Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Chapter 5 The Healing Process

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Soft Tissue Healing Follows a predictable sequence –Critical to decisions regarding immediate management, rehabilitation, and return to participation following injury 3 phase process –Acute inflammatory –Proliferative (fibroblastic) –Maturation

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Inflammatory Phase Inflammatory phase (0-6 days) –Acute or chronic inflammation possible –Exudate forms –Mechanisms for stopping blood flow Local vasoconstriction Platelet reaction Coagulation cascade

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Inflammatory Phase (cont’d) Inflammatory Phase (0-6 days) (cont’d) –Signs & Symptoms: Redness Swelling Warmth Tenderness Loss of function

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Inflammatory Phase (cont’d) –Vasodilation brings neutrophils and macrophages to clean the area via phagocytosis –Mast cells release Heparin: thins the blood and prolongs clotting Histamine: promotes further vasodilation Bradykinin: opens the blood vessel walls; causes pain

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Inflammatory Phase (cont’d) –Zone of primary injury Hematoma forms –Edema occurs Increased permeability and pressure within the vessels forces a plasma exudate into the interstitial tissue

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Inflammatory Phase (cont’d) –Zone of secondary injury Interstitial tissues affected by inflammation, edema, and hypoxia Prostaglandins promote further healing and clearing of debris

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Inflammatory Phase (cont’d) Acute inflammatory process

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Proliferation Phase Proliferative phase (3 days – 6 weeks) –Repair and regeneration of tissue –Processes Angiogenesis Fibroplasia Re-epithelialization Wound contraction

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Proliferation Phase (cont’d) –Hematoma reduces for new healing to take place –Scar formation with soft tissue –Accumulated exudate contains fibroblasts that generate new collagen –Newly formed blood supply and support of matrix will determine overall healing of new tissue

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Maturation Phase Maturation phase (3 weeks – 1+ year) –Remodeling of fibrous matrix to form mature scar tissue Decreased fibroblastic activity Increased organization of new tissue Decreased water content Decreased blood flow Resumption of normal cell activity in the area

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Maturation Phase (cont’d) –Scar tissue is fibrous, inelastic, and nonvascular Less functional and flexible than original tissues Tensile strength 3-4 weeks – 25% of normal 4-5 months – 30% below preinjury strength

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Maturation Phase (cont’d) –Remodeling continues for a year or more Collagen fibers become oriented to the tissue’s normal mechanical stress Tensile strength of scar tissue may continue to increase for as long as 2 years post-injury

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Muscle, Tendon, & Ligament – Healing Muscle fibers form adhesions Tendons and ligaments slower to heal Potential for atrophy with immobilization Loss of strength and decreased rates of healing are directly related to length of immobilization Begin strengthening as soon as it’s safe after injury to ensure hypertrophy of healing tissues and decreased reoccurrence of injury

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Bony Tissue Healing 3 phase process –Acute inflammatory (0-4 days) Vasodilation Edema formation The histochemical changes associated with soft tissue inflammation

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Bony Tissue Healing (cont’d) Bone healing

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Bone Tissue Healing (cont’d) –Repair and regeneration Osteoclast and osteoblast activity Bone healing

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Bone Tissue Healing (cont’d) – Maturation and remodeling Bone healing

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Nerve Tissue Healing If nerve is completely severed: –Healing does not occur and loss of function is typically permanent –Random regrowth occurs, resulting in the formation of a neuroma (nerve tumor) –Surgically repair

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Nerve Tissue Healing (cont’d) If nerve fiber ruptures in a tensile injury and the myelin sheath remains intact: –It is possible for a nerve to regenerate –Regeneration is slow (rate of less than 1 mm per day or about 2.5 cm per month)

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Local Factors that Delay Healing Extent (size) of the injury Extent (amount) of hemorrhage and edema Muscle spasm Inflammation Infection Poor blood supply Prolonged immobilization; excessive motion or repeated adverse stress

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Systemic Factors that Delay Healing Poor nutrition Vascular Age Infection Metabolic disorders

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Check for Understanding! Which of the following processes takes place during the inflammatory phase of healing? A.Phagocytosis B.Angiogenesis C.Epithelialization D.Wound contraction

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Check for Understanding! The proliferative phase of healing begins when the size of the hematoma is sufficiently reduced to permit room for new tissue growth. A.True B.False

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Check for Understanding! The strength of scar tissue in the maturation phase is determined by: A.The amount of collagen laid down by the fibroblasts B.The orientation of the collagen fibers C.The vascularity of the tissue D.Fitness level of the individual

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Check for Understanding! Muscles will hypertrophy and atrophy in response to levels of mechanical stress. A.True B.False

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Check for Understanding! During the repair and regeneration of bone tissue, ______ resorb damaged bone tissues. A.Osteoblasts B.Neutrophils C.Macrophages D.Osteoclasts

Copyright © 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins Check for Understanding! Which of the following factors have the potential to delay the healing process? (select all that apply) A.Size of the injury B.Infection C.Poor blood supply D.Age of the individual