Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins Tissue Healing and Wound...

Copyright © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins

Tissue Healing and Wound CareTissue Healing and Wound Care

Chapter 6


• Two potential effects of force:

– Acceleration

– Deformation

• Factors that determine injury

– Magnitude of force

– Material properties of tissues involved

Force and Its EffectsForce and Its Effects


• Small load - elastic response

– Load is removed, material returns to its original shape

• Load reaching yield point - plastic response

– Load is removed, some amount of deformation remains

• Yield load

– Maximum load a material can handle without permanent deformation

• Failure

– Force such as loss of continuity, rupturing soft tissue or fracturing bone

Response to ForceResponse to Force


• Many tissues are anisotropic

– Different strengths in response to loads from different directions

• Anatomic make-up of joint

– Susceptibility from a given direction

Direction of ForceDirection of Force


• Axial

– Force that acts on the long axis of a structure

• Compression

– Axial load that produces a crushing or squeezing type force

• Tension

– Axial force in opposite direction; pulling or stretching the tissues

• Shear

– Force parallel to a plane passing through the object

– Tends to cause sliding or displacement

Categorize Force Relative to DirectionCategorize Force Relative to Direction


Categorize Force Relative to Direction (cont.)Categorize Force Relative to Direction (cont.)


• Stress

– Force divided by the area over which the force acts

• A given force over a large area vs. a small concentrated area can have very different results

Magnitude of StressMagnitude of Stress


• Strain – The amount of deformation relative to the original

size of the structure– Result

• Compression - shortening and widening• Tension - lengthening and narrowing• Shear - internal deformation

• Problem: high strain rather than high force

• The ability to resist strain relative to strength of tissues

Strain vs. ForceStrain vs. Force


• Acute injury

– Results from a single force

– Causative factor - macrotrauma

– Characterized by a definitive moment of onset

• Chronic or stress injury

– Results from repeated loading

– Causative factor - microtrauma

– Characterized by becoming more problematic over time

Element of TimeElement of Time


• gradual mechanical stress

size & strength

Positive Stress vs. Adverse StressPositive Stress vs. Adverse Stress


• Moment arm

– Perpendicular distance from force line of action to the axis of rotation

• Torque

– Force × moment arm

– Produces rotation of a body

TorqueTorque


Torque (cont.)Torque (cont.)• Injury potential

– Bending

• Tension on one side of object and compression on the other side

– Torsion

• Twisting an object's longitudinal axis


• Collagen

– Primary constituent of skin, tendon, ligaments

– Protein substance strong in resisting tensile forces

– Wavy configuration that allows for an elastic type deformation or stretch but, otherwise, is inelastic

• Elastin

– Protein substance

– Adds elasticity

Soft Tissue – Anatomic PropertiesSoft Tissue – Anatomic Properties


SkinSkin

• Epidermis

• Dermis

– Multidirectional arrangement of collagen


• Muscle to bone• Dense connective tissue with

unidirectional bundles of collagen and some elastin

• Collagen - parallel arrangement– Helps in resisting high,

unidirectional tension loads from the attached muscle

• Two times as strong as muscle it serves

– Yield point 5-8% in length

TendonsTendons


AponeurosesAponeuroses

• Attach muscle to other muscles or bone

• Dense connective tissue

• Strong, flat, sheet-like


• Viscoelastic

– Extensibility - ability to be stretched

– Elasticity - ability to return to normal length

• Viscoelasticity allows muscle to stretch to greater lengths over time in response to a sustained tensile force

MuscleMuscle


• Irritability - ability to respond to a stimulus

– Electrochemical - nerve impulse

– Mechanical - external blow

• Contractility - ability to develop tension

– Isometric

– Concentric

– Eccentric

Muscle (cont.)Muscle (cont.)


