The International Consortium of Orthopaedic Registries: overview and summary

Preliminary feasibility assessment of CDM-based active surveillance using current status of medical device data in medical records and OMOP-CDM

In recent years, there has been an emerging interest in the use of claims and electronic health record (EHR) data for evaluation of medical device safety and effectiveness. In Korea, national insurance electronic data interchange (EDI) code has been used as a medical device data source for common data model (CDM). This study performed a preliminary feasibility assessment of CDM-based vigilance. A cross-sectional study of target medical device data in EHR and CDM was conducted. A total of 155 medical devices were finally enrolled, with 58.7% of them having EDI codes. Femoral head prosthesis was selected as a focus group. It was registered in our institute with 11 EDI codes. However, only three EDI codes were converted to systematized nomenclature of medicine clinical terms concept. EDI code was matched in one-to-many (up to 104) with unique device identifier (UDI), including devices classified as different global medical device nomenclature. The use of UDI rather than EDI code as a medical device data source is recommended. We hope that this study will share the current state of medical device data recorded in the EHR and contribute to the introduction of CDM-based medical device vigilance by selecting appropriate medical device data sources.

The rise of registry-based research: a bibliometric analysis

Background and purpose - The main purpose of arthroplasty registries is to collect information on patients, techniques, and devices to monitor and improve the outcome of the specific procedure. This study analyses the role played by registries in the orthopedic research community and describes publication trends, characteristics, and patterns of this field of research.Patients and methods - A descriptive-bibliometric review was conducted. Scopus was the database used for the research. All articles published from 1991 to December 2020 containing keywords related to registries and arthroplasty were considered. In particular, the following dimensions were analyzed in detail: (i) papers/year; (ii) journals; (iii) countries; (iv) research growth rate; (v) collaboration among countries. VOSviewer software was used to perform the bibliometric analysis. Finally, the 50 most cited papers of the last 10 years were briefly analyzed.Results - 3,933 articles were identified. There has been growing interest in the topic since 2010. Acta Orthopaedica ranked first for the number of articles published. The country with the largest number of articles citing registries was the United States, followed by the United Kingdom and Sweden. The relative number of articles per 100,000 inhabitants is 0.60 for Europe and 0.38 for the United States. The literature in this research area has an average yearly growth rate of 28%.Interpretation - The publication rate in the field of arthroplasty registries is constantly growing with a noteworthy impact in the evolution of this research and clinical area. The growth rate is significantly higher than that of arthroplasty literature (28% vs. 10%) and the collaboration among countries is strong and increasing with time.

Assessment of Extractability and Accuracy of Electronic Health Record Data for Joint Implant Registries

IMPORTANCE

Implant registries provide valuable information on the performance of implants in a real-world setting, yet they have traditionally been expensive to establish and maintain. Electronic health records (EHRs) are widely used and may include the information needed to generate clinically meaningful reports similar to a formal implant registry.

OBJECTIVES

To quantify the extractability and accuracy of registry-relevant data from the EHR and to assess the ability of these data to track trends in implant use and the durability of implants (hereafter referred to as implant survivorship), using data stored since 2000 in the EHR of the largest integrated health care system in the United States.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of a large EHR of veterans who had 45 351 total hip arthroplasty procedures in Veterans Health Administration hospitals from 2000 to 2017. Data analysis was performed from January 1, 2000, to December 31, 2017.

EXPOSURES

Total hip arthroplasty.

MAIN OUTCOMES AND MEASURES

Number of total hip arthroplasty procedures extracted from the EHR, trends in implant use, and relative survivorship of implants.

RESULTS

A total of 45 351 total hip arthroplasty procedures were identified from 2000 to 2017 with 192 805 implant parts. Data completeness improved over the time. After 2014, 85% of prosthetic heads, 91% of shells, 81% of stems, and 85% of liners used in the Veterans Health Administration health care system were identified by part number. Revision burden and trends in metal vs ceramic prosthetic femoral head use were found to reflect data from the American Joint Replacement Registry. Recalled implants were obvious negative outliers in implant survivorship using Kaplan-Meier curves.

CONCLUSIONS AND RELEVANCE

Although loss to follow-up remains a challenge that requires additional attention to improve the quantitative nature of calculated implant survivorship, we conclude that data collected during routine clinical care and stored in the EHR of a large health system over 18 years were sufficient to provide clinically meaningful data on trends in implant use and to identify poor implants that were subsequently recalled. This automated approach was low cost and had no reporting burden. This low-cost, low-overhead method to assess implant use and performance within a large health care setting may be useful to internal quality assurance programs and, on a larger scale, to postmarket surveillance of implant performance.

Evaluating learning and change in orthopaedics: What is the evidence-base?

Learning and change are key elements of clinical governance and are responsible for the progression of our specialty. Although orthopaedics has been slow to embrace quality improvement, recent years have seen global developments in surgical education, quality improvement, and patient outcome research. This review covers recent advances in the evaluation of learning and change and identifies the most important research questions that remain unanswered. Research into proxies of learning is improving but more work is required to identify the best proxy for a given procedure. Learning curves are becoming commonplace but are poorly integrated into postgraduate training curricula and there is little agreement over the most appropriate method to analyse learning curve data. With various organisations promoting centralisation of care, learning curve analysis is more important than ever before. The use of simulation in orthopaedics is developing but is yet to be formally mapped to resident training worldwide. Patient outcome research is rapidly changing, with an increased focus on quality of life measures. These are key to patients and their care. Cost-utility analysis is increasingly seen in orthopaedic manuscripts and this needs to continue to improve evidence-based care. Large-scale international, multi-centre randomised trials are gaining popularity and updated guidance on sample size estimation needs to become widespread. A global lack of surgeon equipoise will need to be addressed. Quality improvement projects frequently employ interrupted time-series analysis to evaluate change. This technique's limitations must be acknowledged, and more work is required to improve the evaluation of change in a dynamic healthcare environment where multiple interventions frequently occur. Advances in the evaluation of learning and change are needed to drive improved international surgical education and increase the reliability, validity, and importance of the conclusions drawn from orthopaedic research.

