51.
Evaluating of bone healing around porous coated titanium implant
and potential systematic bias of the traditional sampling method
Hassan Babiker, Ming Ding, Soeren Overgaard
Orthopedic Research Laboratory, Orthopedic Research Unit, Department of
Orthopaedic Surgery and Trau Odense University Hospital, Institute of
Clinical Research - University of Southern Denmark, Odense,; Orthopedic
Research Laboratory, Orthopedic Research Unit, Department of Orthopaedic
Surgery and Trau, Odense University Hospital, Institute of Clinical Research -
University of Southern Denmark, Odense,; Orthopedic Research Laboratory,
Orthopedic Research Unit, Department of Orthopaedic Surgery and Trau,
Odense University Hospital, Institute of Clinical Research - University of
Southern Denmark, Odense,
Background:
Introduction: The mechanical properties of bone can largely be
explained by bone density, ingrowth to the implant surface and orientation of
the bone. Gap-healing and implant fixation could be affected by the various
quality and quantity of bone in the local environment. Thus, implant fixation in
one part might differ to the other part of the implant.
Purpose / Aim of Study:
This study aimed to investigate the influence of the
sampling method on histological and mechanical data.
Materials and Methods:
Material and Methods: Titanium alloy implants
(
Biomet Inc.) of 10 mm in length and 10 mm in diameter were inserted
bilaterally into the proximal humerus of 8 skeletally mature sheep. Thus two
implants with a concentric gap of 2 mm were implanted in each sheep. The gap
was filled with allograft. Standardised surgical procedure was used. At
sacrifice, 6 weeks after surgery, both proximal humeri were harvested. The
specimens were randomized to superficial or profound groups. In the
superficial group, mechanical testing or histological analysis was carried out at
one side and vice versa on the contralateral side. Through this design we were
able to study variation between the profund and superficial part by using the
assumption that there was no side difference.
Findings / Results:
Result: The mechanical fixation, bone volume and bone
ongrowth showed no statistically significant differences. By mechanical
testing, a slight tendency to increased strength, and failure energy were
observed in the superficial group. By the histomorphomety, bone ongrowth
was slightly increased and volume fraction was decreased in the profound
group.
Conclusions:
Conclusion: No major difference between the profound and
superficial part of the implant was shown suggesting that no bias is introduced
by systematically sampling from either part.
