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

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

Background:

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

Methods:

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

Results:

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

Conclusions:

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

Level of Evidence:

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

What Is the Impact of Advancing Age on the Outcomes of Total Hip Arthroplasty?

BACKGROUND

The global demand for total hip arthroplasty (THA) is increasing, underscoring its moniker as the "operation of the century." However, debate still exists as to whether the elderly who undergo the operation achieve the same outcomes as those younger. In this study, we sought to investigate the association between older age and the risks and benefits of THA.

METHODS

In this study, we aimed to compare the risks and benefits of THA of those aged ≥80 years vs those <80 years. We analyzed the physical status component of the Short-Form 12 Health Survey, complications within 12 months, all-cause mortality, length of hospital stay (LOS), and discharge to rehabilitation in 2457 cases of primary THA using multivariate modeling.

RESULTS

There was no difference in improvement of those older vs the younger group in physical functioning. However, the older group had 2.87 times greater odds of experiencing a post-operative medical complication and 3.49 times the rate of all-cause mortality (P < .001). Additionally, the older group encountered an additional median 0.21-day increase in LOS and had 3.93 times greater odds of being discharged to rehabilitation rather than home (P < .001). We were unable to demonstrate any difference between groups in terms of post-operative surgical or wound-related complications.

CONCLUSION

The elderly stand to gain equivalent benefits from THA as those younger in terms of physical functioning. However, this benefit needs to be balanced against the increased risk of post-operative medical complications, increased LOS, increased requirement for rehabilitation, and ultimately the increased risk of mortality.

Re-admissions treble the risk of late mortality after primary total hip arthroplasty

BACKGROUND

Following a total hip arthroplasty (THA), early hospital re-admission rates of 3-11% are considered as 'acceptable' in terms of medical care cost policies. Surprisingly, the impact of re-admissions on mortality has not been priorly portrayed. Therefore, we sought to determine the mortality rate after 90-day re-admissions following a THA in a series of patients from a captive medical care program.

PATIENTS AND METHODS

We prospectively analysed 90-day readmissions of 815 unilateral, elective THA patients operated upon between 2010 and 2014 whose medical care was the one offered by our institution. We stratified our sample into readmitted and non-readmitted cohorts. Through a Cox proportional hazards model, we compared demographic characteristics, clinical comorbidities, surgical outcomes and laboratory values between both groups in order to determine association with early and late mortality.

RESULTS

We found 37 (4.53%) re-admissions at a median time of 40.44 days (IQR 17.46-60.69). Factors associated with re-admission were hospital stay (p = 0.00); surgical time (p = 0.01); chronic renal insufficiency (p = 0.03); ASA class 4 (p = 0.00); morbid obesity (p = 0.006); diabetes (p = 0.04) and a high Charlson index (p = 0.00). Overall mortality rate of the series was 3.31% (27/815). Median time to mortality was 455.5 days (IQR 297.58-1170.65). One-third (11/37) of the re-admitted patients died, being sepsis non-related to the THA the most common cause of death. After adjusting for confounders, 90-day re-admissions remained associated with mortality with an adjusted HR of 3.14 (CI95% 1.05-9.36, p = 0.04).

CONCLUSIONS

Unplanned re-admissions were an independent risk factor for future mortality, increasing three times the risk of mortality.

Key features of bone and joint infections following the implementation of reference centers in France

OBJECTIVES

French reference centers for bone and joint infections (BJI) were implemented from 2009 onwards to improve the management of complex BJIs. This study compared BJI burden before and after the implementation of these reference centers.

PATIENTS AND METHODS

BJI hospital stays were selected from the 2008 and 2013 national hospital discharge database using a validated algorithm, adding the new complex BJI code created in 2011. Epidemiology and economic burden were assessed.

RESULTS

BJI prevalence increased in 2013 (70 vs. 54/100,000 in 2008). Characteristics of BJI remained similar between 2008 and 2013: septic arthritis (50%), increasing prevalence with age and sex, case fatality 5%, mean length of stay 17.5 days, rehospitalization 20%. However, device-associated BJIs increased (34 vs. 26%) as well as costs (€421 million vs. €259 in 2008). Similar device-associated BJI characteristics between 2008 and 2013 were: septic arthritis (70%), case fatality (3%), but with more hospitalizations in reference centers (34 vs. 30%) and a higher cost per stay. Among the 7% of coded complex BJIs, the mean length of stay was 22.2 days and mean cost was €11,960.

CONCLUSIONS

BJI prevalence highly increased in France. Complex BJI prevalence assessment is complicated by the absence of clinical consensus and probable undercoding. A validation of clinical case definition of complex BJI is required.

Ten-Year Trends in Medical Complications Following 540,623 Primary Total Hip Replacements from a National Database

BACKGROUND

More than 75,000 total hip replacements were performed in England and Wales in 2014, and this figure is predicted to increase. Trends in mortality and complications following total hip replacement from 2005 to 2014 were evaluated to quantify risk and to identify "at-risk" groups to better inform recommendations for patient care.

METHODS

Our primary analysis estimated 90-day inpatient mortality following total hip replacement using Hospital Episode Statistics data from 2005 to 2014. Secondary analyses explored 30-day rates of lower respiratory tract infection, renal failure, myocardial infarction, pulmonary embolism, deep-vein thrombosis, cerebrovascular accident, and Clostridium difficile. Hierarchical logistic regression was used to estimate population averages, adjusting for time and prognostic covariates.

RESULTS

From January 2005 to July 2014, a total of 540,623 total hip replacements were reported. The 90-day mortality rate dropped steadily, from 0.60% in 2005 to 0.15% in 2014. Reported postoperative complications (with the exception of lower respiratory tract infection and renal failure) reduced year-on-year, despite a steady rise in the average Charlson Comorbidity Index score. The 30-day rate of lower respiratory tract infection and renal failure increased from 0.54% to 0.84% and 0.21% to 1.09%, respectively. The risk of mortality was significantly higher for those who developed a lower respiratory tract infection (odds ratio [OR] = 42.3) or renal failure (OR = 36.5) than for those who developed pulmonary embolism (OR = 10.9) or deep-vein thrombosis (OR = 2.6).

CONCLUSIONS

Despite a population with increasing levels of comorbidity, indicators of quality of care improved from 2005 to 2014, with the exception of the rates of lower respiratory tract infection and renal failure. Postoperative care should focus on reducing the risk of lower respiratory tract infection and renal failure, both of which increased and were strongly associated with mortality. Moreover, they appeared to occur in identifiable high-risk groups; modifications to routine care should be considered for these patients.

LEVEL OF EVIDENCE

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

Impact of surgical case order on peri-operative outcomes for total joint arthroplasty

INTRODUCTION

There is growing support in the literatures that peri-operative outcomes are adversely affected by surgical case order in some certain surgical procedures. This study aimed to examine if similar phenomenon is also shared in total joint arthroplasty (TJA).

METHODS

A total of 6548 joints (5183 patients) treated with primary TJA by a total of five surgeons at our institution from December 2011 to December 2015 were retrospectively reviewed in this study. Demographic data, operative duration, blood loss, peri-operative adverse events, medical cost, and length of hospital stay were collected and analyzed. Logistic regression was used to determine risk factors for adverse events.

RESULTS

Of the 6548 cases in this cohort, 1643 TJAs were classified as first round cases, 1744 TJAs were second round cases, 1600 TJAs were third round cases, and 1561 TJAs were fourth or later round cases. Mean operating time was shorter in the intermediate cases (45.0 vs. 41.0 vs. 41.8 vs. 54.1 min, P < 0.01). Peri-operative arthroplastic adverse events were increased in later surgical cases (2.07% vs. 2.18% vs. 3.06% vs. 4.87%, P < 0.01). Later case order (OR = 1.40 [95% CI: 1.22-1.61], P < 0.01) was a significant risk factor of arthroplastic adverse events. Patients undergoing TJA later in the day were more likely to have longer length of stay and higher cost than earlier cases. Peri-operative systemic complications and blood loss did not significantly differ between groups.

CONCLUSION

Surgical case order is an independent risk factor for arthroplastic adverse events in TJA. TJA procedures performed later in the day have a higher risk for arthroplastic adverse events, but not for systematic adverse events. Significantly increased operative time, higher cost, and longer LOS were noted for fourth or later TJA cases. Data in our study reveals that performing more than three TJAs within a single day may imply compromised outcomes.

