Blood metal ion concentrations in metal-on-metal total hip arthroplasty
- 539 Downloads
The hip placement with a metal-on-metal (MOM) bearing has been used for both surface replacement and total hip arthroplasty (THA). Use of MOM bearing for hip replacement reduces the wear compared to conventional bearings.
We prospectively assessed 30 patients who underwent unilateral MOM THA. A control group of 30 patients who underwent metal-on-polyethylene THA using the implants as the other group, except for bearing, were accessed. Blood samples were collected preoperatively and at 3- , 6- , 9- , 12- , 15- , 18- , and 24-month intervals. Changes in mean blood metal ion concentration were compared between the MOM and metal-on-polyethylene groups.
A statistically significant positive correlation was observed between blood cobalt and chromium concentrations in all of the patients. The mean blood ion concentrations of the MOM were significantly higher than those of the metal-on-polyethylene. A statistically significant negative correlation was found between maximum blood cobalt concentration and cup version angle. The maximum blood chromium concentrations in the patients who had larger cup version angles were more likely to decrease.
We considered that cup version angle is one of the factors that have the greatest effect on blood metal ion concentration, and the target cup version angle that did not induce an increase in blood metal ion concentrations was approximately 20°.
KeywordsAngle Metal Ions Metal-on-metal Total hip arthroplasty Cup version angle
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
The study was approved by the Ethical Committee of Tokyo Women’s Medical University dated October 21, 2008 and approval number 1460. Written informed consent was obtained from all patients involved in the study.
- 5.Nakamura M, Shimakawa T, Nakano S, Chikawa T, Yoshioka S, Kashima M, Toki S, Horiguchi H, Sairyo K (2016) Failure rates of Asian-type anatomic medullary locking stemmed metal-on-metal total hip replacement: a cause for adverse tissue reactions to metal debris (ARMD). J Orthop Sci 21:779–785. doi: 10.1016/j.jos.2016.07.020 CrossRefPubMedGoogle Scholar
- 12.Langton DJ, Sprowson AP, Joyce TJ, Reed M, Carluke I, Partington P, Nargol AV (2009) Blood metal ion concentrations after hip resurfacing arthroplasty: a comparative study of articular surface replacement and Birmingham Hip Resurfacing arthroplasties. J Bone Joint Surg Br 91:1287–1295CrossRefPubMedGoogle Scholar
- 15.Ohtsuru T, Morita Y, Munakata Y, Kato Y (2013) The relation of blood metal ion concentrations in a 3rd generation metal-on-metal THA, a component installation angle, an activity, and a patient background factor. Hip Jt 39:772–776 (in Japanese) Google Scholar
- 17.Seki T, Hasegawa Y, Kanoh T, Matsuoka A, Ishiguro N, Tsuboi M, Kawabe K (2011) Relation between activity level and blood metal ion concentrations after metal-on-metal THA. Jpn J Replace Arthroplasty 41:336–337 (in Japanese) Google Scholar