FAILURE STRENGTHS OF SUTURE VERSUS BIODEGRADABLE ARROW FOR MENISCAL REPAIR - AN IN-VITRO STUDY

Advances in our understanding of meniscal function and consequences of menisectomy have spawned meniscal repair techniques that yield succes s rates approaching 90% in properly selected patients. Biodegradable i mplants have been fashioned for meniscal fixation to simplify the tech nique and minimize neurovascular complications. We performed the curre nt study to determine the in vitro biomechanical behavior of the BIOFI X Meniscal Arrow, a polylactic acid tack developed for meniscal repair , Eight pairs of menisci were harvested from cadaveric knees kept froz en before testing. Peripheral vertical tears were created in the poste rior horn of all menisci, and each was subsequently repaired using a v ertical loop suture of 2-0 Ethibond and a Meniscal arrow. Ultimate loa d to failure of each method was determined on a Hounsfield H25KM Unive rsal Testing machine. The mean failure load for the suture group was 5 8.3 N compared with the Arrow group mean of 29.6 N (P <.001). All sutu res failed by rupture at the knot but did not pull through the meniscu s. All but one of the arrows failed by pulling out of the meniscus. Th e Arrows also permitted gapping at the repair site at considerably les ser loads than the sutures subject to strain. The concept of a biodegr adable tack is appealing. Vertical loop sutures should be the standard by which their biomechanical performance is judged. We suggest modifi cations to the Arrow design that could enhance the fixation strength o f this implant.