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.

The Influence of Patient Gender on Morbidity Following Total Hip or Total Knee Arthroplasty

BACKGROUND

Little research has focused on the influence of gender on postoperative morbidity following total hip arthroplasty (THA) and total knee arthroplasty (TKA). This study aimed to compare operative time, length of stay, 30-day complications, and readmissions based on patient gender.

METHODS

The prospectively collected National Surgical Quality Improvement Program registry from 2005 to 2014 was queried to identify primary elective THA and TKA patients. Multivariate regression was used to compare the rates of 30-day adverse events, rates of readmission, operative time, and postoperative length of stay between men and women. Multivariate analyses were controlled for baseline patient characteristics and procedure type.

RESULTS

A total of 173,777 patients were included (63.5% TKA and 36.5% THA). Male gender increased the risk of multiple adverse events, including death (relative risk [RR] 1.1, P < .001), surgical site infection (RR 1.2, P < .001), sepsis (RR 1.4, P < .001), cardiac arrest (RR 1.8, P < .001), and return to the operating room (RR 1.3, P < .001). Men had decreased overall adverse events (RR 0.8, P < .001) secondary to a lower risk of urinary tract infection (RR 0.5, P < .001) and blood transfusion (RR 0.7, P < .001), which were prevalent adverse events. Men had an increased risk of 30-day readmission (RR 1.2, P < .001), slightly increased operative time (+6 minutes, P < .001), and slightly decreased length of stay (-0.2 days, P < .001).

CONCLUSION

Men had increased risk of multiple individual adverse events including death, surgical site infection, cardiac arrest, return to the operating room, and readmission. Conversely, women had increased risk of urinary tract infection and blood transfusion.

Total hip arthroplasty in patients 55 years or younger: Risk factors for poor midterm outcomes

BACKGROUND

Total hip arthroplasty (THA) is increasingly performed in younger patients. The purpose of this study is to report on the midterm outcomes of primary cementless THA in patients 55 years and younger; and specifically to examine the risk factors for aseptic failure, all-cause revision, and mortality in this patient population.

METHODS

Four hundred and twenty-six consecutive patients with minimum 5-year follow-up were retrospectively reviewed. Multivariate analyses were conducted to control for potential confounding factors identified by univariate analyses.

RESULTS

Mean follow-up was 92.12 ± 30.9 months. The overall 5-year implant survival rate was 90.8% and the aseptic survival rate was 92.6%. Among the potential risk factors, only bearing surface had a significant relationship with aseptic revision (P = 0.041). Aseptic revisions occurred more frequently with metal-on-polyethylene articulation (P = 0.012). Higher Charlson comorbidity index (CCI) was a significant risk factor for all-cause complications (P = 0.04) while higher CCI and lower body mass index were significant risk factors for mortality (P = 0.001 and 0.006 respectively).

CONCLUSION

Bearing type was the only risk factor for revision surgery, particularly metal-on-polyethylene bearing. Patients with higher comorbidities were at increased risk for postoperative complications and mortality, while higher body weight appeared to have a protective effect against mortality. These findings should be considered before surgery for risk modification and management of patient expectations. While it appears that bearing couples other than metal-on-polyethylene are especially suitable for young patients, more studies are needed to determine the best bearing couple and to reduce the rates of postoperative complications in this patient population.

Handling the procurement of prostheses for total hip replacement: description of an original value based approach and application to a real-life dataset reported in the UK

OBJECTIVES

In most European countries, innovative medical devices are not managed according to cost-utility methods, the reason being that national agencies do not generally evaluate these products. The objective of our study was to investigate the cost-utility profile of prostheses for hip replacement and to calculate a value-based score to be used in the process of procurement and tendering for these devices.

METHODS

The first phase of our study was aimed at retrieving the studies reporting the values of QALYs, direct cost, and net monetary benefit (NMB) from patients undergoing total hip arthroplasty (THA) with different brands of hip prosthesis. The second phase was aimed at calculating, on the basis of the results of cost-utility analysis, a tender score for each device (defined according to standard tendering equations and adapted to a 0-100 scale). This allowed us to determine the ranking of each device in the simulated tender.

RESULTS

We identified a single study as the source of information for our analysis. Nine device brands (cemented, cementless, or hybrid) were evaluated. The cemented prosthesis Exeter V40/Elite Plus Ogee, the cementless device Taperloc/Exceed, and the hybrid device Exeter V40/Trident had the highest NMB (£152 877, £156 356, and £156 210, respectively) and the best value-based tender score.

CONCLUSIONS

The incorporation of value-based criteria in the procurement process can contribute to optimising the value for money for THA devices. According to the approach described herein, the acquisition of these devices does not necessarily converge on the product with the lowest cost; in fact, more costly devices should be preferred when their increased cost is offset by the monetary value of the increased clinical benefit.

Endoscopic or arthroscopic iliopsoas tenotomy for iliopsoas impingement following total hip replacement. A prospective multicenter 64-case series

INTRODUCTION

Impingement between the acetabular component and the iliopsoas tendon is a cause of anterior pain after total hip replacement (THR). Treatment can be non-operative, endoscopic or arthroscopic, or by open revision of the acetabular component. Few studies have assessed these options. The present study hypothesis was that endo/arthroscopic treatment provides rapid pain relief with a low rate of complications.

METHODS

A prospective multicenter study included 64 endoscopic or arthroscopic tenotomies for impingement between the acetabular component and the iliopsoas tendon, performed in 8 centers. Mean follow-up was 8months, with a minimum of 6months and no loss to follow-up. Oxford score, patient satisfaction, anterior pain and iliopsoas strength were assessed at last follow-up. Complications and revision procedures were collated. Forty-four percent of patients underwent rehabilitation.

RESULTS

At last follow-up, 92% of patients reported pain alleviation. Oxford score, muscle strength and pain in hip flexion showed significant improvement. The complications rate was 3.2%, with complete resolution. Mean hospital stay was 0.8 nights. In 2 cases, arthroscopy revealed metallosis, indicating revision of the acetabular component. The only predictive factor was acetabular projection on oblique view. Rehabilitation significantly improved muscle strength.

CONCLUSION

Endoscopic or arthroscopic tenotomy for impingement between the acetabular component and the iliopsoas tendon following THR significantly alleviated anterior pain in more than 92% of cases. The low complications rate makes this the treatment of choice in case of failure of non-operative management. Arthroscopy also reorients diagnosis in case of associated joint pathology. Projection of the acetabular component on preoperative oblique view is the most predictive criterion, guiding treatment.

Associations between seasonal variation and post-operative complications after total hip arthroplasty

Background

Total hip arthroplasty (THA) complication rates are low, but pose marked challenges during the post-operative care period. Therefore, it is important to determine which risk factors are associated with an increased rate of these complications. The purpose of this paper was to investigate the association between seasonal variations and the 30-day post-operative complication rates following THA. Specifically, we evaluated a large prospectively collected national database for: (I) overall complication rates; (II) seasonal variations in incidence; and (III) specific quarter (Q), if any, associations.

Methods

This multi-center observational cohort study was conducted by analyzing 102,682 THA surgeries listed in the American College of Surgeon National Surgical Quality Improvement Program database (ACS-NSQIP) from January 1st, 2011 to December 31st, 2015. All surgeries were divided into four groups based on the quarter of the year in which the surgery was performed. We identified 20 complications listed in the ACS-NSQIP and calculated 30-day post-operative complication rates. Univariate analysis was performed to compare complication rates between different seasons. Multivariate analysis was performed to control for potential confounding variables.

Results

The overall complication rate in this cohort was 1.09%. Upon tabulation of the different post-operative THA complication incidence rates sorted by quarters, 16 out of 20 outcomes had <1% incidence rate, 3 had between a 1% and 5% incidence rate, and 1 outcome had a complication rate greater than 5% (bleeding transfusion). There were no statistical differences in 19 of the 20 complication rates when compared between the different quarters. Transfusion was the only complication with a statistically significant difference (P value <0.001) between the different quarters, which demonstrated a marked increase in Q3/Q4 (July to December), when compared to Q1 (January to March) (P<0.001).

