Understanding and Managing Healing Process through Rehabilitation Rehabilitation Techniques for Sports Medicine and Athletic Training William E. Prentice

Introduction Rehabilitation requires sound knowledge and understanding of tissue healing process Athletic Trainer designs, implements and supervises rehab programs Rehab protocols and progressions must be based on physiologic responses of tissues to injury and understanding of how various tissues heal

Introduction Primary Injury Secondary Injury Injury from acute or chronic trauma Secondary Injury Inflammatory response to primary injury

3 Phases of Tissue Healing Inflammatory –response phase Fibroblastic-repair phase Maturation-remodeling phase Healing process is a continuum and phases overlap one another with no definitive beginning or end points

Inflammatory-Response Phase After injury, healing process begins immediately Destruction of tissue produces direct injury to cells of various soft tissue Characterized by redness, swelling, tenderness and increased temperature Critical to entire healing process

Inflammatory-Response Phase Leukocytes and other phagocytic cells delivered to injured tissue Dispose of injury by-products through phagocytosis

Inflammatory-Response Phase Vascular reaction Blood coagulation and growth of fibrous tissue occurs First 5-10 minutes vasoconstriction occurs Best time to evaluate Followed by vasodilation Effusion of blood and plasma last 24 to 36 hours Chemical mediators Released from damaged tissue, white blood cells and plasma Histamine, leukotrienes and cytokines assist in limiting exudate/swelling Amt of swelling directly related to extent of vessel damage

Inflammatory Response Con’t Formation of Clot Platelets adhere to collagen fibers and create sticky matrix Platelets and leukocytes adhere to matrix to form plug Clot formation occurs 12 hours after injury and is complete w/in 48 hrs Set stage for fibroblastic phase Chronic inflammation Acute phase dos not respond sufficiently to eliminate injury agent and restore tissue to normal physiologic state Damage occurs to connective tissue and prolongs healing and repair process Response to overuse and overload

Inflammatory Response Con’t Entire phase last 2-4 days Greater tissue damage longer inflammatory phase NSAIDS may inhibit inflammatory response thus delaying healing process Will assist with pain and swelling

Fibroblastic-Repair Phase Proliferative and regenerative activity leads to scar formation Begins w/in 1st few hours after injury and can last as long as 4-6 weeks Signs and Symptoms of inflammatory phase subside Increased O2 and blood flow deliver nutrients essential for tissue regeneration

Fibroblastic-Repair Phase Break down of fibrin clot forms connective tissue called granulation tissue Consist of fibroblast, collagen and capillaries Fills gap during healing process Unorganized tissue/fibers form scar Fibroblast synthesize extracellular matrix consisting of protein fibers (Collagen and Elastin) Day 6 –7 collagen fibers are formed throughout scar Increase in tensile strength increases with rate of collagen synthesis

Fibroblastic-Repair Phase Importance of Collagen Major structural protein that forms strong, flexible inelastic structure Type I, II & III Type I found more in fibroblastic repair phase Holds connective tissue together and enables tissue to resist mechanical forces and deformation Direction of orientation of collagen fibers is along lines of tensile strength

Fibroblastic-Repair Phase Importance of Collagen Mechanical properties Elasticity Capability to recover normal length after elongation Viscoelasticity Allows slow return to normal length and shape after deformation Plasticity Allows permanent change and deformation

Maturation-Remodeling Phase Long term process that involves realignment of collagen fibers that make up scar Increased stress and strain causes collagen fibers to realign to position of maximum efficiency Parallel to lines of tension Gradually assumes normal appearance and function Usually after 3 weeks a firm, contracted, nonvascular scar exist Total maturation phase may take years to be totally complete

Maturation-Remodeling Phase Wolf’s law Bone and soft tissue will respond to physical demands placed on them Remodel or realign along lines of tensile force Critical that injured structures are exposed to progressively increasing loads throughout rehab process As remodeling phase begins aggressive active range of motion and strengthening Use pain and tissue response as a guide to progression

Maturation-Remodeling Phase Controlled mobilization vs. immobilization Animal studies show Controlled mob. Superior to Immobilization for scar formation However, some injuries may require brief period of immob. During inflammatory phase to facilitate healing process

Factors that impede healing Extent of injury Microtears vs. macrotears Edema Increased pressure causes separation of tissue, inhibits neuro-muscular control, impedes nutrition, neurological changes Hemorrhage Bleeding causes same neg. effect as edema Poor vascular supply Tissues with poor vascular supply heal at a slower rate Failure to deliver phagocytic cells and fibroblasts for scar formation

