Flashcards in 1. Shoulder clinical conditions Deck (29)
What is the most common point of fracture of the clavicle?
junction of medial 2/3 and lateral 1/3
How are the bone fragments displaced in a clavicle fracture. Why?
- medial fragment displaced SUPERIORLY - by pull of sternocleidomastoid
- lateral fragment displaced INFERIORLY - by weight of upper limb (trapezius unable to hold it up) and MEDIALLY - by pectoralis major adducting the upper limb
Which important neurovasculure structures are found posterior to the clavicle?
anterior to posterior: clavicle... subclavian vein... subclavian artery... trunks (and divisions) of brachial plexus
Name 3 possible complications of clavicular fractures.
1- damage to underlying vascular structures: subclavian vein and artery
2- damage to trunks and divisions of brachial plexus, or suprascapular nerves
3- pneumothorax due to proximity of lung apex to middle 1/3 of clavicle (chest auscultation must be performed and chest X-ray may be needed)
Which structures could be damaged by fracture of surgical neck of humerus?
1- posterior circumflex humeral artery
2- axillary n.
Which mov. and sensation would be affected by fracture of surgical neck of humerus?
1. arm abduction - paralysis of deltoid and teres minor
2. sensation at regimental badge area
Which structures could be damaged by mid-shaft fracture of humerus?
1- profunda brachii artery
2- radial n.
as are tightly bound in radial groove
Which movements/muscles would be affected by radial n. damage at the radial groove?
paralysis of brachioradialis and all extensor muscles of wrist and fingers = WRIST DROP
(little effect on elbow mov. as nerve supply to 3 heads of triceps given off prior to radial n. entering radial groove)
Name 2 types of distal humeral fractures that might occur from falling on flexed elbow.
supracondylar and medial epicondyle fractures
Which structure might be damaged by a supracondylar humeral fracture?
Which structure might be damaged by a medial epicondyle humeral fracture? How would this affect muscles and sensation?
ulnar n. damage - results in:
1- ulnar claw
2- loss of sensation over medial 1 1/2 fingers (both dorsal and palmar surfaces)
Why is the humeral head relatively prone to dislocation?
glenoid fossa is relatively shallow - accepts only about 1/3 of humeral head
Why does the humeral head usually dislocate inferiorly?
- CORACOACROMIAL LIGAMENT extends between coracoid process and acromion - prevents superior mov. of humeral head
- GH joint weaker inferiorly
In which direction does the humeral head usually displace? Why?
anterior direction due to muscle pull
What usually causes anterior shoulder dislocation?
excessive extension and lateral rotation of humerus
What usually causes posterior shoulder dislocation?
electric shocks, seizures and lightening strikes
How would patients with anterior and posterior shoulder dislocations present differently?
- external rotation of arm
- slight abduction of arm
- internal rotation of arm
- adduction of arm
- flattening/squaring of shoulder with prominent coracoid process
Which neurovascular structures are at risk of damage in an anterior shoulder dislocation?
1- axillary artery damage
2- axillary n. damage (test for sensation in regimental badge area)
3- brachial plexus damage
Which signs would suggest axillary artery damage?
axillary haematoma, cool limb and absent or reduced pulses
Name 4 other complications of anterior shoulder dislocations.
1- associated fracture (30% cases), e.g. humeral head, greater tuberosity, clavicle, acromion
2- recurrent shoulder dislocations
3- rotator cuff injuries
4- anatomical lesions: Bankart (avulsion of antero-inferior glneoid labrum) and Hill-Sachs (posterolateral humeral head indentation fracture as soft base of humeral head impacts against relatively hard anterior glenoid) lesions
What might cause tears of rotator cuff?
Repetitive use of upper limb above horizontal (e.g. racquet sports)... recurrent inflammation of rotator cuff (esp. relatively avascular area of supraspinatus tendon)... tears of rotator cuff.
How might impingement occur at the shoulder joint and what is the result?
Repetitive use of rotator cuff muscles... humeral head and rotator cuff impinge on coracoacromial arch... irritation of arch, degenerative tendinitis of rotator cuff and attrition of supraspinatus tendon.
Describe the signs of a torn supraspinatus tendon.
1. failure of initiation of shoulder abduction (0-15 deg.) - but if arm is passively abducted 15 deg., abduction can be maintained/continued (using deltoid)
2. when patient is asked to lower limb slowly and smoothly, limb suddenly drops to side in uncontrolled manner from approx. 90 deg.
What is calcific supraspinatus tendinitis?
deposition of calcium (hydroxyapatite) in supraspinatus tendon causing pain and inflammation
What might be the result of inflammation in calcific supraspinatus tendinitis?
subacromial bursitis due to irritation of overlying subacromial bursa
What is painful arc syndrome?
- pain of abduction of arm from 60-120 deg. and passive mov. resistance in this direction
- pain referred to region of insertion of deltoid
- may result from any disorder of subacromial region
What is the sign of calcific supraspinatus tendinitis?
Painful arc syndrome:
- pain in abduction from 50-130 deg. as supraspinatus tendon is in intimate contact with inferior surface of acromion
- no pain in adduction
What is adhesive capulitis of GH joint ("frozen shoulder")?
- adhesive fibrosis and scarring between inflamed capsule of GH joint, rotator cuff, subacromial bursa and deltoid
- causes impaired abduction of arm, but can obtain apparent abduction of up to 45 deg. by elevating and rotating scapula