What is the best suture size to use for a laceration over the knee?

Best Suture Size for Knee Laceration Repair

For lacerations over the knee, use 3-0 or 4-0 absorbable monofilament sutures (such as poliglecaprone or polyglyconate) for deep layer closure and 4-0 or 5-0 non-absorbable monofilament sutures (such as nylon or polypropylene) for skin closure.

Rationale for Suture Selection

The knee is a high-tension, high-mobility joint that requires sutures with adequate tensile strength to withstand mechanical stress during movement while minimizing infection risk and optimizing cosmetic outcomes.

Deep Layer Closure (Fascia and Subcutaneous Tissue)

• Use 3-0 or 4-0 absorbable monofilament sutures for fascial and deep subcutaneous closure 1
• Monofilament sutures are strongly preferred over multifilament (braided) sutures because they cause less bacterial seeding and reduce infection risk 2, 3
• Polyglyconate (Maxon) or poliglecaprone (MONOCRYL) are excellent choices as they provide good tensile strength for high-mobility areas 4
• The smallest suture size that accomplishes the purpose should be chosen to minimize tissue trauma 3

Skin Closure

• Use 4-0 or 5-0 non-absorbable monofilament sutures (nylon or polypropylene) for the final skin layer 1
• Non-absorbable sutures provide sustained tensile strength needed for this high-tension area 3
• Consider 6-0 or 7-0 monofilament for areas requiring finer cosmetic closure if the laceration extends to less mobile regions 1

Suturing Technique Considerations

Layered Closure Approach

• Perform layered closure starting from deep to superficial structures to distribute tension appropriately 5
• The dermis provides the skin's greatest tensile strength, so accurate dermal approximation is critical for wound strength 5
• Use fascial tension reduction sutures to place tension on deep and superficial fascial layers rather than on the dermis itself 1
• Dermal sutures can be minimized or avoided if wound edges approximate naturally under minimal tension 1

Continuous vs. Interrupted Technique

• Continuous non-locking suturing technique is preferred as it distributes tension more evenly across the suture line 2, 4
• This technique results in less pain during healing and reduces analgesic requirements 2
• Avoid locking sutures as they can cause excessive tension leading to tissue edema and necrosis 2

Common Pitfalls to Avoid

• Do not use sutures that are too large for the tissue being repaired, as this increases tissue trauma and foreign material burden 3
• Avoid multifilament (braided) sutures in contaminated or high-risk wounds, as they have higher tissue friction and pose greater risks of infection and suture sinus formation 3
• Do not place excessive tension on sutures in this high-mobility area, as tight sutures can strangulate wound edges and impair healing 4
• Ensure adequate deep layer closure before skin approximation, as fat and muscle do not support sutures well 5

Post-Repair Considerations

• Consider immobilization with a splint or knee immobilizer for extensive lacerations near the joint to reduce tension on the repair 5
• Plan for suture removal at 10-14 days for knee lacerations, as this high-tension area requires longer healing time than facial or upper extremity wounds 5
• Examine the wound 2-3 days after repair for signs of infection, including increasing pain, redness, or discharge 5