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

Incidence of Infection and Inhospital Mortality in Patients With Chronic Renal Failure After Total Joint Arthroplasty

BACKGROUND

Patients with chronic renal failure (CRF) may require total joint arthroplasty (TJA) to treat degenerative joint disease, fractures, osteonecrosis, or amyloid arthropathy. There have been conflicting results, however, regarding outcomes of TJA in patients with chronic renal disease. The aim of this case-controlled study was to determine the outcome of TJA in patients with CRF, with particular interest in the incidence of infections and inhospital mortality.

METHODS

We queried our electronic database to determine which patients among the 29,389 TJAs performed at our institution between January 2000 and June 2012 had a diagnosis of CRF. A total of 359 CRF patients were identified and matched for procedure, gender, age (±4 years), date of surgery (±2 years), and body mass index (±5 kg/m²) in a 2:1 ratio to 718 control patients.

RESULTS

The incidence of infection and inhospital mortality was not significantly different between the nondialysis CRF patients and controls, whereas it was significantly higher in dialysis-dependent end-stage renal failure patients compared to controls. Of the 50 CRF patients receiving hemodialysis, 10 (20%) developed surgical site infection, of which 4 (8%) were periprosthetic joint infection, and 4 (8%) died during hospital stay. The odds ratio for infection in the dialysis group was 7.54 (95% confidence interval: 2.83-20.12) and 10.46 (95% confidence interval: 1.67-65.34) for the inhospital mortality.

CONCLUSION

We conclude that end-stage renal failure patients receiving hemodialysis have higher postoperative infection and inhospital mortality rates after an elective TJA procedure, whereas nondialysis CRF patients have similar outcomes compared with the general TJA population.

Individual surgeon mortality rates: can outliers be detected? A national utility analysis

OBJECTIVES

There is controversy on the proposed benefits of publishing mortality rates for individual surgeons. In some procedures, analysis at the level of an individual surgeon may lack statistical power. The aim was to determine the likelihood that variation in surgeon performance will be detected using published outcome data.

DESIGN

A national analysis surgeon-level mortality rates to calculate the level of power for the reported mortality rate across multiple surgical procedures.

SETTING

The UK from 2010 to 2014.

PARTICIPANTS

Surgeons who performed colon cancer resection, oesophagectomy or gastrectomy, elective aortic aneurysm repair, hip replacement, bariatric surgery or thyroidectomy.

OUTCOMES

The likelihood of detecting an individual with a 30-day, 90-day or in-patient mortality rate of up to 5 times the national mean or median (as available). This was represented using a novel heat-map approach.

RESULTS

Overall mortality rates for the procedures ranged from 0.07% to 4.5% and mean/median surgeon volume was between 23 and 75 cases. The national median case volume for colorectal (n=55) and upper gastrointestinal (n=23) cancer resections provides around 20% power to detect a mortality rate of 3 times the national median, while, for hip replacement, this is a rate 5 times the national average. At the mortality rates reported for thyroid (0.08%) and bariatric (0.07%) procedures, it is unlikely a surgeon would perform a sufficient number of procedures in his/her entire career to stand a good chance of detecting a mortality rate 5 times the national average.

CONCLUSIONS

At present, surgeons with increased mortality rates are unlikely to be detected. Performance within an expected mortality rate range cannot be considered reliable evidence of acceptable performance. Alternative approaches should focus on commonly occurring meaningful outcome measures, with infrequent events analysed predominately at the hospital level.

[Pain after major elective orthopedic surgery of the lower limb and type of anesthesia: does it matter?]

BACKGROUND AND OBJECTIVES

Total knee arthroplasty and total hip arthroplasty are associated with chronic pain development. Of the studies focusing on perioperative factors for chronic pain, few have focused on the differences that might arise from the anesthesia type performed during surgery.

METHODS

This was a prospective observational study performed between July 2014 and March 2015 with patients undergoing unilateral elective total knee arthroplasty (TKA) or total hip arthroplasty (THA) for osteoarthritis. Data collection and pain evaluation questionnaires were performed in three different moments: preoperatively, 24hours postoperatively and at 6 months after surgery. To characterize pain, Brief Pain Inventory (BPI) was used and SF-12v2 Health survey was used to further evaluate the sample's health status.

RESULTS

Forty and three patients were enrolled: 25.6% men and 74.4% women, 51,2% for total knee arthroplasty and48.8% for total hip arthroplasty, with a mean age of 68 years. Surgeries were performed in 25.6% of patients under general anesthesia, 55.8% under neuraxial anesthesia and 18.6% under combined anesthesia. Postoperatively, neuraxial anesthesia had a better pain control. Comparing pain evolution between anesthesia groups, neuraxial anesthesia was associated with a decrease in "worst", "medium" and "now" pain at six months. Combined anesthesia was associated with a decrease of "medium" pain scores at six months. Of the three groups, only those in neuraxial group showed a decrease in level of pain interference in "walking ability". TKA, "worst" pain preoperatively and general were predictors of pain development at six months.

CONCLUSIONS

Patients with gonarthrosis and severe pain preoperatively may benefit from individualized pre- and intraoperative care, particularly preoperative analgesia and neuraxial anesthesia.

Pain after major elective orthopedic surgery of the lower limb and type of anesthesia: does it matter?

BACKGROUND AND OBJECTIVES

Total knee arthroplasty and total hip arthroplasty are associated with chronic pain development. Of the studies focusing on perioperative factors for chronic pain, few have focused on the differences that might arise from the anesthesia type performed during surgery.

METHODS

This was a prospective observational study performed between July 2014 and March 2015 with patients undergoing unilateral elective total knee arthroplasty (TKA) or total hip arthroplasty (THA) for osteoarthritis. Data collection and pain evaluation questionnaires were performed in three different moments: preoperatively, 24 hours postoperatively and at 6 months after surgery. To characterize pain, Brief Pain Inventory (BPI) was used and SF-12v2 Health survey was used to further evaluate the sample's health status.

RESULTS

Forty and three patients were enrolled: 25.6% men and 74.4% women, 51,2% for total knee arthroplasty and48.8% for total hip arthroplasty, with a mean age of 68 years. Surgeries were performed in 25.6% of patients under general anesthesia, 55.8% under neuraxial anesthesia and 18.6% under combined anesthesia. Postoperatively, neuraxial anesthesia had a better pain control. Comparing pain evolution between anesthesia groups, neuraxial anesthesia was associated with a decrease in "worst", "medium" and "now" pain at six months. Combined anesthesia was associated with a decrease of "medium" pain scores at six months. Of the three groups, only those in neuraxial group showed a decrease in level of pain interference in "walking ability". TKA, "worst" pain preoperatively and general were predictors of pain development at six months.