An international comparison of THA patients, implants, techniques, and survivorship in Sweden, Australia, and the United States

Background and purpose - International comparisons of total hip arthroplasty (THA) practices and outcomes provide an opportunity to enhance the quality of care worldwide. We compared THA patients, implants, techniques, and survivorship in Sweden, Australia, and the United States. Patients and methods - Primary THAs due to osteoarthritis were identified using Swedish (n = 159,695), Australian (n = 279,693), and US registries (n = 69,641) (2003-2015). We compared patients, practices, and implant usage across the countries using descriptive statistics. We evaluated time to all-cause revision using Kaplan-Meier survival curves. We assessed differences in countries' THA survival using chi-square tests of survival probabilities. Results - Sweden had fewer comorbidities than the United States and Australia. Cement fixation was used predominantly in Sweden and cementless in the United States and Australia. The direct anterior approach was used more frequently in the United States and Australia. Smaller head sizes (≤ 32 mm vs. ≥ 36 mm) were used more often in Sweden than the United States and Australia. Metal-on-highly cross-linked polyethylene was used more frequently in the United States and Australia than in Sweden. Sweden's 5- (97.8%) and 10-year THA survival (95.8%) was higher than the United States' (5-year: 97.0%; 10-year: 95.2%) and Australia (5-year: 96.3%; 10-year: 93.5%). Interpretation - Patient characteristics, surgical techniques, and implants differed across the 3 countries, emphasizing the need to adjust for demographics, surgical techniques, and implants and the need for global standardized definitions to compare THA survivorship internationally.

Cohort profile: the TrueNTH Global Registry - an international registry to monitor and improve localised prostate cancer health outcomes

PURPOSE

Globally, prostate cancer treatment and outcomes for men vary according to where they live, their race and the care they receive. The TrueNTH Global Registry project was established as an international registry monitoring care provided to men with localised prostate cancer (CaP).

PARTICIPANTS

Sites with existing CaP databases in Movember fundraising countries were invited to participate in the international registry. In total, 25 Local Data Centres (LDCs) representing 113 participating sites across 13 countries have nominated to contribute to the project. It will collect a dataset based on the International Consortium for Health Outcome Measures (ICHOM) standardised dataset for localised CaP.

FINDINGS TO DATE

A governance strategy has been developed to oversee registry operation, including transmission of reversibly anonymised data. LDCs are represented on the Project Steering Committee, reporting to an Executive Committee. A Project Coordination Centre and Data Coordination Centre (DCC) have been established. A project was undertaken to compare existing datasets, understand capacity at project commencement (baseline) to collect the ICHOM dataset and assist in determining the final data dictionary. 21/25 LDCs provided data dictionaries for review. Some ICHOM data fields were well collected (diagnosis, treatment start dates) and others poorly collected (complications, comorbidities). 17/94 (18%) ICHOM data fields were relegated to non-mandatory fields due to poor capture by most existing registries. Participating sites will transmit data through a web interface biannually to the DCC.

FUTURE PLANS

Recruitment to the TrueNTH Global Registry-PCOR project will commence in late 2017 with sites progressively contributing reversibly anonymised data following ethical review in local regions. Researchers will have capacity to source deidentified data after the establishment phase. Quality indicators are to be established through a modified Delphi approach in later 2017, and it is anticipated that reports on performance against quality indicators will be provided to LDCs.

The role of national registries in improving patient safety for hip and knee replacements

Background

The serious adverse events associated with metal on metal hip replacements have highlighted the importance of improving methods for monitoring surgical implants.

The new European Union (EU) device regulation will enforce post-marketing surveillance based on registries among other surveillance tools. Europe has a common regulatory environment, a common market for medical devices, and extensive experience with joint replacement registries. In this context, we elaborate how joint replacement registries, while building on existing structure and data, can better ensure safety and balance risks and benefits.

Main text

Actions to improve registry-based implant surveillance include: enriching baseline and diversifying outcomes data collection; improving methodology to limit bias; speeding-up failure detection by active real-time monitoring; implementing risk-benefit analysis; coordinating collaboration between registries; and translating knowledge gained from the data into clinical decision-making and public health policy.

Conclusions

The changes proposed here will improve patient safety, enforce the application of the new legal EU requirements, augment evidence, improve clinical decision-making, facilitate value-based health-care delivery, and provide up-to-date guidance for public health.

A Review of Databases Used in Orthopaedic Surgery Research and an Analysis of Database Use in Arthroscopy: The Journal of Arthroscopic and Related Surgery

PURPOSE

The purpose of this study was to evaluate how database use has changed over time in Arthroscopy: The Journal of Arthroscopic and Related Surgery and to inform readers about available databases used in orthopaedic literature.

METHODS

An extensive literature search was conducted to identify databases used in Arthroscopy and other orthopaedic literature. All articles published in Arthroscopy between January 1, 2006, and December 31, 2015, were reviewed. A database was defined as a national, widely available set of individual patient encounters, applicable to multiple patient populations, used in orthopaedic research in a peer-reviewed journal, not restricted by encounter setting or visit duration, and with information available in English.

