Individualized Surgeon Reports in a Statewide Registry.

ABSTRACT: Despite progress with the development of joint replacement registries in the United States, surgeons may have limited opportunities to determine the cumulative outcome of their own patients or understand how those outcomes compare with their peers; this information is important for quality improvement. In order to provide surgeons with accurate data, it is first necessary to have a registry with complete coverage and patient matching. Some international registries have accomplished this. Building on a comprehensive statewide registry in the United States, a surgeon-specific report has been developed to provide surgeons with survivorship and complication data, which allows comparisons with other surgeons in the state. This article describes funnel plots, cumulative sum reports, complication-specific data, and patient-reported outcome measure data, which are provided to hip and knee arthroplasty surgeons with the goal of improving quality, decreasing variability in the delivery of care, and leading to improved value and outcomes for hip and knee arthroplasty in the state of Michigan.

Total Hip and Knee Arthroplasty Implant Revision Risk to 5 Years From a State-wide Arthroplasty Registry in Michigan.

Background: Information on the revision risk of implants is useful for improving the quality of care for elective hip and knee arthroplasty. The purpose of this study was to report on the revision risk of implants using a state-wide registry in the United States. Methods: The Michigan Arthroplasty Registry Collaborative Quality Initiative systematically collects data on elective primary and revision hip and knee arthroplasty cases in Michigan. It contained data on 139,970 hip and 245,499 knee arthroplasty cases from February 15, 2012, to December 31, 2021. Kaplan-Meier estimates of revision risk were computed using time to first revision as the dependent variable, and the results were computed and expressed as the cumulative percent revision (CPR). CPR estimates were computed for all implants having at least 500 cases in the Michigan Arthroplasty Registry Collaborative Quality Initiative dataset. Results: At 5-years postoperatively, elective primary conventional total hip arthroplasty implant stem/cup combinations had CPR values from 0.95% (0.39%-2.30%, 95% confidence intervals [CI]) to 5.77% (4.22%-7.85%, 95% CI), and elective primary total knee arthroplasty CPR ranged from 1.10% (0.64%-1.89%, 95% CI) to 12.52% (8.37%-18.50%, 95% CI). Unicondylar knee arthroplasty CPR at 5-years went from 4.23% (3.54%-5.06%, 95% CI) to 7.13% (6.20%-8.20%, 95% CI). Conclusions: The wide variation in CPR points to the need for surgeons to choose implants wisely to improve quality of care.

How Much Perioperative Pain and Dysfunction Underlie the HOOS JR and KOOS JR?

