title: A comparison of the disassociation strength of modular acetabular components.
abstract: Five short-term in vivo disassembly of two-piece acetabular cup designs have been reported. This study evaluates the liner retention strengths of eight contemporary cup systems. Both push-out (663 +/- 65.5 pounds force to 29 +/- 1.4 pounds force) and lever-out (684 +/- 114 inch-pounds to 43 +/- 1.5 inch-pounds) test modes show a wide variation in retention strength. Repeat liner separation testing demonstrates a 26% and 32% respective decrease in locking mechanism integrity. These findings indicate that reseating modular liners at the time of surgery or reassembling a previously separated liner should be avoided.
authors.affiliation: Department of Orthopaedic Surgery, Mt. Sinai Medical Center, Cleveland, OH 44106.
authors.forename: S
authors.initials: S
authors.lastname: Tradonsky
authors.forename: P D
authors.initials: PD
authors.lastname: Postak
authors.forename: A I
authors.initials: AI
authors.lastname: Froimson
authors.forename: A S
authors.initials: AS
authors.lastname: Greenwald
mesh_terms: D000077:Acetabulum / Q000601:surgery*; D001696:Biomechanical Phenomena; D006622:Hip Prosthesis; D006801:Humans; D066298:In Vitro Techniques; D011474:Prosthesis Design; D011475:Prosthesis Failure