RESULTS

Databases used in Arthroscopy included PearlDiver, the American College of Surgeons National Surgical Quality Improvement Program, the Danish Common Orthopaedic Database, the Swedish National Knee Ligament Register, the Hospital Episodes Statistics database, and the National Inpatient Sample. Database use increased significantly from 4 articles in 2013 to 11 articles in 2015 (P = .012), with no database use between January 1, 2006, and December 31, 2012.

CONCLUSIONS

Database use increased significantly between January 1, 2006, and December 31, 2015, in Arthroscopy.

LEVEL OF EVIDENCE

Level IV, systematic review of Level II through IV studies.

The surgical management of male breast cancer: Time for an easy access national reporting database?

INTRODUCTION

Male breast cancer is extremely rare with an incidence of less than 1% of all breast cancers. Literature reports a peak of incidence at roughly 71 years of age. Management currently follows the same clinical pathways as female breast cancer as a general rule.

METHODS

A retrospective search for all patients who were referred and diagnosed with male breast cancer at our centre was undertaken. Patients notes were then explored for demographics, histological staging, multidisciplinary team meeting outcome and treatment. A literature search including the search terms 'Male Breast Cancer AND Surgery' or 'Male Breast Cancer AND Experience' were used. Non English language articles, or those without abstracts were excluded.

RESULTS

Seven patients were reviewed over 3 years (2006-2009). Mean agea was 69 years and mean lesion size was 15 mm. Histology was invasive ductal carcinoma for all patients. All patients were ER receptor positive. Two patients were HER2 positive. Five patients were offered mastectomy. One patient refused treatment. In follow up at 36 months there were 3 recurrences. 1 patient was lost to follow up. There were 3 mortalities. The literature search identified 72 articles. Articles were subdivided into those that discussed the surgical management of male breast cancer (n = 8), articles that discussed male breast cancer as podium presentations or posters with no full text article publication (n = 13) and finally full text publications of case experience of male breast cancer (n = 21).

DISCUSSION

We report a series of seven cases of male breast cancer encountered over three years, evaluating patient demographics as well as treatment and outcomes. In our series patients were managed with mastectomy. New evidence is questioning the role of mastectomy against breast conserving surgery in male patients. Furthermore there is a lack of reporting infrastructure for national data capture of the benefits of surgical modalities. Literature review highlights the varied clinical experience between units that remains reported as podium presentation but not published. The establishment of an online international reporting registry would allow for efficient analysis of surgical outcomes to improve patient care from smaller single centres. This would facilitate large scale meta analysis by larger academic surgical centres.

Assessing the comparability of hip arthroplasty registries in order to improve the recording and monitoring of outcome

Aims

We aimed to assess the comparability of data in joint replacement registries and identify ways of improving the comparisons between registries and the overall monitoring of joint replacement surgery.

Materials and Methods

We conducted a review of registries that are full members of the International Society of Arthroplasty Registries with publicly available annual reports in English. Of the six registries which were included, we compared the reporting of: mean age, definitions for revision and re-operation, reasons for revision, the approach to analysing revisions, and patient-reported outcome measures (PROMs) for primary and revision total hip arthroplasty (THA) and hip resurfacing arthroplasty (HRA).

Results

Outcomes were infrequently reported for HRA compared with THA and all hip arthroplasties. Revisions were consistently defined, though re-operation was defined by one registry. Implant survival was most commonly reported as the cumulative incidence of revision using Kaplan-Meier survival analysis. Three registries reported patient reported outcome measures.

Conclusion

More consistency in the reporting of outcomes for specific types of procedures is needed to improve the interpretation of joint registry data and accurately monitor safety trends. As collecting additional details of surgical and patient-reported outcomes becomes increasingly important, the experience of established registries will be valuable in establishing consistency among registries while maintaining the quality of data. Take home message: As the volume of joint replacements performed each year continues to increase, greater consistency in the reporting of surgical and patient-reported outcomes among joint replacement registries would improve the interpretation and comparability of these data to monitor outcomes accurately. Cite this article: Bone Joint J 2016;98-B:442–51.

Predictable and SuStainable Implementation of National Cardiovascular Registries (PASSION) infrastructure: A think tank report from Medical Device Epidemiological Network Initiative (MDEpiNet)

The MDEpiNet is a public-private partnership between the US Food and Drug Administration's Center for Devices and Radiological Health and participating partners. The PASSION program is an MDEpiNet-sponsored program that aims to demonstrate the goals of MDEpiNet by using cardiovascular medical device registries to bridge evidence gaps across the medical device total product life cycle. To this end, a PASSION Think Tank meeting took place in October 2014 in Silver Spring, MD, to facilitate discussion between stakeholders about the successes, challenges, and future novel applications of medical device registries, with particular emphasis on identifying pilot projects. Participants spanned a broad range of groups including patients, device manufacturers, regulators, physicians/academicians, professional societies, providers, and payers. The meeting focus included 4 areas of cardiovascular medicine intended to cultivate interest in 4 MDEpiNet disease-specific/device-specific working groups: coronary intervention, electrophysiology, valvular disease, and peripheral vascular disease. In addition, more general issues applying to registry-based infrastructure and analytical methodologies for assessing device benefit/risk were considered to provide context for the working groups as PASSION programs going forward. This article summarizes the discussions at the meeting and the future directions of the PASSION program.