Factors that impede healing Separation of tissue How tissue is torn will effect healing Smooth vs. jagged Traction on torn tissue, separating 2 ends Ischemia from spasm spasm Atrophy Corticosteroids In early stages shown to inhibit healing Keloids or hypertrophic scars Infection Health, Age and nutrition

Healing Process-Ligament Sprains Tough, relatively inelastic band of tissue that connects bone to bone Stability to joint Provide control of one articulating bone to another during movement Provide proprioceptive input or sense of joint position through mechanoreceptors 3 Grades of lig. tears

Healing Process-Ligament Sprains Physiology Inflammatory phase-loss of blood from damaged vessels and attraction of inflammatory cells During next 6 weeks-vascular proliferation with new capillary growth and fibroblastic activity Immediately to 72 hours If extraarticular bleeding in subcutaneous space If intraarticular bleeping occurs in inside joint capsule

Healing Process-Ligament Sprains Essential that 2 ends of ligament be reconnected by bridging of clot Collagen fibers initially random woven pattern with little organization Failure to produce enough scar and of ligament to reconnect 2 reasons ligaments fail Maturation May take 12 months to complete Realignment/remodeling in response to stress and strains placed on it

Healing Process-Ligament Sprains Factors that effect healing Surgery or non surgical approach Surgery of extraarticular ligaments stronger at first but may not last over time Non surgical will heal through fibrous scarring , but may also have some instability Immobilization Long periods of immobilization may decrease tensile strength weakening of insertion at bone Minimize immobilization time Surrounding muscle and tendon will provide stability through strengthening and increased muscle tension

Healing Process-Cartilage Rigid connective tissue that provides support Hyaline cartilage: articulating surface of bone Fibro cartilage: interverterbral disk and menisci. Withstands a great deal of pressure Elastic cartilage: more flexible than other types-auricle of ear and larynx

Healing Process-Cartilage Physiology of healing Relatively limited healing capacity Dependant on damage to cartilage alone or subchondral bone. Articular cartilage fails to elicit clot formation or cellular response Subchondral bone can formulate granulation tissue and normal collagen can form

Healing Process-Cartilage Articular cartilage repair Patients own cartilage can be harvested and implanted into damages tissue to help form new cartilage Promise for long term results Fibrocartilage/Menisci Depends on where damage occurs 3 zones of various vascularity Greater that blood supply better chance of healing on own

Healing Process-Bone Similar to soft tissue healing, however regeneration capabilities somewhat limited Bone has additional forces such as torsion, bending and compression not just tensile force After 1 week fibroblast lay down fibrous collagen Chondroblast cells lay down fibrocartilage creating callus At first soft and firm, but becomes more firm and rubbery Osteoblast proliferate and enter the callus Form cancellous bone and callus crystallizes into bone

Healing Process-Bone Osteoclasts reabsorb bone fragments and clean up debris Process continues as osteoblast lay down new bone and osteoclasts remove and break down new bone Follow Wolfs law-forces placed on callus-changes size, shape and structure Immobilization longer 3 to 8 weeks depending on the bone

Healing Process-Muscle Similar to other soft tissue discussed Hemorrhage and edema followed by phagocytosis to clean up debris Myoblastic cells from in the area and regenerate new myofibrils Active contraction critical to regaining normal tensile strength according to Wolff's Law Healing time lengthy-Longer than ligament healing Return to soon will lead to re-injury and become very problematic 6-8 weeks?

Healing Process-Tendon Not as vascular as muscle Can cause problems in healing Fibrous union required to provide extensibility and flexibility Abundance of collagen needed to achieve good tensile strength Collagen synthesis can become excessive can result in fibrosis: adhesions from in surrounding structures Interfere with gliding and smooth movement Tensile strength not sufficient to permit strong pull for 4 to 5 weeks At risk of strong contraction pulling tendons ends apart

Healing Process-Nerve Nerve cell is specialized and cannot regenerate once nerve cell dies Injured peripheral nerve- nerve fiber can regenerate if injury does not affect cell body Regeneration is very slow 3-4 mm /day Axon regeneration obstructed by scar formation Damaged nerve within CNS regenerate poorly compared to peripheral nervous system Lack connective tissue sheath and nerve cells fail to proliferate

Rehabilitation philosophy Choose therapeutic exercises/modalities that facilitate healing process at specific phases Stimulate structural function and integrity of injured part Positive influence on the inflammation and repair process to expedite recovery of function Minimize early effects of inflammatory process including pain, edema control, and reduction of muscle spasm. Produce loss of joint motion and contracture Finally concentrate on preventing reoccurrence of injury by assuring structural stability of injured tissue Appropriate return to play guidelines