Conclusions

Overall, our results indicate a low complication rate in this cohort of patients who underwent a THA (1.09%). There was no correlation between seasonal variation and 30-day complication rates following THA, except for bleeding risk, which remains unexplained. These findings suggest that elective THA does not have to be scheduled around specific times of the year in order to avoid 30-day post-operative complications.

An analysis of 30-day mortality after weekend versus weekday elective joint arthroplasty in England and Wales

Aims

To investigate whether elective joint arthroplasty performed at the weekend is associated with a different 30-day mortality versus that performed between Monday and Friday.

Patients and Methods

We examined the 30-day cumulative mortality rate (Kaplan-Meier) for all elective hip and knee arthroplasties performed in England and Wales between 1st April 2003 and 31st December 2014, comprising 118 096 episodes undertaken at the weekend and 1 233 882 episodes performed on a weekday. We used Cox proportional-hazards regression models to assess for time-dependent variation and adjusted for identified risk factors for mortality.

Results

The cumulative 30-day mortality for hip arthroplasty was 0.15% (95% confidence interval (CI) 0.12 to 0.19) for patients operated on at the weekend versus 0.20% (95% CI 0.19 to 0.21) for patients undergoing surgery during the normal working week. For knee arthroplasty, the cumulative 30-day mortality was 0.14% (95% CI 0.11 to 0.17) for weekend-operated patients versus 0.18% (95% CI 0.17 to 0.19) for weekday-operated patients. These differences were independent of any differences in patient age, gender, American Society of Anaesthesiologists grade, surgeon seniority, surgical and anaesthetic practices, and thromboprophylaxis choice in weekend versus weekday-operated patients.

Conclusion

The 30-day mortality rate after elective joint arthroplasty is low. Surgery performed at the weekend is associated with lower post-operative mortality versus operations performed on a weekday. Cite this article: Bone Joint J 2017;99-B:1618–28.

Aspirin and the prevention of venous thromboembolism following total joint arthroplasty: commonly asked questions

The number of arthroplasties being performed increases each year. Patients undergoing an arthroplasty are at risk of venous thromboembolism (VTE) and appropriate prophylaxis has been recommended. However, the optimal protocol and the best agent to minimise VTE under these circumstances are not known. Although many agents may be used, there is a difference in their efficacy and the risk of bleeding. Thus, the selection of a particular agent relies on the balance between the desire to minimise VTE and the attempt to reduce the risk of bleeding, with its undesirable, and occasionally fatal, consequences.

Acetylsalicylic acid (aspirin) is an agent for VTE prophylaxis following arthroplasty. Many studies have shown its efficacy in minimising VTE under these circumstances. It is inexpensive and well-tolerated, and its use does not require routine blood tests. It is also a ‘milder’ agent and unlikely to result in haematoma formation, which may increase both the risk of infection and the need for further surgery. Aspirin is also unlikely to result in persistent wound drainage, which has been shown to be associated with the use of agents such as low-molecular-weight heparin (LMWH) and other more aggressive agents.

The main objective of this review was to summarise the current evidence relating to the efficacy of aspirin as a VTE prophylaxis following arthroplasty, and to address some of the common questions about its use.

There is convincing evidence that, taking all factors into account, aspirin is an effective, inexpensive, and safe form of VTE following arthroplasty in patients without a major risk factor for VTE, such as previous VTE.

Cite this article: Bone Joint J 2017;99-B:1420–30.

Fatal pulmonary embolism following elective total knee replacement using aspirin in multi-modal prophylaxis - A 12year study

BACKGROUND

The National Institute for Health and Clinical Excellence (NICE) has issued guidelines on which thromboprophylaxis regimens are suitable following lower limb arthroplasty. Aspirin is not a recommended agent despite being accepted in orthopaedic guidelines elsewhere. We assessed the incidence of fatal pulmonary embolism (PE) and all-cause mortality following elective primary total knee replacement (TKR) with a standardised multi-modal prophylaxis regime in a large teaching district general hospital.

METHODS

We utilised a prospective audit database to identify those that had died within 42 and 90days postoperatively. Data from April 2000 to 2012 were analysed for 42 and 90day mortality rates. There were a total of 8277 elective primary TKR performed over the 12year period. The multi-modal prophylaxis regimen used unless contraindicated for all patients included 75mg aspirin once daily for four weeks. Case note review ascertained the causes of death. Where a patient had been referred to the coroner, they were contacted for post mortem results.

RESULTS

The mortality rates at 42 and 90days were 0.36 and 0.46%. There was one fatal PE within 42days of surgery (0.01%) who was taking enoxaparin because of aspirin intolerance. Two fatal PE's occurred at 48 and 57days post-operatively (0.02%). The leading cause of death was myocardial infarction (0.13%).

CONCLUSIONS

Fatal PE following elective TKR with a multi-modal prophylaxis regime is a very rare cause of mortality.

Cost-effectiveness of timely versus delayed primary total hip replacement in Germany: A social health insurance perspective

Without clinical guideline on the optimal timing for primary total hip replacement (THR), patients often receive the operation with delay. Delaying THR may negatively affect long-term health-related quality of life, but its economic effects are unclear. We evaluated the costs and health benefits of timely primary THR for functionally independent adult patients with end-stage osteoarthritis (OA) compared to non-surgical therapy followed by THR after progression to functional dependence (delayed THR), and non-surgical therapy alone (Medical Therapy), from a German Social Health Insurance (SHI) perspective. Data from hip arthroplasty registers and a systematic review of the published literature were used to populate a tunnel-state modified Markov lifetime model of OA treatment in Germany. A 5% annual discount rate was applied to costs (2013 prices) and health outcomes (Quality Adjusted Life Years, QALY). The expected future average cost of timely THR, delayed THR and medical therapy in women at age 55 were €27,474, €27,083 and €28,263, and QALYs were 20.7, 16.7, and 10.3, respectively. QALY differences were entirely due to health-related quality of life differences. The discounted cost per QALY gained by timely over delayed (median delay of 11 years) THR was €1270 and €1338 in women treated at age 55 and age 65, respectively, and slightly higher than this for men. Timely THR is cost-effective, generating large quality of life benefits for patients at low additional cost to the SHI. With declining healthcare budgets, research is needed to identify the characteristics of those able to benefit the most from timely THR.

Similar Clinical Outcomes with Preoperative and Postoperative Start of Thromboprophylaxis in THA: A Register-based Study

BACKGROUND

Elective THA is associated with a high risk of thromboembolic events. Although these events may be less common now than they were in the past, they can be serious, and most patients undergoing the procedure therefore still receive thromboprophylaxis. However, controversy remains regarding whether to begin thromboprophylaxis before THA or after to best balance the risks of clotting and bleeding.

QUESTIONS/PURPOSES

We asked the following questions: (1) Is there a difference in bleeding events with pre- versus postoperative thromboprophylaxis? (2) Is there a difference in thromboembolic episodes after THA between the two regimens? (3) How do the two approaches of thromboprophylaxis influence mortality, readmissions, and other complications?

METHODS

We used a population-based followup design with predefined data based on international health codification to assess clinical effects of LMWH prophylaxis initiated before or after THA. We took data limited to primary THAs done in Norway between January 1, 2008, and December 31, 2011, from the Norwegian Arthroplasty Register and the National Patient Register to have necessary data elements to complete the study. The two registers were merged after identifying patients with their 11-digit personal identification number (Social Security number). We obtained data regarding demographics, administrative and surgical details, and episode histories for prophylaxis-related events within 180 days of surgery. A total of 25,163 patients undergoing THA were included for analysis, and 9977(40%) versus 15,186 (60%) patients received pre- and postoperative LMWH, respectively. We performed statistical adjustment for differences in baseline characteristics using multivariate logistic regression.

RESULTS

After adjustment for age, sex, operation time, year of surgery, and American Society of Anesthesiologists class, we could not show major differences in bleeding events; (odds ratio [OR], 1.04; 95% CI, 0.88-1.22; p = 0.660), thromboembolic episodes; (OR, 1.03; 95% CI, 0.84-1.27; p = 0.786), or other postoperative clinical complications; (OR, 0.86; 95% CI, 0.76-0.99; p = 0.034), with the two regimens. Six-month mortality was similar, (OR, 0.76; 95% CI, 0.56-1.05; p = 0.093), and the readmission rate was higher in the preoperative group; (OR, 0.92; 95% CI, 0.85-0.97; p = 0.016).

