This study aims to provide evidence of the most appropriate surgical hand-tying technique for teaching to novice surgeons.

Fifty-eight first-year clinical students were randomly allocated to either a group learning one-handed or two-handed ties. The relevant technique was taught and three 15-minute practice sessions were provided between which students' progress was recorded via filming each student tying one knot in string (2 throws). During each practice session one-to-one tuition was provided to each student lasting approximately two minutes.

Each attempt was analysed and scored for technique and knot formation, 1 for perfect technique and knot formation, 2 for perfect technique or knot formation and 3 for failure in both criteria. The time taken for two throws to be completed was recorded. 'Errors' were noted as forming part of the first or second throw. 'Errors' were defined as incorrect movement of hands or string and dropping the string. These 'errors' had to be corrected by the student for the attempt to be included in the definition of 'good technique.' If no knot was completed individual errors were not recorded. Students completed a survey to record possible confounding factors such as age, gender, hand size, surgical experience and any relevant hobbies.

Statistical analysis of the results revealed no significant differences between scores given to each group (1st attempt p = 0.4660, 2nd p = 0.2311, 3rd p = 0.1898, Mann-Whitney test). Initially scores indicated more rapid learning in the one-handed group but fewer individuals achieved a perfect technique and knot after 45 min practice than the two-handed group. The one-handed group were more error-prone and more students continued to make errors until the end of the practice time (after 30 min p = 0.0005, after 45 min p = 0.0001, Mann-Whitney test). Around a 30% reduction in the mean time taken to complete a square knot was recorded from attempt 1 to attempt 3 for both one-handed and two-handed ties. Confounding factors were found to neither improve nor reduce the knot-tying ability.

In conclusion, over 95% of students in the two-handed group performed the technique and knot perfectly after 45 minutes practice time. They were significantly less error-prone and fewer students continued to make corrected errors after 45 minutes. This evidence indicates that the two-handed technique may be the most reliable primary method where the greatest numbers of students achieve success in a manageable teaching time.