Master the four sutures you will use every shift.
Simple interrupted, simple continuous (running), vertical mattress, and horizontal mattress. Each technique below has 7 videos, full YouTube lessons plus short form clips, and the exact platform mix is labeled in every section: Instagram Reels in all four sets, TikTok in both mattress sets, and extra YouTube lessons where no distinct TikTok original for that stitch could be verified. Plus steps, mistakes to avoid, and a quiz. Learn them in order, then drill until your hands know it without thinking.
Your learning path - do it in this order
Each stitch is tied and cut on its own. One fails, the rest still hold.
One long strand, diagonal on top, knot only at the start and the end.
One stitch stacked in two layers, deep wide bite below, shallow bite on top. Best eversion of the four.
Two parallel passes form a rectangle, knot on the starting side. Spreads tension across a wide bridge of skin.
"If you ever get into trouble with a closure, go back to the simple interrupted."
That line from Suture Mentor and Duke comes up in almost every skills lab for a reason.
Foundations you need for all four
Skip this and every stitch will feel clumsy. Spend 15 minutes here and your first real reps will already look cleaner.
Your kit
- ✓ Needle holder / driver
- ✓ Adson forceps with teeth (hold like a pencil, non dominant hand)
- ✓ Suture scissors
- ✓ Suture pad + 3-0 or 4-0 practice suture
- ✓ Gloves, drape, good light for real wounds
Load the needle right
Grasp the needle with the tip of the driver, two thirds of the way from the needle tip toward the thread end, at 90 degrees to the driver. Straighten the thread so it does not tangle. Wrong loading is the number one beginner wobble.
Memory hook: "Two thirds, tip of the driver."
The instrument tie
Surgeon's knot first: wrap twice around the driver, grab the short tail, pull flat. Then one throw the opposite way, then one more the first way. That makes a square knot that lies flat and will not slip or twist into a granny knot.
Simple Interrupted Suture
One stitch, one knot, cut, repeat. Best for most lacerations, irregular wounds, wounds at risk of infection, and anywhere you need precise control stitch by stitch.
Video 1 of 7 · YouTube - Geeky Medics OSCE Guide (watch this one twice)
Short, clean, and exactly how a skills check is scored. Setup, out to in, in to out, then the three throw tie and trim to 5 to 6 mm.
Video 2 of 7 · YouTube - Suture Mentor, Dr. David Naysmith
Plastic surgeon walkthrough with a calm, read along feel. Great second angle if the Geeky Medics pace felt fast. Same steps, different hands.
Videos 3 to 7 - more angles on the same stitch
Tap any row to watch it on its own platform. Short clips are for quick review right before a rep, not a replacement for Videos 1 and 2.
Honest mix note for this technique: 3 YouTube lessons + 4 Instagram Reels = 7. SurgeryTok clips of this stitch are almost all cross-posted as the Reels above, and no distinct, verified TikTok original teaching only this stitch could be found that was not a duplicate of a clip already listed, so no TikTok slot was padded with a repeat.
Step by step
Right handed version. Mirror it if you are left handed.
Start in the middle
Place your first stitch in the center of the wound, bisecting it. Then bisect each half again. This keeps edges aligned and stops you ending up with a dog ear at one end.
Out to in - first side
Gently evert the far edge with forceps. Enter skin at 90 degrees, about 3 to 5 mm from the edge. Supinate your wrist and follow the needle curve through the dermis, exiting into the middle of the wound.
In to out - second side
Reload the needle. Enter from inside the wound on the opposite side at the same depth, exit 3 to 5 mm from the edge on that side. Symmetry is everything: equal distance, equal depth, flask shaped bite wider at the base.
Leave a 3 cm tail
Pull the thread through until about 3 cm remains on the entry side. That short tail is what your driver will grab to tie.
Tie flat, slide to the side
Surgeon's knot: 2 throws one way, 1 throw back, 1 throw the first way again. Pull horizontally, flat, just to approximate. Slide the knot off to one side so it does not sit on top of the wound line.
Trim and repeat
Cut tails to about 5 to 10 mm (Geeky Medics teaches 5 to 6 mm). Space stitches about 5 mm apart, 3 to 5 mm from the edge, until the wound is closed without gaps.
