Tensile Fixation Strengths of Absorbable Meniscal Repair Devices as a Function of Hydrolysis Time: An in Vitro Experimental Study

To determine the effect of hydrolysis time on the fixation strength of absorbable meniscal repair devices, adult bovine menisci were repaired with five devices and a suture. The ultimate tensile strength of the repair was then tested in six specimens immediately or after 6, 12, or 24 weeks of incubation at 37°C in a saline solution containing antibiotics, antimycotics, and protease inhibitors. Immediately after implantation the Bionx Meniscus Arrow had a significantly higher failure strength (57.7 13.8 N) than the Linvatec BioStinger (35.1 6.7 N), the Innovasive Clearfix screw (34.9 13 N), the Surgical Dynamics S D sorb staple (9.4 4.6 N), and the Mitek Meniscal Repair System (polydioxanone) (27.2 6.0 N). However, there was no significant difference between the Bionx Meniscus Arrow and a 2—0 polydioxanone vertical suture (51.6 2.7 N). The polydioxanone-based implants demonstrated a significant decrease in failure strength at 12 and 24 weeks. Similarly, the Surgical Dynamics S D sorb staple lost all fixation strength by 24 weeks. The remaining devices showed no significant loss of failure strength over the 24-week period, suggesting that 24 weeks of hydrolysis does not adversely affect the ultimate holding power of poly L-lactide-based meniscal fixation devices.