Abstract
The purpose of this study was to compare the effect of hydrolysis time on the fixation strengths of biodegradable Inion Trinion screws, Mitek Clearfix screws and 2-0 polydioxanone sutures. Complete peripheral, vertical, longitudinal lesions in adult bovine medial menisci were repaired with either a Trinion screw, a Clearfix screw, or a 2-0 polydioxanone (PDS) vertical suture. The ultimate tensile strength of the repair was then tested immediately or after 6, 9, or 12 weeks of incubation (N=6/group/time) at 37C in a saline solution containing antibiotics, antimycotics, and protease inhibitors. Immediately after implantation, the mean failure strengths of the Trinion screw (5215 N) and 2-0 PDS suture (646 N) were significantly (P< 0.05) higher than the Clearfix screw (2610 N). At six weeks the maximum failure loads were as follows: Trinion 2611 N; Clearfix 2012 N; and 2-0 PDS suture 71 N. By 9 weeks the PDS suture lost all fixation strength. The mean maximum failure loads for the Trinion and Clearfix screws at 9 weeks (189 N and 2614 N) and at 12 weeks (165 N and 1011 N) were not statistically different (P> 0.05). Conclusions: The fixation strengths of the Trinion screw and the 2-0 polydioxanone vertical suture are significantly higher than the holding power of the Clearfix screw at time zero. Thereafter the fixation strengths of the Trinion screw and the polydioxanone suture start decreasing, and at 6 weeks no significant difference exists between the three groups. The holding power of the Trinion screw is statistically equivalent to the holding power of the Clearfix screw after 6, 9 and 12 weeks of hydrolysis.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
