Publications by authors named "Richard E Hughes"

68 Publications

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

J Arthroplasty 2022 07 9;37(7S):S616-S621. Epub 2022 Mar 9.

Department of Orthopaedic Surgery, The CORE Institute, Novi, MI.

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.
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http://dx.doi.org/10.1016/j.arth.2022.03.014DOI Listing
July 2022

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

J Arthroplasty 2022 06 8;37(6S):S19-S26. Epub 2022 Mar 8.

Department of Orthopaedic Surgery, Ascension Providence Rochester Hospital, Rochester, MI.

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.
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http://dx.doi.org/10.1016/j.arth.2022.02.109DOI Listing
June 2022

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

Orthop Res Rev 2021 24;13:215-228. Epub 2021 Nov 24.

Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA.

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.
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http://dx.doi.org/10.2147/ORR.S325042DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8627892PMC
November 2021

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

J Arthroplasty 2021 06 20;36(6):2068-2075.e2. Epub 2021 Jan 20.

Department of Orthopaedic Surgery, University of Michigan Health System, Ann Arbor, MI.

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.
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http://dx.doi.org/10.1016/j.arth.2021.01.025DOI Listing
June 2021

Why Registries are Important: The Example of the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI).

Arthroplast Today 2020 Dec 30;6(4):747-748. Epub 2020 Aug 30.

Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA.

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http://dx.doi.org/10.1016/j.artd.2020.07.041DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7475173PMC
December 2020

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.

EFORT Open Rev 2020 May 5;5(5):268-272. Epub 2020 May 5.

Department of Orthopaedic Surgery, Michigan Medicine, Ann Arbor, Michigan, USA.

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: 2020;5:268-272. DOI: 10.1302/2058-5241.5.190053.
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http://dx.doi.org/10.1302/2058-5241.5.190053DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7265088PMC
May 2020

Controversies in Hip Arthroplasty: Using Registries to Answer Difficult Questions.

JAMA 2020 03;323(11):1046-1048

Department of Orthopaedic Surgery, University of Michigan, Ann Arbor.

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http://dx.doi.org/10.1001/jama.2020.2274DOI Listing
March 2020

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

J Bone Joint Surg Am 2018 Nov;100(22):e143

Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, 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.
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http://dx.doi.org/10.2106/JBJS.18.00239DOI Listing
November 2018

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

JAMA Surg 2019 01;154(1):65-72

Department of Orthopaedic Surgery, University of Michigan, Ann Arbor.

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.
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http://dx.doi.org/10.1001/jamasurg.2018.3858DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6439863PMC
January 2019

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

Biomed Eng Comput Biol 2018 22;9:1179597218756896. Epub 2018 Feb 22.

Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.

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.
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http://dx.doi.org/10.1177/1179597218756896DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5826097PMC
February 2018

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

Authors:
Richard E Hughes

Appl Bionics Biomech 2017 1;2017:2014961. Epub 2017 Oct 1.

Departments of Orthopaedic Surgery, Biomedical Engineering, and Industrial & Operations Engineering, University of Michigan, Ann Arbor, MI 48109, USA.

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.
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http://dx.doi.org/10.1155/2017/2014961DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5643038PMC
October 2017

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

J Arthroplasty 2017 11 13;32(11):3292-3297. Epub 2017 Jun 13.

Department of Orthopaedic Surgery, University of Michigan Health System, A. Alfred Taubman Health Care Center, Ann Arbor, Michigan.

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.
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http://dx.doi.org/10.1016/j.arth.2017.06.009DOI Listing
November 2017

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

Curr Rev Musculoskelet Med 2017 Jun;10(2):240-252

Department of Orthopaedic Surgery, University of Michigan, 2003 BSRB, 109 Zina Pitcher Pl, Ann Arbor, MI, 48104, USA.

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.
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http://dx.doi.org/10.1007/s12178-017-9408-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5435639PMC
June 2017

Corrigendum to 'Factors Affecting Readmission Cost After Primary Total Knee Arthroplasty in Michigan' [Journal of Arthroplasty 31 (2016) 1179-1182].

J Arthroplasty 2017 04 19;32(4):1407. Epub 2017 Jan 19.

Department of Industrial and Operations Engineering, University of Michigan, Ann Arbor, Michigan; Department of Orthopaedic Surgery, University of Michigan Health System, Ann Arbor, Michigan; Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan.

