Wound Healing

Natasha Holder MD, MSc, FRCSCOrthopaedic Oncology Fellow

For Dr. Joel Werier

Objectives

• Describe the pathophysiology of wound healing• Describe the complications of wound healing• Describe how to treat and prevent wound complications• Describe scar formation and clinical treatments for

abnormal scars

What is a wound?

• A wound is a disruption of the normal structure and function of the skin and underlying soft tissue

Wound Classification

• Acute:– normal, healthy individuals heal through an orderly

sequence of physiological events that include hemostasis, inflammation, epithelialization, fibroplasia, and maturation

– Easily identifiable mechanism e.g. trauma• Chronic:

– Physiologic process is altered or stalled– more likely to occur in patients with underlying

disorders such as peripheral artery disease, diabetes, venous insufficiency, nutritional deficiencies, and other disease states

Phases of Wound Healing

• Mediated by the activation of – Keratinocytes– Fibroblasts– Endothelial cells– Macrophages– Platelets

• Organized cell migration and recruitment of endothelial cells for angiogenesis

• Many growth factors and cytokines are also released

Phases of Wound Healing

Phases of Wound Healing

1. Inflammatory2. Proliferative3. Maturation

Phases of Wound Healing

Phases of Wound Healing

Phases of Wound Healing

Impaired Wound Healing

• Occurs due to disruption of the phases of healing– Local tissue ischemia– Neuropathy– Tissue necrosis– Infection– Wound edema

Risk Factors for Non-healing Wounds

• Peripheral Artery Disease

• Diabetes• Chronic venous

insufficiency• Aging• Immunosuppressive

therapy• Sickle cell disease

• Cancer Therapy• Radiation therapy• Spinal cord disease

and immobilization• Malnutrition• Infection• Smoking

Wound Management

1. Primary Closure (Primary Intention)2. Secondary Closure (Secondary Intention)3. Delayed Primary Closure (Tertiary Intention)

Primary Closure

Skin & Subcutaneous

Secondary Wound Closure

Secondary Wound Healing

Granulation: Capillary proliferation, leukocytes, bacteria

Hemostasis

Platelets and Fibrin – Clot, Cytokines

Inflammation

PMN’s and macrophages

Fibroplasia

Macrophages attract fibroblasts New connective tissue matrix

Maturation

Inflammatory cells decrease, angiogenesis stops, Equalization of collagen synthesis & degradation

Contraction

Powerful mechanical forces in the body Ancient peoples: Skin wounds heal & contract

if kept clean & protected with a dressing Skin margins move together to produce a healed wound Contraction can yield a devastating result

in some injuries ie. burns

Severe Contracture

Excision & Full Thickness Skin Grafting

Delayed Primary Closure

Wound is left open due to gross contamination

Delayed Primary Closure

Open Fracture Wounds Open Fracture Wounds

Delayed Primary or Secondary ClosureDelayed Primary or Secondary Closure But Never Primary ClosureBut Never Primary Closure

Wound Complications

Early• Seroma/Hematoma• Dehiscence• Infection• Hernia• Hypertrophic and

Keloid Scars

Late• Hypertrophic scar• Keloid formation• Necrosis• Abscess

Seroma and Hematoma

Seroma• Collection of serous

fluid• Fluctuation, swelling,

redness, tenderness

TREATMENT:• Sterile punture and

compression• Suction drain

Hematoma• Collection of blood –

Bleeding, anticoagulant

• Risk of infection• Swelling, fluctuation,

pain, redness

TREATMENT• Sterile puncture• Surgical exploration

Wound Dehiscence

• Complete breakdown of the wound closure• Systemic Risk Factors:

– Diabetes, Malnutrition, obesity, COPD, steroids, cytotoxic drugs

• Local Risk factors:– Technical error, infection, hematoma, ischemia,

radiation

VAC Assisted therapy

Skin does not grow over exposed dead bone

Gastrocnemius Rotation Flap

Patella

Right: Lateral View

• 70 yr. old male

• 3B Prox. tibia

• Prop injury

Superficial (Cortical) Osteo

Patella

Patella

Left Tibia

• Typically, medial aspect proximal tibia• Medial gastrocnemius is “workhorse”

Gastrocnemius Muscle:Vascular Supply

Branches of popliteal artery

Medial sural artery

Lateral sural artery

Gastrocnemius Rotation Flap

• Medial goes farther

• Midline defect

• Femoral condyles

• Key is to take a slip

of distal tendon Medial Lateral

Antibiotic-Loaded Acrylic Cement Spacer Block

Right Knee-Calf: Medial View

Right Knee Lateral View

Ankle

8 Weeks Later – IV Antibiotics

Type of Healing Here?

Right Knee

Flap Options

Infection

• Superficial versus deep?• Superficial wound infection:

– Treatment: Antibiotics• Deep wound infection:

– Treatment: • identify organism with cultures• surgical exploration (irrigation and debridement)• IV antibiotics based on cultures and ID

consultation

Wound Debridement

• Gentle handling of tissues minimizes bleeding• Control residual bleeding with compression, ligation or

cautery• Dead or devitalized muscle is dark in color, soft, easily

damaged and does not contract when pinched.• During debridement, excise only a very thin margin of

skin from the wound edge

Wound Debridement

• Debride the wound meticulously to remove any loose foreign material such as dirt, grass, wood, glass or clothing.

• With a scalpel or dissecting scissors, remove all adherent foreign material along with a thin margin of underlying tissue and then irrigate the wound again.

Hypertrophic and Keloid Scars

• Excessive tissue response to dermal injury characterized by local fibroblast proliferation and overproduction of collagen

• Overexpression of growth factors, such as transforming growth factor-beta (TGF-beta), vascular endothelial growth factor (VEGF), and connective tissue growth factor (CTGF)

Hypertrophic Scars

• Sites of surgical wounds, lacerations, burns, or inflammatory or infectious skin conditions (eg, acne, folliculitis, chicken pox, and vaccinations).

• They are raised, may be erythematous, and typically do not exceed the margins of the original wound

Keloid Scars

• Raised dermal lesions that extend beyond the boundaries of the original wound and invade the surrounding healthy skin

• Sites of minor injuries to the skin, such as earlobe piercings, or may develop in the absence of an obvious inciting stimulus

Treatment of Hypertrophic and Keloid Scars

• Intralesional Cortisone injection

• Silicone gel sheets

• Pressure therapy• Cyrotherapy• Surgical Excision

Thank You