Merck Manual

Please confirm that you are a health care professional

honeypot link

How To Repair a Laceration With Horizontal Mattress Sutures


Matthew J. Streitz

, MD, San Antonio Uniformed Services Health Education Consortium

Last full review/revision Mar 2021| Content last modified Mar 2021
Click here for Patient Education
Topic Resources

The horizontal mattress suture uses a simple suture bite followed by a reverse bite adjacent to the first to create a single broad suture that achieves wound approximation and epidermal eversion without constricting the wound edge.

The mattress sutures (both vertical and horizontal) are commonly used to close wounds under tension. Because the suture is looped through the skin lateral to the wound (rather than over the wound), tension is transferred away from the wound edges to the looped lateral skin. Additionally, by having the sutures cross under (rather than over) the laceration, eversion of the edges occurs when the suture is tightened.

The horizontal mattress suture is useful in areas where there is little subcutaneous dermal tissue, making wound edge eversion difficult. Approximation is achieved without causing constriction or tension (and subsequent ischemia, necrosis, or tearing) of the wound edges. Because the second bite is parallel to the first, about half as many sutures are needed to close a wound.


  • Lacerations of volar surfaces of hand and fingers, where simple interrupted sutures may cut through the skin

  • Some wounds under tension, instead of a layered closure, if skin tension is not marked

  • Parallel lacerations

  • Scalp lacerations or lacerations with edges that are macerated, irregular, or have thick or thin edges


Absolute contraindications

  • None

Relative contraindications

  • Wounds under marked tension

  • Wounds that may be contaminated or relatively old and would be at higher risk of infection if closed by sutures, such as small bites to hands or feet, puncture wounds, or high-velocity missile wounds

Wounds involving deep structures (eg, nerves, blood vessels, ducts, joints, tendons, bones) may require specialized techniques or referral to a surgical specialist, as should those covering large areas or involving the face or hands.


  • Infection

  • Cutting or scarring due to pressure on the skin from the sutures

  • Dermal ischemia and necrosis, which occur more often than with simple or continuous sutures


Wound hygiene and closure techniques need not be sterile procedures. Although instruments that touch the wound (eg, forceps, needles, suture) must be sterile, clean nonsterile gloves as well as clean but not sterile water may be used in immunocompetent patients. Some operators prefer the better fit and better barrier protection of sterile gloves.

Clean procedure, barrier protection

  • Face mask and safety glasses (or a face shield), head caps, gowns, gloves

  • Sterile drapes, towels (for wound debridement and suturing)

  • Needle driver, toothed forceps, suture material; typically, a nonabsorbable monofilament suture is used. (For detailed discussion of the various types and sizes of suture material, refer to Lacerations.)

  • Antiseptic solution (eg, chlorhexidine, povidone-iodine), sterile gauze squares

  • Sometimes splinting or other materials (for aftercare, to restrict motion or skin tension that may pull on the sutures)

  • Materials used to dress the wound

Additional Considerations

  • The half-buried horizontal mattress suture, a variation of the horizontal mattress suture, can be used to close flap lacerations.


  • Position the patient comfortably reclined or supine.

  • Adjust the stretcher height so that you will be comfortable either sitting or standing at the bedside.

  • In general, position yourself so that the laceration is roughly parallel to the front of your body.

  • The laceration should be well lit, preferably with an overhead procedure light.

Step-by-Step Description of Procedure

(See How To Cleanse, Irrigate, Debride, and Dress Wounds for step-by-step descriptions of wound preparation and anesthesia; see How To Repair a Laceration With Simple Interrupted Sutures for instructions on how to handle the instruments, work with needles, and tie a surgeon's knot using instruments.)

  • Cleanse, anesthetize, irrigate, and debride the wound as necessary.

  • Place a sterile fenestrated drape over the wound. Place additional drapes nearby as needed to provide a large enough sterile work area.

Horizontal mattress suture

  • Place the first pass of the needle as you would a simple interrupted suture, but insert the needle into the skin a bit farther (eg, 0.5 to 1 cm) from the wound edge.

  • Push the needle through both wound edges in a single bite if this can be done with little resistance. If resistance is significant or if the laceration is relatively wide (eg, as may occur with the first suture), push the needle through each wound edge separately. To do this, pull out the needle from the wound after it passes through the first wound edge and then reattach it to the needle driver and continue with a second bite into the opposite side of the wound and exit 0.5 to 1 cm from the other wound edge. The entry and exit points of the first pass should be symmetric on both sides of the wound.

  • Reverse the direction of the needle in the needle driver.

  • Place the second (reverse) pass, beginning on the same side of the laceration and inserting the needle 0.5 cm next to the exit site of the first pass. The second pass should be identical but parallel to the first pass.

  • Pull gently on the suture ends to achieve wound approximation and epidermal eversion.

  • Tie the suture closed.

Horizontal mattress suture

The needle and suture follow a path from point 1 to point 4, as described in the Step-by-Step Description of Procedure.

Horizontal mattress suture

Half-buried horizontal mattress suture

Also referred to as a tip suture or corner suture, the half-buried horizontal tip suture can be used to approximate the tip of flap laceration into the corner of a V- or Y-shaped laceration if the edges cannot be satisfactorily aligned even with undermining. The suture loop in the flap tip remains entirely intradermal (ie, buried). Because there is no external skin loop, epidermal tension on the flap tip is minimized.

  • Align the flap with the sides of the wound.

  • Place the first bite by inserting the needle into the skin about 0.5 to 1 cm below and lateral to the apex of the V-shaped wound and advance it intradermally until it emerges from the dermal layer into the wound.

  • Keeping the needle on a parallel intradermal path, insert it through the tip of the flap.

  • Insert the needle through the opposite side of the wound and at the same distance and depth as the first bite.

  • Pull gently on the suture ends to draw the flap tip into the V apex, approximating and everting the wound edges.

  • Tie the suture.

  • If excessive tension prevents apposition of the flap to the apex of the laceration, the wound will now appear as a Y (with the half-buried mattress suture at its center). The rest of the laceration (including the shaft of the Y, if present) can be closed as any other laceration.


  • Splint joints whose movement will cause wound tension (eg, an elbow splint for a dorsal elbow laceration).

  • Instruct the patient to keep the dressing dry and in place and to return in 2 days for a wound check.

  • Instruct the patient to return if signs of infection develop (eg, increased pain, swelling, redness, fever, proximally spreading red streaks [infectious lymphangiitis]).

  • Instruct the patient when to return for suture removal, which is generally based on the wound site: 3 to 5 days for the face, 6 to 10 days for the scalp and trunk, 10 to 14 days for the arms and legs, and 14 days for wounds overlying joints. Early suture removal risks wound dehiscence; however, to decrease scarring and cross-hatching of facial sutures, half of the suture line (ie, every other suture) may be removed on day 3, and the remainder are removed on day 5.

Flap laceration repair

A half-buried horizontal mattress suture (described in text) can be used to close flap lacerations. The dotted lines indicate intradermal placement.

Flap laceration repair

Warnings and Common Errors

  • Avoid overly tight sutures and use cautery sparingly because both can cause tissue ischemia.

Tips and Tricks

  • For the half-buried horizontal mattress suture, carefully align the tip of the flap with the notch from which it came.

Click here for Patient Education
NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version
Professionals also read

Also of Interest