When to choose it
- ✓ Most simple lacerations, especially first choice while learning
- ✓ Irregular, curved, or uneven wounds where each stitch needs adjusting
- ✓ Contaminated wounds or infection risk - you can remove one stitch to drain without opening the whole wound
- ✓ Higher tension areas where individual control matters
Common mistakes preceptors flag
- × Unequal bites - one side 2 mm, other side 8 mm, wound puckers
- × Crushing skin with forceps instead of gently everting
- × Tying too tight - edges blanch, invert, and heal poorly
- × Knot sitting right on the wound line
- × Grabbing the needle by its sharp tip and dulling it
Memory hook
"90 in, curve through, mirror out, tie flat, slide aside."
Say it out loud for your first 20 reps. Your mouth will teach your hands.
Continuous Suture - Simple Running
Also called a simple running suture. One strand runs the whole length of the wound. Faster, distributes tension evenly, uses less material, but it is all or nothing if the strand breaks.
Video 1 of 7 · YouTube - University of Washington, Simple Running Closure
University skills lab demo made for trainees. Clear view of spacing, angle, and how tension is kept as you move down the line.
Video 2 of 7 · YouTube - Simple Running Suture, full pass
A complete running line from anchor knot to final tie, so you can see the rhythm and the diagonal pattern build stitch by stitch.
Videos 3 to 7 - locked variant, a second teacher, and short clips
Tap any row to watch it on its own platform.
Honest mix note for this technique: 4 YouTube lessons + 3 Instagram Reels = 7. As with interrupted, findable TikTok originals for a pure simple running stitch were duplicates or cross-posts of clips already listed, so the short form slots here are Instagram Reels and no duplicate was counted twice. Bonus, not counted in the 7: the MedSync live practice session on YouTube (search "LIVE Suturing For Beginners, MedSync", continuous at 46:55) is the best sew-along session for reps once you have watched the 7.
Step by step
Think of it as interrupted stitches that forgot to stop and tie.
Anchor at one end
Start at one end (apex) of the wound with a normal simple interrupted stitch and tie it securely. This time, cut only the short, needle free tail. Leave the long needle end attached - that is your running strand.
Run without tying
Re enter 3 to 5 mm from the edge, about 5 mm along the wound. Pass through both sides with equal bites, just like interrupted, but do not tie or cut. Pull through and keep gentle, even tension.
Keep the pattern even
Repeat at even intervals. Externally the thread should look diagonal and evenly spaced like railroad ties or a baseball stitch. Internally it runs more horizontal. Keep each bite the same depth and distance or the wound will scallop.
Hold your tension
After each pass, hold the strand taut with your non dominant hand or have an assistant follow you. If you let go, the whole line loosens. Snug each throw to approximate, never to blanch.
Finish with a loop tie
On your last pass, do not pull the thread all the way through - leave a loop. Use that loop as your short tail and tie your instrument knot against the needle end. That locks the whole line. Trim both ends.
Know the locked variant
Running locked: pass the needle through the previous loop before pulling tight on each stitch. It gives better hemostasis (helps with oozing edges) and stops loosening, but can strangle tissue if cranked tight. Most beginners learn unlocked first.
When to choose it
- ✓ Long, straight, low tension wounds and surgical incisions
- ✓ When speed matters and edges already line up well
- ✓ Scalp and other areas where even tension helps hemostasis (locked version)
- × Avoid when infection risk is high or you may need to remove part of the closure
- × Avoid on irregular or high tension wounds while learning
Common mistakes preceptors flag
- × Uneven spacing - bunching in one spot, gaps in another
- × Losing tension mid run so early stitches go loose
- × Pulling tighter as you go and purse stringing the wound
- × Forgetting to leave a loop on the final pass, so there is nothing to tie to
Memory hook
"Anchor, run even, hold tension, loop to finish."
If spacing and tension stay even, the scar stays even.
Vertical Mattress Suture
Far-far, near-near. A deep, wide bite takes the tension, then a shallow bite close to the edge on the way back everts the skin. The best eversion of any stitch here, and a lifesaver when edges want to roll inward or the wound is under tension.
Video 1 of 7 · YouTube - BMJ Learning, Vertical Mattress
Short, timestamped, and OSCE friendly: needle grip, the backhand near-near pass, and the knot, with a 3D view of what the thread does under the skin.
Video 2 of 7 · YouTube - Suture Mentor, Dr. David Naysmith
Full narrated lesson with transcript on the Suture Mentor site. Best for understanding why you would pick this stitch instead of a simple interrupted.