Database and Registry Research in Orthopaedic Surgery: Part 2: Clinical Registry Data

The use of large-scale national databases for observational research in orthopaedic surgery has grown substantially in the last decade, and the data sets can be categorized as either administrative claims or clinical registries. Clinical registries contain secondary data on patients with a specific diagnosis or procedure. The data are typically used for patient outcome surveillance to improve patient safety and health-care quality. Registries used in orthopaedic research exist at the regional, national, and international levels, and many were designed to specifically collect outcomes relevant to orthopaedics, such as short-term surgical complications, longer-term outcomes (implant survival or reoperations), and patient-reported outcomes. Although heterogeneous, clinical registries-in contrast to claims data-typically have a more robust list of variables, with relatively precise prospective data input, management infrastructure, and reporting systems. Some weaknesses of clinical registries include a smaller number of patients, inconstant follow-up duration, and use of sampling methods that may limit generalizability. Within the U.S., national joint registry adoption has lagged international joint registries. Given the changing health-care environment, it is likely that clinical registries will provide valuable information that has the potential to influence clinical practice improvement and health-care policy in the future.

[Registries as a tool for optimizing safety of endoprostheses. Experiences from other countries and the setup of the German arthroplasty register]

There has previously been no structured long-term documentation of the results of hip and knee prosthesis operations in Germany. This article presents the objectives, structure and data flow of the newly established German arthroplasty registry (EPRD). The EPRD is run as a subdivision of the German Society for Orthopedics and Orthopedic Surgery (Deutsche Gesellschaft für Orthopädie und orthopädische Chirurgie, DGOOC). It is dedicated to scientific principles and guarantees independency and immediate feedback to surgeons. The cooperation between insurance funds, hospitals, industry and scientific society is the key to success. Additional data acquisition and bureaucratic formalities are limited to a minimum and in particular there is no use of paper. Involving the health insurance funds provides access to relevant routine data. The implant documentation is facilitated by means of an implant library and barcode scanning in the operating room. The EPRD documents the survival of implants including the reasons for revision. Although the highest level of patient data protection is guaranteed, individual patients can be identified in case of implant recalls.

A new universal, standardized implant database for product identification: a unique tool for arthroplasty registries

INTRODUCTION

Every joint registry aims to improve patient care by identifying implants that have an inferior performance. For this reason, each registry records the implant name that has been used in the individual patient. In most registries, a paper-based approach has been utilized for this purpose. However, in addition to being time-consuming, this approach does not account for the fact that failure patterns are not necessarily implant specific but can be associated with design features that are used in a number of implants. Therefore, we aimed to develop and evaluate an implant product library that allows both time saving barcode scanning on site in the hospital for the registration of the implant components and a detailed description of implant specifications.

MATERIALS AND METHODS

A task force consisting of representatives of the German Arthroplasty Registry, industry, and computer specialists agreed on a solution that allows barcode scanning of implant components and that also uses a detailed standardized classification describing arthroplasty components. The manufacturers classified all their components that are sold in Germany according to this classification. The implant database was analyzed regarding the completeness of components by algorithms and real-time data.

RESULTS

The implant library could be set up successfully. At this point, the implant database includes more than 38,000 items, of which all were classified by the manufacturers according to the predefined scheme. Using patient data from the German Arthroplasty Registry, several errors in the database were detected, all of which were corrected by the respective implant manufacturers.

CONCLUSIONS

The implant library that was developed for the German Arthroplasty Registry allows not only on-site barcode scanning for the registration of the implant components but also its classification tree allows a sophisticated analysis regarding implant characteristics, regardless of brand or manufacturer. The database is maintained by the implant manufacturers, thereby allowing registries to focus their resources on other areas of research. The database might represent a possible global model, which might encourage harmonization between joint replacement registries enabling comparisons between joint replacement registries.

Registries in orthopaedics

The first nationwide orthopaedic registry was created in Sweden in 1975 to collect data on total knee arthroplasty (TKA). Since then, several countries have established registries, with varying degrees of success. Managing a registry requires time and money. Factors that contribute to successful registry management include the use of a single identifier for each patient to ensure full traceability of all procedures related to a given implant; a long-term funding source; a contemporary, rapid, Internet-based data collection method; and the collection of exhaustive data, at least for innovative implants. The effects of registries on practice patterns should be evaluated. The high cost of registries raises issues of independence and content ownership. Scandinavian countries have been maintaining orthopaedic registries for nearly four decades (since 1975). The first English-language orthopaedic registry was not created until 1998 (in New Zealand), and both the US and many European countries are still struggling to establish orthopaedic registries. To date, there are 11 registered nationwide registries on total knee and total hip replacement. The data they contain are often consistent, although contradictions occur in some cases due to major variations in cultural and market factors. The future of registries will depend on the willingness of health authorities and healthcare professionals to support the creation and maintenance of these tools. Surgeons feel that registries should serve merely to compare implants. Health authorities, in contrast, have a strong interest in practice patterns and healthcare institution performances. Striking a balance between these objectives should allow advances in registry development in the near future.

Distributed analysis of hip implants using six national and regional registries: comparing metal-on-metal with metal-on-highly cross-linked polyethylene bearings in cementless total hip arthroplasty in young patients

BACKGROUND

The regulation of medical devices has attracted controversy recently because of problems related to metal-on-metal hip implants. There is growing evidence that metal-on-metal implants fail early and cause local and systemic complications. However, the failure associated with metal-on-metal head size is not consistently documented and needs to be communicated to patients and surgeons. The purpose of this study is to compare implant survival of metal on metal with that of metal on highly cross-linked polyethylene.

METHODS

Using a distributed health data network, primary total hip arthroplasties were identified from six national and regional total joint arthroplasty registries (2001 to 2010). Inclusion criteria were patient age of forty-five to sixty-four years, cementless total hip arthroplasties, primary osteoarthritis diagnosis, and exclusion of the well-known outlier implant ASR (articular surface replacement). The primary outcome was revision for any reason. A meta-analysis of survival probabilities was performed with use of a fixed-effects model. Metal-on-metal implants with a large head size of >36 mm were compared with metal-on-highly cross-linked polyethylene implants.

