The Healing Process

The Healing Process Guidelines for Choosing the Proper Modality

Choosing the Proper Modality • How do you know what to use, and how do you know when to use it? • Theoretical knowledge • Practical experience *You can’t follow the same recipe for every patient; avoid “cookie cutter” treatment plans

Modalities in a POC • Modalities should be an adjunct to TEs • ROM and strengthening TEs are the desired end goal • Rehab protocols and progressions must be based primarily on the physiologic responses of the tissues to injury and on an understanding of how various tissues heal • What does this mean? • The therapist must understand the healing process in order to choose the proper modality at the proper time

Modalities in a POC • Decisions on how and when modalities may be best used relies upon: • Recognition of signs and symptoms • Awareness of the time frames associated with the various phases of the healing process • Important to note that the healing process is a continuum • 3 phases are identified • Phases of the healing process overlap and have no true definitive beginning or end points

Phases of Healing • 1. Inflammatory response phase • 2. Fibroblastic-repair phase (granulation) • 3. Maturation-remodeling phase (contraction)

Phase I – Inflammatory Response - Vocabulary • Leukocyte – white blood cell; scavengers and infection fighters • Phagocyte – a cell that engulfs and absorbs waste material, harmful microorganisms, or other foreign bodies in the bloodstream and tissues • Phagocytosis – the process by which certain cells (leukocytes and phagocytes) engulf and destroy microorganisms and cellular debris • Exudate – fluid with a high protein and cellular debris content that has escaped vessels and been deposited in tissues , usually as a result of inflammation • Anemia – reduction of blood components • Hyperemia – excess of blood in a part • Chemical mediators – (histamine, leucotaxin, necrosin) chemicals that limit the amount of exudate and swelling following injury • Secondary hypoxic injury – Disruption of blood flow to the injury site and surrounding uninjured tissue that causes hypoxia and can lead to further tissue damage

Phase I - Inflammatory Response • Once a tissue is injured, the process of healing begins immediately • Destruction of tissue = injury to cells • Cellular injury results in the release of materials (fluid, other cells, wastes) that initiate the inflammatory response • Characterized by redness, swelling, tenderness, and increased temperature

Phase I – Inflammatory Response • Inflammation is a process where leukocytes, other phagocytes, and exudate are delivered to the injured tissue • Protective reaction • Serves to localize or dispose of injury by-products (blood, damaged cells) through phagocytosis • Sets the stage for repair of damaged tissue

Phase I – Inflammatory Response • The immediate response to damage is constriction of the walls of the vessels (spasm) • Lasts 5-10 minutes • Presses the inner walls of the vessels together to cause local anemia • This is followed by rapid hyperemia as the spasm reverses into dilation of the vessels • Eventually the flow slows and stagnates • The initial movement of exudate into the tissues usually lasts 24-36 hours (Swelling)

Phase I – Inflammatory Response • Swelling – Good or bad? • Good • The exudate brings cells to the injured area that help to eliminate dead cells, tissue, etc. • It also helps to “splint” the area to limit movement • Bad • Painful; ROM limitations; spasm; limits blood flow • Can cause secondary hypoxic injury • The disruption of blood flow to the injured and surrounding healthy tissue causes hypoxia • Hypoxia (lack of oxygen) causes pain, spasm, and further tissue damage

Phase I – Inflammatory Response • Chemical mediators limit the amount of exudate and swelling • Histamine, leucotaxin, and necrosin • Histamine – causes vasodilation and increased cell permeability • Leucotaxin – assistsfluid and WBC to move through cell walls to form exudate • Necrosin – responsible for phagocytic activity • *Chemical mediators allow for just enough exudate formation and delivery, but not too much*

Phase I – Inflammatory Response • Platelets do not normally adhere to vessel walls • Good thing, or we would form clots within blood vessels all the time! • Disruption of vessel walls allows platelets and leukocytes to adhere to the damaged spot • This forms a plug to block lymph drainage and localize the injury response • Lastly the damaged cells release a protein that helps to form a fibrin clot that shuts off blood supply to the injured area • Clot formation begins around 12 hours after injury and is completed by 48 hours

