Three-dimensional laser micrometry characterization of surface wear in total hip arthroplasty.
Even after decades of clinical use, our ability to quantify wear across total hip replacement implant surfaces is largely limited to single value measurements. The influence of patient factors on wear remains enigmatic. This pilot study for the development of three-dimensional laser micrometry (3DLM) introduces an easy, accurate means of 'mapping' and quantifying material removal. A three-dimensional laser micrometer was constructed using a laser micrometer having an accuracy of 0.5 microm. A 3D surface map is triangulated from a point cloud consisting of approximately 140,000 individual points. Comparison to a reference sphere determines radial wear over the entire surface. 3DLM was able to map and quantify fine scale surface features. Even for zirconia on relatively soft ultra-high molecular weight polyethylene, this technique maps the contributions of localized wear at the macroscopic level. The 0.5 microm (or greater) accuracy of these lasers allows us to image surfaces with a high degree of confidence. This analysis lends itself well to automation, and we anticipate that this advance will prove valuable in establishing that each head and cup combination emerging from a given clinical environment has unique wear patterns as observed in this trial data set.
Kohm
Andrew
A
Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210, USA.
Gaumer
Jeremy
J
Ravula
Vishnu
V
Urban
Robert
R
Gilbertson
Les
L
Bos
Gary
G
Dey
Tamal
T
Nelson
Laura
L
Dyce
Jonathan
J
Lannutti
John
J
D019644:Arthroplasty, Replacement, Hip; D002858:Chromium Alloys / Q000737:chemistry; D019544:Equipment Failure Analysis / Q000379:methods*; D006622:Hip Prosthesis / Q000592:standards*; D006801:Humans; D007834:Lasers; D013499:Surface Properties; D015040:Zirconium / Q000737:chemistry
D002858:Chromium Alloys; D015040:Zirconium; C028541:zirconium oxide