RESULTS

Metal-on-metal implants with a large head size of >36 mm were used in 5172 hips and metal-on-highly cross-linked polyethylene implants were used in 14,372 hips. Metal-on-metal total hip replacements with a large head size of >36 mm had an increased risk of revision compared with metal-on-highly cross-linked polyethylene total hip replacements with more than two years of follow-up, with no difference during the first two years after implantation. The results of the hazard ratios (and 95% confidence intervals) from the multivariable model at various durations of follow-up were 0.95 (0.74 to 1.23) at zero to two years (p = 0.698), 1.42 (1.16 to 1.75) at more than two years to four years (p = 0.001), 1.78 (1.45 to 2.19) at more than four years to six years (p < 0.001), and 2.15 (1.63 to 2.83) at more than six years to seven years (p < 0.001).

CONCLUSIONS

We conducted a comparison of large-head-size, metal-on-metal implants and metal-on-highly cross-linked polyethylene implants in younger patients with uncemented fixation. We found consistent and strong evidence worldwide that large-head-size, metal-on-metal implants were associated with increased risk of revision after two years compared with metal-on-highly cross-linked polyethylene implants, with the effect becoming more pronounced over time.

Risk of revision following total hip arthroplasty: metal-on-conventional polyethylene compared with metal-on-highly cross-linked polyethylene bearing surfaces: international results from six registries

The results of randomized controlled trials and systematic reviews have suggested reduced radiographic wear in highly cross-linked polyethylene compared with conventional polyethylene in primary total hip arthroplasty. However, longer-term clinical results have not been thoroughly examined, to our knowledge. The purpose of this study was to compare the risk of revision for metal-on-conventional and metal-on-highly cross-linked total hip arthroplasty bearing surfaces with use of a distributed data network of six national and regional registries (Kaiser Permanente, HealthEast, the Emilia-Romagna region in Italy, the Catalan region in Spain, Norway, and Australia). Inclusion criteria were osteoarthritis as the primary diagnosis, cementless implant fixation, and a patient age of forty-five to sixty-four years. These criteria resulted in a sample of 16,571 primary total hip arthroplasties. Multivariate meta-analysis was performed with use of linear mixed models, with survival probability as the unit of analysis. The results of a fixed-effects model suggested that there was insufficient evidence of a difference in risk of revision between bearing surfaces (hazard ratio, 1.20 [95% confidence interval, 0.80 to 1.79]; p = 0.384). Highly cross-linked polyethylene does not appear to have a reduced risk of revision in this subgroup of total hip arthroplasty patients. Arthroplasties involving highly cross-linked polyethylene do not appear to have an increased risk of revision in this subgroup of total hip arthroplasty patients.

International comparative evaluation of knee replacement with fixed or mobile non-posterior-stabilized implants

BACKGROUND

Mobile-bearing total knee prostheses were designed to reduce wear and improve implant survivorship following total knee arthroplasty. However, the benefit of mobile-bearing total knee arthroplasty remains unproven. Both mobile-bearing and fixed-bearing total knee arthroplasty implants are available in posterior-stabilized and non-posterior-stabilized designs. With the latter, the implant does not recreate the function of the posterior cruciate ligament (PCL) with a posterior-stabilizing cam mechanism. The purpose of the present study was to compare mobile-bearing, non-posterior-stabilized devices with fixed-bearing, non-posterior-stabilized devices used in total knee arthroplasty through a novel multinational study design.

METHODS

Through the use of a distributed health data network, primary total knee arthroplasties performed for osteoarthritis from 2001 to 2010 were identified from six national and regional total joint arthroplasty registries. Multivariate meta-analysis was performed with use of linear mixed models, with the primary outcome of interest being revision for any reason. Survival probabilities and their standard errors were extracted from each registry for each unique combination of the covariates.

RESULTS

A total of 319,616 patients (60% female) underwent non-posterior-stabilized total knee arthroplasty. A fixed-bearing, non-posterior-stabilized design was used in 258,190 (81%) of the knees and a mobile-bearing, non-posterior-stabilized design in 61,426 (19%) of the knees. Sixty-nine percent of the patients who received a fixed-bearing implant were over sixty-five years of age, compared with 63% of those who received a mobile-bearing implant. Mobile-bearing designs had a higher risk of revision, with a hazard ratio of 1.43 (95% confidence interval, 1.36 to 1.51; p < 0.001).

CONCLUSIONS

Previous comparisons of mobile-bearing and fixed-bearing total knee arthroplasty outcomes have been inconclusive. The current study utilized an advanced, harmonized distributed analysis of six national and regional joint-replacement registries. To our knowledge, it is the largest analysis of mobile-bearing total knee arthroplasty to date. Mobile-bearing, non-posterior-stabilized designs presented a greater risk of failure than was found for fixed-bearing, non-posterior-stabilized designs. Caution should be used in the selection of the mobile-bearing non-posterior-stabilized design for total knee replacement.

Effect of femoral head size on metal-on-HXLPE hip arthroplasty outcome in a combined analysis of six national and regional registries

BACKGROUND

HXLPE (highly cross-linked polyethylene) has greater wear resistance compared with UHMWPE (ultra-high molecular weight polyethylene), which may contribute to improving the outcomes of total hip arthroplasty with a large femoral head. However, no information is available regarding the effect of femoral head size on the survivorship of HXLPE hip prostheses. The aim of the present study was to provide evidence regarding whether femoral head size has an effect on the risk of revision when an HXLPE liner is used on a metal head.