BACKGROUND: The Hip Disability and Osteoarthritis Outcome Score Joint Replacement (HOOS JR) and Knee Injury and Osteoarthritis Outcome Score Joint Replacement (KOOS JR) scores represent pain and dysfunction as a single number ranging from 0 (extreme pain and dysfunction) to 100 (no pain or functional limitations). However, scores between 0 and 100 lack a simple interpretation because they reflect varying combinations of pain levels and dysfunction. Given that most adverse events and improvement occur within the first 90 days after surgery, a deeper understanding of the level of pain and dysfunction may reveal missed opportunities for patient care. QUESTIONS/PURPOSES: (1) What does a given preoperative or postoperative HOOS JR and KOOS JR score indicate about pain and ability to perform daily activities? (2) How much of a change in score (that is, delta) is needed to indicate significant improvement in pain control and daily functioning? METHODS: The Michigan Arthroplasty Registry Collaborative Quality Initiative contains more than 95% of THAs and TKAs performed in Michigan. Between January 2017 and March 2019, 84,175 people in the registry underwent primary THA or TKA and were potentially eligible for this retrospective, comparative study of the first 90 postoperative days. Eighty-four percent (70,608 of 84,175) were excluded because their surgeons did not attain a target survey collection proportion of 70% and another 6% (5042) were missing covariate information or surveys, leaving 10% (8525) for analysis. The mean age and percentage of women were 65 ± 11 years and 55% (2060 of 3716), respectively, for patients undergoing THA and 67 ± 9 years and 61% (2936 of 4809), respectively, for those undergoing TKA. There were no clinically meaningful differences between patients who were analyzed and those who were excluded except for lower representation of non-White patients in the analyzed group. For interpretation, patient responses to Question 7 (pain) and Question 6 (function) from the Patient-Reported Outcomes Measurement Information System global items (PROMIS-10) were dichotomized into "much pain" (rating of pain 4 to 10 of 10) versus "less pain" (rating of ≤ 3) and "good function" (able to perform most activities) versus "poor function" (not able to perform most activities) and combined into four pain-function categories. We examined the mean preoperative and postoperative HOOS JR and KOOS JR scores for each pain-function category, adjusted for patient characteristics. We calculated the size of the delta associated with an increase to a more favorable category postoperatively (versus staying in the same or worse category) via multivariable logistic regression that controlled for patient characteristics. RESULTS: Patients in the least favorable "much pain, poor function" category preoperatively had adjusted mean scores of 40 (95% confidence interval 39 to 41) for both the HOOS JR and KOOS JR. Those with mixed levels of pain and function had mean scores between 46 and 55. Those in the most favorable "less pain, good function" category had means of 60 (95% CI 58 to 62) and 59 (95% CI 58 to 61) for the HOOS JR and KOOS JR, respectively. The adjusted delta to achieve a pain level of ≤ 3 or the ability to perform most activities was 30 (95% CI 26 to 36) on the HOOS JR and 27 (95% CI 22 to 29) on the KOOS JR scales. CONCLUSION: These adjusted means of the HOOS JR and KOOS JR provide context for understanding the levels of pain and dysfunction for individuals as well for patients reported in other studies. Potential quality improvement efforts could include tracking the proportion of patients with THA or TKA who achieved a sufficient delta to attain pain levels of ≤ 3 or the ability to perform most activities. Future studies are needed to understand pain and function represented by the HOOS JR and KOOS JR at 1 to 2 years, how these may differ by patient subgroups, and whether scores can be improved through quality improvement efforts. LEVEL OF EVIDENCE: Level III, therapeutic study.

Early Survivorship of Uncemented Total Knee Arthroplasty Varies by Age and Sex Based on Data From the Michigan Arthroplasty Registry Collaborative Quality Initiative.

BACKGROUND: Outcome data for newer uncemented total knee arthroplasty (TKA) designs has been mixed. Registry studies showed worse survivorship, but clinical trials have not demonstrated differences compared to cemented designs. There has been renewed interest in uncemented TKA with modern designs and improved technology. The utilizations of uncemented knees in Michigan, 2-year outcomes, and the effects of age and sex were evaluated. METHODS: A statewide database from 2017 through 2019 was analyzed for incidence, distribution, and early survivorship of cemented versus uncemented TKAs. There was 2-year minimum follow-up. Kaplan-Meier survival analysis was used to generate time to first revision cumulative percent revision curves. The impacts of age and sex were examined. RESULTS: Use of uncemented TKAs increased from 7.0 to 11.3%. Uncemented TKAs were more commonly men, younger, heavier, American Society of Anesthesiologists score > 2, and opioid users (P < .05). At 2 years, overall cumulative percent revision was higher in uncemented (2.44% [2.00, 2.99]) versus cemented (1.76% [1.64, 1.89]), particularly in women uncemented (2.41 [1.87, 3.12]) versus cemented (1.64 [1.50, 1.80]). Revision rates were greater with uncemented women >70 years (1.2% 1 year, 1.02% 2 years) versus < 70 years (0.56%, 0.53%), notably uncemented were inferior in both groups (P < .05). Men, regardless of age, had similar survivorships with both cemented and uncemented designs. CONCLUSION: The use of an uncemented TKA had an increased risk of early revision compared to cemented. This finding, however, was only apparent in women, especially those >70 years old. Surgeons should consider cement fixation in women >70 years.

