title: Quantification of material loss from the neck piece taper junctions of a bimodular primary hip prosthesis. A retrieval study from 27 failed Rejuvenate bimodular hip arthroplasties.
abstract: The early failure and revision of bimodular primary total hip arthroplasty prostheses requires the identification of the risk factors for material loss and wear at the taper junctions through taper wear analysis. Deviations in taper geometries between revised and pristine modular neck tapers were determined using high resolution tactile measurements. A new algorithm was developed and validated to allow the quantitative analysis of material loss, complementing the standard visual inspection currently used. The algorithm was applied to a sample of 27 retrievals (in situ from 2.9 to 38.1 months) of the withdrawn Rejuvenate modular prosthesis. The mean wear volumes on the flat distal neck piece taper was 3.35 mm(3) (0.55 to 7.57), mainly occurring in a characteristic pattern in areas with high mechanical loading. Wear volume tended to increase with time to revision (r² = 0.423, p = 0.001). Implant and patient specific data (offset, stem size, patient's mass, age and body mass index) did not correlate with the amount of material loss observed (p > 0.078). Bilaterally revised implants showed higher amounts of combined total material loss and similar wear patterns on both sides. The consistent wear pattern found in this study has not been reported previously, suggesting that the device design and materials are associated with the failure of this prosthesis.
authors.affiliation: TUHH Hamburg University of Technology, Denickestraße 15, 21073 Hamburg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Buente
authors.affiliation: TUHH Hamburg University of Technology, Denickestraße 15, 21073 Hamburg, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Huber
authors.affiliation: Hamburg University of Applied Sciences, Ulmenliet 20, 21033 Hamburg, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Bishop
authors.affiliation: TUHH Hamburg University of Technology, Denickestraße 15, 21073 Hamburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Morlock
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D019544:Equipment Failure Analysis; D006622:Hip Prosthesis; D006801:Humans; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012086:Reoperation
keywords: Bi-Modular Taper; Deviation Pattern; Material Loss; Rejuvenate; Surface Changes; Taper Wear