METHODS

A distributed health data network was developed by the ICOR (International Consortium of Orthopaedic Registries). Six national and regional registries are participating in this network: Kaiser Permanente, HealthEast, the Emilia-Romagna region in Italy, the Catalan region in Spain, Norway, and Australia. Data from each registry were standardized and provided at an aggregate level for each of the variables of interest. Patients with osteoarthritis who were forty-five to sixty-four years of age and had undergone uncemented total hip arthroplasty were included in the present study. Analyses were performed on the basis of individual patient profiles, utilizing the variables collected from each registry. The outcome of interest was the time to the first revision (for any reason). Survival probabilities and their standard errors were extracted from each registry for each unique combination of the covariates and were combined through multivariate meta-analysis utilizing linear mixed models to compare survivorship for <32-mm, 32-mm, and >32-mm femoral head sizes.

RESULTS

A total of 14,372 total hip arthroplasties were included in the study. The five-year rate of revision surgery varied from 1.9% to 3.2% among registries. The risk of revision did not differ significantly between <32-mm and 32-mm head sizes (HR [hazard ratio] = 0.91, 95% CI [confidence interval] = 0.69 to 1.19) or between >32-mm and 32-mm sizes (HR = 1.05, 95% CI = 0.70 to 1.55).

CONCLUSIONS

The results of our study provide relevant data to orthopaedic surgeons deciding on the use of a larger articulation in a metal-on-polyethylene bearing. A larger head diameter should not be considered a detriment to device survival when an HXLPE liner is used. However, efforts to force the use of a large-size implant appear unsupported, as similar survivorship was observed for all head diameter groups.

A distributed health data network analysis of survival outcomes: the International Consortium of Orthopaedic Registries perspective

The International Consortium for Orthopaedic Registries is a multinational initiative established by the United States Food and Drug Administration to develop a health data network aimed at providing a robust infrastructure to facilitate evidence-based decision-making on performance of medical devices. Through the International Consortium for Orthopaedic Registries, individual data holders have complete control of their data and can choose to participate in studies of their choice. In this article, we present an overview of the data extraction process and the analytic strategy employed to answer several device performance-related questions in total hip arthroplasty and total knee arthroplasty. In the process, we discuss some nuances pertinent to International Consortium for Orthopaedic Registries data that pose certain statistical challenges, and we briefly suggest strategies to be adopted to address them.

Comparative effectiveness of ceramic-on-ceramic implants in stemmed hip replacement: a multinational study of six national and regional registries

BACKGROUND

The rapid decline in use of conventional total hip replacement with a large femoral head size and a metal-on-metal bearing surface might lead to increased popularity of ceramic-on-ceramic bearings as another hard-on-hard alternative that allows implantation of a larger head. We sought to address comparative effectiveness of ceramic-on-ceramic and metal-on-HXLPE (highly cross-linked polyethylene) implants by utilizing the distributed health data network of the ICOR (International Consortium of Orthopaedic Registries), an unprecedented collaboration of national and regional registries and the U.S. FDA (Food and Drug Administration).

METHODS

A distributed health data network was developed by the ICOR and used in this study. The data from each registry are standardized and provided at a level of aggregation most suitable for the detailed analysis of interest. The data are combined across registries for comprehensive assessments. The ICOR coordinating center and study steering committee defined the inclusion criteria for this study as total hip arthroplasty performed without cement from 2001 to 2010 in patients forty-five to sixty-four years of age with osteoarthritis. Six national and regional registries (Kaiser Permanente and HealthEast in the U.S., Emilia-Romagna region in Italy, Catalan region in Spain, Norway, and Australia) participated in this study. Multivariate meta-analysis was performed with use of linear mixed models, with survival probability as the unit of analysis. We present the results of the fixed-effects model and include the results of the random-effects model in an appendix. SAS version 9.2 was used for all analyses. We first compared femoral head sizes of >28 mm and ≤28 mm within ceramic-on-ceramic implants and then compared ceramic-on-ceramic with metal-on-HXLPE.

RESULTS

A total of 34,985 patients were included; 52% were female. We found a lower risk of revision associated with use of ceramic-on-ceramic implants when a larger head size was used (HR [hazard ratio] = 0.73, 95% CI [confidence interval] = 0.60 to 0.88, p = 0.001). Use of smaller-head-size ceramic-on-ceramic bearings was associated with a higher risk of failure compared with metal-on-HXLPE bearings (HR = 1.36, 95% CI = 1.09 to 1.68, p = 0.006). Use of large-head-size ceramic-on-ceramic bearings was associated with a small protective effect relative to metal-on-HXLPE bearings (not subdivided by head size) in years zero to two, but this difference dissipated over the longer term.

CONCLUSIONS

Our multinational study based on a harmonized, distributed network showed that use of ceramic-on-ceramic implants with a smaller head size in total hip arthroplasty without cement was associated with a higher risk of revision compared with metal-on-HXLPE and >28-mm ceramic-on-ceramic implants. These findings warrant careful reflection by regulatory and clinical communities and wide dissemination to patients for informed decision-making regarding such surgery.

International comparative evaluation of fixed-bearing non-posterior-stabilized and posterior-stabilized total knee replacements

BACKGROUND

Differences in survivorship of non-posterior-stabilized compared with posterior-stabilized knee designs carry substantial economic consequences, especially with limited health-care resources. However, these comparisons have often been made between relatively small groups of patients, often with short-term follow-up, with only small differences demonstrated between the groups. The goal of this study is to compare the outcomes of non-posterior-stabilized and posterior-stabilized total knee arthroplasties with use of a unique collaboration of multiple established knee arthroplasty registries.

METHODS

A distributed health data network was developed by the International Consortium of Orthopaedic Registries and was used in this study to reduce barriers to participation (such as security, propriety, legal, and privacy issues) compared with a centralized data warehouse approach. The study included only replacements in osteoarthritis patients who underwent total knee procedures involving fixed-bearing devices from 2001 to 2010. The outcome of interest was time to first revision.

