For the socket, I believe it
takes 3 to 6 months before the bone is fully
grown onto the implant. I believe the femoral
bone is something that continually remodels,
since it is alive. I believe that it is weaker
initially after surgery, but strengthens with
gradual activity, to the point that it is
probably strong enough for impact activity at 6
from a DEXA study on BHR patients published from
Japan is that the bone density in the proximal
femur returns to normal 1 year after operation.
The at-risk period for femoral neck fracture
following the BHR is in the 6 months after
surgery. I advise patients not to return to
impact sport for 1 year after surgery. For those
patients who want to road run, I get them
running on a treadmill at 10 months post-op and
they resume road running at 12 months post-op.
My unit published on activity level after
resurfacing some years ago in a group of
patients who followed those rules. In young men
with a single osteoarthritic hip resurfaced, 92
% played sport and 62 % played impact sport. The ladies were
not quite as active, but you can see from the publication
that they still had an impressive activity level. In the
total group their 10 year implant survival is 99.8 % showing
that high activity introduced at a sensible time does not
deteriorate the results.
The bone is well healed at 6-12 weeks. I allow running
at 6 months. I do not use cementless resurfacing. I use
Smith and Nephew Birmingham hip.