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http://dx.doi.org/10.1016/j.arth.2016.12.042DOI Listing
April 2017

The Michigan Experience with Safety and Effectiveness of Tranexamic Acid Use in Hip and Knee Arthroplasty.

J Bone Joint Surg Am 2016 10;98(19):1646-1655

Department of Orthopaedic Surgery, University of Michigan Medical Center, Ann Arbor, Michigan

Background: The efficacy of tranexamic acid (TXA) in reducing blood loss and transfusion requirements in total hip and knee arthroplasty has been well established in small controlled clinical trials and meta-analyses. The purpose of the current study was to determine the risks and benefits of TXA use in routine orthopaedic surgical practice on the basis of data from a large, statewide arthroplasty registry.

Methods: From April 18, 2013, to September 30, 2014, there were 23,236 primary total knee arthroplasty cases and 11,489 primary total hip arthroplasty cases completed and registered in the Michigan Arthroplasty Registry Collaborative Quality Initiative (MARCQI). We evaluated the association between TXA use and hemoglobin drop, transfusion, length of stay (LOS), venous thromboembolism (VTE), readmission, and cardiovascular events by fitting mixed-effects generalized linear and mixed-effects Cox models. We used inverse probability of treatment weighting to enhance causal inference.

Results: For total hip arthroplasty, TXA use was associated with a smaller drop in hemoglobin (mean difference = -0.65 g/dL; 95% confidence interval [CI] = -0.60 to -0.71 g/dL), decreased odds of blood transfusion (odds ratio [OR] = 0.72; 95% CI = 0.60 to 0.86), and decreased readmissions (OR = 0.77; 95% CI = 0.64 to 0.93) compared with no TXA use. There was no effect on VTE (hazard ratio [HR] = 0.91; 95% CI = 0.62 to 1.33), LOS (incident rate ratio [IRR] = 1.00; 95% CI = 0.97 to 1.03), or cardiovascular events (OR = 0.85; 95% CI = 0.47 to 1.52). For total knee arthroplasty, TXA was associated with a smaller drop in hemoglobin (mean difference = -0.68 g/dL; 95% CI = -0.64 to -0.71 g/dL) and one-fourth the odds of blood transfusion (OR = 0.26; 95% CI = 0.21 to 0.31). There was an association with decreased risk of VTE within 90 days after surgery (HR = 0.56; 95% CI = 0.42 to 0.73), slightly decreased LOS (IRR = 0.93; 95% CI = 0.92 to 0.95), and no association with readmissions (OR = 0.90; 95% CI = 0.79 to 1.04) or cardiovascular events (OR = 1.12; 95% CI = 0.74 to 1.71).

Conclusions: In routine orthopaedic surgery practice, TXA use was associated with decreased blood loss and transfusion risk for both total knee and total hip arthroplasty, without evidence of increased risk of complications. TXA use was also associated with reduced risk of readmission among total hip arthroplasty patients and reduced risk of VTE among total knee arthroplasty patients, and did not have an adverse effect on cardiovascular complications in either group.

Level Of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
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http://dx.doi.org/10.2106/JBJS.15.01010DOI Listing
October 2016

Factors Affecting Readmission Cost After Primary Total Knee Arthroplasty in Michigan.

J Arthroplasty 2016 06 7;31(6):1179-1182. Epub 2015 Dec 7.

Department of Industrial and Operations Engineering, University of Michigan, Ann Arbor, Michigan; Department of Orthopaedic Surgery, University of Michigan Health System, Ann Arbor, Michigan; Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan.

Background: The increasing readmission risk of primary total knee arthroplasty (TKA) represents a significant economic burden and public health challenge. Many have investigated the predictors of readmissions after TKA while little work has studied the associated readmission costs. This article investigated the factors affecting readmission cost after primary TKA at the time of initial discharges using clinical and resource-use information and compared the factors between 2 payer groups (Medicare-or-Medicaid and non-Medicare-nor-Medicaid groups).

Methods: We used data from the Michigan State Inpatient Database of the Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality. We identified readmissions after primary TKA in 2012 using International Classification of Diseases, Ninth Revision, code 81.54. Total readmission cost was modeled using multivariate regression to identify predictors.