CONCLUSIONS

Patients with gonarthrosis and severe pain preoperatively may benefit from individualized pre- and intraoperative care, particularly preoperative analgesia and neuraxial anesthesia.

Evaluation of three co-morbidity measures to predict mortality in patients undergoing total joint arthroplasty

OBJECTIVE

To evaluate the 90 days and 1 year mortality predictive ability of the RxRisk-V, Charlson, and Elixhauser co-morbidity measures in total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients.

METHOD

A retrospective study of 11,848 THAs and 18,972 TKAs (2001-2002) was conducted. Death within 90 days and 1 year of the surgery were the main endpoints. Co-morbidity measures were calculated using either medication or hospitalisation history. Logistic regression models were employed and discrimination and calibration were assessed. Specifically, models with unweighted and weighted measure scores, models with the specific conditions, and a model combining conditions identified by all measures were assessed.

RESULTS

In THAs, the best performing prediction models included co-morbidities from all three measures (90 days: c = 0.84, P = 0.284, 1 year: c = 0.79, P = 0.158). Individually, the model with Charlson conditions performed best at 90 days mortality (c = 0.80, P = 0.777) and the Charlson and Elixhauser performed similarly at 1 year (both c = 0.77, P > 0.05). In TKAs, the best performing prediction model included co-morbidities from all measures (90 days: c = 0.82, P = 0.349, 1 year: c = 0.78, P = 0.873). Individually, the model with Elixhauser conditions performed best with 90 days mortality (c = 0.79, P = 0.435) and all performed similarly at 1 year (c = 0.74-0.75, all P > 0.05).

CONCLUSIONS

A combined model with co-morbidities identified by the Elixhauser, Charlson, and RxRisk-V was the best mortality prediction model. The RxRisk-V did not perform as well as the others. Because of the Elixhauser and Charlson's similar performance we suggest basing the choice of measurement use on factors such as the need of specific conditions and modelling limitations.

Post-operative serious adverse events in a mixed surgical population - a retrospective register study

BACKGROUND

The number of surgical procedures is increasing, and knowledge of surgical risk factors, post-operative mortality and serious adverse events (SAE) is essential. The aim with our study was to determine the risk of a composite outcome of post-operative: death; myocardial infarction; pulmonary embolism; stroke; gastrointestinal bleeding; dialysis or reoperation.

METHODS

Data of surgical procedures in the period from January 1, 2012 to June 30, 2012 were retrieved from the Danish Anaesthesia Database (DAD). Follow-up of all patients undergoing hip or knee replacement, abdominal or gynaecological surgery was conducted retrieving data from The Danish Civil Registration System and the National Patient Register. Total observation time was from January 1, 2012 to June 6, 2013.

RESULTS

A total7449 adult patients were included in the final analysis. The risk of the composite outcome during a follow-up until 342 days after inclusion of the last patient was estimated to 8.3%, 95% Confidence Intervals (CI) (7.8-9.0), with a median observation time of 437 days (IQR 387-485, range 0-522). The risk of the composite outcome within 90- and 180-day follow-up of each patient was 4.8% (4.4-5.3) and 5.9% (5.4-6.5), respectively. Mortality within longest follow-up as well as 90 and 180 days post-operatively was 3.6% (3.1-4.0), 1.7% (1.4-2.0), and 2.2% (1.9-2.6), respectively.

CONCLUSION

We found a risk of one or more events in the composite outcome within 342 days after inclusion of the last patients of 8.3% (7.8-9.0). The results are applicable in estimations of adequate sample sizes in future clinical trials investigating effects of interventions on SAEs.

Venous thromboembolism after lower limb arthroplasty: is chemical prophylaxis still needed?

BACKGROUND

Venous thromboembolism (VTE) is a significant complication of lower limb arthroplasty. The National Institute for Health and Care Excellence recommends routine use of chemical and mechanical prophylaxis to prevent VTE. Our high-volume, elective, arthroplasty unit adopted this guidance in 2008.

PURPOSE

We examined our incidence of VTE before and after introduction of chemical thromboprophylaxis to determine whether the incidence of VTE reduced.

METHODS

We retrospectively gathered data on 2 cohorts of patients-from January 2004 to August 2007 (Group 1) and January 2010 to December 2012 (Group 2). Patients in Group 1 received mechanical prophylaxis only (unless particularly high risk for VTE), and patients in Group 2 received mechanical and chemical prophylaxis. We recorded VTE occurring within 6 months of surgery. Patients in Group 1 receiving chemical prophylaxis were excluded.

RESULTS

Group 1 had 2320 cases of primary and revision lower limb arthroplasty, and Group 2 had 1430 cases. VTE occurred in 37 cases in Group 1 (1.6 %), and in 17 cases in Group 2 (1.2 %). This difference was not statistically significant (p = 0.26). In Group 1, 1 patient died within 6 months due to pulmonary embolism (0.04 %); there were no VTE-related deaths in Group 2 (0 %). This was also not statistically significant (p = 0.06).

CONCLUSIONS

Although our VTE rate reduced by 0.4 % and our VTE-related mortality reduced by 0.04 % after introduction of chemical thromboprophylaxis, these differences were not statistically significant. Chemical thromboprophylaxis may not be required in all patients undergoing arthroplasty providing appropriate mechanical prophylaxis is used.

Aspirin for thromboprophylaxis after primary lower limb arthroplasty: early thromboembolic events and 90 day mortality in 11,459 patients

AIMS

The aim of this study was to present data on 11 459 patients who underwent total hip (THA), total knee (TKA) or unicompartmental knee arthroplasty (UKA) between November 2002 and April 2014 with aspirin as the primary agent for pharmacological thromboprophylaxis.

PATIENTS AND METHODS

We analysed the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) then compared the 90-day all-cause mortality with the corresponding data in the National Joint Registry for England and Wales (NJR).

RESULTS

The incidence of PE was 0.6% after THA, 1.47% after TKA and 1.2% after UKA. The 90-day mortality was 0.39% after THA and 0.44% after TKA. No deaths occurred after UKA. The main causes of death were ischaemic heart disease and respiratory failure. PE was responsible for only 18% of deaths. There was a decline in 90-day mortality, from 0.64% between 2002 and 2007, to 0.21% between 2008 and 2013 after THA, and from 0.47% to 0.39% after TKA for the corresponding period. The standardised mortality ratio (SMR) declined from 86.5 (confidence interval (CI) 63.0 to 137.7) to 39.7 (CI 31.2 to 54.3) p = 0.024. The incidence of proximal DVT was 0.3%.

TAKE HOME MESSAGE

With individualised risk assessment and as part of a multimodal approach, Aspirin is safe to use as the main thromboprophylactic agent in primary arthroplasty. It is not associated with an increased incidence of symptomatic DVT, PE or death.

