AT 359
Chapter 10 Outline - Tissue Response to Injury

3 Phases of Healing Process
1)Inflammatory Response - day 0 to 4 days
2)Fibroblastic Repair - day 4 to 6 weeks
3)Maturation-Remodeling - 6 weeks to 2-3 years

Inflammatory Response Phase
-Process begins immediately after injury
-s/s include: redness, swelling, increased temperature, pain, loss of function
-blood vessels around injured site vasoconstrict the first 10 minutes
-after 10 minutes, vasodilation occurs
-the increase in blood flow to the area creates more swelling around injured site
            -swelling is essential for healing; it carries leukocytes, etc. to injured area
            -the blood around the site starts to stagnate which leads to secondary tissue death
-fibrin clot formation begins 12 hours post-injury and is completed by 48 hours
-if inflammatory phase turns into a chronic one, healing will never occur
            -i.e. tendonitis, one of the most common overuse injuries is an example

Fibroblastic Repair Phase
-scar formation is still on going, should be completed by end of phase in most cases
        -as scar tissue progresses, point tenderness tends to subside
-capillaries start to form in the wound, thus delivering oxygen to the tissues to aid in healing
-granulation tissue begins to form with the breakdown of the fibrin clot
-collagen starts to replace the fibroblasts which in turn, increases the tensile strength

Maturation-Remodeling Phase
-main goal is collagen re-alignment
-the scar tissue (collagen) must be subjected to progressive resistive stress in order to re-align
            -PRE - progressive resistive exercise accomplishes this
-scar tissue is not as strong or as elastic as normal muscle tissue
            -there will always be scar tissue after injury but with proper rehab, the scar tissue will be minimal

Controlled Mobility During the Healing Process
-brief immobilization can aid in healing process by limiting additional swelling which is detrimental
-controlled mobility is better for the healing process than ROM
-if you are too conservative or overly aggressive, the healing process will take longer

Factors that Impede Healing
-Extent of Injury
        -microtears - associated with overuse conditions; minor damage
        -macrotears - associated with acute injuries; significant damage
-Edema
        -delays healing process because of decreased nutrition to tissues, inhibition of neuromuscular control,
                causes separation of tissue
        -this is why RICE is so important - to control and limit swelling as much as possible. 
                -swelling is necessary and good for healing but too much swelling is detrimental
-Hemorrhage
        -can create a pooling of blood which produces a stagnation or "stasis" of surrounding area, thus limiting
                oxygen to surrounding tissues causing secondary tissue damage
-Poor Vascular Supply
        -injured tissues with a poor supply of blood do not heal very well
-Separation of Tissue
        -if wound has smooth edges, it will heal fast with minimal scarring
        -if wound has jagged edges, it will heal slower and with more scarring because it has to "fill the gap"
-Muscle Spasm
        -spasm of the muscle causes traction which pulls on and separates the two damaged ends
-Atrophy
        -wasting away of muscle tissue
        -early strengthening and mobilization decrease atrophy
-Corticosteroids
        -can inhibit certain aspects of healing process; more detrimental than good
-Keloids
        -hypertrophied scars occur when collage production is faster than collagen breakdown
-Infection
        -delays healing, causes increase of granulation tissue which causes large, deformed scarring
-Humidity, Climate and Oxygen Tension
        -keeping a wound moist and sterile will promote faster healing
        -scar formation can be detrimental especially in sports when they get knocked off and they never heal
        -Duoderm actually acts on this principle
-Health, Age and Nutrition
        -skin loses elasticity with age
        -disease such as diabetes can affect wound healing
        -nutrition is critical as well for healing:
                    -vitamin C (collagen synthesis, immune system)
                    -vitamin K (clotting)
                    -zinc (enzyme systems)
                    -amino acids

Cartilage Healing
-if injury is just to articular cartilage and not subchondral bone, healing will not occur
-if injury is to both cartilage and subchondral bone, granulation tissue will form and healing will occur