Joint CapsuleJoint Capsule

• Membrane that encloses a joint; composed primarily of collagen

• Function: hold bones in place

• Inner lining: synovial membrane

– Exit for waste; entrance for nutrients

– Secretes synovial fluid (lubricates and nourishes)


• Bone to bone

• Collagen is parallel and interwoven

– Resists large tensile loads along the long axis of the ligament and smaller loads from other directions

• Collagen and elastin intermixed (more elastic than tendons)

LigamentsLigaments


BursaBursa

• Fluid-filled sacs

• Reduce friction

• Common sites – areas of friction


Classification of JointsClassification of Joints

• Fibrous (synarthrosis)

– Held together by fibrous tissue

– Can absorb shock but permits little or no movement of the articulating bones

– Example: sutures in the skull

– Syndesmoses

• Joined by dense fibrous tissue

• Permit extremely limited motion

• Example: interosseous membrane


Classification of Joints (cont.)Classification of Joints (cont.)

• Cartilaginous (amphiarthroses)

– Primary

• Held together by hyaline cartilage

• Example: sternocostal joints; epiphyseal plates

• Can absorb shock, but permits little or no movement

– Secondary

• Held together by fibrocartilage

• Movement of the articulating bones

• Designed for strength and shock absorption



• Synovial (diarthroses)

– Freely movable joints

– Classified according to their shape – dictates type and range of motion permitted

• Plane

• Hinge

• Pivot

• Condyloid

• Saddle

• Ball and socket


Classification of Joints (cont.)Classification of Joints (cont.)• Synovial joint

– Articular cartilage

• Covers ends of long bones, cushion and protection, no nerve or blood supply

– Joint cavity

• Filled with synovial fluid



– Articular capsule

• Joint capsule

– Synovial fluid

• Reduces friction

– Ligaments

• Capsular, extracapsular


Skin Injury ClassificationsSkin Injury Classifications• Abrasions

– Scraping away of layers of skin• Blisters

– Accumulation of fluid between epidermis and dermis

• Skin bruises – Accumulation of blood within skin

• Incisions – Clean cut


Skin Injury Classifications (cont.)Skin Injury Classifications (cont.)

• Lacerations– Irregular tear

• Avulsions – Complete separation of skin

• Punctures– Penetration of skin and underlying tissue


• Mechanism: compression• Signs and symptoms (S&S)

– Onset - acute– Pain - localized– Ecchymosis: if superficial– Restrictions in ROM – Swelling– Associated nerve compression

Classification of Muscle/ Tendon InjuriesClassification of Muscle/ Tendon Injuries

ContusionContusion


Contusion (cont.)Contusion (cont.)

• Basis for rating severity – ROM– 1st – little or no restriction– 2nd – noticeable reduction– 3rd – severe restriction

• Concern: can lead to muscle strain


• Stretch or tear of a muscle

• Mechanism: tension force

• Most common site for tears: near the musculotendinous junction

• Key factor: magnitude of force and structure's cross-sectional area

StrainStrain


Classification of StrainsClassification of Strains1st 2nd 3rd

damage to fibers few fibers torn nearly half torn all fibers torn

weakness mild moderate (reflex inhibition)

severe

muscle spasm mild moderate severe

loss of function mild moderate severe (reflex inhibition)

swelling mild moderate severe

palpable defect no no yes (if early)

pain-contraction mild moderate /severe none/mild

pain-stretching yes yes no

ROM decreased decreased depends on swelling


• Involuntary muscle contraction

• Cramp

– Biochemical imbalance, fatigue

– Types

• Clonic - alternating contraction/relaxation

• Tonic - constant

• Spasm

– Reflex action due to:

• Biochemical or

• Mechanical blow to nerve or muscle

Cramps and SprainsCramps and Sprains


• Myositis

– Inflammation of connective tissue

• Fasciitis

– Inflammation of the fascia surrounding portions of a muscle

Myositis and FasciitisMyositis and Fasciitis


• Tendinitis

– Inflammation of tendon

– Pain and swelling with tendon movement

– Problems - repeated microtrauma

• Degenerative changes

• Tenosynovitis

– Inflammation of synovial sheath

– S&S

• Acute: rapid onset, crepitus, local swelling

• Chronic: thickened tendon, nodule formation in sheath

Tendinitis and TenosynovitisTendinitis and Tenosynovitis


• Ectopic calcification - located in place other than normal

• Bone (calcium) is deposited within a muscle

• Usually macrotrauma, but can be microtrauma

Myositis OssificansMyositis Ossificans


• Result of repeated irritation of tissues

• Classification

– Stage 1: pain after activity only

– Stage 2: pain during activity, does not restrict performance

– Stage 3: pain during activity, restricts performance

– Stage 4: chronic unremitting pain, even at rest

• Problem – low-grade inflammatory condition that results in collagen resorption and scarring

