Lecture 2

• Anatomical Properties of Bone

  • A specialized type of connective tissue consisting of calcium phosphate, collagen, and water
  • The minerals provide stiffness and strength in resisting compression and the collagen provides flexibility and strength in resisting tension
  • The outer surface is made of cortical bone whereas the inner surface is composed of a more porous tissue known as cancellous bone
  • Bone has a complex network of blood vessels and lymphatic vessels that form canals known as the haversian system
• Gross Structure of Bone

  • Diaphysis: Main shaft of a long bone
  • Hollow, cylindrical, and covered by cortical bone (periosteum) - resists tension and compression
• Epiphysis

  • Located at the end of long bones
  • Bulbous in shape and serves as an attachment for muscles and ligaments
  • Composed primarily of cancellous bone
  • The ends are covered by hyaline cartilage
• Metaphysis

  • Narrow portion of along bone located between the diaphysis and the epiphysis
  • It contains the growth plate; part of the bone that grows during childhood
  • As growth occurs, it ossifies near the diaphysis and epiphysis
• Functions of Bone

  • Body support
  • Organ protection
  • Movement
  • Reservoir for calcium
  • Formation of blood cells (haemopoiesis)
• Mechanical Forces Affecting Bones

  • Tension/compression/shear/bending and torsion
  • Stronger in resisting compression than both tension
• Classification of Fractures

  • Fractures may be classified by the following

  1. Anatomical Site
  2. Mechanism of Injury
  3. Extent of the Injury to Soft Tissues
• Avulsion Fracture

  • Tendon/ligament pulls a piece of bone fragment off
  • Result of sudden powerful twist or stretch
  • commonly occurs in ankle
• Epiphyseal Fracture

  • Growth plate fracture in the developing child that could result in disruption of normal growth
• Traumatic Fracture

  • Caused by a direct blow or sudden force applied to the bone
  • Reduction means having to move the bone back in place
• Stress and Fatigue

  • Also called a stress fracture 
  • Caused by repeated stress on a bone
• Pathological 

  • Fracture to a bone that is already weakened
  • Bone may be weakened due to the osteoporosis, tumor, prolonged corticosteroid medication use
• Extent of Injury to the Soft Tissue

  • The area may be contaminated and infection may set in
  • Must be treated as a medical emergency
• Open Fracture

  • Also known as Compound fracture
  • Communication of the fractured bone with the exterior of body
• Closed Fracture

  • Also known as a simple fracture
  • There is no communication of the fractured bone with the exterior of the body
• Diagnosis of a Fracture

  Subjective History

  • Mechanism of injury
  • Audible snap or crack
  • Presence of nausea
  • Onset of swelling or bruising
  • Functional level
  • Presence of crepitus
  • Intensity of pain
• Objective Physical Assessment

  • Visible deformity in the bone
  • The presence of bruising and swelling (may not be evident initially but usually develops rapidly
  • Local tenderness on palpation
  • Palpable crepitus and grinding with movement
  • Marked functional impairment
  • Decreased active ROM and pain with all active movements
  • Weakness and pain with all movements
  • Pain with the use of a tuning fork and with percussion (vibration)
  • Pain with compression and decreased pain with distraction
• Diagnostic Tests

  • Fracture site in the bone is usually evident on the following
  • X-ray
  • CT (computed tomography) Scan
  • MRI
  • Bone scan
• Treatment

  Reduction

  • May be required if the fracture is displaced
  • May be achieved manually or with surgical intervention

  Immobilization

  • Required to decrease movement that will interfere with union of the fracture
  • Decreases pain
  • Not always necessary for all fractures
  • Must also be aware of the negative effects of immobilization
• Complex Regional Pain Syndrome (CRPS)

  • A negative effect of casting and complication post injury
  • The nerve and blood supply is blocked off and the muscles may atrophy and die as a result
  • May see a decrease in the pulse
  • Visible changes in the skin color 
  • Numbness or paralysis may be evident 
  • Also known as reflex sympathetic dystrophy, sudeck's atrophy, and Volkmann's contracture 
• Avascular Necrosis

  • Death of the bone due to disruption of the blood supply to area
• Preservation of Function

  When In The Cast

  • Move the joints above and below the fracture site to insure increased circulation to area and to prevent a decrease in the range of motion of the other joints
  • Perform isometric and isotonic exercises
• Progression of Treatment

  When out of the cast:

  • Stretching and strengthening exercises of the affected joints
  • Gradual return to normal functional activities and sports
• Stress Fractures

  • Micro fracture that is secondary to repeated stress
  • Also known as a fatigue fracture
  • May begin as a small fracture in the outer layer and end as a complete cortical fracture with possible displacement of the bone
• Stress fractures Can result from

  • Repeated low magnitude force
  • Overload on a bone from a muscle contraction
  • Altered stress distribution on a bone due to muscle fatigue or a muscle imbalance
  • Increased ground reaction forces from changing training surfaces
  • Due to decreased estrogen levels during menopause
• Diagnosis

  Subjective History

  • Stress fracture
  • As per the diagnosis of fractures but the patient usually cannot report a single traumatic event causing the pain
• Objective Physical Assessment

  • Initial pain is present with activity but decreases with rest (early stages)
  • Constant pain throughout the day and at night (later stages)
  • Pain with percussion and the use of tuning fork

  -if night pain is present (constant pain/night pain) boney injury -stress fracture or bone fracture
• Night Pain

  • Night pain is constant pain (could also be cancer -metastatic lesion)
  • Tumour is very vascular
  • Blood and circulation attract tumour and that causes throbbing
  • When they get up the blood moves throughout whole body the tumour isn't using all blood so no throbbing
• Objective Diagnostic Physical Assessments

  X-Ray

  • A stress fracture is not visualized initially but may be present after one month post injury

  Bone Scan

  • The most definitive diagnostic tool for stress fractures
  • Radioactive dye that moves through body which shows up in affected area
• Treatment for stress fractures

  • Rest from activity for at least weeks
  • Replace regular training with an alternative non weight bearing activity or sport such as running in a pool, swimming, or cycling
  • Modify the possible cause of the problem such as the equipment, training schedule, or training surface
• Dislocations

  • A complete displacement of the end of a bone from the joint usually injuring the joint capsule ligaments, and the surrounding musculature
  • Common sites include the patella, shoulder, elbow, finger, and hip joints
  • in adults often hip just breaks but not in children
• Signs and Symptoms of Dislocations

  • Joint deformity and swelling evident on observation
  • Palpable tenderness throughout the joint
  • Gross limitation in the active ROM of the affected joint
  • Marked functional impairment
• treatment for dislocations

  • Splint and immobilize the affected joint in position that it is found and then seek medical attention
  • Reduction of the dislocation by the attending physician
• Subluxation

  • A partial displacement of the end of a bone from the joint
  • This is also results in injury to joint capsule, ligaments, and the surrounding musculature