CSTiTM vs. Other Porous Coatings
The clinical results speak for themselves
100X
|
75X
|
75X
|
100X
|
50X
|
|
|
CSTi |
CoCr Beads |
Ti Fiber Mesh |
Plasma Spray |
Trabecular Metal |
|
| Manufacturer |
Zimmer |
Howmedica Osteonics |
Zimmer |
Biomet |
Zimmer |
| Physical Characteristics | |||||
|
Pore Size |
400-600µm |
Variable |
NA |
Variable |
300µm |
|
Pore Volume |
50-60% |
35% |
68% |
VariableA |
70% |
|
Coating Material |
Ti |
CoCr |
Ti |
Ti |
Ta |
| Retrieval Results | |||||
|
%-IngrowthC Tibial Baseplates |
6-22%iii, iv |
6-9%iii,v |
9.5%vi |
NA |
NA |
|
ABID Tibial Baseplates |
73%iv |
36%v |
27%vi |
NA |
NA |
|
%-Ingrowth Acetabular Shells |
12%vii |
0-10%viii |
12%ix |
NA |
NA |
|
ABI Acetabular Cups |
84%vii |
NA |
0-55%ix |
NA |
NA |
| Advantages and Features | |||||
|
Optimal pore size |
• |
• |
|||
|
Optimal pore volume |
• |
• |
• |
||
|
Micro Surface Roughness |
• |
• |
• |
||
|
Bimetal (Ti on CoCr substrate) |
• |
• |
|||
|
Interconnected pores |
• |
• |
• |
• |
|
|
Coating does not dissociate |
• |
•B |
A Does not have true, interconnected pores.
B
Trabecular metal implants have no substrate. The polyethylene is molded
directly into the metal structure.
C Ingrowth: The percent
volume of bone in the total volume of pores available. This is determined
through BSE (backscattered electron microscopy).
D ABI
(appositional bone index): A measure of the percent of bone in direct
contact with the porous surface.
i Bobyn JD, Pilliar RM, Cameron HU, Weatherby GC. The optimum pore size for the fixation of porous-surfaced metal implants by the ingrowth of bone. Clin Orthop. 1980;150:263-70.
ii Bloebaum RD, Bachus KN, Mitchell W, Hoffman G, Hofmann AA. Analysis of the bone surface area in resected tibia. Implications in tibial component subsidence and fixation. Clin Orthop. 1994;309:2-10.
iii Bloebaum RD, Rhodes DM, Rubman MH, Hofmann AA. Bilateral tibial components of different cementless designs and materials. Clin Orthop. 1991;268:179-87.
iv Bloebaum RD, Bachus KN, Jensen JW, Hofmann AA. Postmortem analysis of consecutively retreived asymmetric porous-coated tibial components. J Arthroplasty. 1997;12(8):920-9.
v Vigorita VJ, Minkowitz B, Dichiara JF, Higham PA. A histomorphometric and histologic analysis of the implant interface in five successful, autopsy-retrieved, noncemented porous-coated knee arthroplasties. Clin Orthop. 1993;293:211-8.
vi Sumner DR, Kienapfel H, Jacobs JJ, Urban RM, Turner TM, Galante JO. Bone ingrowth and wear debris in well-fixed cementless porous-coated tibial components removed from patients. J Arthroplasty. 1995;10(2):157-67.
vii Bloebaum RD, Mihalopoulus NL, Jensen JW, Dorr LD. Postmortem analysis of bone growth into porous-coated acetabular components. J Bone Joint Surg Am. 1997;79(7):1013-22.
viii Cook SD, Barrack RL, Thomas KA, Haddad RJ. Quantitative analysis of tissue growth into human porous total hip components. J Arthroplasty. 1988;3(3):249-62.
ix Pidhorz LE, Urban RM, Jacobs JJ, Sumner DR, Galante JO. A quantitative study of bone and soft tissues in cementless porous-coated acetabular components retrieved at autopsy. J Arthroplasty. 1993;8(2):213-25.