RESULTS

On average, not resurfacing showed a more harmful effect than resurfacing did when posterior-stabilized and non-posterior-stabilized knee replacements were compared, while the risk of revision for posterior-stabilized compared with non-posterior-stabilized knees was highest in year zero to one, followed by year one to two, years eight through ten, and years two through eight. Posterior-stabilized knees did significantly worse than non-posterior-stabilized knees did when the patella was not resurfaced. This difference was most pronounced in the first two years (year zero to one: hazard ratio [HR] = 2.15, 95% confidence interval [CI] = 1.56 to 2.95, p < 0.001; year one to two: HR = 1.61, 95% CI = 1.48 to 1.75, p < 0.001). When the patella was resurfaced, posterior-stabilized knees did significantly worse than non-posterior-stabilized knees did. This was again most pronounced in the first two years (year zero to one: HR = 1.75, 95% CI = 1.27 to 2.42, p = 0.001; year one to two: HR = 1.31, 95% CI = 1.19 to 1.45, p < 0.001). There was a reduced risk of revision with a patient age of more than sixty-five years (HR = 0.57, 95% CI = 0.55 to 0.60, p < 0.001).

CONCLUSIONS

We found that fixed non-posterior-stabilized total knee arthroplasty performed better with or without patellar resurfacing than did fixed posterior-stabilized total knee arthroplasty. This effect was most pronounced in the first two years. The risk of revision for posterior-stabilized total knee arthroplasties was reduced with patellar resurfacing. Also, a patient age of more than sixty-five years and female gender reduced the risk of revision.

International comparative evaluation of knee replacement with fixed or mobile-bearing posterior-stabilized prostheses

BACKGROUND

Posterior-stabilized total knee prostheses were introduced to address instability secondary to loss of posterior cruciate ligament function, and they have either fixed or mobile bearings. Mobile bearings were developed to improve the function and longevity of total knee prostheses. In this study, the International Consortium of Orthopaedic Registries used a distributed health data network to study a large cohort of posterior-stabilized prostheses to determine if the outcome of a posterior-stabilized total knee prosthesis differs depending on whether it has a fixed or mobile-bearing design.

METHODS

Aggregated registry data were collected with a distributed health data network that was developed by the International Consortium of Orthopaedic Registries to reduce barriers to participation (e.g., security, proprietary, legal, and privacy issues) that have the potential to occur with the alternate centralized data warehouse approach. A distributed health data network is a decentralized model that allows secure storage and analysis of data from different registries. Each registry provided data on mobile and fixed-bearing posterior-stabilized prostheses implanted between 2001 and 2010. Only prostheses associated with primary total knee arthroplasties performed for the treatment of osteoarthritis were included. Prostheses with all types of fixation were included except for those with the rarely used reverse hybrid (cementless tibial and cemented femoral components) fixation. The use of patellar resurfacing was reported. The outcome of interest was time to first revision (for any reason). Multivariate meta-analysis was performed with linear mixed models with survival probability as the unit of analysis.

RESULTS

This study includes 137,616 posterior-stabilized knee prostheses; 62% were in female patients, and 17.6% had a mobile bearing. The results of the fixed-effects model indicate that in the first year the mobile-bearing posterior-stabilized prostheses had a significantly higher hazard ratio (1.86) than did the fixed-bearing posterior-stabilized prostheses (95% confidence interval, 1.28 to 2.7; p = 0.001). For all other time intervals, the mobile-bearing posterior-stabilized prostheses had higher hazard ratios; however, these differences were not significant.

CONCLUSIONS

Mobile-bearing posterior-stabilized prostheses had an increased rate of revision compared with fixed-bearing posterior-stabilized prostheses. This difference was evident in the first year.

Joint registries as continuous surveillance systems: the experience of the Catalan Arthroplasty Register (RACat)

The aim was to present results on prosthesis performance in Catalonia for the period 2005-2010. All publicly funded hospitals submit in an electronic format data on hip and knee arthroplasties: patients' insurance identification number, hospital, joint (hip/knee), type of arthroplasty (primary/revision), side (right/left), date of surgery and prosthesis (manufacturer name and catalogue number). A standard survival analysis based on Kaplan-Meier estimation was carried out. Fifty-two hospitals have sent information to the RACat which has data on 36,951 knee and 26,477 hip arthroplasties. Cumulative prostheses revision risks at 3 years were 3.3% (95% CI: 3.1-3.6) for knee, 2.9% (95% CI: 2.5-3.3) for total hip and 2.5% (95% CI: 2.0-3.1) for partial hip. When compared to other registries a higher risk of revision was observed.

Registry data trends of total ankle replacement use

Joint arthroplasty registry data are meaningful when evaluating the outcomes of total joint replacement, because they provide unbiased objective information regarding survivorship and incidence of use. Critical evaluation of the registry data information will benefit the surgeon, patient, and industry. However, the implementation and acceptance of registry data for total ankle replacement has lagged behind that of hip and knee implant arthroplasty. Currently, several countries have national joint arthroplasty registries, with only some procuring information for total ankle replacement. We performed an electronic search to identify publications and worldwide registry databanks with pertinent information specific to total ankle replacement to determine the type of prostheses used and usage trends over time. We identified worldwide registry data from 33 countries, with details pertinent to total ankle replacement identified in only 6 countries. The obtained information was arbitrarily stratified into 3 distinct periods: 2000 to 2006, 2007 to 2010, and 2011. Within these study periods, the data from 13 total ankle replacement systems involving 3,980 ankles were identified. The vast majority (97%) of the reported ankle replacements were 3-component, mobile-bearing, uncemented prostheses. Three usage trends were identified: initial robust embracement followed by abrupt disuse, minimal use, and initial embracement followed by sustained growth in implantation. Before the widespread acceptance of new total ankle replacements, the United States should scrutinize and learn from the international registry data and develop its own national joint registry that would include total ankle replacement. Caution against the adoption of newly released prostheses, especially those without readily available revision components, is recommended.