Ligament Healing
-if extra-articular ligament is damaged, bleeding occurs in a subcutaneous space
-if intra-articular ligament is damaged, bleeding occurs inside the joint capsule
-healing process occurs through regular collagen scar formation

Muscle Healing
-can take longer to heal than ligament damage
-same scar formation process except for myoblastic cells form in area to create myofibrils

Tendon Healing
-requires a fair amount of scar tissue, however, too much collagen synthesis can lead to excessive scar
        formation resulting in adhesions

Nerve Healing
-most tissues cannot regenerate
-healing is slowest in nerve tissue - 3 to 4 millimeters per day

Modification of Soft-Tissue Healing
-Anti-Inflammatory Medications
            -NSAIDS are sometimes used, however, there is controversy over whether or not NSAIDs used
                        acutely interfere with the inflammatory phase, thus delaying healing
-Therapeutic Modalities
            -can use hot or cold therapy to stimulate or inhibit inflammation
-Therapeutic Exercise
            -collagen re-alignment and early mobilization are key in a quick recovery

Bone Healing
-same process as soft tissue except for callus formation
-chondroblasts produce fibrocartilage to make a callus which turns into cartilage
-osteoblasts begin to produce bone which eventually replaces the cartilage
-osteoclasts resorb bone fragments and clean up debris

Complications of Acute Fractures
-poor blood supply - can lead to avascular necrosis
        -occurs when there is a poor blood supply to the broken bone or fragment
        -the bone dies and turns soft, thus allowing other bones to migrate
        -common sites is scaphoid(navicular) bone of wrist and femoral head of femur
-poor immobilization
        -poor casting can permit too much motion causing a non-union or mal-union
-infection
        -bone union cannot heal with infection

PAIN
-an unpleasant sensory and emotional experience associated with actual or potential tissue damage
-main goal is to change athlete's perception of pain
-pain is as much psychological as it is physiological
-acute vs. chronic
-referred pain - myofascial pain (trigger points)?

Nociceptors
-pain receptors (SAME acronym - sensory, afferent; motor efferent)
        -afferent nerve fibers transmit impulses from the nociceptors toward the brain
        -efferent nerve fibers transmit impulses from the brain toward the periphery
       
Different Models of Pain Control
1)Gate Control Theory -
            -non-painful stimulus of large, fast nerves can block painful stimulus of small, slow nerves
            -treatment options: heat, TENS, analgesic balm, massage, ice, interferential current (80-150pps)

2)Central Biasing -
            -mental thoughts have affect on pain impulses
            -anxiety, depression, previous pain perceptions can activate pain impulses
            -ex: "pain projector"
            -treatment options: brief, intense TENS, accupressure, encourage good thoughts (stay positive),
                    don't focus on pain

3)B-endorphin release -
            -stimulate "pain" in order for endorphins to be released to block ascending pain signals
            -ex: "runners high"
            -treatment options: TENS (low frequency and long pulse duration)

Assessing Pain
-Visual Analog Scales
        -a line ranging from no pain to severe
        -athlete indicates their pain level by marking where on the line they feel that their pain is
-Pain Chart
        -athlete indicates on a body diagram exactly where and what type of pain they are having
-McGill Pain Questionnaire
        -athlete chooses from about 80 pain descriptive terms
        -takes longer to complete
        -only done about every 2 weeks
-Activity Pain Indicators Profile
        -64 question report to indicate the frequency of pain when doing certain everyday tasks
-Numeric Pain Scale
        -athlete indicates pain on a scale from "1" to "10" with "10" being the worst pain ever

Treating Pain
-You must know what is going on with the body to effectively treat pain
-You need to know what is causing the pain to treat it, if you do not correct the problem, the pain will remain

Psychological Aspects of Pain
-Be careful when dealing with an injured athlete because there may be certain psychological factors at work
-Pain projectors, Low pain tolerance people, etc.

   
Web Sites for further study/learning:
www.aapainmanage.org -

www.ccsd.k12.wy.us/CCHS_web/cramerfirstaider/fstaider.htm - Cramer First Aider

www.medmedia.com/med.htm - Wheeless' Textbook of Orthopedics