Management of Lacerations: Forehead and Knee

General Principles (Both Sites)

Step 1 - Haemostasis

• Apply direct pressure first.
• For scalp/forehead: the area is highly vascular. Control brisk bleeding by clamping vessels at wound edges (e.g. Raney clips) or placing a figure-of-eight suture at the bleeding edge.
• Local anaesthetics with epinephrine help control haemorrhage from small vessels in highly vascular wounds (face, scalp).

Step 2 - Assessment

• Assess for intracranial injury before wound care - a laceration may be part of a bigger injury.
• Palpate gently with a gloved finger to detect galeal involvement or depressed skull fracture. If a palpable depression is found, obtain CT.
• Classify as superficial (frontalis muscle not involved) or deep (frontalis muscle involved) - this determines repair technique.
• Note the orientation relative to skin tension lines. Horizontal forehead lacerations (parallel to tension lines, perpendicular to frontalis) give the best cosmetic results.

• Assess for joint capsule penetration - if the wound communicates with the joint, it requires urgent orthopaedic referral and washout.
• Assess neurovascular status (sensation, capillary refill, pulses) before giving local anaesthetic.
• Look for tendon injury (assess active extension against resistance).
• Exclude foreign bodies, fractures or dislocations with imaging as appropriate.

Step 3 - Anaesthesia

• Topical: lidocaine-epinephrine-tetracaine (LET) or lidocaine-prilocaine (EMLA) - especially useful in children to reduce pain of injection.
• Local infiltration: most commonly used for both sites.
• Nerve block: supraorbital/supratrochlear nerve block for forehead lacerations.

Step 4 - Irrigation and Debridement

• Irrigate all wounds as early as possible with warm normal saline to reduce bacterial contamination and allow better visualisation.
• Debride non-viable tissue until healthy bleeding occurs at wound edges.
  • Healthy subcutaneous fat: yellow and soft.
  • Muscle viability: judged by colour, capacity to bleed, and contractility.
• Do not shave hair on the scalp or eyebrows before closure - it increases infection risk and removes important anatomical landmarks.
• For the forehead, if hair obscures the field, brush it aside or matt it with petrolatum/bacitracin ointment.

Step 5 - Wound Closure

Forehead Laceration

• Close with 6-0 nonabsorbable monofilament simple interrupted sutures or tissue adhesive.
• Place key stitches first to align skin tension lines and the hairline.
• Remove sutures at 5 days to minimize scarring (early removal on the face is important).

• First close muscle fascia with 4-0 absorbable suture (not removed).
• Then close skin with 5-0 or 6-0 nonabsorbable monofilament or tissue adhesive.
• Suture removal at 5 days.

• Suitable for superficial, low-tension wounds on the forehead.
• May need a deep layer first if there is any tension.

• The forehead is one of the sites particularly suited to tape closure.
• Primary indication: superficial, straight laceration under little or no tension.
• Can also be applied after early suture removal to maintain wound edge approximation while reducing risk of permanent suture marks.

Knee Laceration

• The knee is a high-tension, mobile site - closure must account for movement.
• Simple superficial lacerations: 4-0 or 5-0 nonabsorbable monofilament interrupted sutures.
• Deeper lacerations with subcutaneous tissue involvement: layered closure using absorbable suture for subcutaneous layer, nonabsorbable for skin.
• Avoid excessive tension on skin edges - undermining may be needed.
• Do not tape-close over the knee as primary closure (tape fails over joints due to movement).
• If joint capsule is involved: do NOT close in the ED - requires orthopaedic washout.
• Suture removal: typically 10-14 days (longer than face, due to tension and movement).

Step 6 - Tetanus Prophylaxis

• Puncture-type injuries in a contaminated environment
• Bites, compound fractures, wounds containing foreign bodies
• Wounds with systemic sepsis

• Heavy contamination (soil, manure)

• 6-hour delay before surgery

• Extensive devitalised tissue

Step 7 - Dressings and Aftercare

• Apply a non-adherent wound dressing.
• Forehead: pressure dressing over deep scalp lacerations for the first 24 hours post-repair helps prevent wound hematoma formation.
• Knee: padded dressing; advise patient to limit flexion initially to avoid wound dehiscence.
• Keep wound clean and dry for 24-48 hours.
• Wound check at 48 hours in contaminated or complex wounds.
• Antibiotic prophylaxis: for contaminated/dirty wounds, high-risk patients, or wounds with delayed presentation. Not routinely needed for clean lacerations.

Step 8 - Suture Removal Timing

Special Considerations