title: Wear analysis of 39 conserve plus metal-on-metal hip resurfacing retrievals.
abstract: There have been increasing concerns regarding adverse local tissue reactions (ALTR) following metal-on-metal (MOM) hip arthroplasties. This study examined wear rates in retrievals of one design of MOM resurfacing arthroplasty, and assessed the differences in wear between those with and without ALTR. Wear measurements were made on 39 MOM resurfacing components (30 femoral, 9 acetabular) which were at least 2years in vivo. Seven hips (6 patients; 4 acetabular components, 7 femoral components) were identified to have ALTR. Acetabular component abduction and anteversion angles were determined using EBRA, and the contact-patch-to-rim (CPR) distance was calculated. The ALTR group had higher linear femoral and acetabular wear rates, acetabular anteversion and abduction angles, lower CPR, and longer time to revision. Given the increased risk for ALTR associated with acetabular component malpositioning, patients with malpositioned acetabular components may require closer clinical follow-up and monitoring.
authors.affiliation: Joint Replacement Institute at St. Vincent Medical Center, Los Angeles, California.
authors.forename: Karren M
authors.initials: KM
authors.lastname: Takamura
authors.affiliation: Joint Replacement Institute at St. Vincent Medical Center, Los Angeles, California.
authors.forename: Harlan C
authors.initials: HC
authors.lastname: Amstutz
authors.affiliation: J. Vernon Luck Sr., Orthopaedic Research Center, Orthopaedic Hospital/UCLA, Los Angeles, California.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Lu
authors.affiliation: J. Vernon Luck Sr., Orthopaedic Research Center, Orthopaedic Hospital/UCLA, Los Angeles, California.
authors.forename: Pat A
authors.initials: PA
authors.lastname: Campbell
authors.affiliation: J. Vernon Luck Sr., Orthopaedic Research Center, Orthopaedic Hospital/UCLA, Los Angeles, California.
authors.forename: Edward
authors.initials: E
authors.lastname: Ebramzadeh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D001672:Biocompatible Materials; D019544:Equipment Failure Analysis; D005260:Female; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008670:Metals; D008875:Middle Aged; D011475:Prosthesis Failure; D055815:Young Adult
chemical_list: D001672:Biocompatible Materials; D008670:Metals
keywords: ALTR; arthroplasty; hip resurfacing; implant retrieval; metal-on-metal; wear