Results: Of 1358 readmissions after primary TKA, 949 were in the Medicare-or-Medicaid group, and 409 were in the non-Medicare-nor-Medicaid group. The overall mean and median total readmission costs were $9335 (standard deviation $10,528) and $6810, respectively. Significant predictors of total readmission cost for the Medicare-or-Medicaid group included length of stay (P < .001), discharge disposition (P < .001), number of chronic conditions (P = .001), and total cost of initial admission (P < .001). Only total cost of initial admission was significant in predicting total readmission cost for the non-Medicare-nor-Medicaid group (P < .001).

Conclusion: Total cost of initial admission was a significant predictor of total readmission cost in both Medicare-or-Medicaid and non-Medicare-nor-Medicaid groups, independent of length of stay and number of chronic conditions.
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http://dx.doi.org/10.1016/j.arth.2015.11.037DOI Listing
June 2016

Ulnar collateral ligament strain of the thumb metacarpophalangeal joint: biomechanical comparison of two postoperative immobilization techniques.

Hand (N Y) 2015 Dec 18;10(4):721-5. Epub 2015 Feb 18.

Department of Orthopaedic Surgery, University of Michigan Health System, 2098 South Main Street, Ann Arbor, MI 48103 USA.

Background: The aim of this study was to compare postoperative immobilization techniques of the thumb metacarpophalangeal (MP) ulnar collateral ligament (UCL) in a cadaver model of a noncompliant patient.

Methods: A cadaveric model with fresh-frozen forearms was used to simulate pinch under two immobilization conditions: (1) forearm-based thumb spica splint alone and (2) forearm-based thumb spica splint with supplemental transarticular MP Kirschner wire fixation. Pinch was simulated by thumb valgus loading and flexor pollicis longus (FPL) loading. Ulnar collateral ligament displacements were measured and strain values calculated. Statistical analysis was performed using a repeated measures analysis of variance model.

Results: With valgus thumb loading, we noted a significantly lower UCL strain in the splint and pin group compared to splint immobilization alone. Increased load was associated with a statistically significant increase in UCL strain within each immobilization condition. FPL loading resulted in negative displacement, or paradoxical shortening, of the UCL in both immobilization groups.

Conclusions: While immobilized, valgus thumb force, as opposed to MP flexion, is a likely contributor to UCL strain during simulated pinch representing noncompliance during the postoperative period. Supplemental thumb MP pin fixation more effectively protects the UCL from valgus strain. UCL shortening with FPL loading likely represents paradoxical MP extension due to flexion of the distal phalanx against the distal splint, suggesting attempted thumb flexion with splint immobilization alone does not jeopardize UCL repair.

Clinical Relevance: This study provides a foundation to aid clinical decision-making after UCL repair. It reinforces the practice of surgeons who routinely pin their MP joints, but also brings to attention that the use of temporary MP pin fixation may be considered in difficult cases, such as those with potential noncompliance or tenuous repair.
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http://dx.doi.org/10.1007/s11552-015-9747-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4641096PMC
December 2015

Effects of biceps tension on the torn superior glenoid labrum.

J Orthop Res 2015 Oct 24;33(10):1545-51. Epub 2015 Jul 24.

Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan.

The purpose of this study was to evaluate the role of the tension on the long head of the biceps tendon in the propagation of SLAP tears by studying the mechanical behavior of the torn superior glenoid labrum. A previously validated finite element model was extended to include a glenoid labrum with type II SLAP tears of three different sizes. The strain distribution within the torn labral tissue with loading applied to the biceps tendon was investigated and compared to the inact and unloaded conditions. The anterior and posterior edges of each SLAP tear experienced the highest strain in the labrum. Labral strain increased with increasing biceps tension. This effect was stronger in the labrum when the size of the tear exceeded the width of the biceps anchor on the superior labrum. Thus, this study indicates that biceps tension influences the propagation of a SLAP tear more than it does the initiation of a tear. Additionally, it also suggests that the tear size greater than the biceps anchor site as a criterion in determining optimal treatment of a type II SLAP tear.
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http://dx.doi.org/10.1002/jor.22888DOI Listing
October 2015

Sex distribution of study samples reported in American Society of Biomechanics annual meeting abstracts.

PLoS One 2015 4;10(3):e0118797. Epub 2015 Mar 4.