Phase I – Inflammatory Response • This combination of factors walls the injured area off during this stage • The leukocytes phagocytize most of the debris toward the end of the phase, which sets the stage for the fibroblastic phase • The initial inflammatory response phase lasts for approximately 2 to 4 days following injury

Phase II – Fibroblastic-Repair - Vocabulary • Collagen – the major protein of the white fibers of connective tissue, cartilage, and bone; “the glue that holds the body together” • Fibroblast– an immature, fiber-producing cell • Fibroplasia – period of scar formation • Granulation tissue – delicate connective tissue consisting of fibroblasts, collagen, and capillaries

Phase II – Fibroblastic-Repair • Fibroplasia begins within the first few hours following injury and may last for as long as 4 to 6 weeks • Production and regeneration of tissues leads to scar formation and repair of injured tissue • During this period many of the s/s associated with the inflammatory response subside • Patients typically still report some tenderness and pain with certain stressful movements • As scar formation progresses, tenderness and pain gradually subside

Phase II – Fibroblastic-Repair • Inflammation causes a lack of oxygen to the injured area (hypoxia) • The body responds by growing new capillaries to deliver oxygenated blood • Along with increased blood and oxygen delivery comes nutrients essential for tissue regeneration in the injured area • The fibrin clot begins to break down as new capillaries grow

Phase II – Fibroblastic Repair • The delivery of the nutrients, plus the breakdown of the fibrin clot, causes formation of granulation tissue • Fills in the gaps during the healing process • The fibroblasts in the granulation tissue begin to (perform magic to) form the immature scar tissue • On day 6 or 7 they also begin depositing collagen fibers throughout the scar tissue • Collagen fibers increase tensile strength of the scar • As tensile strength increases, the number of fibroblasts decreases to signal the beginning of the next phase of healing

Phase III – Maturation-Remodeling • The is a long-term process • Features realignment or remodeling of the collagen fibers that make up the scar tissue according to the tensile forces to which the scar in subjected • Ongoing process of breakdown and synthesis of collagen that causes an increase in tensile strength of the scar

Phase III – Maturation-Remodeling • With increased stress and strain the collagen fibers realign in a position of maximum efficiency parallel to the lines of tension • The tissue gradually assumes a normal appearance and function • Rarely as strong as uninjured tissue • Usually by the end of approximately 3 weeks a firm, strong, contracted, nonvascular scar exists • The maturation phase of healing may require several years to be totally complete

Factors That Impede Healing • Extent of the injury • Determines extent and length of the inflammatory response • Microtears • Involve only minor damage • Most often associated with overuse • Macrotears • Involve significantly greater destruction of soft tissue • Result in clinical symptoms and functional alterations • Generally caused by acute trauma

Factors That Impede Healing • Edema • Increases pressure caused by swelling slows the healing process via: • Separation of tissues • Inhibiting neuromuscular control • Impeding nutrient delivery in the injured part • This is why edema control is so important during initial first aid

Factors That Impede Healing • Hemorrhage • Even the smallest amount of damage to the capillaries causes bleeding • Produces the same negative effects as edema • The presence of bleeding produces additional tissue damage and thus makes the injury worse

Factors That Impede Healing • Poor vascular supply • Tissues that have a poor blood supply heal poorly and slowly • Related to: • Lack of nutrient delivery • Failure in delivery of phagocytic cells and fibroblasts necessary for formation of scar tissue

Factors That Impede Healing • Separation of tissue • Physical separation of the edges of the wound • A wound with smooth edges and good approximation will usually heal with minimal scarring • A wound with jagged, separated edges must heal by filling in the gaps with granulation tissue, resulting in excessive scarring

Factors That Impede Healing • Muscle spasm • Spasms cause pull on both ends of the wound, separating the ends and disallowing approximation • Spasms can cause swelling and lack of blood flow

Factors That Impede Healing • Atrophy • Wasting away of muscle tissue begins immediately with injury • Strengthening and early movement of the injured structure minimizes atrophy

Factors That Impede Healing • Corticosteroids • Use of corticosteroids in early stages of healing can inhibit fibroplasia, capillary formation, and collagen synthesis

Factors That Impede Healing • Keloids and hypertrophic scars • Keloids occur when the rate of collagen production exceeds the rate of collagen breakdown during the maturation phase • Leads to hypertrophy of scars