Chronic ConditionsChronic Conditions


SprainSprain• Stretch or tear of ligament

• Mechanism of injury (MOI) – tension force

• Compromises the ability of the ligament to stabilize the joint

Joint Injury ClassificationsJoint Injury Classifications


Classification of SprainsClassification of Sprains1st 2nd 3rd

damage to ligament few fibers torn nearly half torn all fibers torn

distraction stress <5 mm 5-10 mm >10 mm

weakness mild moderate/severe moderate/severe

muscle spasm none none/minor none/minor

loss of function mild moderate/severe severe

swelling mild moderate moderate/severe

pain-contraction none none none

pain-stretching yes yes no

ROM decreased decreased increase or decrease


Dislocation/SubluxationDislocation/Subluxation

• Joint force beyond normal limits

• MOI: tension

• S&S

– Loss of limb function

– Deformity

– Swelling

– Point tenderness


Dislocation/SubluxationDislocation/Subluxation

• Problem of reoccurrence

– Due to overstretching of capsule to the extent that it will not return to normal; unstable joint


Bursitis Bursitis

• Inflammation of bursa

• Acute or chronic

• MOI: compression

• S&S: swelling, pain, loss of function, eventual degeneration


OsteoarthritisOsteoarthritis

• Degeneration of articular cartilage

• S&S: pain and limited movement

• No definitive cause; rather, several contributing factors


Soft Tissue HealingSoft Tissue Healing

• Inflammatory phase (0-6 days)– Acute or chronic inflammation possible– Exudate forms– Mechanisms for stopping blood flow

• Local vasoconstriction • Platelet reaction• Coagulation cascade


Soft Tissue Healing (cont.)Soft Tissue Healing (cont.)

– 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



• Inflammatory phase (cont.)– Zone of primary injury

• Hematoma forms– Edema occurs

• Increased permeability and pressure within the vessels forces a plasma exudate into the interstitial tissue



– Zone of secondary injury

• Interstitial tissues affected by inflammation, edema, and hypoxia

• Prostaglandins promote further healing and clearing of debris




Soft Tissue Healing (cont.)Soft Tissue Healing (cont.)• Proliferative phase (3-42 days)

– Repair and regeneration of tissue

– Processes

• Angiogenesis

• Fibroplasia

• Re-epithelialization

• Wound contraction



– 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



• Maturation phase (3 weeks – 1 year)– Associated processes– 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



– 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



• Maturation phase (cont.)

– 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


Soft Tissue Wound CareSoft Tissue Wound Care• Open wound

– Follow universal precautions and infection control standards

– General

• Apply pressure

• Cleanse the wound

• Dress and bandage the wound

• Use of creams or ointments

• Re-dress and inspect


Soft Tissue Wound Care (cont.)Soft Tissue Wound Care (cont.)

• Closed wound

– Goal: reduce inflammation, pain, and secondary hypoxia

– Treatment: ice, compression, and elevation


Long Bones – Anatomic PropertiesLong Bones – Anatomic Properties• Primary constituents:

minerals, collagen, water

• Components

– Diaphysis

• Shaft - hollow, cylindrical

• Medullary cavity - shock potential improves


Long Bones – Anatomic Properties (cont.)Long Bones – Anatomic Properties (cont.)

