[The use of a thermomechanical cleaning procedure for removal of residual particles of corund blasted or glass bead peened implants in total hip arthoplasty].
BACKGROUND
Shot peening and grit blasting techniques are used to modify surfaces of hip endoprostheses. Alumina blasting techniques using highly pure corund (Al (2)O (3)) particles create a rough surface of Titanium implants to achieve a better osteointegration in cementless total hip arthroplasty. An increasing number of publications in maxillo-facial-surgery and orthopedic surgery show that there is a significant contamination with remnants on corund blasted surfaces. To our knowledge no previous study analysed the effects of cleaning procedures of hip endoprostheses in respect to glass beads and Al (2)O (3) remnants.


METHODS
The surface of the flexible anisotropic Vector cup and the stiff modular MRP-Titan stem (one implant each) were analysed with respect to Al (2)O (3) or glass particles before and after the cleaning procedure. The implants were cleaned using an ultrasound bath for 10 or 20 minutes under nitrogen cooling or simple ultrasound bath with water. A field emission scanning electron microscopy (LEO 1525) was used for the detection of the particles on the implant surface with a backscattered electron detector. The proportion of the surface covered with particles was determined with an imaging analyze software (analySIS, Soft Imaging System GmbH).


RESULTS
A reduction of corund particles on the surface of the flexible anisotropic Vector cup of up to 5.2 % (from 40.0 % to 34.8 %) after 10 minutes nitrogen cooling was achieved. A reduction of corund particles on the surface of the stiff MRP-Titan stem of up to 2.2 % (from 38.8 % to 36.6 %) was observed after 20 minutes of non cooled ultrasound bath whereas a reduction up to 3.2 % (from 25.8 % to 22.6 %) of glass particles after 10 minutes of nitrogen cooled ultrasound bath was detected.


CONCLUSIONS
With the cleaning procedure tested only incomplete removal of just the small glass and Al (2)O (3) particles is possible. Further research is needed to reduce or even avoid residual particles in total hip arthoplasty.
Schuh
A
A
Orthopädische Klinik Rummelsberg, Schwarzenbruck.
Uter
W
W
Holzwarth
U
U
Kachler
W
W
Göske
J
J
Müller
T
T
D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation; D004866:Equipment Contamination; D005898:Glass; D006622:Hip Prosthesis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D011474:Prosthesis Design; D012984:Software; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium; D014465:Ultrasonics
D014025:Titanium