Factors That Impede Healing • Infection • The presence of bacteria in the wound can delay healing • Often causes excessive granulation tissue and large scars

Factors That Impede Healing • Humidity, climate, oxygen tension • Humidity increases the process of forming epithelium • A moist wound promotes the migration of the necrotic tissue to the surface where it is shed • Oxygen tension relates to optimal oxygen saturation and maximal tensile strength development

Factor That Impede Healing • Health, age, and nutrition • Elastic qualities of skin decrease with age • Degenerative diseases also affect wound healing • Nutrition greatly affects wound healing • Vitamins C (scurvy), K (clotting), and A & E (collagen synthesis) • Zinc (enzyme systems) • Amino acids (cell walls)

Injury Management Using Modalities • No matter how old an injury is, it should be classified according to the signs and symptoms (acute vs. chronic) • If the classic s/s of inflammation are present, treat injury as if it is in the inflammatory response phase • S/S of active inflammation present = acute injury • S/S are no longer present = chronic injury

Injury Management Using Modalities • Based upon this definition of acute and chronic, the rehab progression following injury will be based upon 4 phases: • 1. Initial acute • 2. Inflammatory response • 3. Fibroblastic-repair • 4. Maturation-remodeling • The phases overlap, and time frames vary between patients

Initial Acute Injury Phase • Modality use should be directed toward limiting swelling and reducing pain • Cryotherapy (+ elevation) • Compression (+ elevation) • Electrical stimulation • Ultrasound • Laser • (Rest – 48-72 hours)

Initial Acute Injury Phase • Cryotherapy – reduce swelling and pain • Ice bags, cold packs, ice massages • Not cold baths or cold whirlpools • Most important function is to produce analgesia • Should be used with elevation

Initial Acute Injury Phase • Compression (+ elevation) • Intermittent compression (pumping action) • Compression + cold = better • Compression + cold + elevation = best

Initial Acute Injury Phase • Electrical stimulation • Used to address pain in this phase • Avoid intensities that cause muscle contraction as it may increase clotting time

Initial Acute Injury Phase • Ultrasound • Can be used to facilitate healing when used immediately after injury through the 1st 48 hours • Lower intensities produce nonthermal effects that alter cell membrane permeability to ions that aide in healing

Initial Acute Injury Phase • Low-power laser • Effective in pain modulation • Low power is used so as not to cause tissue death

Inflammatory Response Phase • Begins as early as day 1 and may last as long as day 6 post injury • Goals similar to initial acute injury phase • Cryotherapy • Important to not switch to heat modalities too early • May use contrast baths with longer cold to hot ratio • Compression, e-stim, l-p laser

Inflammatory Response Phase • After initial acute injury phase, the patient should work on AROM and PROM • Exercise progression determined by injury’s response to exercise • If s/s of inflammation increase with exercise, reduce intensity • Aggressive rehab is desirable, but will always be limited by the healing process

Fibroblastic-Repair Phase • As early as day 4 post-injury and may last a few weeks • Swelling has usually stopped • Tenderness remains with touch and ROM exercises • Modalities include: • Cryotherapy => Thermotherapy • Compression • E-stim • Low-power laser • ROM and strengthening exercises

Fibroblastic-Repair Phase • Treatments may switch from cold to heat • Use swelling as an indicator • Thermotherapy increases circulation to an area to promote healing and reduce pain • Includes moist hot packs, paraffin, fluidotherapy, and warm whirlpool

Fibroblastic-Repair Phase • Intermittent compression – facilitates removal of by-products from area • E-stim – now used to elicit muscle contraction for a muscle pumping action to aid in lymphatic flow and to reduce pain • Low-power laser to reduce pain

Maturation-Remodeling Phase • May last several years • Main goal is to return to activity • The collagen fibers must be realigned according to tensile stresses and strains placed upon them • Most to all modalities are typically safe to use in this phase • Massage is particularly effective in this phase to assist in scar remodeling

Maturation-Remodeling Phase • Thermotherapy • Deep heating most beneficial • Ultrasound, shortwave and microwave diathermy • Increased blood and lymphatic flow • Superficial heating less effective, though helpful for pain and flexibility • E-stim • Pain modulation • Muscle contractions for increasing ROM and strength • Low-powered laser • Pain modulation

The Healing Process