A Reduction in Opioid Prescription Size After Total Joint Arthroplasty Can be Safely Performed Without an Increase in Complications.

BACKGROUND: Excessive opioid prescriptions after total joint arthroplasty (TJA) increase risks for adverse opioid-related events, chronic opioid use, and unlawful opioid diversion. Decreasing postoperative prescriptions may improve quality after TJA. Concerns exist that a decrease in opioids prescribed may increase complications, such as readmissions, emergency department (ED) visits, or worsened patient-reported outcomes (PROs). The purpose of this study was to explore whether a reduction in opioids prescribed after TJA resulted in increased complications. METHODS: Data originated from a statewide database prospectively abstracted, including oral morphine equivalents prescribed at discharge, readmissions, ED visits, and PROs. Data were collected from 84,998 TJA occurring 1 year before and after the creation of an opioid-prescribing protocol that had decreased prescriptions by approximately 50%. Trends were monitored using Shewhart control charts. Regression models were used to determine statistically significant changes over time. RESULTS: All groups showed a reduction in opioids prescribed by almost 50% without an increase in emergency room visits or readmissions and without a detrimental effect on PROs. Compared to baseline data before opioid reduction, opioid-naive total knee arthroplasty had significant improvements in all outcomes (P = .03, P = .02, P < .001, P < .001). Opioid-tolerant total knee arthroplasty and total hip arthroplasty had no worsened outcomes and significant improvement in (Knee Injury and Osteoarthritis Outcome score for Joint Replacement P = .03) and (Hip Disability and Osteoarthritis Outcome Score for Joint Replacement P = .03). Opioid-naive total hip arthroplasty had significant improvements in Hip Disability and Osteoarthritis Outcome Score Joint Replacement (P = .003) and Patient Reported Outcomes Measurement Information System (P = .001). CONCLUSIONS: Postoperative opioid prescription recommendations from a statewide registry decreased prescribing by approximately 50% without decreasing PROs or increasing ED visits or readmissions. A reduction in opioids prescribed after TJA can be accomplished safely and without increased complications.

Are Short Stems Associated With Higher Fracture Rates and Early Revision Rates in Primary Total Hip Arthroplasty? A Noninferiority Analysis.

BACKGROUND: This study aimed to determine if "short" femoral stems were noninferior to (at least as good as) standard-length stems in regards to 90-day periprosthetic fracture and 1-year revision rates. METHODS: Using the MARCQI implant registry, a retrospective study of statewide data was carried out on 64,084 total hip arthroplasties (THAs) between 2012 and 2017. We noticed an increase in the use of "short" uncemented femoral hip stems during THA. Chi-square tests were used to test homogeneity of categorical variables. The covariates included in the analyses were identified using modern epidemiological methods. A Type I probability of 0.05 was used as the level of statistical significance. Inverse probability of treatment weighting (IPTW) was used to mitigate confounding variables. RESULTS: One hundred and seven stems were implanted by surgeons in the state of Michigan. They were classified according to the Khanuja Classification System as Type 2A (trapezoidal, double-tapered calcar loading, n = 3,281), Type 3 (calcar loading with lateral flare, n = 1,898), and Type 4 (shortened, tapered, conventional, n = 19,580), and were compared to standard-length, type 5, stems (n = 33,322) in regards to the 2 outcomes (periprosthetic fractures and 1-year revision rates). Overall, 1-year revision and the 90-day fracture rates were 1.3% (791/57,853) and 1.1% (631/57,968), respectively. Noninferiority was established for all short stems at the clinical threshold of an odds ratio (OR) of 1.5 with P-values <0.05 for 90-day fractures. In regards to 1-year revision rates, noninferiority was also established for Type 3 and 4 stems (P < .05). CONCLUSION: The increased use of "short stems" in Michigan did not lead to increased 1-year revision or 90-day fracture rates.