CONCLUSIONS

The risk for postoperative complications seems to be comparable whether LMWH prophylaxis is initiated before or after THA. The postoperative approach reduces costs, decreases risks related to neuraxial anesthesia, and facilitates same-day admissions. Methods for individual risk assessment including laboratory tests would be feasible.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Patient education and anesthesia choice for total knee arthroplasty

OBJECTIVES

Spinal anesthesia (SA) for Total Knee Arthroplasty (TKA) may be associated with better patients' outcomes. This study aims to assess the association between preoperative education about the advantage of SA over general anesthesia (GA) for TKA and the likelihood of patient choice of NA.

METHODS

Patients undergoing unilateral primary TKA were identified. Type of anesthesia (GA or SA), attendance of the (joints class), patient demographics, ASA status, anticoagulation status, and diagnosis of back problems were recoded. Regression analysis was used to assess the association between the type of anesthesia and attendance of the joints class.

RESULTS

1010 patients were identified to have unilateral primary TKA. 31% of patients attended the joint class. Patients who attended the joints class were more likely to receive SA when compared to those who did not attend (OR=1.7, CI: 1.2-2.5, P=0.004) after adjusting for other variables.

CONCLUSION

Preoperative education about advantages of SA may be associated with an increase in patients receiving SA for TKA.

PRACTICE IMPLICATIONS

Increase in patients receiving SA for TKA may improve outcomes.

Local infiltration analgesia: a 2-year follow-up of patients undergoing total hip arthroplasty

Purpose

Local infiltration analgesia (LIA) is commonly used for postoperative pain management following total hip arthroplasty (THA). However, the long-term effects of the component drugs are unclear. The aim of our study was to investigate functional outcome, quality of life, chronic post-surgical pain, and adverse events in patients within 2 years of undergoing THA.

Methods

The study was a secondary analysis of data from a previous larger study. Eighty patients were randomized to receive either intrathecal morphine (Group ITM) or local infiltration analgesia (Group LIA) for pain management in a double-blind study. The parameters measured were patient-assessed functional outcome [using the Hip dysfunction and Osteo-arthritis Outcome Score (HOOS) questionnaire], health-related quality of life [using the European Quality of Life–5 dimensions (EQ-5D) questionnaire and the 36-Item Short Form Health Survey (SF-36) score], and pain using the numeric rating score (NRS), with persistent post-surgical pain having a NRS of > 3 or a HOOS pain sub-score of > 30. All complications and adverse events were investigated during the first 2 years after primary surgery.

Results

Pain intensity and rescue analgesic consumption were similar between the groups after hospital discharge. No differences were found in HOOS or SF-36 score between the groups up to 6 months after surgery. A significant group × time interaction was seen in the EQ 5D form in favor of the LIA group. No between-group difference in persistent post-surgical pain was found at 3 or 6 months, or in adverse events up to 2 years after surgery.

Conclusion

Analysis of functional outcome, quality of life, and post-discharge surgical pain did not reveal significant differences between patients receiving LIA and those receiving ITM. LIA was found to be a safe technique for THA during the long-term follow-up. However, it should be noted that these conclusions are based on a limited number of patients.

Caution is required in the implementation of 90-day mortality indicators for radiotherapy in a curative setting: A retrospective population-based analysis of over 16,000 episodes

Background

90-day mortality (90 DM) has been proposed as a clinical indicator in radiotherapy delivered in a curative setting. No large scale assessment has been made. Its value in allowing robust comparisons between centres and facilitating service improvement is unknown.

Methods

All radiotherapy treatments delivered in a curative setting over seven years were extracted from the local electronic health record and linked to cancer registry data. 90 DM rates were assessed and factors associated with this outcome were investigated using logistic regression. Cause of death was identified retrospectively further characterising the cause of 90 DM.

Results

Overall 90 DM was 1.25%. Levels varied widely with diagnosis (0.20–5.45%). Age (OR 1.066, 1.043–1.073), year of treatment (OR 0.900, 0.841–0.969) and diagnosis were significantly associated with 90 DM on multi-variable logistic regression. Cause of death varied with diagnosis; 50.0% post-operative in rectal cancer, 40.4% treatment-related in head and neck cancer, 59.4% disease progression in lung cancer.

Conclusion

Despite the drive to report centre level comparative outcomes, this study demonstrates that 90 DM cannot be adopted routinely as a clinical indicator due to significant population heterogeneity and low event rates. Further national investigation is needed to develop a meaningful robust indicator to deliver appropriate comparisons and drive improvements in care.

Efficacy evaluation of a protocol for safe hip surgery (total hip arthroplasty)

Objective

To propose a multidisciplinary protocol to standardize the care of patients undergoing total hip arthroplasty (THA) and evaluate it effectiveness after implementation.

Methods

Retrospective evaluation of 95 consecutive patients undergoing THA divided into two groups, one group of 47 patients operated before the protocol implementation and 48 after.

Results

Assessing the re-admission rate, among 47 patients evaluated prior to implementation of the protocol, seven (14.9%) were re-admitted, and when observing the 48 patients evaluated after implementation, one (2.1%) was re-admitted, showing statistical significance (p < 0.05). The chance of re-admission before the protocol was eight times the chance of hospitalization after implementation (95% CI: 1.01 to 377.7). By comparing the clinical complications among the groups, it was observed that there was a lower rate of complications following implementation of the protocol (p = 0.006).

Conclusion

The introduction of a multidisciplinary protocol to standardize the management of patients undergoing THA decreased the rates of rehospitalization and clinical complications after the procedure.

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.

A unified multi-level model approach to assessing patient responsiveness including; return to normal, minimally important differences and minimal clinically important improvement for patient reported outcome measures

OBJECTIVE

This article reviews and compares four commonly used approaches to assess patient responsiveness with a treatment or therapy (return to normal (RTN), minimal important difference (MID), minimal clinically important improvement (MCII), OMERACT-OARSI [Outcome Measures in Rheumatology-Osteoarthris Reseach Society International] (OO)) and demonstrates how each of the methods can be formulated in a multilevel modelling (MLM) framework.

DESIGN

Cohort study.

SETTING

A cohort of patients undergoing total hip and knee replacement were recruited from a single UK National Health Service hospital.

POPULATION

400 patients from the Arthroplasty Pain Experience cohort study undergoing total hip (n=210) and knee (n=190) replacement who completed the Intermittent and Constant Osteoarthritis Pain questionnaire prior to surgery and then at 3, 6 and 12 months after surgery.

PRIMARY OUTCOMES

The primary outcome was defined as a response to treatment following total hip or knee replacement. We compared baseline scores, change scores and proportion of individuals defined as 'responders' using traditional and MLM approaches with patient responsiveness.

RESULTS

Using existing approaches, baseline and change scores are underestimated, and the variance of baseline and change scores overestimated in comparison with MLM approaches. MLM increases the proportion of individuals defined as responding in RTN, MID and OO criteria compared with existing approaches. Using MLM with the MCII criteria reduces the number of individuals identified as responders.

CONCLUSION

MLM improves the estimation of the SD of baseline and change scores by explicitly incorporating measurement error into the model and avoiding regression to the mean when making individual predictions. Using refined definitions of responsiveness may lead to a reduction in misclassification when attempting to predict who does and does not respond to an intervention and clarifies the similarities between existing methods.

A comparison of the omega and posterior approaches on patient reported function and radiological outcomes following total hip replacement

BACKGROUND

The omega approach represents a modification of the lateral approach to the hip for joint replacement. It was developed to reduce the potential for gluteus muscle dysfunction and thereby improve functional outcome following hip replacement.

METHODS

A cohort of 415 consecutive hip replacements receiving the same type of cemented femoral component were followed up at a mean of three years postoperatively and invited to complete functional outcome and satisfaction scores.

RESULTS

There were no differences between the omega and the posterior approach in terms of post-operative Oxford Hip Score, Short Form-12 score, patient satisfaction and a range of radiographic parameters.

CONCLUSIONS

The omega approach appears to perform equally to the posterior approach in this cohort of patients.

