Rotator cuff tendons are typically reattached to the proximal humerus using either transosseous sutures or suture anchors. Their primary mode of failure is at the tendon bone interface 1. Surgical adhesives are used to bond cartilage, tendons and bone, and to close wounds. In an attempt to increase the tendon-bone interface we investigated the addition of a novel adhesive secreted from a species of Australian frog (Notaden bennetti) 2 to different methods of rotator cuff repair.

Forty two fresh frozen sheep infraspinatus tendons were repaired using 3 different techniques: transosseous sutures; two Mitek RC Quickanchors with 1 suture per anchor and two Opus Magnum anchors with 1 suture per anchor all using a mattress stitch configuration. In each group 7 shoulders were repaired with the addition of a small amount of frog glue to the infraspinatus footprint while 7 were used as control with no adhesive. Mechanical testing was performed using a mechanical tensile testing machine.

The strongest construct in the control groups was the Mitek suture anchors (mean 86±5 N) followed by the Opus suture anchor (69±6N) and transosseous repair (50±6N). This proved significant (p< 0.05) between both metallic anchors and the transosseous repair.{BR}The addition of frog glue resulted in a significant increase in load to failure and total energy required until failure in all repair techniques (p< 0.01). There was a 2 fold increase in load to failure of both the Opus Magnum (143±8N) and Mitek RC Fastin (165N±20 N) anchors while the transosseous repair (86± 8 N) had a 1.7 fold increase in its load to failure.

This data suggests that:

suture anchor fixation is a stronger construct requiring a larger amount of total force to fail than transosseous repair using a one suture repair technique, that

The unique properties of this frog glue (strong, flexible, sets in water and biocompatibility) may ultimately lead to the production of a useful adjunct for rotator cuff repair in humans.