Rethinking analytical strategies for surveillance of medical devices: the case of hip arthroplasty

Journal Medical Care
Authors Normand, Sharon-Lise; Marinac-Dabic, Danica; Sedrakyan, Art; Kaczmarek, Ronald
Year Published 2010
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Abstract

BACKGROUND: Randomized trials that sometimes serve as the basis for device approval are small, short term, and generalizable to an increasingly smaller percentage of patients. Some of the most common and challenging devices are those used in hip replacement. Artificial hips are implanted in thousands to alleviate pain caused by noninflammatory joint disease and to restore patient mobility. During 2004 in the United States, although 68% of hospital stays for partial or total hip replacements were for those aged 65 years and older, younger patients will account for 52% by 2030.

METHODS: Using hierarchical modeling, we propose a framework for combining information from premarket and postmarket settings. Our key assumption is that device performance characteristics and outcomes obtained from 1 cohort are related to device characteristics and outcomes of the same or similar devices observed in other cohorts. We illustrate methods by jointly modeling Harris Hip Scores (HHSs) and revision-success data from 1851 subjects who participated in 3 pivotal randomized or observational studies of artificial hips.

RESULTS AND CONCLUSIONS: Subjects participating in randomized studies had better 2-year HHS than those in observational studies (posterior mean increase in HHS = 4.1, posterior standard deviation = 0.6). Patients implanted with ceramic-on-polyethylene hip used in 1 study had higher 2-year HHS than those implanted with a different ceramic-on-polyethylene hip in another study (mean difference = 4.2, standard deviation = 0.6). Our approach is feasible and will advance regulatory science using a transparent and dynamic new paradigm for knowledge management throughout the total product life cycle.

Comparative assessment of implantable hip devices with different bearing surfaces: systematic appraisal of evidence

Journal BMJ
Authors Sedrakyan, Art; Normand, Sharon-Lise; Dabic, Stefan; Jacobs, Samantha; Graves, Stephen; Marinac-Dabic, Danica
Year Published 2011
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Abstract

OBJECTIVE: To determine comparative safety and effectiveness of combinations of bearing surfaces of hip implants.

DESIGN: Systematic review of clinical trials, observational studies, and registries.

DATA SOURCES: Medline, Embase, Cochrane Controlled Trials Register, reference lists of articles, annual reports of major registries, summaries of safety and effectiveness for pre-market application and mandated post-market studies at the United States Food and Drug Administration.

STUDY SELECTION: Criteria for inclusion were comparative studies in adults reporting information for various combinations of bearings (such as metal on metal and ceramic on ceramic). Data search, abstraction, and analyses were independently performed and confirmed by at least two authors. Qualitative data syntheses were performed.

RESULTS: There were 3139 patients and 3404 hips enrolled in 18 comparative studies and over 830 000 operations in national registries. The mean age range in the trials was 42-71, and 26-88% were women. Disease specific functional outcomes and general quality of life scores were no different or they favoured patients receiving metal on polyethylene rather than metal on metal in the trials. While one clinical study reported fewer dislocations associated with metal on metal implants, in the three largest national registries there was evidence of higher rates of implant revision associated with metal on metal implants compared with metal on polyethylene. One trial reported fewer revisions with ceramic on ceramic compared with metal on polyethylene implants, but data from national registries did not support this finding.

CONCLUSIONS: There is limited evidence regarding comparative effectiveness of various hip implant bearings. Results do not indicate any advantage for metal on metal or ceramic on ceramic implants compared with traditional metal on polyethylene or ceramic on polyethylene bearings.

A multinational assessment of metal-on-metal bearings in hip replacement

Journal Journal of Bone and Joint Surgery, American Volume
Authors Graves, Stephen; Rothwell, Alastair; Tucker, Keith; Jacobs, Joshua; Sedrakyan, Art
Year Published 2011
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Abstract

There is emerging evidence that many metal-on-metal (MoM) bearings, when used with large femoral heads in conventional hip replacement and some resurfacing prostheses, are associated with increased rates of revision arthroplasty. Registries are the main sources of data on MoM prostheses. At the recent International Consortium of Orthopaedic Registries (ICOR) meeting, data were presented from the Australian, England and Wales, and New Zealand registries. All registries reported an increased rate of revision for large femoral head MoM prostheses when prostheses were aggregated compared with the aggregated data of hip prostheses with other bearing surfaces. There was also evidence, however, that the outcome varied, depending on the type of prostheses used, in both large femoral head MoM conventional hip replacement as well as resurfacing hip replacement.The relevance of the recent isolated case reports on systemic metal toxicity was also discussed at the ICOR meeting. Although systemic metal toxicity appears to be a rare occurrence, there is a need to undertake appropriately designed studies to define the true prevalence of this phenomenon. There may be advantages in nesting these studies within registries. The ICOR meeting highlighted the implications of the MoM experience for the orthopaedic industry, regulators, and surgeons.

Use of patient-reported outcomes in the context of different levels of data

Journal Journal of Bone and Joint Surgery, American Volume
Authors Rolfson, Ola; Rothwell, Alastair; Sedrakyan, Art; Chenok, Kate Eresian; Bohm, Eric; Bozic, Kevin; Garellick, Göran
Year Published 2011
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Abstract

There is increasing interest in measuring patient-reported outcomes as part of routine medical practice, particularly in fields like total joint replacement surgery, where pain relief, satisfaction, function, and health-related quality of life, as perceived by the patient, are primary outcomes. We review some well-known outcome instruments, measurement issues, and early experiences with large-scale collection of patient-reported outcome measures in joint registries. The patient-reported outcome measures are reviewed in the context of multidimensional outcome assessment that includes the traditional clinical outcome parameters as well as disease-specific and general patient-reported outcome measures.