State-Based and National U.S. Registries: The Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI), California Joint Replacement Registry (CJRR), and American Joint Replacement Registry (AJRR).

ABSTRACT: The concept of a total joint registry as a tool to gather and compare longitudinal clinical outcome data emerged in the early 1970s; although initially begun as a single-institution effort, it soon spread to the development of large nationwide registries, first in Scandinavia and subsequently around the world. These national registries established the value of population-wide results, large cohorts, and the importance of ongoing implant surveillance efforts, as detailed elsewhere in this series. In the United States, concerted efforts to establish a national total joint registry for the hip and knee began in earnest in the early 2000s and culminated with the incorporation of the American Joint Replacement Registry (AJRR) in 2009. Parallel efforts soon followed to establish state-based total joint registries, either as stand-alone entities or in affiliation with the AJRR. Some of these state-based efforts succeeded, and some did not.In the first section of this article, Brian Hallstrom, MD, details the highly successful Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI). This state-based effort was made possible by a unique partnership between a single dominant statewide private payer and the Michigan orthopaedic surgery community; it has already successfully advanced the quality of care for patients in Michigan, and efforts are ongoing.The second section, by James I. Huddelston, MD, details a different path to the establishment of a focused state-based registry. The California Joint Replacement Registry (CJRR) was the result of a partnership with representatives of the statewide business community and resulted in a pioneering effort to successfully collect and publicly report patient-reported outcome measures as part of the registry data set. Further discussed are the establishment, development, and status of the AJRR and its current place among the family of American Academy of Orthopaedic Surgeons (AAOS) registries, which were inspired by the AJRR and span a range of orthopaedic specialties.

John N. Insall Award: MARCQI's Pain-Control Optimization Pathway (POP): Impact of Registry Data and Education on Opioid Utilization.

BACKGROUND: In 2019, the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI) recommended an evidence-based opioid pain pathway to participating physicians and hospitals for patients undergoing total joint arthroplasty (TJA). The purpose of this study was to determine if the education could influence and have lasting effects on the prescribing patterns for TJA patients. METHODS: Using the MARCQI database, the number of oral morphine equivalents (OMEs) prescribed at discharge were collected from January 2018 through December 2019 for all primary arthroplasty procedures. Periods compared included before and after July 2018 Michigan opioid laws as well as before and after the March 2019 MARCQI recommendations. The data compared total hip arthroplasty (THA) and total knee arthroplasty (TKA) patients, opioid-naive vs opioid-tolerant patients, individual surgeons, and MARCQI sites. RESULTS: The data included 84,998 TJAs: 22,774 opioid-naive THAs, 9124 opioid-tolerant THAs, 40,882 opioid-naive TKAs, and 12,218 opioid-tolerant TKAs. In all the groups and at all time periods there were a significant decrease in prescriptions (P < .001). Individual surgeons and participating sites also demonstrated decreased OMEs on discharge after the recommendations. Between the first and last months of collection, this represented an overall decrease of opioid OMEs for THA by 47.1% for opioid-naive patients and 53.4% for opioid-tolerant patients. For TKA patients, the OME decrease was 48.3% for opioid-naive patients, and 48.4% for opioid-tolerant patients. CONCLUSION: The MARCQI pain control optimization pathway (POP) program has been successful in drastically reducing opioid prescribing with lasting effects, which has substantially limited the overall opioid prescription burden for patients undergoing arthroplasty.

Causes of Early Hip Revision Vary by Age and Gender: Analysis of Data From a Statewide Quality Registry.

