The Journal of Bone and Joint Surgery, Vol 72, Issue 10 1527-1533, Copyright © 1990 by Journal of Bone and Joint Surgery, Inc
Effects of radiation on fixation of non-cemented porous-coated implants in a canine model
DR Sumner, TM Turner, RH Pierson, H Kienapfel, RM Urban, EJ Liebner and JO Galante
Department of Orthopedic Surgery, Rush-Presbyterian-St. Luke's Medical Center, Chicago, Illinois 60612.
A non-weight-bearing porous-coated rod was implanted bilaterally in the
proximal part of the humerus in thirty-five adult male mongrel dogs. In all
of the animals, one limb was treated with radiation and the opposite limb
served as the control. In twenty-one animals, the dose was 1000 centigrays
(rads) and in fourteen, it was 500 centigrays. The strength of fixation and
the volume fraction of ingrowth of bone were determined two, four, and
eight weeks after the operation in the group that received 1000 centigrays
and two and four weeks after the operation in the group that received 500
centigrays. Treatment with 500 centigrays had no significant effect on the
strength of fixation or the amount of ingrowth of bone. In contrast, at two
weeks, treatment with 1000 centigrays had reduced the strength of fixation
to 50 per cent of the control value (p less than 0.01), although, at four
and eight weeks, the strength of fixation was not significantly different
than that in the control limb. The amount of ingrowth of bone in the
irradiated limb was significantly reduced at two weeks (30 per cent of the
control value) (p less than 0.01), four weeks (70 per cent of the control
value) (p less than 0.05), and eight weeks (56 per cent of the control
value) (p less than 0.05).