Bone block fixation by ultrasound activated resorbable XXXX osteosynthesis: a biomechanical in vitro analysis of stability.

@entity702 @entity7894
OBJECTIVES: 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 @entity702 miniscrews. Resorbable pins were up to 17 mm long. STUDY DESIGN: Two synthetic bone blocks (Sawbone) were fixed by either a resorbable @entity7894 or miniscrew osteosynthesis. Maximum tensile forces were determined mechanically. @entity7894 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 @entity702 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 @entity702 miniscrews. This in vitro study was the basis for a clinical trial of ultrasound-guided resorbable @entity7894 osteosynthesis.
