Week 1 Fractures Flashcards
Definition of a Fracture
A break on tissue continuity of a bone
Bone F# Epidemiology
Young Ages 15-24
Elderly > 65
What bones are commonly fractures (15-24)? How?
- Tibia, clavicle, lower humerus
- Traumatic
What bones are commonly fractured in elderly >65? How?
- Upper Femur, upper humerus, vertebra, pelvis
- Secondary to Osteoperosis
How are fractures classified?
According to Physiological and Pathological
Physiological Classification
- Fatigue: muscles are less able to absorb forces acting on bones
- Accident/injury
- Unusually strong muscle contractions
- Prolonged/repetitive physical stress fracture occurs as a result of excessive repetitive activity, resulting in inadequate healing times for osseous microtrauma
Pathological Fracture Definition:
-When a MODERATE/SMALL forces acts on a weakened of diseased bone causing a fracture
What causes a pathological fracture?
- Focal bone lesions: neoplasms; cysts; infections etc.
- Metabolic disorders: poor mineral absorption & hormonal changes decrease bone calcification causing weakened bones
- Disuse: atrophic muscles & osteopenia cause weakened bones
What are ways we classify fractures?
According to:
- Where the force causing the fracture acts
- The degree/extent of the fracture
- Whether the skin overlying it is broken
- The shape or appearance of the fracture line
Classification of Fractures BASED ON THE SITE OF THE FORCE?
- Direct: The bone breaks at the point of application of the force
- Indirect: The bone breaks at a site distant to the point of application of the force e.g. clavicular fractures following falls onto the palm of an outstretched arm
Compression F#:
Frequently seen with vertebral fractures. Bone has been compressed by other bones
Comminuted F#:
Bone broken, splintered or crushed into several fragments
Avulsion F#:
A fracture occurring when a joint capsule, ligament, tendon, or muscle is pulled from a bone, taking with it a fragment of the bone to which it was attached
Greenstick F#:
- A crack
- Bending of a bone with incomplete fracture
- Only affects one side of the periosteum
- Common in skull fractures or in young children when bones are pliable
Complete F#:
Bone is broken with disruption of both sides of the periosteum
What is the importance of fracture classification?
- Mechanism of fracture
- Seriousness of the fracture
- Stability of the fracture
- Time required for healing
- Type of treatment needed
- Prognosis
- Expected complications etc
Stages of healing of a fracture?
- Fracture occurs
- Haemorrhage
- Procallus Formation: Organsation of haematoma
- Fibrocartilaginous Callus Formation
- Bony Callus Formation
- Remodelling
Fracture healing timeline?
- Fracture occurs (day 1)
- Haemorrhage (2-5 days)
- Procallus formation; haematoma is organised (3-7 days)
- Fibrous cartilaginous callus formation (1-3 weeks)
- Bony Callus Formation (3-4 weeks, up to 2-5 months)
- Remodelling Stage (Months to years)
What is woven bone?
AKA non-lamellar bone: Immature type of bone tissue found in developing embryos. Collagen fibers of the woven bone matrix are arranged irregularly in the form of interlacing networks.
Osteoblasts make osteoid which matures, via calcification, into woven bone
Osteoid
- The unmineralized organic component of bone.
Stages of Healing
- Haemorrhage:
Takes place due to the highly vascular nature of bone tissue.
Events occurring in this stage:
•Intense inflammatory response
•Activation of local inflammatory cells
•Migration of inflammatory cells into the region
•Activation & proliferation of local CONNECTIVE TISSUE CELLS
What are the Local Connective Tissue Cells that proliferate following a fracture?
- Osteoblasts
- Osteogenic cells
- Fibroblasts
- Chondroblasts
What are Osteoblasts def:
(bone forming cells)
What are Osteogenic cells?
(stem cells that differentiate into large numbers of osteoblasts)
What are Fibroblasts?
Connective tissue forming cells
What are chondroblasts?
(Cartilage forming cells)
Stage 3 of Fracture healing:
PROCALLUS* FORMATION
THE HAEMATOMA IS ORGANISED (i.e. it becomes a mass of Granulation Tissue) also called a provisional callus.