Department of Industrial & Operations Engineering, University of Michigan, Ann Arbor, Michigan, United States of America; Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, Michigan, United States of America.

Background: Study samples should be appropriately selected to maximize generalizability of results. Excluding one sex from studies of conditions that affect both sexes is problematic and has received attention as a public policy issue in the United States, resulting in legislation and recommendations made by the National Institutes of Health to address this deficiency of study designs. It is unknown to what extent biomechanical studies have inappropriately excluded one sex. The objective of this study was to provide objective data on this question.

Methods: A retrospective review of random samples of abstracts presented at American Society of Biomechanics annual meetings from 1983 to 2013 was conducted to assess reporting of sex of study samples and whether the study samples were approximately balanced with respect to sex.

Findings: We did not find a statistically significant increasing trend in the percentage of abstracts reporting sex over time. However, increasing trends were noted in the percentage of abstracts including both sexes (p < 0.05) and percentage of abstracts having an "approximately balanced" study sample containing 50 ± 20% females (p > 0.05). In 2013 the percentage of abstracts reporting studies having approximately balanced study samples was only 28%, far from the ideal level of 100%.

Interpretation: While there has been modest change since 1983, there remains significant room for improvement in the reporting and composition of experimental studies reported at American Society of Biomechanics annual meetings.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0118797PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4349743PMC
December 2015

Effects of biceps tension and superior humeral head translation on the glenoid labrum.

J Orthop Res 2014 Nov 28;32(11):1424-9. Epub 2014 Jul 28.

School of Kinesiology, University of Michigan, Ann Arbor, Michigan; Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan.

We sought to understand the effects of superior humeral head translation and load of the long head of biceps on the pathomechanics of the superior glenoid labrum by predicting labral strain. Using micro-CT cadaver images, a finite element model of the glenohumeral joint was generated, consisting of humerus, glenoid bone, cartilages, labrum, and biceps tendon. A glenohumeral compression of 50 N and biceps tensions of 0, 22, 55, and 88 N were applied. The humeral head was superiorly translated from 0 to 5 mm in 1-mm increments. The highest labral strain occurred at the interface with the glenoid cartilage and bone beneath the origin of the biceps tendon. The maximum strain was lower than the reported failure strain. The humeral head motion had relatively greater effect than biceps tension on the increasing labral strain. This supports the mechanistic hypothesis that superior labral lesions result mainly from superior migration of the humeral head, but also from biceps tension
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http://dx.doi.org/10.1002/jor.22688DOI Listing
November 2014

Shoulder labral pathomechanics with rotator cuff tears.

J Biomech 2014 May 29;47(7):1733-8. Epub 2014 Jan 29.

School of Kinesiology, University of Michigan, Ann Arbor, MI, USA; Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA. Electronic address:

Rotator cuff tears (RCTs), the most common injury of the shoulder, are often accompanied by tears in the superior glenoid labrum. We evaluated whether superior humeral head (HH) motion secondary to RCTs and loading of the long head of the biceps tendon (LHBT) are implicated in the development of this associated superior labral pathology. Additionally, we determined the efficacy of a finite element model (FEM) for predicting the mechanics of the labrum. The HH was oriented at 30° of glenohumeral abduction and neutral rotation with 50N compressive force. Loads of 0N or 22N were applied to the LHBT. The HH was translated superiorly by 5mm to simulate superior instability caused by RCTs. Superior displacement of the labrum was affected by translation of the HH (P<0.0001), position along the labrum (P<0.0001), and interaction between the location on the labrum and LHBT tension (P<0.05). The displacements predicted by the FEM were compared with mechanical tests from 6 cadaveric specimens and all were within 1 SD of the mean. A hyperelastic constitutive law for the labrum was a better predictor of labral behavior than the elastic law and insensitive to ±1 SD variations in material properties. Peak strains were observed at the glenoid-labrum interface below the LHBT attachment consistent with the common location of labral pathology. These results suggest that pathomechanics of the shoulder secondary to RCTs (e.g., superior HH translation) and LHBT loading play significant roles in the pathologic changes seen in the superior labrum.
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http://dx.doi.org/10.1016/j.jbiomech.2014.01.036DOI Listing
May 2014

Variation in use of reverse total shoulder arthroplasty across hospitals.

