The Three Phases of Wound Healing
The correct statement regarding the three phases of wound healing is B. Inflammation, fibroplasia, contracture.
Understanding the Wound Healing Process
According to the most recent and comprehensive evidence, wound healing involves a complex, sequential process that can be organized into distinct but overlapping phases. While some sources describe four phases, the traditional and most widely recognized classification consists of three main phases 1:
Inflammatory Phase
- Begins immediately after injury
- Involves hemostasis (blood clot formation)
- Platelets release growth factors like PDGF, TGF-β, and VEGF
- Neutrophils, monocytes, and macrophages arrive to clean the wound
- Macrophages play a crucial role in debridement and secreting additional growth factors
Fibroplasia Phase (Proliferative Phase)
- Characterized by formation of granulation tissue
- Fibroblasts proliferate and produce extracellular matrix
- Angiogenesis (new blood vessel formation) occurs
- Epithelial cells migrate across the wound surface
- Growth factors like PDGF, FGF-2, and TGF-β stimulate fibroblast proliferation
Contracture Phase (Maturation/Remodeling Phase)
- Final stage of wound healing
- Fibroblasts differentiate into myofibroblasts (crucial for wound contraction)
- Collagen reorganization and cross-linking occurs
- Wound contracts and closes
- PDGF and TGF-β promote fibroblast differentiation into myofibroblasts
Why Other Options Are Incorrect
Option A (Inflammation, epithelization, contracture) is incorrect because epithelialization is a component of the proliferative/fibroplasia phase, not a separate major phase.
Option C (Fibroplasia, epithelization, contracture) is incorrect because it omits the critical inflammatory phase that initiates the healing process.
Option D (Granulation, haemostasis, fibroplasia) is incorrect because hemostasis is part of the inflammatory phase, not a separate major phase, and granulation tissue formation occurs during the fibroplasia/proliferative phase.
Clinical Implications
Understanding the correct phases of wound healing is essential for proper wound management and assessment. Each phase requires specific interventions:
- During inflammation: Focus on preventing infection, removing debris, and supporting the natural inflammatory response
- During fibroplasia: Support granulation tissue formation, maintain moist wound environment, and promote angiogenesis
- During contracture: Monitor for excessive contraction that could lead to contracture deformities, especially over joints
Common Pitfalls in Wound Healing Assessment
- Misinterpreting normal inflammation: The inflammatory phase is essential and should not be suppressed completely
- Confusing granulation with a separate phase: Granulation tissue formation is part of the fibroplasia phase
- Overlooking the importance of myofibroblasts: These specialized cells are crucial for wound contraction during the final phase
Understanding these three phases (inflammation, fibroplasia, and contracture) provides the framework for assessing wound healing progress and implementing appropriate interventions to optimize outcomes and minimize complications that could affect morbidity and mortality.