total hip arthroplasty after operatively treated acetabular fractures.

METHODS

We included 52 patients treated with a secondary total hip arthroplasty at a median of 2.4 (0.1-14.1) years after an operatively treated acetabular fracture. The median age was 54 (11-82) years. Cemented arthroplasty was used for 33 patients, 10 patients had an uncemented arthroplasty and 9 patients received a hybrid arthroplasty. Average follow up was 8.0 (SD 5.0) years.

RESULTS

Ten-year revision free arthroplasty survival was 79%. Uncemented arthroplasties had a significantly worse 10-year survival of 57%. Arthroplasties performed at a centre without a pelvic fracture service also had a significantly worse 10-years survival of 51%. Cox regression showed similar results with an 8-fold increase in risk of revision for both uncemented arthroplasties and operations performed at a non-pelvic trauma centre.

CONCLUSION

Total hip arthroplasty secondary to an operatively treated acetabular fracture provides good symptomatic relief. These patients are, however, complex cases and are probably best treated at specialist centres with both pelvic trauma surgeons and arthroplasty surgeons proficient in complex revisions present.

Is Preoperative Patient-Reported Health Status Associated with Mortality after Total Hip Replacement?

The influence of comorbidities and worse physical status on mortality following total hip replacement (THR) leads to the idea that patient-reported health status may also be a predictor of mortality. The aim of this study was to investigate the relationship between patient-reported health status before THR and the risk of dying up to 5 years post-operatively. For these analyses, we used register data on 42,862 THR patients with primary hip osteoarthritis operated between 2008 and 2012. The relative survival ratio was calculated by dividing the observed survival in the patient group by age- and sex-adjusted expected survival of the general population. Pre-operative responses to the five EQ-5D-3L (EuroQol Group) dimensions along with age, sex, education status, year of surgery, and hospital type were used as independent variables. Results shown that, as a group, THR patients had a better survival than the general population. Broken down by the five EQ-5D-3L dimensions we observed differentiated survival patters. For all dimensions, those reporting extreme problems had higher mortality than those reporting moderate or no problems. In conclusion, worse health status according to the EQ-5-3L before THR is associated with higher mortality up to five years after surgery. EQ-5D-3L responses may be useful in a multifactorial individualized risk assessment before THR.

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.