J Shoulder Elbow Surg 2013 Dec 14;22(12):1633-8. Epub 2013 Oct 14.

Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA.

Background: The opportunity for variation exists in the choice between anatomic and reverse total shoulder arthroplasty. Quality improvement methods seek to reduce variation. We used supply-chain data to characterize variation in the selection of anatomic versus reverse total shoulder arthroplasty across hospitals and to analyze the effect of hospital volume on this variation.

Methods: Mendenhall Associates, Inc (Ann Arbor, MI, USA) provided us with a database of hospital supply-chain data from orthopaedic surgical cases. This study included hospitals in which at least one total shoulder arthroplasty was performed. We calculated, for each hospital, the percentages of each type of prosthesis implanted and examined the distribution of these percentages across all hospitals. We also divided the sample of hospitals into tertiles, by volume of total shoulder arthroplasties performed, and examined the distributions of percentage reverse shoulder arthroplasty performed in each tertile.

Results: Across all hospitals, we saw wide variation in the volume of total shoulder arthroplasties and the percentage of reverse shoulder arthroplasties performed. Hospitals with lower total shoulder arthroplasty volumes exhibited greater variation in the percentages of each type of total shoulder arthroplasty performed. Higher volume hospitals exhibited smaller variation.

Conclusions: This study revealed wide variation in the selection of anatomic and reverse total shoulder arthroplasty across all hospitals and an inverse relationship between hospital volume and variation. This variation signals uncertainty about the best application of each device and that there is need for improvement in the consistency of treatment of patients with shoulder disease.

Level Of Evidence: Level II, cost-effectiveness study, economic and decision analysis.
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http://dx.doi.org/10.1016/j.jse.2013.09.002DOI Listing
December 2013

Surgeon variability in total knee arthroplasty component alignment: a Monte Carlo analysis.

Comput Methods Biomech Biomed Engin 2014 Nov 16;17(15):1738-50. Epub 2013 Apr 16.

a Laboratory for Optimization and Computation in Orthopaedic Surgery, University of Michigan , Ann Arbor , MI , USA.

Component mal-alignment in total knee arthroplasty has been associated with increased revision rates and poor clinical outcomes. A significant source of variability in traditional, jig-based total knee arthroplasty is the performance of the surgeon. The purpose of this study was to determine the most sensitive steps in the femoral and tibia arthroplasty procedures. A computational model of the total knee arthroplasty procedure was created, and Monte Carlo simulations were performed that included surgeon variability in each step of the procedure. The proportion of well-aligned components from the model agrees with clinical literature in most planes. When components must be aligned within ±3° in all planes, component alignment was most sensitive to the accuracy of identifying the lateral epicondyle for the femoral component, and to the precision of the transverse plane alignment of the extramedullary guide for the tibial component. This model can be used as a tool for evaluating different procedural approaches or sources of variability to improve the quality of the total knee arthroplasty procedure.
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http://dx.doi.org/10.1080/10255842.2013.765948DOI Listing
November 2014

Relationship between implant use, operative time, and costs associated with distal biceps tendon reattachment.

Orthopedics 2012 Nov;35(11):e1618-24

Department of Orthopaedic Surgery, Saint John Regional Hospital, Saint John, New Brunswick, Canada.

The suture anchor and transosseous drill hole techniques for reattachment of the distal biceps tendon to the radius have been found to have similar clinical and biomechanical outcomes. However, a comparison of the cost effectiveness of these techniques is lacking. The purpose of this study was to determine whether the use of suture anchors decreases operative time enough to offset the additional cost of the implants. The records of all patients undergoing a distal biceps tendon reattachment were reviewed to determine the method of fixation, operative time, and associated surgical costs. Two surgeons used a technique of fixing the tendon directly to the bone (transosseous group), whereas 3 surgeons used suture anchors. Given the standard nature of the surgical procedure (other than the fixation technique), only the costs that differed between the 2 groups were included. Surgical center costs were obtained from the local outpatient surgical center in 2011 US dollars. Five surgeons treated 70 men (mean age, 45.9±9.2 years). Mean time from injury to surgery was 14 days. Mean operative times for the transosseous and suture anchor groups were 97.6±14.9 and 95.8±25.8 minutes, respectively (P=.74). Two anchors were used in 79% of the anchor cases. The use of anchors cost $474.33 more per patient. However, this value is sensitive to the cost of the individual anchors, intersurgeon variation in operative time, and per-minute value of saved operative time. No operative time was saved with the use of suture anchors. This cost comparison framework can be used to evaluate the balance in surgical resource use due to implant cost vs savings in operative time.
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http://dx.doi.org/10.3928/01477447-20121023-19DOI Listing
November 2012

Evaluation of utility in shoulder pathology: Correlating the American Shoulder and Elbow Surgeons and Constant scores to the EuroQoL.

