It is well documented that torn meniscal tissue increases the likelihood of degenerative arthritis of the knee. Efforts have therefore been directed toward meniscal repair techniques. Surgical adhesives have the theoretical advantage of minimizing the tear gap and providing full contact of the bonded surfaces, which would aid in meniscal repair. The purpose of this study was to determine the mechanical strength of a newly discovered biological adhesive (frog glue) and to compare its strength to currently available biological adhesives for meniscal tissue repair.
A longitudinal tear was created along the periphery of freshly dissected sheep menisci. Four adhesives were used to reduce the cut surfaces: (1) frog glue (nontoxic, biocompatible glue secreted by an Australian species of frogs of the genus Notaden, n = 12); (2) fibrin glue (n = 11); (3) gelatin glue (n = 12); and (4) cyanoacrylate glue (n = 12). The samples were incubated in wet conditions for 24 hours, tested using a tear propagation method, and the peel strength was calculated. The test groups were compared using analysis of variance. In all cases, tearing occurred along the tissue-adhesive interface. Cyanoacrylate formed a hard brittle film on the glued surfaces, whereas the other glues remained rubbery. The strongest bond (mean ± SEM) was made by the cyanoacrylate glue (149 ± 10 N/m) followed by the frog glue (97 ± 9 N/m). The frog glue was found to be 5 times stronger than the fibrin glue (20 ± 3 N/m), and 2.5 times stronger than the gelatin glue (39 ± 8 N/m). There was a statistically significant difference between each of the groups (P < 0.001), except between the gelatin and fibrin glues.
Cyanoacrylate provided the strongest bond, whereas gelatin and fibrin glues were weak bonding agents. The frog glue demonstrated superior mechanical strength over the 2 other biological glues. Based on its excellent mechanical properties and advantageous biological and structural characteristics, the frog glue has great potential for further investigations and could be considered for meniscal repair in the future.