Background: The geometry of lockable, ratchet, or jamming sliding surgical knots was assessed to enhance practical and topological understanding of knots among surgeons.
Methods: Using a database of more than 100 surgical knots, 29 knots that reportedly feature locking, ratchet, or jamming mechanisms were topologically assessed for their ability to lock antegradely or retrogradely, to lock by assuming their flat geometry, or to jam.
Results: Eighteen of the 29 investigated surgical knots have previously been mistakenly categorized. Topologically, the concept of a true ratchet knot is a fallacy.
Conclusions: Surgical knots may be consistently classified on the basis of precise and detailed definition of various anti-backsliding geometrical characteristics of knots.