Abstract
Background Surgeons are not always cognizant of the knots they tie. It has been thought that suture material does not determine what types of knots are tied. Design Experienced surgeons were asked to tie square monofilament knots that were salvaged and microscopically evaluated. Results Tightly cinched monofilament knots assume sliding conformation in vivo regardless of configuration, instrumentation, suture polymer, or surgeon. Conclusions When monofilament suture is securely cinched in vivo, kinetic energy forces even a flat throw into sliding conformation. A well-crafted, intentionally sliding square knot appears compacter than any other monofilament knot.