Relative effects of wound healing and mechanical stimulus on early bone response to porous-coated implants.
We hypothesized that early bone adaptation to well fixed porous-coated implants is influenced more by wound healing than by mechanical loading. To test this hypothesis, two groups of dogs with identical, hydraulically controlled porous-coated implants interference fit within distal femoral trabecular bone were used. One group had no load: the other had 35 N of load applied to the implants. At 5 weeks after surgery, the resulting adaptation of bone around the implants was quantified on a cellular basis by cytochemical analysis of type-I procollagen synthesis and on a structural basis using three-dimensional micro-computed tomography imaging. The percentage of trabecular surfaces covered by osteoblasts expressing type-I procollagen was significantly increased in bone surrounding the implant in both groups compared with contralateral control bone tissue. There was no difference between the groups with no load or 35 N of load. In addition, measures of trabecular bone structure did not differ significantly between the load and no-load groups. Taken together, these results suggest that wound healing plays a much greater role in the early response of bone to well fixed porous-coated implants than does mechanical stimulus.
Hollister
S J
SJ
Orthopaedic Research Laboratory, University of Michigan, Ann Arbor 48109-0486, USA.
Guldberg
R E
RE
Kuelske
C L
CL
Caldwell
N J
NJ
Richards
M
M
Goldstein
S A
SA
D000818:Animals; D001860:Bone Plates; D001842:Bone and Bones / Q000166:cytology / Q000601:surgery*; D004285:Dogs; D008297:Male; D010006:Osteoblasts / Q000737:chemistry; D011347:Procollagen / Q000032:analysis; D013314:Stress, Mechanical; D016474:Weight-Bearing / Q000502:physiology; D014945:Wound Healing / Q000502:physiology*
D011347:Procollagen