Metal-on-Metal vs Metal-on-Polyethylene

Posted by Lew on July 7, 2009

Hi and thanks so much for returning to my blog. RSS feed. Thanks for visiting!

Here is part of an abstract on the site ” Ortho Supersite ” written by the following contributors…By Wierd P. Zijlstra, MD, MSc; John Cheung, MD, PhD; Maurits S. Sietsma, MD; Jos J.A.M. van Raay, MD, PhD; Robert Deutman, MD, PhD
ORTHOPEDICS 2009; 32:479

” A randomized controlled trial was performed to compare the cemented Stanmore metal-on-metal (Biomet, Warsaw, Indiana) total hip arthroplasty (THA; 102 hips) to the cemented Stanmore metal-on-polyethylene (Biomet) THA (98 hips). The primary outcome was clinical performance. Radiological performance, serum cobalt analysis, and prosthetic survival were secondary outcome measures. At a mean follow-up of 5.6 years, 5 patients were lost to follow-up, 18 died, and 4 were revised (3 metal-on- metal, 1 metal-on-polyethylene). Harris Hip Scores improved from 48 to 90 in the metal-on-metal patients (P <.001) and from 46 to 87 in the metal-on-polyethylene patients (P <.001). Oxford Hip Scores changed from 40 to 19 in the metal-on-metal group (P <.001) and from 40 to 18 in the metal-on-polyethylene group (P <.001). For both Harris and Oxford Hip Scores, there was no significant difference between the 2 groups. Five-year survival with revision for any reason was 97% (95% CI 93%-100%) in the metal-on-metal group and 99% (95% CI 97%-100%) in the metal-on-polyethylene group. ”

Materials and Methods

Patients

” Patients with non-inflammatory degenerative hip joint disease, including osteoarthritis, avascular necrosis, and traumatic arthritis, were included. Exclusion criteria were active infection, revision arthroplasty, marked bone loss precluding adequate fixation, unwillingness or inability to follow instruction, severe Vascular nsufficiency of the affected limb, and severe instability or deformity of the soft tissues precluding stability of the prosthesis. ”

The full article is here.