Medizinische Universität Graz Austria/Österreich - Forschungsportal - Medical University of Graz
Gewählte Publikation:
Höfler, P.
The ASR™ Implant Recall: A Single Center Experience
Humanmedizin; [ Diplomarbeit ] Graz Medical University; 2016. pp. 73
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- Autor*innen der Med Uni Graz:
- Betreuer*innen:
- Friesenbichler Jörg
- Leithner Andreas
- Altmetrics:
- Abstract:
- Introduction: The third generation of metal-on-metal hip arthroplasties with large diameter heads were brought up to the market within the last decade and gained wide popularity. These metal-on-metal devices were especially implanted in young and physically active patients. However, in the short run national joint registries observed an increment of revision rates due to ineffective metal-on-metal hip arthroplasties. The circumstance of increasing revision rates of failed metal-on-metal devices induced DePuy to a voluntarily recall of its Articular Surface Replacement™ (ASR™) hip prostheses. In this survey we reveal the number of adverse events and revision rates of patients treated with the ASR™ system at our institute. Patients & Methods: In our institute, a total of 64 ASR™ hip prostheses were implanted in 56 patients, beginning in 2005 until 2008. Twenty patients received an ASR™ Resurfacing and 44 an ASR™ XL-Head device. The mean postoperative follow-up was 90 months, ranging from 20 to 109 months. Within the scope of the recall following proceedings were realised in every patient: clinical examination, plain radiographs and serum metal ion determination. Furthermore MRI scans were performed in all patients who showed increased serum metal ion levels or who complained about pain. Results: The cumulative revision rate in the ASR™ XL Head cohort was 32% and 30% in the ASR™ Resurfacing cohort. The average time from index surgery to revision was 48 months, regardless from the complication. Revisions have been performed due to increased metal ion levels, dislocation or subluxation, aseptic loosening of the femoral stem, adverse reaction to metal debris (ARMD) and infection. However, it has to be said that after revision surgery no further re-revision had to be done. During revision surgery all ASR™ cups were revised into a press-fit cup and the metal-on-metal bearing was replaced by a ceramic-on-ceramic liner. The calculated implant survival for the ASR™ Resurfacing devices was 90% after 60 months, whereas the survival was 79% in der ASR™ XL Head group. Discussion: According to the current literature, our study revealed unsatisfying results of the ASR™ system with high complication- and revision rates. Overall, we suggest that symptomatic patients, regardless whether they have high or low serum metal ion levels, should receive magnetic resonance imaging to rule out ARMD. Revision surgery should be considered if patients complain about local pain, if they have high serum metal ion levels or if formation of ARMD can be detected. Considering the high revision rates of the ASR™ system, it would be advisable to implement an appropriate surveillance program of new launched devices to avoid such complications. Hence, the voluntarily recall of the ASR™ systems illustrates the importance of national implant registries.