BACKGROUND: While total hip arthroplasty (THA) is extremely successful, early failures do occur. The purpose of this study was to determine the cause of revision in specific patient demographic groups at 3 time points to potentially help decrease the revision risk. METHODS: Data for cases performed between 2012 and 2018 from a statewide, quality improvement arthroplasty registry were used. The database included 79,205 THA cases and 1,433 revisions with identified etiology (1,584 in total). All revisions performed at <5 years from the primary THA were reviewed. Six groups, men/women, <65, 65-75, and >75 years, were compared at revision time points <6 months, <1 year, and <5 years. RESULTS: There were obvious and significant differences between subgroups based on demographics and time points (P < .0001). Seven hundred and fifty-six (53%) of all revisions occurred within 6 months. The most common etiologies within 6 months (756 revisions) were fracture (316, 41.8%), dislocation/instability (194, 25.7%), and infection (98, 12.9%). At this early time point, the most common revision cause was fracture for all age/gender-stratified groups, ranging from 27.6% in young men to 60% in older women. Joint instability became the leading cause for revision after 1 year in all groups. CONCLUSION: This quality improvement project demonstrated clinically meaningful differences in the reason for THA revision between gender, age, and time from surgery. Strategies based on these data should be employed by surgeons to minimize the factors that lead to revision.

Early Benchmarking Total Hip Arthroplasty Implants Using Data from the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI).

BACKGROUND: Benchmarking arthroplasty implant revision risk is an informative way to address implant performance. National benchmarking efforts exist in the United Kingdom, Netherlands, and Australia. Recently, the International Prosthesis Benchmarking Working Group, including representatives from industry, academia, and national registries, produced a guideline describing arthroplasty benchmarking methodology. The proposal was applied to data from the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI) to assess its feasibility for benchmarking implants in the United States. METHODS: Primary elective total hip arthroplasty procedures performed for osteoarthritis between 2/15/2012 and 12/31/2018 and their associated revisions were identified in the MARCQI registry. The guidelines recommend that all prostheses combinations receive an early benchmark if they have at least 250 procedures at risk and the revision rate does not exceed the pre-determined standard of 2% at 2 years and 3% at 5 years. RESULTS: A total of 72,949 primary cases met the inclusion criteria. Of these, 1369 had revisions. Twenty-nine and six stem/cup combinations satisfied the minimum case requirement at 2 and 5 years, respectively. Three implant combinations would not receive a benchmark at 2 years: Secur-Fit/Trident, Anthology/Reflection 3, Taperloc 133/G7. CONCLUSION: The guideline can be implemented in the United States by a regional registry. Moreover, not all hip implants currently in use would receive an early benchmark. This raises concern as these implant combinations represent a significant number of cases in Michigan, some with increasing utilization.

Non-Inferiority of Aspirin for Venous Thromboembolism Prophylaxis After Hip Arthroplasty in a Statewide Registry.

BACKGROUND: Uncertainty remains surrounding the use of aspirin as a sole chemoprophylactic agent to reduce the risk of venous thromboembolism (deep vein thrombosis or pulmonary embolism) and bleeding after primary total hip arthroplasty. METHODS: We performed a non-inferiority analysis of a retrospective cohort of patients undergoing total hip arthroplasty from April 1, 2013 to December 31, 2018. Cases were retrieved from the Michigan Arthroplasty Registry Collaborative Quality Initiative database and performed by 355 surgeons at 61 hospitals throughout Michigan. Surgical setting ranged from small community hospitals to large academic and non-academic centers. The primary outcomes were post-operative venous thromboembolism event or death and bleeding event. RESULTS: Of the 59,747 patients included, 32,878 (55.03%) were female, and the mean age was 64.5. A total of 462 (0.77%) composite venous thromboembolism events occurred. There were 221 (0.71%) and 129 (0.80%) venous thromboembolism events in patients receiving aspirin only and anticoagulants only, respectively. Aspirin was non-inferior to anticoagulants for composite venous thromboembolism events (odds ratio 0.99, 95% confidence interval 0.79-1.26, P < .001). Bleeding events occurred in 767 (1.28%) patients, with 304 (0.97%) and 281 (1.74%) bleeding events in patients receiving aspirin only and anticoagulants only, respectively. Aspirin was non-inferior to anticoagulants for bleeding events (odds ratio 0.62, 95% confidence interval 0.52-0.74, P < .001). CONCLUSION: Aspirin is not inferior to other anticoagulants as pharmacologic venous thromboembolism prophylaxis with regards to post-operative risk of venous thromboembolism or bleeding. Sole use of aspirin for venous thromboembolism prophylaxis after total hip arthroplasty should be considered in the appropriate patient.

