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Updated: Jun 21, 2026
An Improved Mechanical Testing Method to Assess Bone-implant Anchorage
Published on: February 10, 2014
Effect of local TGF-beta1 and IGF-1 release on implant fixation: comparison with hydroxyapatite coating: a paired
Anders Lamberg1, Joan E Bechtold, Jørgen Baas
1Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Aarhus University Hospital, Denmark. anders@lamberg.dk
Background And Purpose:
Hydroxyapatite (HA) coating stimulates the osseointegration of cementless orthopedic implants. Recently, locally released osteogenic growth factors have also been shown experimentally to stimulate osseointegration so that bone fills gaps around orthopedic implants. Here, we have compared the effect of local release of TGF-beta1 and IGF-1 with that of hydroxyapatite coating on implant fixation.
Method:
Weight-bearing implants with a 0.75-mm surrounding gap were inserted bilaterally in the knees of 10 dogs. Growth factors were incorporated in a biodegradable poly(D,L-lactide) coating on porous coated titanium implants. Plasma-sprayed HA implants served as controls. The dogs were killed at 4 weeks and the implants were evaluated by mechanical push-out test and by histomorphometry.
Results:
There was no difference in any of the mechanical parameters. Bone ongrowth was 3-fold higher for HA-coated implants (p < 0.001). For growth factor-coated implants, bone volume was 26% higher in the inner half of the gap and 28% higher in the outer half compared to HA (p < 0.03).
Interpretation:
The mechanical fixation of porous-coated titanium implants with local growth factor release is comparable to that of HA coating. While HA mainly stimulated bone ongrowth, local release of TGF-beta1 and IGF-1 stimulated gap healing.