The manufacture of generic replicas of implants for arthroplasty of the hip and knee

Joint replacement of the hip and knee remain very satisfactory operations. They are, however, expensive. The actual manufacturing of the implant represents only 30% of the final cost, while sales and marketing represent 40%. Recently, the patents on many well established and successful implants have expired. Companies have started producing and distributing implants that purport to replicate existing implants with good long-term results.

The aims of this paper are to assess the legality, the monitoring and cost saving implications of such generic implants. We also assess how this might affect the traditional orthopaedic implant companies.

Cite this article: Bone Joint J 2016;98-B:892–900.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Quality measures for total ankle replacement, 30-day readmission and reoperation rates within 1 year of surgery: a data linkage study using the NJR data set

OBJECTIVE

To report on the rate of 30-day readmission and the rate of additional or revision surgery within 12 months following total ankle replacement (TAR).

DESIGN

A data-linkage study of the UK National Joint Registry (NJR) data and Hospital Episodes Statistics (HES) database. These two databases were linked in a deterministic fashion. HES episodes 12 months following the index procedure were isolated and analysed. Logistic regression was used to model predictors of reoperation and revision for primary ankle replacement.

PARTICIPANTS

All patients who underwent primary and revision ankle replacements according to the NJR between February 2008 and February 2013.

RESULTS

The rate of 30-day readmission following primary and revision ankle replacement was 2.2% and 1.3%, respectively. In the 12 months following primary and revision ankle replacements, the revision rate (where implants needed to be removed) was 1.2% with increased odds in those orthopaedic units preforming <20 ankle replacements per year and patients with a preoperative fixed equinus deformity. The reoperation other than revision (where implants were not removed) in the 12 months following primary and revision TARs was 6.6% and 9.3%, respectively. Rheumatoid arthritis, cemented prosthesis and high ASA grade significantly increased the odds of reoperation.

CONCLUSIONS

TAR has a 30-day readmission rate of 2.2%, which is similar to that of knee replacement but lower than that of total hip replacement. 6.6% of patients undergoing primary TAR require a reoperation within 12 months of the index procedure. Early revision rates are significantly higher in low-volume centres.

Fatal pulmonary embolism following elective total hip arthroplasty

Aims

The place of thromboprophylaxis in arthroplasty surgery remains controversial, with a challenging requirement to balance prevention of potentially fatal venous thrombo-embolism with minimising wound-related complications leading to deep infection. We compared the incidence of fatal pulmonary embolism in patients undergoing elective primary total hip arthroplasty (THA) between those receiving aspirin, warfarin and low molecular weight heparin (LMWH) for the chemical component of a multi-modal thromboprophylaxis regime.

Patients and Methods

A prospective audit database was used to identify patients who had died within 42 and 90 days of surgery respectively between April 2000 and December 2012. A case note review was performed to ascertain the causes of death.

Results

During this period 7983 THAs were performed. The rate of mortality was 0.43% and 0.58% at 42 and 90 days respectively. The groups comprised 1571 patients (19.7%) on warfarin, 1838 (23.0%) on LMWH and 4574 (57.3%) on aspirin. The 90-day mortality for these three groups was 0.38%, 1.09% and 0.43% respectively. The higher mortality rate for LMWH was significant (p < 0.05). There were six fatal pulmonary emboli (PEs) (0.08%). A total of three occurred within 42 days, all in the LMWH group. A total of three occurred between 42 and 90 days; one on warfarin, two on LMWH. The leading causes of death in all three groups were lower respiratory tract infections and myocardial infarction.

Conclusion

We confirmed that fatal PE following elective THA with a multi-modal prophylaxis regime is rare. We further found that LMWH conferred no benefit over aspirin in this context, and is associated with a higher all-cause rate of mortality. Take home message: This study proposes that aspirin may be an appropriate thromboprophylaxis agent when used as part of a multi-modal regimen, suggesting current guidelines should be reviewed. Cite this article: Bone Joint J 2016;98-B:585–8.

Factors influencing the choice of anesthetic technique for primary hip and knee arthroplasty

Despite evidence in the literature, continuing wide variation exists in anesthetic technique for primary joint arthroplasties. Recent evidence suggests that neuraxial anesthesia has advantages over general anesthesia in terms of mortality, major morbidity and healthcare utilization. Yet, despite the proposed benefits, utilization of these two techniques varies greatly across geographical locations, with general anesthesia being most common for total hip arthroplasty (THA) and total knee arthroplasty (TKA) in parts of the world. We uncover some factors that promote or hinder the use of neuraxial anesthesia in THA and TKA. Healthcare professionals should be familiarized with the evidence for neuraxial anesthesia, and unbiased educational material should be developed for patients regarding anesthetic options for THA and TKA in order to promote best practice.

Good outcome of total hip replacement in patients with cerebral palsy: A comparison of 389 patients and 425,813 controls from the National Joint Registry for England and Wales

BACKGROUND AND PURPOSE

People with cerebral palsy (CP) often have painful deformed hips, but they are seldom treated with hip replacement as the surgery is considered to be high risk. However, few data are available on the outcome of hip replacement in these patients.

PATIENTS AND METHODS

We linked Hospital Episode Statistics (HES) records to the National Joint Registry for England and Wales to identify 389 patients with CP who had undergone hip replacement. Their treatment and outcomes were compared with those of 425,813 patients who did not have CP. Kaplan-Meier estimates were calculated to describe implant survivorship and the curves were compared using log-rank tests, with further stratification for age and implant type. Reasons for revision were quantified as patient-time incidence rates (PTIRs). Nationally collected patient-reported outcomes (PROMS) before and 6 months after operation were compared if available. Cumulative mortality (Kaplan-Meier) was estimated at 90 days and at 1, 3, and 5 years.

RESULTS

The cumulative probability of revision at 5 years post-surgery was 6.4% (95% CI: 3.8-11) in the CP cohort as opposed to 2.9% (CI 2.9-3%) in the non-CP cohort (p < 0.001). Patient-reported outcomes showed that CP patients had worse pain and function preoperatively, but had equivalent postoperative improvement. The median improvement in Oxford hip score at 6 months was 23 (IQR: 14-28) in CP and it was 21 (14-28) in non-CP patients. 91% of CP patients reported good or excellent satisfaction with their outcome. The cumulative probability of mortality for CP up to 7 years was similar to that in the controls after stratification for age and sex.

INTERPRETATION

Hip replacement for cerebral palsy appears to be safe and effective, although implant revision rates are higher than those in patients without cerebral palsy.