Summary of knee implant one, three, five, and 10-year revision risk reported by national and regional arthroplasty registries: a valuable source of evidence for clinical decision-making.

Optimal implant selection is a major component of high-quality arthroplasty care, and revision risk is an important parameter characterizing knee arthroplasty implant clinical performance.National and regional arthroplasty registries are essential sources of revision risk data, but these data are often difficult to find because they are buried within extensive annual reports. Summarizing total knee arthroplasty (TKA) implant revision risks as presented in registry reports can maximize the usefulness of registry data for orthopaedic surgeons.The findings summarize the revision risk data found in national arthroplasty reports from the Australian, Danish, Finnish, and the England, Wales, Northern Ireland and the Isle of Man registries, and in regional arthroplasty reports from the Emilia-Romagna Region (Italty), and the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI) registries.The six supplemental summary tables present revision risk data for TKA implants by cemented, uncemented, hybrid, and unreported fixation types. Additional summary tables are presented for revision risk of unicondylar (UKA) and patellofemoral joint (PFJ) revisions. Within TKA fixation categories, revision risks at 10 years ranged from 2.4% to 35.7% (cemented), 2.8% to 25.0% (uncemented), 2.0% to 9.2% (hybrid), and 0.0% to 39.7% (unreported). Unicondylar 10-year revision risk ranged from 4.9% to 17.2%. Patellofemoral joint 10-year revision risk ranged from 15.2% to 21.7%.There is substantial variation in one, three, five, and 10-year revision risk across implants, which suggests surgeons should choose implants carefully. Cite this article: EFORT Open Rev 2020;5:268-272. DOI: 10.1302/2058-5241.5.190053.

Association of Aspirin With Prevention of Venous Thromboembolism in Patients After Total Knee Arthroplasty Compared With Other Anticoagulants: A Noninferiority Analysis.

Importance: There has been significant debate in the surgical and medical communities regarding the appropriateness of using aspirin alone for venous thromboembolism (VTE) prophylaxis following total knee arthroplasty (TKA). Objective: To determine the acceptability of aspirin alone vs anticoagulant prophylaxis for reducing the risk of postoperative VTE in patients undergoing TKA. Design, Setting, and Participants: Noninferiority study of a retrospective cohort of TKA cases submitted to the Michigan Arthroplasty Registry Collaborative Quality Initiative at 29 member hospitals, ranging from small community hospitals to large academic and nonacademic medical centers in Michigan. The study included 41 537 patients who underwent primary TKA between April 1, 2013, and October 31, 2015. Clinical events were monitored for 90 days after surgery. Data were analyzed between September and October 2016. Exposures: The method of pharmacologic prophylaxis: neither aspirin nor anticoagulants for 668 patients (1.6%), aspirin only for 12 831 patients (30.9%), anticoagulant only (eg, low-molecular-weight heparin, warfarin, and Xa inhibitors) for 22 620 patients (54.5%), and both aspirin/anticoagulant for 5418 patients (13.0%). Most patients were also using intermittent pneumatic compression stockings. Main Outcome and Measures: The primary composite outcome was the first occurrence of VTE or death. The noninferiority margin was specified as 0.3. The secondary outcome was bleeding events. Results: Of the 41 537 patients, 14 966 were men (36%), and the mean age was 65.8 years. A VTE event occurred in 573 of 41 537 patients (1.38%); 32 of 668 (4.79%) who received no pharmacologic prophylaxis, 149 of 12 831 (1.16%) treated with aspirin alone, 321 of 22 620 (1.42%) with anticoagulation alone, and 71 of 5418 (1.31%) prescribed both aspirin and anticoagulation. Aspirin only was noninferior for the composite VTE outcome compared with those receiving other chemoprophylaxis (adjusted odds ratio, 0.85; 95% CI, 0.68-1.07, P for inferiority = .007). Bleeding occurred in 457 of 41 537 patients (1.10%), 10 of 668 (1.50%) without prophylaxis, 116 of 12 831 (0.90%) in the aspirin group, 258 of 22 620 (1.14%) with anticoagulation, and 73 of 5418 (1.35%) of those receiving both. Aspirin alone was also noninferior for bleeding complications (adjusted odds ratio, 0.80; 95% CI, 0.63-1.00, P for inferiority <.001). Conclusions and Relevance: In this study of patients undergoing TKA, aspirin was not inferior to other anticoagulants in the postoperative rate of VTE or death. Aspirin alone may provide similar protection from postoperative VTE compared with other anticoagulation treatments.

