Surgery Websites
Advanced Open Surgical Skills »  ATOSS Tasks »  Task 2: Tying with needles

Task 2: Suture Tying With Needle

Instructional Video


Task Details


Summary: This task requires using 1-handed technique to tie 10 knots with double armed suture.

Equipment: One fine needle holder, one fine forceps, one 75cm 6-0 Prolene double armed suture on a C1 needle.

Task set-up: Position fabric at the base of the model (lowest platform level) as follows:


Task steps:

  1. Load needle into fine needle holder.
  2. Throw a single suture through the fabric on either side of the slit.
  3. Set needle holder and forceps aside.
  4. Hold the suture ends in each hand (uncrossed) with equal tails.
  5. Tie 2 slip knots then 8 square knots. For each throw, use as many gathering maneuvers as needed and forefinger to lay down the knot securely.
  6. The task is completed when the last (10th) knot is secured.

Tips & tricks:

  • Transiently release the tension on the post hand to allow the needle to have sufficient space to navigate through the suture without catching. If the needle does catch, gently moving both hands and relaxing tension on the post will help with recovery.
  • Also see Tips & Tricks of Task 1 (suture tying without needle), as these also apply.

Cutoff time: Maximum time for task completion is 90 seconds. During formal assessment, the timing will start after the suture is in place and hand movement is initiated. If the task is not completed within the allotted time, you will be asked to stop.

Scoring: A score will be assigned for each micro-skill. Score assignments are based on the following:








Unable to complete task

Completed task w/ major errors

Completed task w/ minor errors

Proficient, no errors, some awkward moves

Expert, no errors, smooth and efficient


Score (1-5)

1. Throwing knot


2. Gently allowing needle through without catching


3. Suture gathering


4. Suture sliding


5. Atraumatic technique


6. Maintenance of post


7. Overall rating


Total (Sum of Scores for All Micro-Skill) [Max = 35]


Scoring Formula: see Task & Scoring Overview or score calculator (access via Google doc or download excel file)

Expert Score: 50

Example Video

Site Directory