Each year in the United Kingdom 80,000 hip replacement operations are performed.
Revision surgery is necessary in about 1/3 of these cases due to aseptic loosening
of the prosthesis. Initially an oversized prosthesis is press fitted into the
femur. Revision surgery employs the THA or Total Hip Arthoplasty method where
an under sized prosthesis is fixed into bone graft packed into the femur.
Both short term and long term strength are required of the replaced hip, but in the THA method these are conflicting requirements. High mechanical strength of the bone graft is required in the short term. This is achieved using well graded bone graft compacted to high levels. However, long term stability requires large pore sizes in the graft so that it may be incorporated into the host bone.
This research examines how permeability may be related to pore size in samples of different grading. Initial clinical trials have been promising.
For more information, see the geotechnical group home page.