The Michigan Arthroplasty Registry Collaborative Quality Initiative Experience: Improving the Quality of Care in Michigan.

The Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI) is a regional quality improvement effort that is focused on hip and knee arthroplasty. From its inception in 2012, MARCQI has grown to include data from 66 hospitals and surgery centers, and contains over 209,000 fully abstracted cases in its database. Using high-quality risk-standardized outcomes data, MARCQI drives quality improvement through a collaborative and nonpunitive structure. Quality improvement initiatives have included transfusion reduction, infection prevention, venous thromboembolism reduction, and reduction of discharge to nursing homes. In addition, MARCQI focuses on postmarket surveillance of implants by computing revision-risk estimates based on the cases that were registered prior to the end of 2016. This paper describes the impact of MARCQI on the quality of hip and knee arthroplasty care in the state of Michigan since its inception in 2012, and it briefly summarizes the recently released 5-year report.

Application of a Causal Discovery Algorithm to the Analysis of Arthroplasty Registry Data.

Improving the quality of care for hip arthroplasty (replacement) patients requires the systematic evaluation of clinical performance of implants and the identification of "outlier" devices that have an especially high risk of reoperation ("revision"). Postmarket surveillance of arthroplasty implants, which rests on the analysis of large patient registries, has been effective in identifying outlier implants such as the ASR metal-on-metal hip resurfacing device that was recalled. Although identifying an implant as an outlier implies a causal relationship between the implant and revision risk, traditional signal detection methods use classical biostatistical methods. The field of probabilistic graphical modeling of causal relationships has developed tools for rigorous analysis of causal relationships in observational data. The purpose of this study was to evaluate one causal discovery algorithm (PC) to determine its suitability for hip arthroplasty implant signal detection. Simulated data were generated using distributions of patient and implant characteristics, and causal discovery was performed using the TETRAD software package. Two sizes of registries were simulated: (1) a statewide registry in Michigan and (2) a nationwide registry in the United Kingdom. The results showed that the algorithm performed better for the simulation of a large national registry. The conclusion is that the causal discovery algorithm used in this study may be a useful tool for implant signal detection for large arthroplasty registries; regional registries may only be able to only detect implants that perform especially poorly.

Using a Bayesian Network to Predict L5/S1 Spinal Compression Force from Posture, Hand Load, Anthropometry, and Disc Injury Status.

