Fractures

Discontinuity in a bone (or cartilage) resulting from mechanical forces which exceed the bones ability to withstand them

-Acute trauma/mechanical load -Fragility fracture, mechanical forces not normally causing fractures (low level traumas) -Insufficiency fracture, normal repetitive stress on abnormal bone -Stress fracture, Abnormal loading on normal bone -Pathological fracture, Bone may have a lesion that weakens a bone (eg bone cyst)

-Transverse- across the bone -Oblique- diagonal -Spiral- twists the bone -Comminuted- bone breaks into multiple pieces -Avulsion- small fragment off end of bone -Impacted- broken ends of bone are jammed together by the force -Fissure- hairline or crack extending through surface of bone -Greenstick- bone bends or cracks along edge

-Babies have more bones -Children’s bones are continuously growing -Kids bones are more flexible -Children heal faster than adults and can remodel/reshape their bones -Kids ligaments are stronger than some of their bones (more likely to have avulsion fracture)

-Displaced - middle on bone downwards -Angulated - breaks at an angle -Shortened - breaks and ends move up towards each other -Rotated - bone twists so end is facing opposite side

-The breaking pattern -Displacement of fragments -Incomplete or complete -Stable or unstable -Soft tissue damage -Articular involvement (intra + extra) -Presence of wounds

4

Haematoma Formation -Immediately after fracture, space fills with blood -Forms a haemotoma to provide structural support and prevents further bleeding

Hours- days

Callus formation Internal = -Macrophages clean up debris -Osteoclats breakdown dead tissue -Fibroplasts produce collagen and fibrous network -Chondroblasts produce cartliage -Osteoblasts start to produce new bone External = -Osteoblasts and chondroblasts activate to produce bone cartilage (stabilising fracture site)

Days- weeks

Callus Ossification -Internal and external callus cartilage model under goes endochondral ossification to form woven/spongy bone = stronger callus

One- four months

Bone remodelling Repair = -Only complete once the woven /spongy bone has been replaced with compact bone Remodel = -Internal callus become stronger -External callus is reduced via osteoclasts activity -During remodelling, the healed fracture and surrounding callus responds to activity, functional demands and growth. -Bone that is no longer needed is removed and fractured site is smoothed and remodelled -May not be perfect remodelling

-Joint movement and function must be preserved whilst pain at fracture site is minimised to achieve better healing -Loading of bone from muscle activity to help heal

-Reduce oedema -Muscle function -Joint range -Maintain function -education

-Shock -Compartment syndrome (pressure increases restrict blood flow) -Tetanus (infection from bacteria) -Wound infection -Fat embolism (fat globules in circulation) to brain/lung -Deep vein thrombosis -Non union (inability to heal fracture) -Mal union (fractured bone heals in abnormal position) -Growth disturbance