The osseous response to corundum blasted implant surfaces in a canine hip model

The purpose of this study was to examine the radiographic and histologic re sponse to corundum blasted implant surfaces of varying roughness in a canin e total hip arthroplasty model. Three types of tapered femoral implants wer e made from titanium alloy and were identical in every respect except surfa ce finish. The entire surface of the femoral implant had a 2.9-, 4.2-, or 6 .7-mu m average surface roughness (R-a) from blasting with 60-, 24-, or 16- grit corundum particles, respectively. Twenty-two stems in 11 dogs were eva luated at 6 months, Twenty-one of the stems showed osseointegration, wherea s in one stem a fibrous interface developed. Abundant new periimplant bone formation occurred, particularly within the intramedullary canal where trab eculae spanned implant to endosteal cortex gaps as large as 5 mm, Bone appo sition with the 60-, 24-, and 16-grit stems averaged 31.7%, 32%, and 27.9%, respectively; the differences were not statistically significant, However, the pattern of new bone formation was different in that the average length of each region of bone apposition for the 60- and 24-grit surfaces was 50% greater than that for the coarser 16-grit surface, The observations of thi s study indicate that because of their highly osteoconductive nature, corun dum blasted surfaces represent an important and valuable technology for the design of noncemented implants.