FAILURE STRENGTH OF A NEW MENISCUS ARROW REPAIR TECHNIQUE - BIOMECHANICAL COMPARISON WITH HORIZONTAL SUTURE

A new method for arthroscopic all-inside repair of Vertical meniscus l esions by use of a biodegradable fixation device (''meniscus arrow'') has been developed, including a set of cannulas for easy insertion via standard arthroscopic portals. The technique is described. A study to test the fixation properties was performed in the laboratory. Twenty- four fresh frozen bovine medial menisci were defreezed and divided int o three groups. In all menisci an artificial vertical lesion was creat ed with a scalpel 3 mm from the peripheral rim. Repair in group I was done with a single horizontal Maxon-0 suture using an Acufex double-ba rrel cannula (Acufex Meniscal Stitcher; Acufex Microsurgical, Norwood, MA). A knot was tied on the capsular side. Repair in group II was mad e with one 13 mm Biofix Meniscus arrow (Bioscience Ltd, Tampere, Finla nd). In group III repair was performed like in group II but the menisc i were incubated in isotonic saline at 21 degrees C for 24 hours befor e testing. Menisci in group I and II were tested within 3 hours after defreezing. Prior to testing total separation of central and periphera l part of meniscus was performed. Thus only the repair site was tested . Pull-out tests to failure were made in a computer-based Nene M5 test ing machine with a cross-head speed of 5 mm/min. Median failure load i n group I: 49 N (range 43 to 77 N), in group II: 53 N (range 42 to 65 N) and in group III: 54 N (range 35 to 74 N). No statistically signifi cant difference in failure load was found between the groups. Thus ini tial failure strength for arrow-repaired bovine menisci is comparable to that of a horizontal suture.