Enhanced Recovery After Surgery for Hip and Knee Replacements

BACKGROUND

Enhanced recovery after surgery (ERAS) programs or hip and knee replacements have had a significant effect on streamlining patient care with shorter stays, no increase in complications, and improved outcomes including reduced mortality.

PURPOSE

To compare outcomes following the introduction of an ERAS program for hip and knee replacements developed at our institution with a historical cohort of patients.

METHODS

ERAS protocols were developed at our institution for patients undergoing hip and knee joint replacements. Key aspects were changes in preadmission, a new education session, improved management of perioperative anemia, standardized anesthetic guidelines, day of surgery mobilization, and improved discharge planning. The results of the first 18 months (528 consecutive patients) were compared with those of a historical cohort of 507 patients from the 18 months prior to their introduction.

RESULTS

In the ERAS group, the mean age was 68.3 years for patients who underwent hip replacement and 70.4 years for patients who underwent knee replacement. Thirty-two percent of patients were ASA (American Society of Anesthesiologists) Grades III and IV. The average preoperative Oxford score was 11. The average length of stay (ALOS) fell from 5.6 to 4.3 days for patients who underwent hip replacement and from 5.7 to 4.8 days for patients who underwent knee replacement (p < .001). Ninety-six percent of patients were discharged home. The 30-day readmission rate increased from 3.2% to 5.5% (p = .065). Six-month Oxford knee scores were higher in the ERAS group (39.8 vs. 36.3, p = .03). There was no increase in mortality or early revision rate.

CONCLUSIONS

Substantial reductions in ALOS can be gained with the introduction of ERAS protocols, with high patient satisfaction and no increase in complications in a consecutive unselected group of public hospital patients. This requires a multidisciplinary approach and a strong clinical input.

Outcomes following revision surgery performed for adverse reactions to metal debris in non-metal-on-metal hip arthroplasty patients: Analysis of 185 revisions from the National Joint Registry for England and Wales

OBJECTIVES

Few studies have assessed outcomes following non-metal-on-metal hip arthroplasty (non-MoMHA) revision surgery performed for adverse reactions to metal debris (ARMD). We assessed outcomes following non-MoMHA revision surgery performed for ARMD, and identified predictors of re-revision.

METHODS

We performed a retrospective observational study using data from the National Joint Registry for England and Wales. All non-MoMHAs undergoing revision surgery for ARMD between 2008 and 2014 were included (185 hips in 185 patients). Outcome measures following ARMD revision were intra-operative complications, mortality and re-revision surgery. Predictors of re-revision were identified using Cox regression.

RESULTS

Intra-operative complications occurred in 6.0% (n = 11) of the 185 cases. The cumulative four-year patient survival rate was 98.2% (95% CI 92.9 to 99.5). Re-revision surgery was performed in 13.5% (n = 25) of hips at a mean time of 1.2 years (0.1 to 3.1 years) following ARMD revision. Infection (32%; n = 8), dislocation/subluxation (24%; n = 6), and aseptic loosening (24%; n = 6) were the most common re-revision indications. The cumulative four-year implant survival rate was 83.8% (95% CI 76.7 to 88.9). Multivariable analysis identified three predictors of re-revision: multiple revision indications (hazard ratio (HR) = 2.78; 95% CI 1.03 to 7.49; p = 0.043); selective component revisions (HR = 5.76; 95% CI 1.28 to 25.9; p = 0.022); and ceramic-on-polyethylene revision bearings (HR = 3.08; 95% CI 1.01 to 9.36; p = 0.047).

CONCLUSIONS

Non-MoMHAs revised for ARMD have a high short-term risk of re-revision, with important predictors of future re-revision including selective component revision, multiple revision indications, and ceramic-on-polyethylene revision bearings. Our findings may help counsel patients about the risks of ARMD revision, and guide reconstructive decisions. Future studies attempting to validate the predictors identified should also assess the effects of implant design (metallurgy and modularity), given that this was an important study limitation potentially influencing the reported prognostic factors.Cite this article: G. S. Matharu, A. Judge, D. W. Murray, H. G. Pandit. Outcomes following revision surgery performed for adverse reactions to metal debris in non-metal-on-metal hip arthroplasty patients: Analysis of 185 revisions from the National Joint Registry for England and Wales. Bone Joint Res 2017;6:405-413. DOI: 10.1302/2046-3758.67.BJR-2017-0017.R2.

Is decreasing mortality in total hip and knee arthroplasty patients dependent on patients' comorbidity?

Background and purpose - Mortality after primary total hip and knee arthroplasty (THA and TKA) has declined, and the proportion of THA and TKA patients with comorbid conditions has increased. We therefore wanted to examine changes in comorbidity burden over time and the impact of comorbid on mortality following primary total hip and knee arthroplasty in patients with osteoarthritis. Patients and methods - We used the Danish arthroplasty registers to identify THA and TKA patients from 1996 through 2013. From administrative databases, we collected data on pre-surgery hospital history for all patients, which were used to calculate the Charlson comorbidity index (CCI). Patients were divided into 4 groups: CCI-none, CCI-low, CCI-moderate, and CCI-high. We calculated the relative risk (RR) of mortality within 90 days after surgery with a 95% confidence interval (CI), with stratification according to CCI group and year of surgery. Results - 99,962 THAs and 63,718 TKAs were included. The proportion of THAs with comorbidity increased by 3-4% in CCI-low, CCI-moderate, and CCI-high patients, from 1996-1999 to 2010-2013. The overall 90-day mortality risk declined for both procedures. Compared to CCI-none, THA patients with low, moderate, and high comorbidity burdens had an RR of 90-day mortality of 1.9 (95% CI: 1.6-2.4), 1.9 (CI: 1.5-2.5), and 3.3 (CI: 2.6-4.2), respectively. Similar increases in proportions and RRs were observed in TKAs. Interpretation - Despite the fact that the proportion of THA and TKA patients with comorbidities has increased over the past 18 years, the overall mortality has declined. The mortality risk depended on the comorbidity burden and did not decline during the study period for THA and TKA patients with a moderate or high comorbidity burden at the time of surgery.

Characteristics of Orthopedic Publications in High-Impact General Medical Journals

Orthopedic studies are occasionally published in high-impact general medical journals; these studies are often given high visibility and have significant potential to impact health care policy and inform clinical decision-making. The purpose of this review was to investigate the characteristics of operative orthopedic studies published in high-impact medical journals. The number of orthopedic studies published in high-impact medical journals is relatively low; however, these studies demonstrate methodological characteristics that may bias toward nonoperative treatment. Careful analysis and interpretation of orthopedic studies published in these journals is warranted. [Orthopedics. 2017; 40(3):e405-e412.].

Thoracic Unilateral Spinal Cord Injury After Spinal Anaesthesia for Total Hip Replacement: Fate or Mistake?

Spinal anaesthesia is the most preffered anesthesia technique for total hip replacement, and its complications range from low entity (insignificant) to life threatening. The incidence of neurologic complications after neuraxial anaesthesia is not perfectly clear, although there are several described cases of spinal cord ischaemia. We present a case of unilateral T8-T11 spinal cord ischaemia following L2-L3 spinal anaesthesia for total hip replacement. Magnetic resonance imaging showed a hyperintense T8-T11 signal alteration on the leftside of paramedian spinal cord. A temporal epidemiologic linkage between the damage and the surgery seems to be present. The injury occurred without anatomical proximity between the injury site and the spinal needle entry site. This may be due to multiple contributing factors, each of them is probably not enough to determine the damage by itself; however, acting simultaneously, they could have been responsible for the complication. The result was unpredictable and unavoidable and was caused by unforeseeable circumstances and not by inadequate medical practice.

The effect of patient age at intervention on risk of implant revision after total replacement of the hip or knee: a population-based cohort study

BACKGROUND

Total joint replacements for end-stage osteoarthritis of the hip and knee are cost-effective and demonstrate significant clinical improvement. However, robust population based lifetime-risk data for implant revision are not available to aid patient decision making, which is a particular problem in young patient groups deciding on best-timing for surgery.

METHODS

We did implant survival analysis on all patients within the Clinical Practice Research Datalink who had undergone total hip replacement or total knee replacement. These data were adjusted for all-cause mortality with data from the Office for National Statistics and used to generate lifetime risks of revision surgery based on increasing age at the time of primary surgery.

