An evaluation of knot integrity when tied robotically and conventionally

Objective

The purpose of this study was to evaluate the knot integrity of 3 commonly used sutures in sacrocolpopexy that were tied conventionally (by hand) and robotically.

Study Design

Knots were tied with polyglactin 910, polypropylene, and polyester, with 5-6 knots tied, depending on the suture used. We compared the knots that were subjected to tensile force until the suture broke or untied.

Results

The mean force that was required for the suture to untie was 47.7 ± 18.8 (SD) Newtons and was seen only among the robotically tied polyglactin 910 knots. Robotically tied polyglactin 910 knots were significantly weaker than all other robotic and conventional knots that were tested (P < .05). The tying modality and material interaction was significant (P < .001), which suggests that the effect of suture material varied, depending on the tying modality.

Conclusion

Knot failure rates for conventional or robotically tied suture varied based on the suture material that was used.

Key words: procedure, square knot, suture, tensile strength