Grit-blasted and hydroxyapatite-coated total hip arthroplasty: an 11- to 14-year follow-up study

Mechanical and Histological Evaluation of Improved Grit-Blast Implant in Dogs: Pilot Study

“…Tsukeoka et al [33] reported similar findings in relation to time, i.e., (i) that sufficient attachment strength could be achieved between bone and implant through interlocking of bone grown in titanium fiber mesh, and (ii) that the mechanical interlocking was a major contributor to the adhesive strength between bone and implant after long-term implantation. Clinical studies have reported, however, that, in actual prostheses, surface coatings are not necessary on grit blast roughened surfaces [1,20]. In a 5-to 8-year clinical study of femoral prostheses slightly roughened by grit blast and used in human joint fixation, Blaha et al [1] reported results comparable to those achieved with porous-coated implants and concluded that surface roughening by grit blast achieves satisfactory noncemented results without any addition of porous coatings.…”

“…In clinical cases of total hip arthroplasty in 33 patients followed up for 11 to 14 years, Miyakawa et al concluded that secure stability at implantation is essential for overcoming interfacial shear forces between implant and host bone [20]. Accordingly, in a 24-month clinical study of 25 implants in the human tibia, Linder et al attributed lack of osseointegration to inadequate primary contact with bone [18].…”

“…In a 5-to 8-year clinical study of femoral prostheses slightly roughened by grit blast and used in human joint fixation, Blaha et al [1] reported results comparable to those achieved with porous-coated implants and concluded that surface roughening by grit blast achieves satisfactory noncemented results without any addition of porous coatings. Similarly, Miyakawa et al [20] noted that, in hip prostheses, an entirely grit blasted straight tapered stem facilitates solid biological fixation without porous or hydroxyapatite coatings.…”

“…But, the fastness of such coatings is markedly reduced by fatigue, often ending in avulsion of the surface coating from the metallic substrate [16,31]. Uncoated grit blast implants, on the other hand, are notably weak in shear strength between the bone and implant [10,20,30]. Attempts to increase the roughness, or porosity, of the grit blast implants, have demonstrated that hydroxyapatite or A-W glass ceramic accelerated the vascularization and ossification within a short period after implantation [21,30].…”

“…This peculiarity raises the question as to whether bone ongrowth might be accelerated if the roughness, i.e., the peak-to-valley contrast, was to be increased on the surface of the grit blast implant itself rather than by coating. Much understanding has been gained from a wide range of experimental work addressing the surface geomorphology of implants tested in the femur, tibia, ulna, and mandible of animals [3, 6-17, 19, 21, 23-25, 27-30, 33, 34] as well as from orthopedic and oral surgery in human clinical studies [1,4,5,18,20,26], and from bioengineering studies in vitro [32] and biological examination of cell attraction to roughened surfaces in vitro [2]. Despite an ongoing proliferation of reports, however, controversy remains on how to design the implant surface most conducive to osseointegration and apposition of remodeled bone matrix to the implant.…”