FINDINGS

We identified 63 158 patients who had undergone total hip replacement and 54 276 who had total knee replacement between Jan 1, 1991, and Aug 10, 2011, and followed up these patients to a maximum of 20 years. For total hip replacement, 10-year implant survival rate was 95·6% (95% CI 95·3-95·9) and 20-year rate was 85·0% (83·2-86·6). For total knee replacement, 10-year implant survival rate was 96·1% (95·8-96·4), and 20-year implant survival rate was 89·7% (87·5-91·5). The lifetime risk of requiring revision surgery in patients who had total hip replacement or total knee replacement over the age of 70 years was about 5% with no difference between sexes. For those who had surgery younger than 70 years, however, the lifetime risk of revision increased for younger patients, up to 35% (95% CI 30·9-39·1) for men in their early 50s, with large differences seen between male and female patients (15% lower for women in same age group). The median time to revision for patients who had surgery younger than age 60 was 4·4 years.

INTERPRETATION

Our study used novel methodology to investigate and offer new insight into the importance of young age and risk of revision after total hip or knee replacement. Our evidence challenges the increasing trend for more total hip replacements and total knee replacements to be done in the younger patient group, and these data should be offered to patients as part of the shared decision making process.

FUNDING

Oxford Musculoskeletal Biomedical Research Unit, National Institute for Health Research.

The Main Cause of Death Following Primary Total Hip and Knee Replacement for Osteoarthritis: A Cohort Study of 26,766 Deaths Following 332,734 Hip Replacements and 29,802 Deaths Following 384,291 Knee Replacements

BACKGROUND

Patients undergoing primary total joint replacement are selected for surgery and thus (other than having a transiently increased mortality rate postoperatively) have a lower mortality rate than age and sex-matched individuals do. Understanding the causes of death following joint replacement would allow targeted strategies to reduce the risk of death and optimize outcome. We aimed to determine the rates and causes of mortality for patients undergoing primary total hip or knee replacement compared with individuals in the general population who were matched for age and sex.

METHODS

We compared causes and rates of mortality between age and sex-matched individuals in the general population (National Joint Registry for England, Wales and Northern Ireland; Hospital Episode Statistics; and Office for National Statistics) and a linked cohort of 332,734 patients managed with total hip replacement (26,766 of whom died before the censoring date) and 384,291 patients managed with primary total knee replacement (29,802 of whom died before the censoring date) from 2003 through 2012.

RESULTS

The main causes of death were malignant neoplasms (33.8% [9,037] of 26,766 deaths in patients with total hip replacement and 33.3% [9,917] of 29,802 deaths in patients with total knee replacement), circulatory system disorders (32.8% [8,784] of the deaths in patients with total hip replacement and 33.3% [9,932] of the deaths in patients with total knee replacement), respiratory system disorders (10.9% [2,928] of the deaths in patients with total hip replacement and 9.8% [2,932] of the deaths in patients with total knee replacement), and digestive system diseases (5.5% [1,465] of the deaths in patients with total hip replacement and 5.3% [1,572] of the deaths in patients with total knee replacement). There was a relative reduction in mortality (39%) compared with the individuals in the general population that equalized to the rate in the general population by 7 years for hips (overall standardized mortality ratio [SMR], 0.61; 95% confidence interval [CI], 0.60 to 0.62); for knees, the relative reduction (43%) partially attenuated by 7 years but still had not equalized to the rate in the general population (overall SMR, 0.57; 95% CI, 0.56 to 0.57). Ischemic heart disease was the most common cause of death within 90 days (29% [431] of the deaths in patients with primary hip replacement and 31% [436] of the deaths in patients with primary knee replacement). There was an elevated risk of death from circulatory, respiratory, and (most markedly) digestive system-related causes within 90 days postoperatively compared with 91 days to 1 year postoperatively.

CONCLUSIONS

Ischemic heart disease is the leading cause of death in the 90 days following total joint replacement, and there is an increase in postoperative deaths associated with digestive system-related disease following joint replacement. Interventions targeted at reducing these diseases may have the largest effect on mortality in total joint replacement patients.

LEVEL OF EVIDENCE

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

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.

Effects of preoperative chronic hypoxemia on geriatrics outcomes after hip arthroplasty: A hospital-based retrospective analysis study

The partial pressure of oxygen decreases as altitude increases, the preoperative chronic hypoxemia (CH) may have a plausible clinical impact. Risk factors for postoperative serious adverse events (pSAEs) in patients living in high altitudes during primary hip arthroplasty (HA) are not clear.This is an observational study embracing patients from January 1, 2011 to December 31, 2015 at Yan'an Hospital of Kunming City, a 1338-bed municipal teaching hospital of Kunming Medical University. Univariate analysis revealed that significant differences between patients with and without preoperative CH occurred in intraoperative hypotension (77 [33%] vs 34 [47%], P = .040) and that significant differences between patients with and without pSAEs occurred in following variables: preoperative CH (32 [57%] vs 199 [80%], P < .001), intraoperative hypotension (37 [66%] vs 74 [30%], P < .001), highest noradrenaline support (.09 [.01-.21] vs .03 [.01-.05] μg/kg/min, P < .001), higher application of general anesthesia (15 [27%] vs 29 [12%], P = .004), and lower of combined-spinal epidural anesthesia (CSEA) (21 [37%] vs 165 [66%], P < .001). The general anesthesia and intraoperative hypotension remained the independent risk factors for pSAEs (P < .05), while the preoperative CH presented by decreasing its risk (P < .05).This study suggests that various intraoperative events including general anesthesia, hypotension were risk factors for the development of pSAEs. Preoperative CH, presenting with decreased incidence of intensive care unit (ICU) admission and pSAEs, may mimic hypoxic preconditioning in organic protection, for which further study is needed to uncover the underlying mechanisms.

Time course and reasons for 90-day mortality in fast-track hip and knee arthroplasty

BACKGROUND

Post-operative mortality is an important adverse outcome, including in total hip (THA) and knee arthroplasty (TKA). However, whether mortality is due to anaesthetic/surgical complications, surgically induced organ dysfunction or unrelated to surgery is rarely considered.

METHODS

Prospective observational study in 13,775 consecutive THA/TKAs with similar fast-track protocols and a median length of stay of 2 days. Complete 90-days follow-up through national registries, followed by review of medical records and death certificates. Relation between mortality and surgically induced organ dysfunction were classified as certain, probable, possible or unlikely.

RESULTS

Of a total of 44 deaths (0.3%), 28 (0.2%) were found to have certain or probably relation with surgery and were considered as surgery-related. Surgery-related deaths were more common after THA than TKA (0.3% vs. 0.1% P = 0.044), occurred after median 14 days and 19 of 28 were between day 0-30. Of the remaining 16 deaths (0.1%), nine were found to be possible and seven to be unlikely related to surgery, and occurred a median of 42 and 61 days after surgery. The most common initial organ dysfunction for surgery-related deaths was pulmonary (6/28) and gastrointestinal (6/28), while the most common reported cause of death were pulmonary (9/28) and cardiac events (6/28). In five of the seven unlikely related deaths mortality was attributed to underlying cancer.

CONCLUSION

Ninety-days mortality was 0.3% in THA and TKA, but only 28 of 44 deaths (64%) were found to be surgery-related. Reporting total mortality rate or cause of death without considerations on surgery induced organ dysfunction, may be insufficient for future aims to reduce post-operative mortality.

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.