Increased Long-Term Cardiovascular Risk After Total Hip Arthroplasty: A Nationwide Cohort Study

Total hip arthroplasty is a common and important treatment for osteoarthritis patients. Long-term cardiovascular effects elicited by osteoarthritis or the implant itself remain unknown. The purpose of the present study was to determine if there is an increased risk of late cardiovascular mortality and morbidity after total hip arthroplasty surgery.A nationwide matched cohort study with data on 91,527 osteoarthritis patients operated on, obtained from the Swedish Hip Arthroplasty Register. A control cohort (n = 270,688) from the general Swedish population was matched 1:3 to each case by sex, age, and residence. Mean follow-up time was 10 years (range, 7-21).The exposure was presence of a hip replacement for more than 5 years. The primary outcome was cardiovascular mortality after 5 years. Secondary outcomes were total mortality and re-admissions due to cardiovascular events.During the first 5 to 9 years, the arthroplasty cohort had a lower cardiovascular mortality risk compared with the control cohort. However, the risk in the arthroplasty cohort increased over time and was higher than in controls after 8.8 years (95% confidence interval [CI] 7.0-10.5). Between 9 and 13 years postoperatively, the hazard ratio was 1.11 (95% CI 1.05-1.17). Arthroplasty patients were also more frequently admitted to hospital for cardiovascular reasons compared with controls, with a rate ratio of 1.08 (95% CI 1.06-1.11).Patients with surgically treated osteoarthritis of the hip have an increased risk of cardiovascular morbidity and mortality many years after the operation when compared with controls.

Prophylactic antibiotics in elective hip and knee arthroplasty: an analysis of organisms reported to cause infections and National survey of clinical practice

Objectives

We wanted to investigate regional variations in the organisms reported to be causing peri-prosthetic infections and to report on prophylaxis regimens currently in use across England.

Methods

Analysis of data routinely collected by Public Health England’s (PHE) national surgical site infection database on elective primary hip and knee arthroplasty procedures between April 2010 and March 2013 to investigate regional variations in causative organisms. A separate national survey of 145 hospital Trusts (groups of hospitals under local management) in England routinely performing primary hip and/or knee arthroplasty was carried out by standard email questionnaire.

Results

Analysis of 189 858 elective primary hip and knee arthroplasty procedures and 1116 surgical site infections found statistically significant variations for some causative organism between regions. There was a 100% response rate to the prophylaxis questionnaire that showed substantial variation between individual trust guidelines. A number of regimens currently in use are inconsistent with the best available evidence.

Conclusions

The approach towards antibiotic prophylaxis in elective arthroplasty nationwide reveals substantial variation without clear justification. Only seven causative organisms are responsible for 89% of infections affecting primary hip and knee arthroplasty, which cannot justify such widespread variation between prophylactic antibiotic policies.

Cite this article: Bone Joint Res 2015;4:181–189.

Implant Optimisation for Primary Hip Replacement in Patients over 60 Years with Osteoarthritis: A Cohort Study of Clinical Outcomes and Implant Costs Using Data from England and Wales

BACKGROUND

Hip replacement is one of the most commonly performed surgical procedures worldwide; hundreds of implant configurations provide options for femoral head size, joint surface material and fixation method with dramatically varying costs. Robust comparative evidence to inform the choice of implant is needed. This retrospective cohort study uses linked national databases from England and Wales to determine the optimal type of replacement for patients over 60 years undergoing hip replacement for osteoarthritis.

METHODS AND FINDINGS

Implants included were the commonest brand from each of the four types of replacement (cemented, cementless, hybrid and resurfacing); the reference prosthesis was the cemented hip procedure. Patient reported outcome scores (PROMs), costs and risk of repeat (revision) surgery were examined. Multivariable analyses included analysis of covariance to assess improvement in PROMs (Oxford hip score, OHS, and EQ5D index) (9159 linked episodes) and competing risks modelling of implant survival (79,775 procedures). Cost of implants and ancillary equipment were obtained from National Health Service procurement data.

RESULTS

EQ5D score improvements (at 6 months) were similar for all hip replacement types. In females, revision risk was significantly higher in cementless hip prostheses (hazard ratio, HR = 2.22, p<0.001), when compared to the reference hip. Although improvement in OHS was statistically higher (22.1 versus 20.5, p<0.001) for cementless implants, this small difference is unlikely to be clinically important. In males, revision risk was significantly higher in cementless (HR = 1.95, p = 0.003) and resurfacing implants, HR = 3.46, p<0.001), with no differences in OHS. Material costs were lowest with the reference implant (cemented, range £1103 to £1524) and highest with cementless implants (£1928 to £4285). Limitations include the design of the study, which is intrinsically vulnerable to omitted variables, a paucity of long-term implant survival data (reflecting the duration of data collection), the possibility of revision under-reporting, response bias within PROMs data, and issues associated with current outcome scoring systems, which may not accurately reflect level of improvement in some patients.

CONCLUSIONS

Cement fixation, using a polyethylene cup and a standard sized head offers good outcomes, with the lowest risks and at the lowest costs. The most commonly used cementless and resurfacing implants were associated with higher risk of revision and were more costly, while perceptions of improved function and longevity were unsupported.

A Consideration of the Perspectives of Healing Practitioners on Research Into Energy Healing

Energy healing is a complex intervention with the purpose of enhancing wholeness within the client. Approaches to complex interventions require thoughtful utilization of a wide range of research methods. In order to advance the research in this field, we sought to understand the healing practitioners' point of view by reviewing qualitative literature, research reviews, and commentary written by and about practitioners. Further, we conducted a brief survey among healers, asking their opinions on types and topics of research in this field. Emerging from this inquiry is an overview of the healers' state required for successful healing, the importance of the clients' contribution, the heterogeneity of the process of healing, and the importance of choosing appropriate outcomes to reflect the goal of wholeness. Beyond attending to measurement of these nuanced aspects, we propose utilization of research designs appropriate for complex interventions, more use of qualitative research techniques, consideration of large data registries, and adoption of the perspectives of realist research. An important gap identified was the overall lack of understanding of the clients' experience and contribution to the healing encounter.

Effect of surgeon and anesthesiologist volume on surgical outcomes

BACKGROUND

Little is known regarding the effects of caseload volume of other relevant members of the "surgical team." The present study sought to report variations in health care utilization and outcomes relative to surgeon and anesthesiologist volume among patients undergoing pancreatic surgery.

METHODS

A total of 969 patients undergoing pancreatic surgery from 2011-2013 were identified at a large, tertiary care center. Multivariable regression analyses explored the effects of provider volume on crystalloid administration, blood transfusions, mortality, length of stay, and hospital charges.

