Denis Nam1, Rondek Salih2, Katherine M Brown2, Ryan M Nunley2, Robert L Barrack2. 1. Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois. 2. Department of Orthopedic Surgery, Washington University School of Medicine, Barnes-Jewish Hospital, St. Louis, Missouri.
Abstract
BACKGROUND: Dual mobility total hip arthroplasty (THA) components improve stability, yet use of a modular cobalt alloy acetabular liner may be associated with metal ion release. This study's purpose was to measure blood metal ion levels in young, active patients receiving a dual mobility THA prosthesis. METHODS: This is a prospective study of young, active patients undergoing primary THA. Twenty-six patients received a 22-mm cobalt alloy (n = 10) or a 28-mm ceramic (n = 16) femoral head, a modular cobalt chrome acetabular liner, with a highly cross-linked polyethylene insert (dual mobility). Seventeen control patients received a 32-mm cobalt alloy (n = 6), oxidized zirconium (n = 5), or ceramic (n = 6) femoral head and polyethylene acetabular liner (conventional). All patients received a cementless, titanium femoral stem. Blood metal ion levels (μg/L) were measured preoperatively and at 1 year postoperatively. RESULTS: No difference was present for age or body mass index (P = .5 and .9). At 1 year postoperatively, mean cobalt levels were greater in the dual mobility cohort (0.23 ± 0.39 vs 0.15 ± 0.07, P < .001). Four patients in the dual mobility cohort had a cobalt level outside the reference range (0.03-0.29), with values from 0.34 to 1.81 μg/L. One patient in the conventional cohort had a cobalt level outside the reference range with a value of 0.39 μg/L. CONCLUSION: The presence and clinical significance of increased cobalt levels in 4 patients with the use of a modular dual mobility prosthesis demonstrates the necessity of continued surveillance.
BACKGROUND: Dual mobility total hip arthroplasty (THA) components improve stability, yet use of a modular cobalt alloy acetabular liner may be associated with metal ion release. This study's purpose was to measure blood metal ion levels in young, active patients receiving a dual mobility THA prosthesis. METHODS: This is a prospective study of young, active patients undergoing primary THA. Twenty-six patients received a 22-mm cobalt alloy (n = 10) or a 28-mm ceramic (n = 16) femoral head, a modular cobalt chrome acetabular liner, with a highly cross-linked polyethylene insert (dual mobility). Seventeen control patients received a 32-mm cobalt alloy (n = 6), oxidized zirconium (n = 5), or ceramic (n = 6) femoral head and polyethylene acetabular liner (conventional). All patients received a cementless, titanium femoral stem. Blood metal ion levels (μg/L) were measured preoperatively and at 1 year postoperatively. RESULTS: No difference was present for age or body mass index (P = .5 and .9). At 1 year postoperatively, mean cobalt levels were greater in the dual mobility cohort (0.23 ± 0.39 vs 0.15 ± 0.07, P < .001). Four patients in the dual mobility cohort had a cobalt level outside the reference range (0.03-0.29), with values from 0.34 to 1.81 μg/L. One patient in the conventional cohort had a cobalt level outside the reference range with a value of 0.39 μg/L. CONCLUSION: The presence and clinical significance of increased cobalt levels in 4 patients with the use of a modular dual mobility prosthesis demonstrates the necessity of continued surveillance.
Authors: Chelsea Matzko; Brandon Naylor; Ryan Cummings; Yevgeniy Korshunov; H John Cooper; Matthew S Hepinstall Journal: Arthroplast Today Date: 2020-12-04
Authors: Alexander Greenberg; Allina Nocon; Ivan De Martino; David J Mayman; Thomas P Sculco; Peter K Sculco Journal: Arthroplast Today Date: 2021-10-29