Summary of events in this phase:
•Phagocytes: remove debris & kill bacteria
•Osteoblasts: multiply & make woven bone
•Fibroblasts: multiply & make collagen
•Chondroblasts: multiply & make cartilage
•Blood vessels: begin to grow into the region
End result: The haematoma has been replaced by a collection of cells & extracellular material called “granulation tissue”
Stage 4 of Fracture healing:
Fibrous Cartilaginous Callus Formation
Summary of events in this phase:
•Osteoblasts: function is limited by low O2
•Fibroblasts: multiply & make collagen
•Chondroblasts: multiply & make cartilage
•Blood vessels: continue to invade the callus
End result: Callus mainly composed of fibrous connective tissue mixed with cartilage
Stage 5 of Fracture healing:
Bony Callus Formation
Summary of events in this phase:
•Blood vessels: have formed a rich network throughout the callus
•Osteoblasts: Make more woven bone. Their function is accelerated by increased O2 levels
•Osteoclasts: Destroy fibrocartilagenous tissue. Their function is accelerated by increased O2 levels
End result: Osteoclasts destroy fibrocartilagenous tissue; osteoblasts make osteoid which matures, via calcification, into woven bone
Lamella bone definition
Is the bone type found in normal adults. In mature bone, the bone tissue is laid down in concentric layers These layers form a basic repeating structure called the osteon. Many Osteons combine to make up mature, compact bone.
What is the strength of woven bone?
Previously fractured ends of the bone are firmly held in place by woven bone.
However, woven bone is not as strong as mature, lamellar bone. For full bone strength to be attained, the woven bone needs to be replaced
Stage 6 of Fracture healing:
Remodelling Stage
Osteoclastic > Osteoblastic
As remodelling of bony the callus progresses:
- Woven bone is destroyed and replaced by compact bone (lamellar bone)
- Internal and external calluses are reabsorbed
Healing Fracture times can be affected by:
BOAT
- Bone affected
- Overall health of patient
- Age
- Type of fracture
Fracture Clinical Manifestation Classification?
- General
- Local
General F# SSX?
•Shock
•Ssx 20 damage sustained by:
-CNS
-Other viscera
•Ssx due to underlying (predisposing) diseaseLocal F# SSX?
These manifestations may be identified: •Via history (i.e. pain) •Via observation •Via palpation •On movement of the affected body part
Local F# SSX observation?
- Pulselessness
- Tenderness
- Impaired Sensation/ Paraesthesia
SSX evident during movement?
- Creptiation
- Abnormal Movement
- Local mm Spasm
Delayed healing:
When a fracture has failed to heal within the expected time frame for that particular #F and patient profile
Delayed healing Fracture Local reasons?
- Malalignment
- Excessive movement
- Comminution
- Bone disease
- Severe soft tissue injury
- Infection
- Ischemia
- Soft-tissue interposition
Delayed healing fracture Systemic reasons?
- Mineral deficiency
- Vitamin deficiency
- Systemic infections
- Bone disease
- Ischaemia (e.g. Atherosclerosis)
- Endocrine disease (e.g. hyperparathyroidism, hyperthyroidism etc.)
- Medications
- Poor general health
- Advanced age
Delayed Union definition:
Abnormally prolonged healing time
Non-union
Failure of the fractures bones to unite usually due to:
i. infection ii. movement
Pseudoarthrosis
Non-union in which a fluid filled space forms within the fibrous tissue between the fracture ends; it thus resembles a joint.
Malunion
Union of fragments in a non-anatomical position that causes modification of function of the limb or part
Complications
- Delayed healing
- Bone necrosis
- Shock
- Infection
- Deformity
- Fat embolism
- Thrombophlebitis/PE
- Compartment syndrome
- Ectopic bone formation (laying down of new bone material (via a process called ossification) in areas again where this material does not belong. This ossification process is performed by osteoblasts)
- Local organ/soft tissue injury
- Post traumatic degenerative arthritis
- Sudeck/Leriche syndrome (post traumatic osteoporosis)
Compartment Syndrome
Increased pressure within a muscle fascial compartment following a fracture, due to bleeding and oedema.
The nature of the problem: Resultant ischemia can cause tissue necrosis in as little as 30 minutes Elevated pressure for more than 4 hours can result in irreversible damage & limb loss.
6 P’s of Compartment Syndrome
Signs & symptoms (6 P’s):
•Pain
o severe
o unrelenting
o unrelieved by analgesia
o increased by elevation of the extremity
•Pallor and coolness, slow capillary refill
•Pulselessness: diminished or absent pulses
•Pressure increase
•Paresthesia
•Paralysis
Fat Embolism Syndrome
Fat globules & tissue thromboplastin are released from the bone marrow The fat molecules enter the venous circulation The fat travels to the lungs & embolises the small capillaries & arterioles
SSX of Fat Embolism Syndrome
- Hypoxemia
- Tachypnea
- Fever of unknown origin (FUO)
- Chest pain
- Altered mental status
- ± Petechiae (is a small (1–2 mm) red or purple spot on the skin, caused by a minor bleed from broken capillary blood vessels)
Treatment for F#:
Reduction and immobilisation
Reduction
i.e. the ends of the fracture must be brought into close approx.
This can be achieved in two ways:
-External and Internal
External Reduction
ie. external manipulation
Internal reduction
ie surgical reduction
Immobilisation of F#
a. Strapping
b. Slings
c. Plaster
d. Internal fixation (pins, screws, plates)
e. External fixation