RESULTS

A total of 11 surgeons were identified while 100 anesthesiologists were involved in providing care to all patients. Annual case volume for surgeons ranged from 5-101 pancreatic resections per year; each anesthesiologist was involved in a fewer number of cases per year with a maximum of 15 patients treated by the same anesthesiologist. Higher volume surgeons had higher transfusions (odds ratio [OR], 1.85; 95% confidence interval [CI], 1.38-2.47; P < 0.001), greater crystalloid administration (OR, 1.62; 95% CI, 1.24-2.12; P < 0.001), and longer length of stay (OR, 1.74; 95% CI, 1.20-2.53; P = 0.003). In contrast, 30-d readmission was lower among higher volume surgeons (low volume versus high volume; 23.1% versus 11.6%; P < 0.001). Variations in patient-related outcomes were not associated with anesthesia provider volume (all P > 0.05). Similarly, total hospital charges and mortality were not associated with provider volumes (both P > 0.05).

CONCLUSIONS

Although variability exists in health care practices among providers at the surgeon level, less is observed among anesthesiologists. Although a proportion of this variability can be explained by provider volumes, a significant proportion remains unexplained possibly due to nonmodifiable factors such as patient case mix.

Surgical Site Infection After Primary Hip and Knee Arthroplasty: A Cohort Study Using a Hospital Database

BACKGROUND

Hip or knee arthroplasty infection (HKAI) leads to heavy medical consequences even if rare.

OBJECTIVE

To assess the routine use of a hospital discharge detection algorithm of prosthetic joint infection as a novel additional tool for surveillance.

METHODS

A historic 5-year cohort study was built using a hospital database of people undergoing a first hip or knee arthroplasty in 1 French region (2.5 million inhabitants, 39 private and public hospitals): 32,678 patients with arthroplasty code plus corresponding prosthetic material code were tagged. HKAI occurrence was then tracked in the follow-up on the basis of a previously validated algorithm using International Statistical Classification of Disease, Tenth Revision, codes as well as the surgical procedures coded. HKAI density incidence was estimated during the follow-up (up to 4 years after surgery); risk factors were analyzed using Cox regression.

RESULTS

A total of 604 HKAI patients were identified: 1-year HKAI incidence was1.31%, and density incidence was 2.2/100 person-years in hip and 2.5/100 person-years in knee. HKAI occurred within the first 30 days after surgery for 30% but more than 1 year after replacement for 29%. Patients aged 75 years or older, male, or having liver diseases, alcohol abuse, or ulcer sore had higher risk of infection. The inpatient case fatality in HKAI patients was 11.4%.

CONCLUSIONS

The hospital database method used to measure occurrence and risk factors of prosthetic joint infection helped to survey HKAI and could optimize healthcare delivery.

Infect Control Hosp Epidemiol 2015;36(10):1198–1207

Relationship between patient-reported outcomes of elective surgery and hospital and consultant volume

OBJECTIVE

Our aim was to analyze the relationship for 3 elective operations between outcome [patient-reported outcome measures (PROMs) for functional status, health-related quality of life, and postoperative complications] and both hospital and consultant volume.

METHODS

Hospitals (NHS and independent) and consultants undertaking at least 10 NHS-funded procedures during 2011/2012 were included (230 hospitals for hip and knee replacement, 257 for hernia repair; 978 consultants for hip replacement, 1172 for knee replacement, and 1288 for hernia repair). Outcomes (disease-specific and generic PROMs, patient-reported complications) were available from the NHS National PROMs Programme for 2009/2010 to 2011/2012. Relationship between case-mix adjusted outcomes and volume investigated using multilevel modeling.

RESULTS

There was considerable variation in hospital volumes (about 10-fold) and consultant volumes (about 5-fold). No significant association was observed between hospital volume and outcome for all 3 procedures. For consultant volume, there was no significant association for knee replacement or hernia repair. However, outcomes were statistically significantly better for hip replacement, although the effect was of little clinical significance: an additional 10 cases was associated with a higher Oxford Hip Score (0.06), higher EQ-5D score (0.001), and lower odds ratio of complications (0.992).

CONCLUSIONS

There are unlikely to be any benefits to patients from centralization of elective surgery into higher volume hospitals as regards the effectiveness of surgery or the avoidance of minor complications. There is some evidence that very low volume consultants achieve poorer outcomes than higher volume colleagues but the difference is slight and of little or no clinical significance.

Early postoperative mortality after simultaneous or staged bilateral primary total hip arthroplasty: an observational register study from the Swedish Hip Arthroplasty Register

BACKGROUND

Approximately a fifth of all total hip arthroplasty (THA) patients suffers from bilateral osteoarthritis of the hip. It is unclear whether mortality risks differ between simultaneous bilateral THA and staged bilateral THA. We investigated mortality after simultaneous THA compared with staged bilateral THA in the largest cohort hitherto reported.

METHODS

The 42,238 patients reported to have received bilateral primary THA from 1992 to 2012 in the Swedish Hip Arthroplasty Register were included. Tumours and fractures as underlying diagnoses were excluded. The time interval between the first and second THA was divided into four categories or treated as a continuous variable. Unadjusted survival was calculated according to Kaplan-Meier and adjusted Cox regression models were fitted in order to calculate crude and adjusted hazard ratios (HR) for the risk of death within different time frames.

RESULTS

Patients selected for simultaneous bilateral surgery were younger, more often male, and had lower ASA (American Society of Anesthesiologists) class than patients receiving staged procedures. The adjusted 90-day mortality after the second procedure did not differ between the four investigated groups (simultaneous bilateral [HR 1.3, CI 0.5-3.3], surgeries within 6 months [HR 1.1, CI 0.6-2.0], surgeries between 7 and 12 months [HR 0.7, CI 0.4-1.2], with second surgery after >12 months as the reference group). For patients older than 75 years, men, patients with ASA class 3 or above, and for patients with rheumatoid arthritis (RA) the 90-day mortality was increased. The unadjusted risk of implant revision of any hip was slightly higher for patients with simultaneous bilateral THA compared to those with staged procedure within one year, but after adjustment for age, gender, diagnosis and implant fixation these differences were no longer statistically significant.

CONCLUSION

There were no clinically relevant differences in early postoperative mortality between simultaneous and staged bilateral surgery in healthy patients. Advanced age, RA, a high ASA class and male sex increased the risk of death within 90 days. There may be an issue with enhanced risk of implant revision in patients with simultaneous bilateral THA that needs to be explored further.

The rise of multiple imputation: a review of the reporting and implementation of the method in medical research

Background

Missing data are common in medical research, which can lead to a loss in statistical power and potentially biased results if not handled appropriately. Multiple imputation (MI) is a statistical method, widely adopted in practice, for dealing with missing data. Many academic journals now emphasise the importance of reporting information regarding missing data and proposed guidelines for documenting the application of MI have been published. This review evaluated the reporting of missing data, the application of MI including the details provided regarding the imputation model, and the frequency of sensitivity analyses within the MI framework in medical research articles.

