Bone block fixation by ultrasound activated resorbable pin osteosynthesis: a biomechanical in vitro analysis of stability.
OBJECTIVE
The aim of this study was to determine the compound strength of the fixation between 2 blocks of synthetic bone using ultrasound activated resorbable pins (regarding drill hole diameter) and compare them to fixation with titanium miniscrews. Resorbable pins were up to 17 mm long.


METHODS
Two synthetic bone blocks (Sawbone) were fixed by either a resorbable pin or miniscrew osteosynthesis. Maximum tensile forces were determined mechanically. Pin lengths of 7 mm, 11 mm, and 17 mm were analyzed in relation to different drill hole diameters.


RESULTS
The ideal drill hole configuration was a combination of diameters of 2.1/1.6 mm (in a lag screw configuration). Mean maximum tensile force was 80 N for 7 mm pins (105 N/11 mm, 69 N/17 mm). In comparison, tensile forces of titanium screws were 20 N (7 mm), 97 N (11 mm), and 135 N (17 mm).


CONCLUSIONS
Osteosynthesis by resorbable pins reached equal compound strength levels compared with titanium miniscrews. This in vitro study was the basis for a clinical trial of ultrasound-guided resorbable pin osteosynthesis.
Schneider
Matthias
M
Department of Oral and Maxillofacial Surgery, Faculty of Medicine, University of Technology Dresden, Dresden, Germany. matthias.schneider@uniklinikum-dresden.de
Loukota
Richard
R
Reitemeier
Bernd
B
Meissner
Heike
H
Stadlinger
Bernd
B
Eckelt
Uwe
U
Richter
Gerd
G
D020341:Absorbable Implants; D001696:Biomechanical Phenomena; D001858:Bone Nails; D001863:Bone Screws; D018786:Bone Substitutes; D003799:Dental Stress Analysis; D005593:Fracture Fixation, Internal / Q000295:instrumentation*; D050723:Fractures, Bone / Q000601:surgery; D011140:Polyurethanes; D018709:Statistics, Nonparametric; D013718:Tensile Strength; D014465:Ultrasonics
D018786:Bone Substitutes; D011140:Polyurethanes