Comparison of intra- and extraosseally placed self-reinforced poly-L-lactide plates in the fixation of distal femoral osteotomies in rabbits.
OBJECTIVE
We have developed the intraosseal plating method with self-reinforced poly-L-lactide (SR-PLLA) plates. In the present study for comparison, the other plates were implanted on both sides of the bone because two plates separated by a 2-5 mm bony bridge in the intraosseal fixation proved successful. The two fixation methods may have different effects on the formation of new bone, and we measured this event histomorphometrically.


METHODS
Osteotomies of the distal femora in 20 adults rabbits were fixed intraosseally with two SR-PLLA plates and four titanium screws and in 20 adult rabbits with identical plates fixed on both sides of the bone with four metallic screws. The follow-up times were three, six, 12, and 24 weeks. The amount of trabecular bone at the osteotomy site was evaluated histomorphometrically.


RESULTS
In both groups and after each follow-up time greater trabecular bone percentage values were noticed on the operated sides. The amount of bone was greatest near the plates and particularly strong between the plates in intraosseal plating.


CONCLUSIONS
Intraosseally implanted SR-PLLA plates do not seem to diminish the amount of trabecular bone when compared to similar plates on the bone.
Koskikare
K
K
Department of Orthopaedics and Traumatology, Helsinki University Central Hospital, Finland.
Pihlajamäki
H
H
Pätiälä
H
H
Rokkanen
P
P
D000042:Absorption; D000818:Animals; D001672:Biocompatible Materials; D001860:Bone Plates; D001863:Bone Screws; D005260:Female; D005269:Femur / Q000601:surgery*; D020007:Implants, Experimental; D008297:Male; D010012:Osteogenesis; D010027:Osteotomy; D011091:Polyesters / Q000627:therapeutic use*; D011817:Rabbits
D001672:Biocompatible Materials; D011091:Polyesters; C033616:poly(lactide)