Videos 3 to 7 - one more lesson, a real TikTok, and three Reels
Tap any row to watch it on its own platform.
Mix for this technique: 3 YouTube lessons + 1 TikTok + 3 Instagram Reels = 7, every one teaching the vertical mattress specifically.
Step by step
One stitch, two layers, knot ends up back where you started.
Far - first side, deep and wide
Enter at 90 degrees about 5 to 8 mm from the edge, go deep through the dermis. Wider and deeper than a simple interrupted bite, this is the bite that carries the tension.
Far - exit the other side
Come out the opposite side the same distance from the edge, about 5 to 8 mm, at the same depth. Far to far, mirror image.
Reverse the needle (backhand)
Reload the needle so it points back the way you came. Beginners: take this as a separate pass, exactly like the TikTok in Video 4 shows.
Near - shallow bite back across
Re enter on the exit side only 1 to 3 mm from the edge, take a shallow, superficial bite just under the skin surface across the wound.
Near - exit on the starting side
Exit 1 to 3 mm from the edge on your original side. Both thread ends are now on the same side, ready to tie.
Tie gently and watch it evert
Tie your usual 2-1-1 flat knot on the starting side. As it snugs down, the edges should pop up and evert. Snug only, this stitch strangulates faster than any other if you crank it.
When to choose it
- ✓ Edges that invert or roll inward, like on the back, neck, or concave areas
- ✓ Wounds under tension, swollen wounds, or thick skin
- ✓ Poorly supported or mobile skin that needs a strong, deep hold plus eversion
- × Avoid where blood supply is fragile or on very delicate skin, the deep loop can compromise it
- × Avoid as your default, it is slower and leaves more marks than a simple interrupted
Common mistakes preceptors flag
- × Near bite taken too deep, so nothing everts
- × Far and near distances swapped, shallow wide and deep narrow
- × Tying too tight, edges blanch inside the loop
- × Forgetting to reverse the needle, then fighting the backhand pass
Memory hook
"Far-far, near-near. Deep takes tension, shallow everts."
If you can only remember two words per stitch, these are the two for this one.
Horizontal Mattress Suture
Think rectangle. Two simple interrupted passes placed side by side in parallel, tied as one stitch. It spreads tension across a wide bridge of skin, everts well, and is a favorite for fragile skin and palms. Its weakness is the same as its strength: that loop can strangle the tissue inside it if tied too tight.
Video 1 of 7 · YouTube - Geeky Medics, Horizontal Mattress OSCE Guide
The matching Geeky Medics guide for this stitch: square shaped suture, knot lying parallel to the wound, taught the way a skills check scores it.
Video 2 of 7 · YouTube - Oxford, Horizontal Mattress
Clear textbook demo of the rectangle: in, across, shift down the wound, back across, tie on the starting side.
Videos 3 to 7 - one more lesson, a real TikTok, and three Reels
Tap any row to watch it on its own platform.
Mix for this technique: 3 YouTube lessons + 1 TikTok + 3 Instagram Reels = 7, every one teaching the horizontal mattress specifically.
Step by step
Two parallel passes, one knot. If it does not look like a rectangle, it is not a horizontal mattress yet.
First pass, like a simple interrupted
Enter at 90 degrees about 5 mm to 1 cm from the edge, pass deep across the wound, exit the far side the same distance from the edge.
Shift down the wound on the far side
Move about 5 mm to 1 cm along the wound on that same far side. This gap between passes is the long side of your rectangle, keep it tidy and parallel.
Second pass, straight back across
Re enter on the far side and pass back across at the same depth and distance, exiting on your original side. The thread on top should now show two parallel lines.
Tie on the starting side
Both ends are back where you started. Tie your 2-1-1 flat knot there, sitting parallel to the wound.
Check the bridge before you trim
The loop of skin inside the rectangle should look pink and everted, not pale or blanched. If it is pale, it is too tight, redo it looser. Trim tails as usual.