The influence of comorbidity scores on re-operations following primary total hip replacement: comparison and validation of three comorbidity measures

While an increasing amount of arthroplasty articles report comorbidity measures, none have been validated for outcomes. In this study, we compared commonly used International Classification of Diseases-based comorbidity measures with re-operation rates after total hip replacement (THR). Scores used included the Charlson, the Royal College of Surgeons Charlson, and the Elixhauser comorbidity score. We identified a nationwide cohort of 134 423 THRs from the Swedish Hip Arthroplasty Register. Re-operations were registered post-operatively for up to 12 years. The hazard ratio was estimated by Cox's proportional hazards regression, and we used C-statistics to assess each measure's ability to predict re-operation. Confounding variables were age, gender, type of implant fixation, hospital category, hospital implant volume and year of surgery. In the first two years only the Elixhauser score showed any significant relationship with increased risk of re-operation, with increased scores for both one to two and three or more comorbidities. However, the predictive C-statistic in this period for the Elixhauser score was poor (0.52). None of the measures proved to be of any value between two and 12 years. They might be of value in large cohort or registry studies, but not for the individual patient.

Strategies to improve clinical research in surgery through international collaboration

More than 235 million patients undergo surgery every year worldwide, but less than 1% are enrolled in surgical clinical trials--few of which are international collaborations. Several levels of action are needed to improve this situation. International research collaborations in surgery between developed and developing countries could encourage capacity building and quality improvement, and mutually enhance care for patients with surgical disorders. Low-income and middle-income countries increasingly report much the same range of surgical diseases as do high-income countries (eg, cancer, cardiovascular disease, and the surgical sequelae of metabolic syndrome); collaboration is therefore of mutual interest. Large multinational trials that cross cultures and levels of socioeconomic development might have faster results and wider applicability than do single-country trials. Surgeons educated in research methods, and aided by research networks and trial centres, are needed to foster these international collaborations. Barriers to collaboration could be overcome by adoption of global strategies for regulation, health insurance, ethical approval, and indemnity coverage for doctors.

Quality and reproducibility of French publications on total hip arthroplasty

INTRODUCTION

The goal of the Quality of Literature in Arthroplasty (QoLA) project launched in 2009 was to compare the implant results from clinical studies published in indexed scientific journals with those found in reference national registers. The potential biases in the chosen articles (country of origin, inventor involved in study, methodological quality) were systematically analyzed and the revisions per 100 observed component years (Revp100OCY) index was calculated. For a given implant, a differential factor greater than 3 between the Revp100OCY index for published series and the one from registers was considered as indicative of a potential selection (inventor) or publication (conflict of interest) bias. Although initially performed on English publications, this methodology was subsequently applied to French publications in the field of total hip arthroplasty (THA).

MATERIAL AND METHODS

French publications indexed in Medline (Rev Chir Orthop and Orthop Trauma Surg Res since 2009) were analyzed. These studies involved implants designed in France (ABG, Corail stem, Cerafit/Osteal, Bousquet) or that were used worldwide (Omnifit stem, Alloclassic and Charnley-type or Müller-type implants). The articles or abstracts selected had to contain sufficient information (number of revisions, number of cases and/or revisions, average follow-up) to allow the Revp100OCY index to be calculated.

RESULTS

Overall, the average Revp100OCY index for THA series published in French was 0.76, which is consistent with the worldwide average of 1.29. For the ABG System, the Revp100OCY index was 1.5, which was higher than register data (0.77). Cemented Charnley-type stems had a Revp100OCY index of 1.68 (register 0.64) and low friction arthroplasty type THA had a Revp100OCY index of 0.59 (register 0.33). The Revp100OCY index was slightly lower relative to register data for the Müller THA (0.22 versus 0.33), Corail stem (0.1 versus 0.24), Omnifit (0.26 versus 0.37) and Alloclassic (0.21 versus 0.49). Other implants without comparable register data had a relatively high Revp100OCY index: 1.2 for the Bousquet dual mobility cup and 1.35 for the Osteal/Cerafit hybrid system.

CONCLUSIONS

The few studies published in French include only a limited number of cases, but their follow-up is long and the revision rate consistent with register data. There is no indication of any type of bias in French scientific publications relative to the reproducibility of THA results.

FDA working to ensure the safety of medical devices used in the pediatric population

Special initiatives exist in FDA's Center for Devices and Radiological Health (CDRH), the Center for Drug Evaluation and Research, and the Center for Biologics Evaluation and Research to ensure the safety and effectiveness of medical products used in the vulnerable pediatric population. This article focuses on the special programs, projects, and special studies implemented by CDRH to ensure this safety and effectiveness in devices used in pediatric patients throughout the devices' total product life-cycles. Pediatricians play a major role in keeping medical devices safe for use in children by reporting device problems to FDA.

The New Zealand Joint Registry: report of 11-year data for ankle arthroplasty

This article describes the results of the first 11 years of ankle arthroplasty data for the New Zealand Joint Registry. The main purpose is to collect accurate outcome information regarding these procedures and to guide orthopedic surgeons in the care of their patients. Trends can often be identified early, and implants with higher revision rates can be identified. In addition, individual surgeons can be given data that compare their performance with the collective data, providing invaluable feedback. Patient-based questionnaires are highly important for gauging the results of surgery. Patient response rates have been less than optimal, particularly after revision surgery.