Postoperative start compared to preoperative start of low-molecular-weight heparin increases mortality in patients with femoral neck fractures

Background and purpose - Controversies exist regarding thromboprophylaxis in orthopedic surgery. Using data in the nationwide Norwegian Hip Fracture Register (NHFR) with postoperative death and reoperation in the first 6 months after surgery as endpoints in the analyses, we determined whether the thromboprophylaxis in patients who undergo hemiarthroplasty for femoral neck fracture should start preoperatively or postoperatively. Patients and methods - After each operation for hip fracture in Norway, the surgeon reports information on the patient, the fracture, and the operation to the NHFR. Cox regression analyses were performed with adjustments for age, ASA score, gender, type of implant, length of surgery, and year of surgery. Results - During the period 2005-2014, 25,019 hemiarthroplasties as treatment for femoral neck fractures were reported to the registry. Antithrombotic medication was given to 99% of the patients. Low-molecular-weight heparin predominated with dalteparin in 57% of the operations and enoxaparin in 41%. Only operations with these 2 drugs and with known information on preoperative or postoperative start of the prophylaxis were included in the analyses (n = 20,241). Compared to preoperative start of thromboprophylaxis, postoperative start of thromboprophylaxis gave a higher risk of death (risk ratio (RR) = 1.13, 95% CI: 1.06-1.21; p < 0.001) and a higher risk of reoperation for any reason (RR =1.19, 95% CI: 1.01-1.40; p = 0.04), whereas we found no effect on reported intraoperative bleeding complication or on the risk of postoperative reoperation due to hematoma. The results did not depend on whether the initial dose of prophylaxis was the full dosage or half of the standard dosage. Interpretation - Postoperative start of thromboprophylaxis increased the mortality and risk of reoperation compared to preoperative start in femoral neck fracture patients operated with hemiprosthesis. The risks of bleeding and of reoperation due to hematoma were similar in patients who received low-molecular-weight heparin preoperatively and in those who received it postoperatively.

ORIF or Arthroplasty for Displaced Femoral Neck Fractures in Patients Younger Than 65 Years Old: An Economic Decision Analysis

BACKGROUND

The decision between open reduction and internal fixation (ORIF) and arthroplasty for a displaced femoral neck fracture in a patient ≤65 years old can be challenging. Both options have potential drawbacks; if a fracture treated with ORIF fails to heal it may require a revision operation, whereas a relatively young patient who undergoes arthroplasty may need revision within his/her lifetime. The purpose of this study was to employ decision analysis modeling techniques to generate evidence-based treatment recommendations in this clinical scenario.

METHODS

A Markov decision analytic model was created to simulate outcomes after ORIF, total hip arthroplasty (THA), or hemiarthroplasty in patients who had sustained a displaced femoral neck fracture between the ages of 40 and 65 years. The variables in the model were populated with values from studies with high-level evidence and from national registry data reported in the literature. The model was used to estimate the threshold age above which THA would be the superior strategy. Results were tested using sensitivity analysis and probabilistic statistical analysis.

RESULTS

THA was found to be a cost-effective option for a displaced femoral neck fracture in an otherwise healthy patient who is >54 years old, a patient with mild comorbidity who is >47 years old, and a patient with multiple comorbidities who is >44 years old. The average clinical outcomes of THA and ORIF were similar for patients 40 to 65 years old, although ORIF had a wider variability in outcomes based on the success or failure of the initial fixation. For all ages and cases, hemiarthroplasty was associated with worse outcomes and higher costs.

CONCLUSIONS

Compared with ORIF, primary THA can be a cost-effective treatment for displaced femoral neck fractures in patients 45 to 65 years of age, with the age cutoff favoring THA decreasing as the medical comorbidity and risk of ORIF fixation failure increase. Hemiarthroplasty has worse outcomes at higher costs and is not recommended in this age group.

LEVEL OF EVIDENCE

Economic and decision analysis Level III. See Instructions for Authors for a complete description of levels of evidence.

Risk of early mortality after cemented compared with cementless total hip arthroplasty

Aims

It has been suggested that cemented fixation of total hip arthroplasty (THA) is associated with an increased peri-operative mortality compared with cementless THA. Our aim was to investigate this through a nationwide matched cohort study adjusting for age, comorbidity, and socioeconomic background.

Patients and Methods

A total of 178 784 patients with osteoarthritis who underwent either cemented or cementless THA from the Swedish Hip Arthroplasty Register were matched with 862 294 controls from the general population. Information about the causes of death, comorbidities, and socioeconomic background was obtained. Mortality within the first 90 days after the operation was the primary outcome measure.

Results

Patients who underwent cemented THA had an increased risk of death during the first 14 days compared with the controls (hazard ratio (HR) 1.3, confidence interval (CI) 1.11 to 1.44), corresponding to an absolute increase in risk of five deaths per 10 000 observations. No such early increase of risk was seen in those who underwent cementless THA. Between days 15 and 29 the risk of mortality was decreased for those with cemented THA (HR 0.7, CI 0.62 to 0.87). Between days 30 and 90 all patients undergoing THA, irrespective of the mode of fixation, had a lower risk of death than controls. Patients selected for cementless fixation were younger, healthier and had a higher level of education and income than those selected for cemented THA. A supplementary analysis of 16 556 hybrid THAs indicated that cementation of the femoral component was associated with a slight increase in mortality up to 15 days, whereas no such increase in mortality was seen in those with a cemented acetabular component combined with a cementless femoral component.

Conclusion

This nationwide matched cohort study indicates that patients receiving cemented THA have a minimally increased relative risk of early mortality that is reversed from day 15 and thereafter. The absolute increase in risk is very small. Our findings lend support to the idea that cementation of the femoral component is more dangerous than cementation of the acetabular component. Cite this article: Bone Joint J 2017;99-B:37–43.

The Relative Merits of Cemented and Uncemented Prostheses in Total Hip Arthroplasty

The results of modern cemented and uncemented total hip arthroplasties are outstanding and both systems have their advantages and disadvantages. This paper aims to examine the designs of different types of prostheses, some history behind their development and the reported results. Particular emphasis is placed on cemented stem design and the details of cementing technique.

Adverse reactions to metal debris occur with all types of hip replacement not just metal-on-metal hips: a retrospective observational study of 3340 revisions for adverse reactions to metal debris from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man

BACKGROUND

Adverse reactions to metal debris (ARMD) have resulted in the high short-term failure rates observed with metal-on-metal hip replacements. ARMD has recently been reported in non-metal-on-metal total hip replacements (non-MoM THRs) in a number of small cohort studies. However the true magnitude of this complication in non-MoM THRs remains unknown. We used a nationwide database to determine the risk of ARMD revision in all non-MoM THRs, and compared patient and surgical factors associated with ARMD revision between non-MoM and MoM hips.

METHODS

We performed a retrospective observational study using data from the National Joint Registry for England, Wales, Northern Ireland and the Isle of Man. All primary hip replacements undergoing revision surgery for ARMD were included (n = 3,340). ARMD revision risk in non-MoM THRs was compared between different commonly implanted bearing surfaces and femoral head sizes (Chi-squared test). Differences in patient and surgical factors between non-MoM hips and MoM hips revised for ARMD were also analysed (Chi-squared test and unpaired t-test).

RESULTS

Of all ARMD revisions, 7.5% (n = 249) had non-MoM bearing surfaces. The relative risk of ARMD revision was 2.35 times (95% CI 1.76-3.11) higher in ceramic-on-ceramic bearings compared with hard-on-soft bearings (0.055 vs. 0.024%; p < 0.001), and 2.80 times (95% CI 1.74-4.36) higher in 36 mm metal-on-polyethylene bearings compared to 28 mm and 32 mm metal-on-polyethylene bearings (0.058 vs. 0.021%; p < 0.001). ARMD revisions were performed earlier in non-MoM hips compared to MoM hips (mean 3.6-years vs. 5.6-years; p < 0.0001). Non-MoM hips had more abnormal findings at revision (63.1 vs. 35.7%; p < 0.001), and more intra-operative adverse events (6.4 vs. 1.6%; p < 0.001) compared to MoM hips.

CONCLUSIONS

Although the overall risk of ARMD revision surgery in non-MoM THRs appears low, this risk is increasing, and is significantly higher in ceramic-on-ceramic THRs and 36 mm metal-on-polyethylene THRs. ARMD may therefore represent a significant clinical problem in non-MoM THRs.

Fluoroscopy-guided biodegradable spacer implantation using local anesthesia: safety and efficacy study in patients with massive rotator cuff tears

BACKGROUND

The management of massive rotator cuff tears (MRCTs) is challenging and associated with a high failure rates. Studies have shown that advanced age, lower American Society of Anesthesiologists physical status score and concomitant comorbidities are associated with higher risks of death and postoperative complications. This study was designed to assess the safety and efficacy of fluoroscopy-guided biodegradable spacer implantation under local anesthesia, in patients with MRCT and comorbidities completely or partially contraindicating surgeries under general anesthesia.

