Soft Tissue Healing

Cell Structure and Function Soft Tissue Epithelial Skin Organ linings Connective Tendons, Ligaments, Cartilage, Fatty tissues Blood vessels Muscle Skeletal Cardiac Smooth Nervous Brain Spinal Cord Nerves

Adaptations Metaplasia Conversion of one kind of tissue into a form that is not normal for that tissue Dysplasia Abnormal development of a tissue Hyperplasia Excessive proliferation of normal cells in normal tissue arrangement Atrophy Decrease in size due to cell death and reabsorption or decreased cell proliferation Hypertrophy Increase in size of tissue without increasing the number of cells

Adaptations Metaplasia Displasia

Adaptations Hyperplasia

Adaptations Atrophy

Adaptations Hypertrophy

Soft Tissue Healing Cartilage Limited healing capacity Injury to cartilage does not elicit a clot formation or a cellular response Collagen formed by 2 months post injury Ligament First 72 hours loss of blood and the attraction of inflammatory cells EXTRAARTICULAR bleeding occurs in the subcutaneous space INTRAARTICULAR bleeding occurs inside the joint capsule Vascular proliferation Formation of a fibrin clot – reconnects torn ends of ligaments Scars begin soft and viscous and eventually become more elastic Failure to produce enough scar or failure to connect ends of torn tissue are reasons for failure to repair damaged ligament Maturation can take up to 12 months

Soft Tissue Healing Muscle Hemorrhage and edema followed by PHAGOCYTOSIS to clear debris Myoblastic cells form in the area of injury leading to the regeneration of MYOFIBRILS It is important to have active contraction of the muscle to regain normal tensile strength Rehabilitation can be fairly long (RTP too soon can cause reinjury of the strained area) Tendon Injury requires dense fibrous union of the separated ends Week 2 – healing tendon adheres to the surrounding tissue and forms a single mass Week 3 – tendon separates to varying degrees from the surrounding tissues Tensile strength is not sufficient to allow strong pull for about 4-5 more weeks

Soft Tissue Healing Nerve Slow regeneration 3-4 mm a day Axon regeneration can be obstructed by scar formation Peripheral Nervous System regenerates better than the Central Nervous System

Soft Tissue Healing Modifications to the healing process Anti-inflammatory medication Minimize pain and swelling Therapeutic Modalities Cold Heat Electrical Ultrasound Therapeutic Exercise Pain free movement, full-strength power, full extensibility of surrounding muscles ***Immobilization is not good for all injuries: can result in changes in the collagenous tissue

Bone Healing Bone healing Effected by TORSION, BENDING, COMPRESSION When a fracture occurs Blood vessels are damaged resulting in bleeding and clot formation Week 1 Fibroblasts begin laying fibrous collagen network Chondroblasts – create a CALLUS Osteoblasts – form enter callus forms TRABECULAE which replaces cartilage Callus crystallizes into bone and REMODELING begins External callus – on the outside of the fx Internal callus – inbetween bone fragments Osteoclasts – reabsorb bone Immobilization – 3-8 weeks Osteoblastic and osteoclastic activity can continue for 2-3 years post fx

Bone Healing

Pain Nociceptors Pain receptors that are sensitive to mechanical, thermal, and chemical energy Primary afferent Transmit impulses from nociceptor -> dorsal horn of the spinal cord A-alpha and A-beta are large diameter nerves A-delta and C are small diameter Transmits pain sensation and temperature A-delta (fast pain) skin C (slow pain) skin and deeper tissues

Mechanism of Pain Control Gate Control Theory (level 1) Decreased pain during stimulation, tingling sensation, high pulse duration and frequency Central Biasing (level 2) Intense stimulation of small pain fibers at trigger and acupuncture points, high intensity stimulation Release of Beta Endorphins (level 3) Opiate Pain Control stimulation releases endorphins from the CNS (pituitary gland)