[Damage analysis illustrated by two cases of broken ceramic inserts. Recommendations for avoiding breakages caused by handling].
Due to modular design today's total hip endoprostheses provide the choice of different bearing surfaces. Particle-induced osteolysis is the major reason for implant failure. Therefore, minimization of wear rates is the essential factor for the improvement of long-term function of the implants. The bearing couple ceramic-on-ceramic offers a linear wear rate of about 0.005 mm/year. That is an essential prerequisite for successful treatment of young and active patients. Ceramic femoral heads and taper fixation became standard. After some problems in the 1970s, manufacturers achieved all kinds of improvements. Surgeons learned how to handle ceramic femoral heads correctly. Nowadays ceramic heads are reliable implants. Ceramic inserts have been used since the mid-1990s. Some acetabular systems with ceramic inserts are used in clinical studies, some are approved. Complications with ceramic inserts are rare, e.g., fracturing or chipping off. Mostly those problems are due to mishandling. In this study some clinical failures are analyzed. Recommendations how to improve the handling of ceramic inserts are proposed and discussed.
Abteilung Biomechanik, Klinik für Orthopädie und Sportorthopädie, Technische Universität, München, Munich. erwin.steinhauser@LRZ.tum.de
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Steinhauser
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Bader
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Mittelmeier
D000077:Acetabulum / Q000601:surgery*; D019644:Arthroplasty, Replacement, Hip / Q000379:methods; D001696:Biomechanical Phenomena; D002516:Ceramics; D019544:Equipment Failure Analysis; D006622:Hip Prosthesis; D006801:Humans; D011183:Postoperative Complications / Q000209:etiology*; D011474:Prosthesis Design; D017755:Prosthesis Fitting / Q000379:methods; D012307:Risk Factors