Stochastic biomechanical modeling has become a useful tool most commonly implemented using Monte Carlo simulation, advanced mean value theorem, or Markov chain modeling. Bayesian networks are a novel method for probabilistic modeling in artificial intelligence, risk modeling, and machine learning. The purpose of this study was to evaluate the suitability of Bayesian networks for biomechanical modeling using a static biomechanical model of spinal forces during lifting. A 20-node Bayesian network model was used to implement a well-established static two-dimensional biomechanical model for predicting L5/S1 compression and shear forces. The model was also implemented as a Monte Carlo simulation in MATLAB. Mean L5/S1 spinal compression force estimates differed by 0.8%, and shear force estimates were the same. The model was extended to incorporate evidence about disc injury, which can modify the prior probability estimates to provide posterior probability estimates of spinal compression force. An example showed that changing disc injury status from false to true increased the estimate of mean L5/S1 compression force by 14.7%. This work shows that Bayesian networks can be used to implement a whole-body biomechanical model used in occupational biomechanics and incorporate disc injury.

Quality Initiative Programs Can Decrease Total Joint Arthroplasty Transfusion Rates-A Multicenter Study Using the MARCQI Total Joint Registry Database.

BACKGROUND: The Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI) noted wide variability between member hospitals in blood transfusion rates after primary total hip and knee arthroplasty (THA and TKA). Blood transfusion has substantial risks and accepted recommendations exist to guide transfusion practices. MARCQI began an initiative to decrease unnecessary transfusions by identifying/reporting outliers, discussing conservative transfusion practices, and recommending transfusion guidelines. There was a later recommendation to consider intraoperative use of tranexamic acid. METHODS: All MARCQI-registered unilateral TKA and THA cases from the 28 member hospitals (pre-November 2013) were included. For 3 time periods (before November 13, 2013; November 13, 2013, to November 12, 2014; and after November 12, 2014), we calculated average risk and range of transfusion, transfusion with nadir hemoglobin >8 g/dL, mean length of stay, and 90-day risk of discharge to nursing home, readmission, deep infection, and emergency department visits. RESULTS: For THA, risk and range of transfusion decreased over the 3 time periods: 12.6% (2.5%-36.2%), 7.6% (2.2%-23.8%), and 4.5% (0.7%-14.4%); for TKA, 6.3% (1.3%-15.6%), 3.1% (0%-12.5%), and 1.3% (0%-7.4%). Decreases were also noted for transfusion with a nadir hemoglobin >8 g/dL with a near elimination of "unnecessary" transfusions. There was no evidence of increase in length of stay, discharge to nursing home, readmission, deep infection, or emergency department visits. CONCLUSION: A simple intervention can decrease unnecessary blood transfusions during and after elective primary unilateral THA or TKA. A collaborative registry can be used effectively to improve the quality of patient care and set a new benchmark for transfusion.

Arthroplasty registries around the world: valuable sources of hip implant revision risk data.

PURPOSE OF REVIEW: National and regional arthroplasty registries have proliferated since the Swedish Knee Arthroplasty Register was started in 1975. Registry reports typically present implant-specific estimates of revision risk and patient- and technique-related factors that can inform clinical decision-making about implants and techniques. However, annual registry reports are long and it is difficult for clinicians to extract comparable revision risk data. Since implants may appear in multiple registry reports, it is even more difficult to gather relevant data for clinical decision-making about implant selection. The purpose of this paper is to briefly describe arthroplasty registry concepts, international registries around the world, US registries, and provide a parsimonious summary of total hip arthroplasty (THA) implant revision risk reports across registries. RECENT FINDINGS: Revision risk data for conventional stem/cup combinations reported by the Australian, R.I.P.O. (Italian), Finnish, and Danish registries are summarized here. These registries were selected because they presented 10-year data on revision risk by stem/cup combination. Four tables of revision risk are presented based on fixation: cemented, uncemented, hybrid, and reverse hybrid. Review of these tables show there is wide variation in revision risk across conventional THA implants. It also demonstrates that some cemented implants have better 10-year risk than the best uncemented implants. Many arthroplasty registries prepare annual reports that include revision risk data for implants and they are posted on the registry websites. Arthroplasty surgeons should stay current with these registry reports on implant performance and potential outliers and keep them in mind when making implant decisions.