METHODS

In this open-label, single arm, prospective study, subjects with MRCTs underwent subacromial fluoroscopy-guided implantation with a biodegradable spacer (InSpace™ system) under local anesthesia. Fifteen patients were treated and assessed. Follow-up visits were scheduled according to routine clinical practice. Shoulder function was evaluated using Constant (CS) and American Shoulder and Elbow Society (ASES) scores.

RESULTS

All patients demonstrated an overall improvement in the total CS and ASES beginning at 6 weeks and sustained by at least 12 months postoperatively. Of the 15 patients who reached the 1-year follow-up, 85% showed a clinically significant improvement of at least 15 points in their Constant score starting at 6 weeks postoperation and maintained throughout the entire follow-up period.

CONCLUSIONS

We conclude that in this initial patient's cohort, fluoroscopy-guided implantation of InSpace™ system under local anesthesia, represented an effective alternative to the existing procedures. This procedure may be considered as a treatment option for elderly patients or for patients with multiple comorbidities complicating or contraindicating surgery under general anesthesia. Technically easy, this technique can be an effective tool in the armamentarium of most orthopedic surgeons. Level of proof: single-arm prospective study, Level II.

Choice of hospital: Which type of quality matters?

The implications of hospital quality competition depend on what type of quality affects choice of hospital. Previous studies of quality and choice of hospitals have used crude measures of quality such as mortality and readmission rates rather than measures of the health gain from specific treatments. We estimate multinomial logit models of hospital choice by patients undergoing hip replacement surgery in the English NHS to test whether hospital demand responds to quality as measured by detailed patient reports of health before and after hip replacement. We find that a one standard deviation increase in average health gain increases demand by up to 10%. The more traditional measures of hospital quality are less important in determining hospital choice.

Incidence, Risk Factors, and Sources of Sepsis Following Total Joint Arthroplasty

BACKGROUND

Sepsis is a rare but serious complication following total joint arthroplasty (TJA). Common sources include urinary tract infection (UTI), surgical site infection (SSI), and pneumonia. The purpose of this study is to characterize the incidence, risk factors, and sources of sepsis following TJA.

METHODS

Patients undergoing primary total hip arthroplasty or total knee arthroplasty during 2005-2013 were identified in the American College of Surgeons National Surgical Quality Improvement Program database. Independent associations were tested for using multivariate regression adjusting for baseline characteristics.

RESULTS

A total of 117,935 patients were identified (45,612 undergoing total hip arthroplasty and 72,323 undergoing total knee arthroplasty). Of these, 402 (0.34%) developed sepsis following surgery. Patients who developed sepsis had an elevated mortality rate (3.7% vs 0.1%, P < .001). Among the 402 patients who developed sepsis, 124 (31%) had concomitant UTI, 110 (27%) SSI, and 60 (15%) pneumonia. Twenty-one patients (5%) had multiple infectious sources and 129 patients (32%) had no identifiable source. Independent risk factors for sepsis included greater age, male sex, functional dependence, insulin-dependent diabetes, hypertension, chronic obstructive pulmonary disease, current smoker, and greater operative time.

CONCLUSION

These findings suggest that the rate of sepsis following TJA is about 1 in 300, and that sepsis is associated with a high risk of mortality. The most common sources of sepsis are UTI, SSI, and pneumonia, potentially accounting for at least two-thirds of cases. The information provided here can be used to guide the diagnostic workup of sepsis in patients following TJA.

Direct lateral vs posterolateral approach to hemiarthroplasty for femoral neck fractures

INTRODUCTION

Adopting the direct lateral (DL) instead of the posterolateral (PL) approach in hip arthroplasty for femoral neck fracture (FNF) patients could lower the rate of prosthetic dislocation. However, little is known about how the approach influences the functional outcome.

HYPOTHESIS

We hypothesized that both approaches would give comparable results.

MATERIAL AND METHODS

In a prospective cohort study, we enrolled 185 hips (183 patients, 128 women, median age 84 years) with a displaced FNF. Subjects were assigned to treatment using DL (n=102) or PL approach (n=83) with a hemiarthroplasty (HA). Functional outcome was assessed by Harris Hip Score (HHS), Western Ontario and McMaster Universities Arthritis (WOMAC) index, pain numeric rating scale (PNRS) for pain, mortality and hip complications. Patients were followed-up after 1 year.

RESULTS

The HHS was 71 (SD 18) in the DL group and 72 (SD 17) in the PL group (P=0.59). We found no difference in WOMAC, PNRS and mortality. Seven patients (6.9%) in the DL group and 11 patients (13.3%) in the PL group had undergone a major reoperation (adjusted OR 0.51; 95% CI, 0.18-2.07; P=0.23).

DISCUSSION

In this prospective cohort study, patients treated with HA for FNF using either the DL or PL approaches had comparable functional outcome after 1 year. The PL approach had a tendency towards a higher reoperation rate.

TYPE OF STUDY

Prospective cohort study.

LEVEL OF PROOF

Level 2.

Early mortality and morbidity after total hip arthroplasty in patients with femoral neck fracture

Background and purpose - Early postoperative mortality is relatively high after total hip arthroplasty (THA) that has been performed due to femoral neck fracture. However, this has rarely been investigated after adjustment for medical comorbidity and comparison with the mortality in an age-matched population. We therefore assessed early mortality in hip fracture patients treated with a THA, in the setting of a nationwide matched cohort study. Patients and methods - 24,699 patients who underwent THA due to a femoral neck fracture between 1992 and 2012 were matched with 118,518 controls. Kaplan-Meier survival analysis was used to calculate cumulative unadjusted survival, and Cox regression models were fitted to compute hazard ratios (HRs) and 95% confidence intervals (CIs), with adjustment for age, sex, comorbidity, and socioeconomic background. Results - 90-day survival was 96.3% (95% CI: 96.0-96.5) for THA cases and 98.7% (95% CI: 98.6-98.8) for control individuals, giving an adjusted HR of 2.2 (95% CI: 2.0-2.4) for THA cases compared to control individuals. Comorbidity burden increased in THA cases over time, but the adjusted risk of death within 90 days did not differ statistically significantly between the time periods investigated (1992-1998, 1999-2005, and 2006-2012). A Charlson comorbidity index of 3 or more, an American Society of Anesthesiologists (ASA) grade of 3 and above, male sex, an age of 80 years and above, an income below the first quartile, and a lower level of education were all associated with an increased risk of 90-day mortality. Interpretation - The adjusted early mortality in femoral neck fracture patients who underwent THA was about double that in a matched control population. Patients with femoral neck fracture but with no substantial comorbidity and an age of less than 80 years appear to have a low risk of early death. Patients older than 80 years and those with a Charlson comorbidity index of more than 2 have a high risk of early death, and such patients would perhaps benefit from treatment strategies other than THA, but this should be investigated further.

No Increased Risk for Primary Osteoarthritis in Liver Cirrhosis - A Danish Nationwide Cohort Study

Objective

Chronic synovial inflammation causes primary osteoarthritis, but it is unknown whether chronic systemic inflammation does, too. Patients with cirrhosis have chronic systemic inflammation and therefore we examined the association between cirrhosis and primary osteoarthritis of the hip and knee.

Methods

In Danish healthcare databases we identified all residents over 60 years diagnosed with cirrhosis in 1994–2011, and for each of them we sampled five age- and gender-matched reference persons from the general population. We excluded everyone with risk factors for secondary osteoarthritis and computed incidence rates of primary osteoarthritis of the hip or knee. We used stratified Cox regression to estimate the hazard ratios of primary osteoarthritis for cirrhosis patients vs. reference persons in strata defined by gender, age, cirrhosis etiology, and ascites vs. no ascites. We also computed separate HRs for primary osteoarthritis of the hips or knees.

Results

We identified 10,049 cirrhosis patients. Their median age was 67 years, and 65% were men. Among the cirrhosis patients the crude incidence rate of primary osteoarthritis was 8.40 (95% CI: 7.30–9.63) per 1000 person-years. The rate was similar in the reference persons: 8.76 (95% CI: 8.43–9.12) per 1000 person-years. Accordingly, the hazard ratio for primary osteoarthritis for cirrhosis patients vs. reference persons was 0.99 (95% CI: 0.85–1.16), and we found the same null association in all patient strata and in both joints.

Conclusion

Cirrhosis, and thus chronic systemic inflammation, is not a risk factor for primary osteoarthritis.