– Epiphysis

• Ends of long bones

• Epiphyseal plate - cartilaginous disc found near ends of long bones

– Periosteum

• Sheath covers bone

• Life support system



• Bone growth

– Longitudinal

• Continues until epiphysis closes

– Diameter

• Can continue to grow through the lifespan



• New bone formed via the periosteum; bone is resorbed around the medullary cavity

– Osteoblasts – form new bone

– Osteoclasts – resorb bone

• Bone experiences constant remodeling


Internal Composition: Long Bones – Anatomic Properties (cont.)Internal Composition: Long Bones – Anatomic Properties (cont.)• Cortical

– Compact bone tissue of high density (low porosity)

– Outside

– Can withstand greater stress but less strain

• Cancellous

– Bone tissue of low density (high porosity)

– Inside

– Can tolerate more strain



• Size will increase in response to increased stress (conditioning)

• Hollow cylinder - strongest structure in resisting tension and compression

• Anatomic weakness - site where bone changes shape and direction (especially sudden change)


Mechanical Forces Affecting BonesMechanical Forces Affecting Bones

• Tension, compression, shear, bending, torsion

• Stronger in resisting compression than both tension and shear


FracturesFractures• Disruption in the continuity of bone

– Closed or open

• Type of fracture determined by:

– Force applied

– The health and maturity of bone at the time of injury

Classification of Bone InjuriesClassification of Bone Injuries


Types of FracturesTypes of Fractures


Stress FractureStress Fracture

• Stress fracture

– Fracture results from repeated loading with lower magnitude forces

– Can become worse over time


OsteopeniaOsteopenia

• Osteopenia

– Reduced bone mineral density that predisposes individual to fracture

– Possible causes: amenorrhea, hormonal factors, dietary insufficiencies


Epiphyseal InjuriesEpiphyseal Injuries

• Injury to growth plate could result in alteration in normal growth

• Acute injury

– Types I-V

• Osteochondrosis


Epiphyseal Injuries (cont.)Epiphyseal Injuries (cont.)

• Osteochondrosis

– Disruption of blood supply to epiphysis

– Idiopathic

– Example: Legg-Calvé-Perthes disease

• Apophysitis

– Osteochondrosis of apophysis

– Example:

• Sever’s disease

• Osgood-Schlatter disease


Bony Tissue HealingBony Tissue Healing• Acute inflammatory phase

– Formation of hematoma

– Inflammatory response

• Proliferative phase

– Osteoclasts – resorb damaged tissue; osteoblasts – deposit new bone

– Callus formation

• Maturation phase

– Continued activity of osteoclasts and osteoblasts

– Remodeling of bone


Bony Tissue Healing (cont.)Bony Tissue Healing (cont.)






Bone Injury ManagementBone Injury Management

• Fracture detection

– Palpation, percussion, tuning fork, compression, distraction

• Management – splinting (refer to Application Strategy 6.3)


Nerve – Anatomic PropertiesNerve – Anatomic Properties

• Spinal nerve

– Roots

• Posterior – afferent

• Anterior – efferent

– Heavily vascularized

– Myelin sheath


Spinal NervesSpinal Nerves


Classification of Nerve InjuriesClassification of Nerve Injuries• Tensile force injuries

– Neurapraxia (grade 1)

• Localized conduction block: temporary loss of sensation and/or motor

• Resolves within days to a few weeks

– Axonotmesis (grade 2)

• Significant motor and mild sensory deficits

• Lasts at least 2 weeks


Classification of Nerve Injuries (cont.)Classification of Nerve Injuries (cont.)

– Neurotmesis (grade 3)

• Motor and sensory deficit

• Lasts up to 1 year

• Compressive injuries


Classification of Nerve Injuries (cont.)Classification of Nerve Injuries (cont.)

• Nerve injuries result in a variety of afferent symptoms

– Hyperesthesia

– Hypoesthesia

– Paresthesia

• Neuralgia

– Chronic pain along nerve’s course

• Healing: if completely severed, healing does not occur


Management of Nerve InjuriesManagement of Nerve Injuries

• Mild – follow acute care protocol

• Moderate to severe – physician referral


PainPain• Sources

– Somatic, visceral, and psychogenic

• Nociceptors

– Mechanosensitive

– Chemosensitive

• Fibers transmitting pain

– A fibers

– C fibers

– T cells

• Gate control theory of pain


Pain (cont.)Pain (cont.)• Factors than mediate pain

– Brain production of opioid peptides and endorphins

– Cognitive and affective filters

• Referred pain

– Pain perceived at a location remote from the site actually causing the pain

• Radiating pain

– Pain felt both at its source and along a nerve

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