World J Orthop 2012 Mar;3(3):20-4

Blaine T Bafus, Department of Orthopaedic Surgery, Cleveland Clinic Foundation, Cleveland, OH 44115-2325, United States.

Aim: To study whether health utility scores can be derived from shoulder-specific scores.

Methods: Authors investigated two questions: (1) do the American Shoulder and Elbow Surgeons (ASES) score and the Constant score correlate with the EuroQoL (EQ-5D), a measure of health utility? (2) can the ASES and Constant scores be obtained from a complete study sample without bias? Thirty subjects with various shoulder diagnoses completed ASES, Constant, and EQ-5D instruments. Pearson correlations were calculated to assess the associations between EQ-5D score and ASES and Constant scores.

Results: The correlation between EQ-5D score and ASES score was 0.60 (P < 0.001); it was 0.54 for EQ-5D and Constant scores (P < 0.003). A multiple regression model containing ASES score, Constant score, age, and gender failed to adequately predict EQ-5D. Moreover, 25% of patients meeting the inclusion criteria did not complete the ASES questionnaire because they did not feel that specific questions, such as "do usual sport - list" and "throw ball overhand," applied to them.

Conclusion: Authors' results do not support the use of the ASES and Constant scores in predicting EuroQol health utility values. However, the Constant score was more suitable for this patient population because all patients were able to complete it.
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http://dx.doi.org/10.5312/wjo.v3.i3.20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3329619PMC
March 2012

"Grand piano sign," a marker for proper femoral component rotation during total knee arthroplasty.

Am J Orthop (Belle Mead NJ) 2011 Jul;40(7):348-52

Sharp Health Care, San Diego, California 91942, USA.

A malpositioned femoral component is an established risk factor for patellar instability and pain after total knee arthroplasty (TKA). In the assessment of femoral rotation, several axes, including the transepicondylar axis, the posterior condylar axis, and the anteroposterior axis, are useful. However, these axes are not always easily applicable, particularly when significant deformity exists. An anecdotal method used by some surgeons involves assessing the shape of the anterior femoral surface osteotomy. Our observations from saw bone models and TKA led to our hypothesis that proper femoral component placement is indicated by a bimodal peak on the anterior femur, approximately twice as high on the lateral side than on the medial side. We use the term "grand piano sign" to describe the shape of the trochlea after the osteotomy is correctly completed. To our knowledge, this common observation has not been studied either in the laboratory or in vivo. Our cadaveric models demonstrated that the grand piano sign correlated with proper femoral rotation during TKA. Surgeons who are knowledgeable about this marker should find it helpful when orienting components during knee replacement surgery.
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July 2011

When do rotator cuff repairs fail? Serial ultrasound examination after arthroscopic repair of large and massive rotator cuff tears.

Am J Sports Med 2011 Oct 7;39(10):2064-70. Epub 2011 Jul 7.

Division of Sports Medicine, Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI 48105, USA.

Background: Despite advances in arthroscopic repair of rotator cuff tears, recurrent tears after repair of large and massive tears remain a significant clinical problem. The primary objective of this study was to define the timing of structural failure of surgically repaired large and massive rotator cuff tears by serial imaging with ultrasound. The secondary objective of this study was to investigate the association between recurrent tears and clinical outcome after rotator cuff repair.

Hypothesis: Recurrent tear after arthroscopic repair of large rotator cuff tears is more likely to occur late (>3 months) in the postoperative period and will be associated with inferior clinical outcome scores.

Study Design: Cohort study; Level of evidence, 3.

Methods: Twenty-two consecutive patients with large (>3 cm) rotator cuff tears underwent arthroscopic repair with a standardized technique. Serial ultrasound examinations were performed at 2 days, 2 weeks, 6 weeks, 3 months, 6 months, 12 months, and 24 months after surgery. Western Ontario Rotator Cuff (WORC) Index scores were also collected at these time points.