When to choose it
- ✓ Fragile or thin skin that a single stitch might tear through
- ✓ Palms, soles, and other thick, glabrous skin, and wounds under some tension
- ✓ When you want eversion plus tension spread over a wider area, and one stitch doing the work of two
- × Avoid in cosmetically sensitive areas if you can, it can leave cross hatch (railroad track) marks
- × Avoid on tissue with borderline blood supply, and plan earlier removal than usual
Common mistakes preceptors flag
- × Cranking the knot tight and strangling the skin bridge inside the loop
- × Passes not parallel, so the rectangle twists and puckers
- × Two passes too close together, losing the tension spreading benefit
- × Leaving it in too long on delicate skin, track marks set in
Memory hook
"Rectangle. Two parallel passes, knot on the start side, never crank it."
Horizontal spreads it sideways, vertical stacks it deep. That one line separates the two mattress stitches in every exam.
All four - which one, when?
Preceptors love asking this out loud. The first table is the classic head to head, the cards under it place the two mattress stitches.
Vertical mattress in one line
Pick it when edges invert, skin is thick or under tension, and you need maximum eversion from a single stitch. Watch out: slowest of the mattress pair to place, can compromise fragile blood supply, tie gently.
Horizontal mattress in one line
Pick it when skin is fragile, on palms or soles, or tension needs spreading across a wide bridge. Watch out: the loop can strangle the bridge and leave track marks, remove earlier on delicate skin.
| Simple Interrupted | Continuous / Running | |
|---|---|---|
| How it is built | Each stitch tied and cut separately | One strand, knot at start and end only |
| Speed | Slower, more knots and cutting | Faster for long wounds |
| Tension control | Best - adjust each stitch on its own | Even distribution, but harder to adjust one spot |
| If one part fails | Other stitches still hold | Whole line can loosen or unravel |
| Infection / drainage | Safer - remove a single stitch to drain | Riskier - removing means opening the line |
| Best wounds | Irregular, contaminated, higher tension, most lacerations | Long, straight, clean, low tension incisions |
| Scar / cosmesis | Excellent with precise bites | Good when spacing is even, can leave diagonal marks if too tight |
Your practice plan
Watching does not build the skill, reps do. Short daily sessions beat a single long one, especially with NP school on top of everything else.
7 session starter plan
- 1Session 1: Instrument ties only. 20 ties, focus on flat square knots.
- 2Session 2: Interrupted only. One straight line, center out, equal bites.
- 3Session 3: Interrupted again, timed but not rushed. Photo your line and compare spacing.
- 4Session 4: Add continuous. Anchor, run, loop tie. Do 3 full lines.
- 5Session 5: Vertical mattress. Far-far deep, near-near shallow, in two passes until the backhand feels normal.
- 6Session 6: Horizontal mattress. Rectangles only, check the bridge stays pink after every knot.
- 7Session 7: Mix all four on one pad, name each stitch out loud before you place it, then take the quiz below.
Rep counter - for today
Tap after you finish a full stitch or a full running line. It resets when you leave the page, it is just for focus today.
Goal today: 10 clean reps. Quality over speed.
Before a real patient - safety pause
- ✓ Consent, allergies (including latex and anesthetic), tetanus status
- ✓ Anesthetize, irrigate thoroughly, inspect for foreign body and deeper injury
- ✓ Sterile field, correct suture size for the site (finer for face, stronger for high tension)
- ✓ Aftercare plan: wound care, return precautions, removal timing by location
This page teaches technique on a pad. Real wound care always follows your program and supervising clinician guidance.
What size suture should I use? Quick orientation, not a rule
When do sutures come out? The timing everyone asks
How do I get faster without getting sloppy?
16 question quiz
Tap an answer for instant feedback. Read the explanation even when you get it right, that is where the preceptor pearls live.
Your one page cheat sheet
Load 2/3 - Enter 90° at 3-5 mm - Curve through - Mirror out - Leave 3 cm tail - Tie 2-1-1 flat - Slide knot aside - Trim 5-6 mm - Space 5 mm apart - Start in the middle
Anchor like interrupted - Cut only the short tail - Run even diagonal stitches - Hold tension as you go - Do not tie between passes - Leave a loop on last pass - Tie loop to needle end - Trim
Far: enter 5-8 mm, deep, across, exit matched - Reverse needle - Near: re enter 1-3 mm, shallow, back across - Exit on start side - Tie 2-1-1 gently - Edges must evert, never blanch
Pass across at 5 mm to 1 cm - Shift 5 mm to 1 cm down the wound - Pass straight back - Rectangle on top - Tie on start side - Bridge inside must stay pink