Methods

A systematic review of articles published in the Lancet and New England Journal of Medicine between January 2008 and December 2013 in which MI was implemented was carried out.

Results

We identified 103 papers that used MI, with the number of papers increasing from 11 in 2008 to 26 in 2013. Nearly half of the papers specified the proportion of complete cases or the proportion with missing data by each variable. In the majority of the articles (86%) the imputed variables were specified. Of the 38 papers (37%) that stated the method of imputation, 20 used chained equations, 8 used multivariate normal imputation, and 10 used alternative methods. Very few articles (9%) detailed how they handled non-normally distributed variables during imputation. Thirty-nine papers (38%) stated the variables included in the imputation model. Less than half of the papers (46%) reported the number of imputations, and only two papers compared the distribution of imputed and observed data. Sixty-six papers presented the results from MI as a secondary analysis. Only three articles carried out a sensitivity analysis following MI to assess departures from the missing at random assumption, with details of the sensitivity analyses only provided by one article.

Conclusions

This review outlined deficiencies in the documenting of missing data and the details provided about imputation. Furthermore, only a few articles performed sensitivity analyses following MI even though this is strongly recommended in guidelines. Authors are encouraged to follow the available guidelines and provide information on missing data and the imputation process.

Electronic supplementary material

The online version of this article (doi:10.1186/s12874-015-0022-1) contains supplementary material, which is available to authorized users.

Primary collared uncemented total hip arthroplasties in the elderly: a safe and reliable treatment option

The age of patients undergoing primary Total Hip Arthroplasty (THA) remains fairly constant despite an increasingly elderly population, possibly owing to concern over postoperative complications. This study evaluated 90-day outcomes in patients over 80, undergoing uncemented collared primary THA for osteoarthritis in a high volume unit. Data were recorded from 153 consecutive patients. There were 0.65% mortality rate and 1.3% major systemic complication rate. American Society of Anesthesiologist (ASA) grade was an independent predictor of inpatient complications. Mean preoperative and 90-day postoperative Oxford Hip Score was 24 and 46 respectively. No radiological evidence of femoral stem migration was seen. Our cohort shows low morbidity and mortality rates. ASA not age helps predict inpatient complications. Uncemented collared femoral prosthesis resulted in excellent functional and radiological outcomes.

Total intravenous general anaesthesia vs. spinal anaesthesia for total hip arthroplasty: a randomised, controlled trial

BACKGROUND

The choice of anaesthetic technique for patients undergoing joint arthroplasty is debatable. The hypothesis of this study was that general anaesthesia would generate a more favourable recovery profile than spinal anaesthesia.

METHODS

We randomly allocated 120 patients to either intrathecal bupivacaine or general anaesthesia with target-controlled infusion of remifentanil and propofol. Length of hospital stay assessed as meeting discharge criteria was the primary outcome parameter. Other outcome parameters were actual time of discharge, pain, use of rescue pain medication, blood loss, length of stay in the post-operative care unit, dizziness, post-operative nausea, need of urinary catheterisation and patient satisfaction.

RESULTS

General anaesthesia resulted in slightly reduced length of hospital stay (26 vs. 30 h, P = 0.004), less nausea (P = 0.043) and dizziness (P < 0.001). General anaesthesia patients had higher pain scores during the first two post-operative hours (P < 0.001) but lower after 6 h compared with the spinal anaesthesia group (P < 0.01 and P < 0.05). General anaesthesia patients had better orthostatic function compared with spinal anaesthesia patients (P = 0.008). Patients in the spinal anaesthesia group fulfilled the discharge criteria from the post-operative care unit earlier compared with the general anaesthesia patients (P = 0.004). General anaesthesia patients requested a change in the method of anaesthesia for a subsequent operation less often than the spinal anaesthesia patients (5 vs. 13, P = 0.022).

CONCLUSION

General anaesthesia resulted in a more favourable recovery profile compared with spinal anaesthesia.

Hip Arthroplasty: Back to the Future?

This review examines the future of total hip arthroplasty, aiming to avoid past mistakes

Biofilm-based implant infections in orthopaedics

The demand for joint replacement surgery is continuously increasing with rising costs for hospitals and healthcare systems. Staphylococci are the most prevalent etiological agents of orthopedic infections. After an initial adhesin-mediated implant colonization, Staphylococcus aureus and Staphylococcus epidermidis produce biofilm. Biofilm formation proceeds as a four-step process: (1) initial attachment of bacterial cells; (2) cell aggregation and accumulation in multiple cell layers; (3) biofilm maturation and (4) detachment of cells from the biofilm into a planktonic state to initiate a new cycle of biofilm formation elsewhere. The encasing of bacteria in biofilms gives rise to insuperable difficulties not only in the treatment of the infection, but also in assessing the state and the nature of the infection using traditional cultural methods. Therefore, DNA-based molecular methods have been developed to provide rapid identification of all microbial pathogens. To combat biofilm-centered implant infections, new strategies are being developed, among which anti-infective or infective-resistant materials are at the forefront. Infection-resistant materials can be based on different approaches: (i) modifying the biomaterial surface to give anti-adhesive properties, (ii) doping the material with antimicrobial substances, (iii) combining anti-adhesive and antimicrobial effects in the same coating, (iv) designing materials able to oppose biofilm formation and support bone repair.

Return to theatre for elective hip and knee replacements

The aim of this study was to define return to theatre (RTT) rates for elective hip and knee replacement (HR and KR), to describe the predictors and to show the variations in risk-adjusted rates by surgical team and hospital using national English hospital administrative data.

We examined information on 260 206 HRs and 315 249 KRs undertaken between April 2007 and March 2012. The 90-day RTT rates were 2.1% for HR and 1.8% for KR. Male gender, obesity, diabetes and several other comorbidities were associated with higher odds for both index procedures. For HR, hip resurfacing had half the odds of cement fixation (OR = 0.58, 95% confidence intervals (CI) 0.47 to 0.71). For KR, unicondylar KR had half the odds of total replacement (OR = 0.49, 95% CI 0.42 to 0.56), and younger ages had higher odds (OR = 2.23, 95% CI 1.65 to 3.01) for ages < 40 years compared with ages 60 to 69 years). There were more funnel plot outliers at three standard deviations than would be expected if variation occurred on a random basis.

Hierarchical modelling showed that three-quarters of the variation between surgeons for HR and over half the variation between surgeons for KR are not explained by the hospital they operated at or by available patient factors. We conclude that 90-day RTT rate may be a useful quality indicator for orthopaedics.

Cite this article: Bone Joint J 2014; 96-B:1663–8.

