Flashcards in Injuries To The Upper Limb Deck (28):
Stretching of the joint capsule and ligaments of a joint, which is not sufficient to cause dislocation or subluxation
Causes of fractures
Mechanical stress / trauma
Can be due to excess force on normal bone
or normal force on weakened bone (osteoporosis, osteogenesis imperfecta, pagets)
How is integrity if the bone maintained?
Calcium, provides rigidity.
Use/stress on the bone encourages remodelling and strengthens the bone
Collagen fibres reinforce structure of bone
Clinical signs and symptoms of fracture
Deformity - defining feature
Source of pain in a fracture
Bleeding due to fracture increases pressure in the bone. Sensory fibres in the periosteum which are compressed due to pressure causing pain
Fracture of the bone together with a breach of the skin, bone is exposed to the air, which may allow an infection to enter
Two types: protrusion of bone out due to fracture, bone exposed due to crushing injury
Risks in compound fracture
Can lead to infection, site needs to be washed with saline, some tissue may need to be removed. ,
Fracture with damage to the surrounding soft tissues and associated structures e.g. blood vessels, nerves, viscera
Bone takes longer to heal than expected (different for each bone)
Bone does not unite after a fracture.
Can be due to the bone dying and becoming sclerotic. Requires surgical intervention e.g. Replacement
Bones join in the incorrect alignment
Diagnosis of fractures
Ultrasound (particularly in children)
Complication of posterior displacement of sternoclavicular joint
Compression of the subclavian. Causes ischemia of the limb
Caused by overuse of joint ( repetitive strain damages ligaments)
Why is callus formation common following clavicle fractures?
Because the clavicle is highly mobile, healing tends to form excess bone as the two ends unite. Process normally takes 6-9 weeks
Breach in integrity of part or all of the bone
Complete separation of articulate surfaces in a joint
Caused due to compromised joint support, excess forces through the joint, or if the joint is stressed in a position of instability
Partial separation of articular surfaces of a joint
Dislocation where there is a fracture involving one or more or the articular joint surfaces.
Results in degenerative changes
Complication of supra condylar fracture of humerus
Loss of anterior interosseus nerve
Damage to median nerve, loss of flexion of 1st digit (pointing finger sign)
Flexor compartment syndrome
Damage to brachial artery
Complication of elbow dislocation
Damage to ulnar nerve, loss of muscles in the hand.
First sign is lack of flexion in terminal joints, progresses to claw hand and muscle wasting
Conditions which cause an increased risk of fractures
Osteoporosis - reduction of bone density due to increased osteoclast activity
Pagets disease - excessive bone remodelling results in weakened (woven) mishapen bone, increased blood flow reduces calcium levels
Osteogenesis imperfecta - insufficient or defective collagen production, bones are weakened.
Complications of clavicular fractures
Damage to brachial plexus
Damage to subclavian vein
Common sites of scapula fractures
Complications of fractures at the neck of the humerus
Damage to axillary circumflex nerve and circumflex humeral arteries
Common sites of proximal humerus fractures
Volkmann's ischemic contracture
Permanent flexion contracture of the hand at the wrist, resulting in a claw-like deformity of the hand and fingers
Caused following supracondylar fracture of the humerus which can lead to obstruction of the brachial artery/compartment syndrome. Fibrosis and shortening of flexor muscles causes contracture