Calcium phosphate‐coated porous titanium implants for enhanced skeletal fixation

Abstract

Porous titanium fiber implants for cementless skeletal fixation by bone ingrowth were treated with a calcium phosphate coating applied by a plasma flame-spray technique. In a paired experiment, treated and control implants were inserted in the humeri and olecranons of 36 adult dogs for periods of 1, 2, 4, and 6 weeks. After the animals were sacrificed, a biomechanical evaluation of the strength of skeletal fixation of the implants and a histologic evaluation of bone ingrowth was done. The mean shear strength of skeletal fixation at four weeks for the calcium phosphate-coated implants was 24% greater (P less than .01) than for paired controls. No difference in strength of fixation between treated and control implants was present at other time periods. The osteoconductive properties of the ceramic coating were demonstrated by bone forming in direct contact with the calcium phosphate coating on the metal fibers of the treated implants. No significant increase for the volume of bone ingrowth was established for treated implants compared to paired controls at any time period.

Hydroxyapatite coating enhances fixation of porous coated implants: A comparison in dogs between press fit and noninterference fit

“…Geesink et al (1987) used uncoated smooth titanium implants as controls and Thomas et al (1987) used macroscopic grooved-configuration implants without porouscoating. In contrast, the control implants used by Rivero et al (1988) consisted of fiber-metal porous surfaces, which presumably may be considered similar to the porous plasma-sprayed controls used in the present study in terms of anchorage capacity. Using porous-surfaced controls instead of smoothsurfaced controls, skeletal fixation is increased, which again increases the demands on the osteoconductive effect of the relatively smooth surfaced hydroxyapatite implant; the opposite is true for smooth-surfaced controls (Skalak 1983, Carlsson et al 1988b, Thomas and Cook 1985.…”

“…Using similar slight press fit (0.05 undersized holes) for insertion, Cook et al (1988) found no increased anchorage of HAcoated transcortical implants compared with porouscoated Ti-alloy implants. Rivero et al (1988) used a tight pressfit (drill hole 9 mm, implant 10 mm) and found only 24 percent increased fixption of intramedullary implants after 4 weeks and no effect after observation periods of 1, 2, and 6 weeks. Our findings correspond well with Rivero et al (1988) in that no mechanical effect of HA was obtained in the implants in tight press fit (0.4-mm undersized holes), whereas a twofold increased fixation was attained in the gap situation.…”

“…Rivero et al (1988) used a tight pressfit (drill hole 9 mm, implant 10 mm) and found only 24 percent increased fixption of intramedullary implants after 4 weeks and no effect after observation periods of 1, 2, and 6 weeks. Our findings correspond well with Rivero et al (1988) in that no mechanical effect of HA was obtained in the implants in tight press fit (0.4-mm undersized holes), whereas a twofold increased fixation was attained in the gap situation. However, differences in purity of HA, Ca/P ratio, surface texture, surface on control implants, and the testing conditions might also be responsible for the differences in fixation.…”

Development and Applications of Varieties of Bioactive Glass Compositions in Dental Surgery, Third Generation Tissue Engineering, Orthopaedic Surgery and as Drug Delivery System

“…This problem may be overcome by modifying the implant/bone interface for improved osseous integration. Improved osseous integration may be obtained by the use of hydroxyapatite (HAp), b-tri calcium phosphate (b-TCP) and their composite coatings as nominally HAp to enhance the osteoconductivity of metallic implant (Thomas et al, 1987;Filiaggi, et al, 1991;Rivero et al, 1988). These coatings have been shown to promote osseointegration by stimulating bone growth onto the surface (Dey et al, 2011).…”

Effects of Tricalcium Phosphate Coated Titanium on Adjacent Early Bone Formation

“…It has been shown that at 2 weeks, the strength of fixation to this material begins to increase. 30 This may explain why there is such an increase in ALP attachment in TCP as we get closer to 2 weeks.…”