45-day mortality after 467,779 knee replacements for osteoarthritis from the National Joint Registry for England and Wales: an observational study

BACKGROUND

Understanding the risk factors for early death after knee replacement could help to reduce the risk of mortality after this procedure. We assessed secular trends in death within 45 days of knee replacement for osteoarthritis in England and Wales, with the aim of investigating whether any change that we recorded could be explained by alterations in modifiable perioperative factors.

METHODS

We took data for knee replacements done for osteoarthritis in England and Wales between April 1, 2003, and Dec 31, 2011, from the National Joint Registry for England and Wales. Patient identifiers were used to link these data to the national mortality database and the Hospital Episode Statistics database to obtain details of death, sociodemographics, and comorbidity. We assessed mortality within 45 days by Kaplan-Meier analysis and assessed the role of patient and treatment factors by Cox proportional hazards models.

FINDINGS

467,779 primary knee replacements were done to treat osteoarthritis during 9 years. 1183 patients died within 45 days of surgery, with a substantial secular decrease in mortality from 0·37% in 2003 to 0·20% in 2011, even after adjustment for age, sex, and comorbidity. The use of unicompartmental knee replacement was associated with substantially lower mortality than was total knee replacement (hazard ratio [HR] 0·32, 95% CI 0·19–0·54, p<0·0005). Several comorbidities were associated with increased mortality: myocardial infarction (HR 3·46, 95% CI 2·81–4·14, p<0·0005), cerebrovascular disease (3·35, 2·7–4·14, p<0·0005), moderate/severe liver disease (7·2, 3·93–13·21, p<0·0005), and renal disease (2·18, 1·76–2·69, p<0·0005). Modifiable perioperative risk factors, including surgical approach and thromboprophylaxis were not associated with mortality.

INTERPRETATION

Postoperative mortality after knee replacement has fallen substantially between 2003 and 2011. Efforts to further reduce mortality should concentrate more on older patients, those who are male and those with specific comorbidities, such as myocardial infarction, cerebrovascular disease, liver disease, and renal disease.

FUNDING

National Joint Registry for England and Wales.

Adverse outcomes after total and unicompartmental knee replacement in 101,330 matched patients: a study of data from the National Joint Registry for England and Wales

BACKGROUND

Total knee replacement (TKR) or unicompartmental knee replacement (UKR) are options for end-stage osteoarthritis. However, comparisons between the two procedures are confounded by differences in baseline characteristics of patients undergoing either procedure and by insufficient reporting of endpoints other than revision. We aimed to compare adverse outcomes for each procedure in matched patients.

METHODS

With propensity score techniques, we compared matched patients undergoing TKR and UKR in the National Joint Registry for England and Wales. The National Joint Registry started collecting data in April 1, 2003, and is continuing. The last operation date in the extract of data used in our study was Aug 28, 2012. We linked data for multiple potential confounders from the National Health Service Hospital Episode Statistics database. We used regression models to compare outcomes including rates of revision, revision/reoperation, complications, readmission, mortality, and length of stay.

FINDINGS

25,334 UKRs were matched to 75,996 TKRs on the basis of propensity score. UKRs had worse implant survival both for revision (subhazard ratio [SHR] 2·12, 95% CI 1·99–2·26) and for revision/reoperation (1·38, 1·31–1·44) than TKRs at 8 years. Mortality was significantly higher for TKR at all timepoints than for UKR (30 day: hazard ratio 0·23, 95% CI 0·11–0·50; 8 year: 0·85, 0·79–0·92). Length of stay, complications (including thromboembolism, myocardial infarction, and stroke), and rate of readmission were all higher for TKR than for UKR.

INTERPRETATION

In decisions about which procedure to offer, the higher revision/reoperation rate of UKR than of TKR should be balanced against a lower occurrence of complications, readmission, and mortality, together with known benefits for UKR in terms of postoperative function. If 100 patients receiving TKR received UKR instead, the result would be around one fewer death and three more reoperations in the first 4 years after surgery.

FUNDING

Royal College of Surgeons of England and Arthritis Research UK.

An update on surgical approaches in hip arthoplasty: lateral versus posterior approach

In this update we searched the literature about the outcome of the lateral versus posterior approach in hip arthoplasty for osteoarthritis (OA) and femoral neck fracture (FNF) patients. The available evidence shows that the use of posterior approach in OA patients is associated with lower mortality and better functional outcome while the use of lateral approach in FNF patients gives lower dislocation rate. We recommend therefore the use of posterior approach in OA patients and lateral approach in FNF patients.

A systematic review and meta-analysis of the standard versus mini-incision posterior approach to total hip arthroplasty

The mini-incision posterior approach may appeal to surgeons comfortable with the standard posterior approach to the hip. We present the first systematic review and meta-analysis of these two approaches. Twelve randomised controlled trials and four non-randomised trials comprising of 1498 total hip arthroplasties were included. The mini-incision posterior approach was associated with an early improvement in Harris hip score of 1.8 points (P<0.001), reduced operating time (5minutes, P<0.001), length of hospital stay (14hours, P<0.001), intraoperative and total blood loss (63ml, P<0.001 and 119ml, P<0.001 respectively). There were no statistically significant differences in the incidence of dislocation, nerve injury, infection or venous thromboembolic events. The minimally invasive posterior approach appears to provide a safe and acceptable alternative to the standard incision posterior approach.

Morbidity and mortality in the thirty-day period following total hip arthroplasty: risk factors and incidence

The study sought to ascertain the incidence rates and risk factors for 30-day post-operative complications after primary total hip arthroplasty (THA). Complications were categorized as systemic or local and subcategorized as major or minor. There were 17,640 individuals who received primary THA identified from the 2006-2011 ACS NSQIP. The mortality rate was 0.35% and complications occurred in 4.9%. Age groups ≥ 80 years (P <0.001) and 70-79 years old (P = 0.003), and renal insufficiency (P = 0.02) best predicted mortality. Age ≥80 years (P <0.001) and cardiac disease (P = 0.01) were the strongest predictors of developing any postoperative complication. Morbid obesity (P <0.001) and operative time > 141 minutes (P <0.001) were strongly associated with the development of major local complications.

Single shot spinal anaesthesia with hypobaric bupivacaine for hip fracture repair surgery in the elderly. Randomized, double blinded comparison of 3.75 mg vs. 7.5 mg

BACKGROUND

Arterial hypotension is the most frequent adverse effect of subarachnoid anaesthesia in the elderly sustaining a femoral proximal fracture. Decreasing the local anaesthetic dose reduces the incidence of hypotension but shortens sensory block duration that could be insufficient in some surgical procedures. Sensory block duration could be prolonged using hypobaric local anaesthetics. We evaluated whether low hypobaric bupivacaine doses were adequate for this type of surgery while maintaining the haemodynamic stability.

