Long‐term follow‐up of metal‐on‐metal total hip replacement

Abstract

Metal-on-metal articulations were reintroduced to reduce polyethylene particleinduced osteolysis. Elevated serum metal levels have been detected at short-and intermediateterm follow-up. There is little knowledge about long-term effects of increased ionic metal generation. Our study was undertaken to provide information about long-term survival, clinical outcome, radiographic appearance, and serum metal concentrations after a minimum 10 years follow-up with a metal-on-metal hip prosthesis: 105 cementless primary total hip prostheses with metal-on-metal articulating surfaces were implanted in 98 patients with a mean age of 56 years. Clinical data, radiographs, and blood samples were obtained at a follow-up visit 10 years after implantation. Serum cobalt and chromium levels were determined with use of atomic absorption spectrometry. General laboratory analyses included a full blood count and kidney function parameters. The Harris score was 92 points and the UCLA score 6 points after 10 years. Small osteolytic lesions and radiolucent lines were found in Gruen's zones 1, 7, 8, and 14. The probability of survival was 98.6%. The median serum cobalt concentration of the 22 patients with their hip replacement as the only source of cobalt was 0.75 mg/L (range, 0.3-50.1 mg/L). No patient was diagnosed with renal insufficiency during the study period. Five patients were diagnosed with a malignancy between surgery and the follow-up. We do not have evidence of an increased rate of primary malignancies nor could we detect renal failure in our study group. Serum metal levels did not differ from short-and intermediate term follow-up values. ß

Low Incidence of Groin Pain and Early Failure with Large Metal Articulation Total Hip Arthroplasty

“…Observations on MOM THAs with 28-and 32-mm articulations have been extensively reported [13,18,19,21,29,43,46,47]. Some authors have noted intermediate Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article.…”

Adverse Reactions to Metal on Metal Are Not Exclusive to Large Heads in Total Hip Arthroplasty

“…Several studies have reported good results with the Metasul at followup of more than 10 years with survival ranging from 81% to 100% (Table 2) [10,12,15,20,22,35,42,43,45]. Two other studies have reported mid-to long-term followup for small-diameter MoM THA devices other than Metasul [36,39].…”

“…A contraindication for use of MoM devices was in patients known to have renal insufficiency, as recommended in some studies [7,15,32,33]. Use of MoM devices gradually shifted from small-diameter head devices to larger diameter head devices, which were touted to provide greater stability as the large head designs became available with no change in indications.…”

Osteocyte physiology and response to fluid shear stress are impaired following exposure to cobalt and chromium: Implications for bone health following joint replacement

“…In well‐functioning prostheses at 10‐year follow‐up, median Co and Cr concentrations in the circulation have been reported to be 0.75 μg/L (range: 0.3–50.1 μg/L) and 0.95 μg/L (range: 0.3–58.6 μg/L) respectively 17. Periprosthetic concentrations are several fold higher (median Co, 113 μg/L; median Cr, 54 μg/L),18 while patients with failing prosthesis have reported Co and Cr concentrations as high as 528 μg/L (range: 0–13,000 μg/L) and 1,844 μg/L (range: 0–38,600 μg/L), respectively 19.…”