Results: Nine (41%) of the 22 arthroscopically repaired rotator cuff tears demonstrated recurrent tears. Seven of the 9 retears occurred within 3 months of surgery, and the other 2 occurred between 3 and 6 months. No retears occurred after 6 months. At 24-month follow-up, WORC scores favoring intact rotator cuffs over retears approached statistical significance (mean WORC intact 123.9 vs retear 659.8; P = .07).

Conclusion: Recurrent rotator cuff tears are not uncommon after arthroscopic repair of large and massive tears. These recurrent tears appear to occur more frequently in the early postoperative period (within the first 3 months) and are associated with inferior clinical outcomes.
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http://dx.doi.org/10.1177/0363546511413372DOI Listing
October 2011

Bone density of the greater tuberosity is decreased in rotator cuff disease with and without full-thickness tears.

J Shoulder Elbow Surg 2011 Sep 21;20(6):904-8. Epub 2011 Mar 21.

Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI 48106, USA.

Background: Despite the high prevalence of rotator cuff disease in the aging adult population, the basic mechanisms initiating the disease are not known. It is known that changes occur at both the bone and tendon after rotator cuff tears. However, no study has focused on early or "pretear" rotator cuff disease states. The purpose of this study was to compare the bone mineral density of the greater tuberosity in normal subjects with that in subjects with impingement syndrome and full-thickness rotator cuff tears.

Materials And Methods: Digital anteroposterior shoulder radiographs were obtained for 3 sex- and age-matched study groups (men, 40-70 years old): normal asymptomatic shoulders (control), rotator cuff disease without full-thickness tears (impingement), and full-thickness rotator cuff tears (n = 39 per group). By use of imaging software, bone mineral densities were determined for the greater tuberosity, the greater tuberosity cortex, the greater tuberosity subcortex, and the cancellous region of the humeral head.

Results: The bone mineral density of the greater tuberosity was significantly higher for the normal control subjects compared with subjects with impingement or rotator cuff tears. No differences were found between the two groups of patients with known rotator cuff disease. The greater tuberosity cortex and greater tuberosity subcortex outcome measures were similar.

Conclusion: Bone mineral changes are present in the greater tuberosity of shoulders with rotator cuff disease both with and without full-thickness tears. The finding of focal diminished bone mineral density of the greater tuberosity in the absence of rotator cuff tears warrants further investigation.
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http://dx.doi.org/10.1016/j.jse.2010.12.009DOI Listing
September 2011

Effect of ankle flexion angle on axial alignment of total ankle replacement.

Foot Ankle Int 2010 Dec;31(12):1093-8

Division of Foot and Ankle Surgery, Department of Orthopaedic Surgery, The University of Michigan, Ann Arbor, MI 48103-5827, USA.

Background: The Salto Talaris Anatomic® (Tornier) total ankle replacement (TAR) has found widespread use in the United States and features rotationally mobile trial components that auto-align the final components, which themselves are rotationally fixed and highly congruent. Based on recent work on prosthetic and native ankle kinematics, we investigated the influence of the ankle flexion angle at the time of final component preparation on the axial alignment of the Salto Talaris TAR.

Materials And Methods: Following a power analysis based on a clinically meaningful difference of five degrees, eight fresh-frozen cadaveric thigh-to-foot specimens underwent installation of trial components using the Salto Talaris TAR system. Specimens were cycled from maximal dorsiflexion (DF) to plantarflexion (PF), as called for in the surgical technique guide, and drilling for the final component was carried out in both five degrees of DF and 15 degrees of PF using separate drill holes. These were compared with a reference drill hole previously placed along the axis of distal tibial cutting guide. Data were analyzed to determine whether components prepared in DF differed from those prepared in PF with respect to median (and variance) rotation.

Results: We found no significant difference in median axial alignment (p = 0.139) or in variances between the two groups (p=0.937).

Conclusion: The ankle flexion angle at the time of final component preparation did not significantly alter the axial alignment of the Salto Talaris TAR.

Clinical Relevance: Therefore, the rotational alignment of the tibial component is determined by the tibial bone cuts and will not auto-align to the rotation of the talar component.
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http://dx.doi.org/10.3113/FAI.2010.1093DOI Listing
December 2010
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