METHODS

A prospective, randomized, double blinded study was designed. Patients over 65 years old, sustaining traumatic hip fracture, were assigned to one of two groups: B0.5 group, hypobaric bupivacaine 7.5mg 5mg/ml (control group), and B0.25 group, hypobaric bupivacaine 3.75 mg 2.5mg/ml (study group). After subarachnoid injection, sensory level and motor blockade degree were registered, as were blood pressure, and heart rate at basal time and at 2, 5, 10, 15, 20 and 30 min after injection. The doses of vasopressor needed were registered as well. Surgical conditions and the duration of the surgical procedure-whether rescue analgesia or anaesthesia was needed-and sensory level regression to T12, were registered as well.

RESULTS

Sixty four patients was the calculated sample size. The study was stopped in an interim analysis because an elevated number of patients in the B0.25 group needed iv rescue anaesthesia. In the analyzed cases, blood pressure was significantly lower in the B0.5 group at the 15 and 30 min measurements. Vasopressor drugs needs were similar between groups [ephedrine accumulated mean (SD) doses 11.4 (5.2) mg vs. 9.1 (2.7) mg, p=0.045)]. Sensory block regression to T12 was faster in the B0.25 group, [(mean (SD) 68.2 (29.0) min vs. 112.8 (17.3) min in the B0.5 group, p<0.05]. Five out of 19 patients in the B0.25 group needed intravenous anaesthesia rescue before surgery started.

CONCLUSION

Lowering hypobaric bupivacaine dose to 3.75 mg in subarachnoid anaesthesia for hip fracture repair surgery in elderly patients decrease intraoperative blood pressure, but in an important number of patients intravenous anaesthesia rescue was needed and preclude recommendation.

Mortality following hip arthroplasty--inappropriate use of National Joint Registry (NJR) data

Mortality following hip arthroplasty is affected by a large number of confounding variables each of which must be considered to enable valid interpretation. Relevant variables available from the 2011 NJR data set were included in the Cox model. Mortality rates in hip arthroplasty patients were lower than in the age-matched population across all hip types. Age at surgery, ASA grade, diagnosis, gender, provider type, hip type and lead surgeon grade all had a significant effect on mortality. Schemper's statistic showed that only 18.98% of the variation in mortality was explained by the variables available in the NJR data set. It is inappropriate to use NJR data to study an outcome affected by a multitude of confounding variables when these cannot be adequately accounted for in the available data set.

Risk of re-admission, reoperation, and mortality within 90 days of total hip and knee arthroplasty in fast-track departments in Denmark from 2005 to 2011

PURPOSE

To compare the risks of re-admission, reoperation, and mortality within 90 days of surgery in orthopedic departments with well-documented fast-track arthroplasty programs with those in all other orthopedic departments in Denmark from 2005 to 2011.

METHODS

We used the Danish hip and knee arthroplasty registers to identify patients with primary total hip arthroplasty or total knee arthroplasty. Information about re-admission, reoperation, and mortality within 90 days of surgery was obtained from administrative databases. The fast-track cohort consisted of 6 departments. The national comparison cohort consisted of all other orthopedic departments. Regression methods were used to calculate relative risk (RR) of adverse events, adjusting for age, sex, type of fixation, and comorbidity. Cohorts were divided into 3 time periods: 2005-2007, 2008-2009, and 2010-2011.

RESULTS

79,098 arthroplasties were included: 17,284 in the fast-track cohort and 61,814 in the national cohort. Median length of stay (LOS) was less for the fast-track cohort in all 3 time periods (4, 3, and 3 days as opposed to 6, 4, and 3 days). RR of re-admission due to infection was higher in the fast-track cohort in 2005-2007 (1.3, 95% CI: 1.1-1.6) than in the national cohort in the same time period. This was mainly due to urinary tract infections. RR of re-admission due to a thromboembolic event was lower in the fast-track cohort in 2010-2011 (0.7, CI: 0.6-0.9) than in the national cohort in the same time period. No differences were seen in the risk of reoperation and mortality between the 2 cohorts during any time period.

INTERPRETATION

The general reduction in LOS indicates that fast-track arthroplasty programs have been widely implemented in Denmark. At the same time, it appears that dedicated fast-track departments have been able to optimize the fast-track program further without any rise in re-admission, reoperation, and mortality rates.

Early death following primary total hip arthroplasty

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

Perioperative outcomes and type of anesthesia in hip surgical patients: An evidence based review

Over the last decades the demand for hip surgery, be it elective or in a traumatic setting, has greatly increased and is projected to expand even further. Concurrent with demographic changes the affected population is burdened by an increase in average comorbidity and serious complications. It has been suggested that the choice of anesthesia not only affects the surgery setting but also the perioperative outcome as a whole. Therefore different approaches and anesthetic techniques have been developed to offer individual anesthetic and analgesic care to hip surgery patients. Recent studies on comparative effectiveness utilizing population based data have given us a novel insight on anesthetic practice and outcome, showing favorable results in the usage of regional vs general anesthesia. In this review we aim to give an overview of anesthetic techniques in use for hip surgery and their impact on perioperative outcome. While there still remains a scarcity of data investigating perioperative outcomes and anesthesia, most studies concur on a positive outcome in overall mortality, thromboembolic events, blood loss and transfusion requirements when comparing regional to general anesthesia. Much of the currently available evidence suggests that a comprehensive medical approach with emphasis on regional anesthesia can prove beneficial to patients and the health care system.

New oral pharmacotherapeutic agents for venous thromboprophylaxis after total hip arthroplasty

Patients undergoing total hip arthroplasty (THA) are at high risk for developing venous thromboembolism and, therefore, require short term prophylaxis with antithrombotic agents. Recently, target specific oral anticoagulants (TSOA) including the direct thrombin inhibitor, dabigatran, and the factor Xa inhibitors rivaroxaban, apixaban, and edoxaban have been approved for THA thrombopropylaxis in various countries. The TSOAs provide a rapid acting, oral alternative to parenteral agents including low-molecular weight heparins (LMWH) and fondaparinux; and compared to warfarin, they do not require routine laboratory monitoring and possess much fewer drug-drug interactions. Based on phase III clinical studies, TSOAs have established themselves as an effective and safe option for thromboprophylaxis after THA compared to LMWH, particularly enoxaparin, but require additional evaluation in specific populations such as the renally impaired or elderly. The ability to monitor and reverse these TSOAs in the case of bleeding complications or suspected sub- or supra-therapeutic anticoagulation is of importance, but remains investigational. This review will focus on the drug-specific characteristics, efficacy, safety, and economic impact of the TSOAs for thromboprophylaxis following THA, as well as the aspects of therapeutic monitoring and anticoagulation reversal in the event of bleeding complications or a need for urgent reversal.