TY - JOUR

T1 - Metal release and metal allergy after total hip replacement with resurfacing versus conventional hybrid prosthesis 5-year follow-up of 52 patients

AU - Gustafson, Klas

AU - Jakobsen, Stig S

AU - Lorenzen, Nina D

AU - Thyssen, Jacob P

AU - Johansen, Jeanne D

AU - Bonefeld, Charlotte M

AU - Stilling, Maiken

AU - Baad-Hansen, Thomas

AU - Søballe, Kjeld

PY - 2014/8

Y1 - 2014/8

N2 - BACKGROUND: Metal-on-metal (MOM) total hip arthroplasties were reintroduced because of the problems with osteolysis and aseptic loosening related to polyethylene wear of early metal-on-polyethylene (MOP) arthroplasties. The volumetric wear rate has been greatly reduced with MOM arthroplasties; however, because of nano-size wear particles, the absolute number has been greatly increased. Thus, a source of metal ion exposure with the potential to sensitize patients is present. We hypothesized that higher amounts of wear particles result in increased release of metal ions and ultimately lead to an increased incidence of metal allergy.METHODS: 52 hips in 52 patients (median age 60 (51-64) years, 30 women) were randomized to either a MOM hip resurfacing system (ReCap) or a standard MOP total hip arthoplasty (Mallory Head/Exeter). Spot urine samples were collected preoperatively, postoperatively, after 3 months, and after 1, 2, and 5 years and tested with inductively coupled plasma-sector field mass spectrometry. After 5 years, hypersensitivity to metals was evaluated by patch testing and lymphocyte transformation assay. In addition, the patients answered a questionnaire about hypersensitivity.RESULTS: A statistically significant 10- to 20-fold increase in urinary levels of cobalt and chromium was observed throughout the entire follow-up in the MOM group. The prevalence of metal allergy was similar between groups.INTERPRETATION: While we observed significantly increased levels of metal ions in the urine during the entire follow-up period, no difference in prevalence of metal allergy was observed in the MOM group. However, the effect of long-term metal exposure remains uncertain.

AB - BACKGROUND: Metal-on-metal (MOM) total hip arthroplasties were reintroduced because of the problems with osteolysis and aseptic loosening related to polyethylene wear of early metal-on-polyethylene (MOP) arthroplasties. The volumetric wear rate has been greatly reduced with MOM arthroplasties; however, because of nano-size wear particles, the absolute number has been greatly increased. Thus, a source of metal ion exposure with the potential to sensitize patients is present. We hypothesized that higher amounts of wear particles result in increased release of metal ions and ultimately lead to an increased incidence of metal allergy.METHODS: 52 hips in 52 patients (median age 60 (51-64) years, 30 women) were randomized to either a MOM hip resurfacing system (ReCap) or a standard MOP total hip arthoplasty (Mallory Head/Exeter). Spot urine samples were collected preoperatively, postoperatively, after 3 months, and after 1, 2, and 5 years and tested with inductively coupled plasma-sector field mass spectrometry. After 5 years, hypersensitivity to metals was evaluated by patch testing and lymphocyte transformation assay. In addition, the patients answered a questionnaire about hypersensitivity.RESULTS: A statistically significant 10- to 20-fold increase in urinary levels of cobalt and chromium was observed throughout the entire follow-up in the MOM group. The prevalence of metal allergy was similar between groups.INTERPRETATION: While we observed significantly increased levels of metal ions in the urine during the entire follow-up period, no difference in prevalence of metal allergy was observed in the MOM group. However, the effect of long-term metal exposure remains uncertain.

KW - Arthroplasty, Replacement, Hip

KW - Chromium

KW - Cobalt

KW - Female

KW - Follow-Up Studies

KW - Hip Prosthesis

KW - Humans

KW - Hypersensitivity

KW - Lymphocyte Activation

KW - Male

KW - Metals

KW - Middle Aged

KW - Nanoparticles

KW - Osteolysis

KW - Patch Tests

KW - Polyethylene

KW - Prosthesis Failure

KW - Questionnaires

KW - Titanium

U2 - 10.3109/17453674.2014.922730

DO - 10.3109/17453674.2014.922730

M3 - Journal article

C2 - 24930546

VL - 85

SP - 348

EP - 354

JO - Acta Orthopaedica

JF - Acta Orthopaedica

SN - 1745-3674

IS - 4

ER -