Blue Boxes 1: Joints of the Upper Limb Flashcards
Why is it more likely for the clavicle to fracture near the junction of its middle and lateral thirds than for the SC joint to dislocate?
Because the blow of most forces are usually transmitted along the length of the clavicle
What is an ankylosis?
Stiffening or fixation of a joint
When ankylosis of the SC joint occurs, what is surgically done to maintain shoulder movement?
A section of the center of the clavicle is removed, creating a pseudojoint or flail joint to permit scapular movement
Which joint is weaker, AC or SC?
AC?
What is an AC joint dislocation often called?
shoulder separation
What is the name of the extrinsic ligament supporting the AC joint?
coracoclavicular ligament
What happens when the coracoclavicular ligament tears?
The shoulder separates from the clavicle and falls because of the weight of the upper limb.
This dislocation of the AC joint makes the acromion more prominent.
What is calcific scapulohumeral bursitis?
Inflammation and calcification of the subacromial bursa resulting in pain, tenderness, and limitation of movement of the glenohumeral joint
What rotator cuff tendon commonly has a deposition of calcium?
Supraspinatus tendon
What is subacromial bursitis?
when a calcium deposit of the supraspinatus tendon irritates the overlying subacromial bursa, producing an inflammatory reaction
What is painful arc syndrome?
Paint from subacromial bursitis that occurs during 50-130 degrees of abduction of the upper limb. During this arc the supraspinatus tendon is in intimate contact with the inferior surface of the acromion
Why do people with subacromial bursitis usually not feel pain as long as the glenohumeral joint is adducted?
Becuase in this position the painful lesion is away from the inferior surface of the acromion
What is commonly injured during repetitive use of the upper limb above the horizontal?
The rotator cuff
How does degenerative tendonitis of the rotator cuff develop?
Repetitive use of the rotator cuff muscles may allow the humeral head and rotator cuff to impinge on the conraco-acromial arch, producing irritation of the arch and inflammation of the rotator cuff
How would you test for degenerative tendonitis of the rotator cuff?
THE person is asked to lower the fully abducted limb slowly. From approximately 90 deg abduction, the limb will suddenly drop to the side in an uncontrolled manner if the rotator cuff (especially the supraspinatus part) is diseased or torn
The deltoid starts to help with arm abduction at what degree?
15 degrees
Most dislocations of the glenohumreal joint occur in what direction?
downward (inferior)
They are described clinically as anterior or posterior (rare) indicating whether the humeral head has descended anterior or posterior to the infraglenoid tubercle and long head of the triceps. THe head ends up lying anterior or posterior to the glenoid cavity
What often occurs after an avulsion fracture of the greater tubercle of the humerus?
Inferior dislocation of the glenohumeral joint
There is an absence of the upward and medial pull produced by muscles attaching tot he tubercle
What nerve may be injured when the glenohumeral joint dislocates? Head of humerus moves into quadrangular space
Axillary nerve
What is adhesive capsulitis?
“frozen shoulder”by elevating and rotating the scapula
Can’t abduct the arm and can obtain an apparent abduction of up to 45 degrees
What causes adhesive capsulitis?
adhesive fibrosis and scarring between the inflamed joint capsule of the glenohumeral joint
What is subcutaneous olecranon bursitis commonly called?
student’s elbow
dart thrower’s elbow
miner’s elbow
What does subtendinous olecranon bursitis result from?
excessive friction between the triceps tendon and olecranon
When is pain from subtendinous olecranon bursitis most severe?
Durnig flexion of the forearm because of pressure exerted on the inflamed bursa by the triceps tendon
When would someone experience pain from bicipitoradial bursitis?
when the forearm is pronated because this action compresses the bicipitoradial bursa against the anterior half of the tuberosity of the radius
Avulsion of the medial epicondyle is much more common in children than adults because?
The epiphysis fro the medial epicondyle may not fuse with the distal end of the humerus until up to age 20
What nerve is commonly injured by a avulsion of the medial epicondyle?
Ulnar
What is the Tommy John procedure?
Reconstruction of the ulnar collateral ligament
Where do they commonly take a tendon to replace the UCL in tommy john surgery?
palmaris longus or plantaris
What ligament is often torn in elbow dislocations?
Ulnar collateral ligament
What is subluxation?
Incomplete dislocation
What ligament forms a socket for the radius at the elbow?
Anular ligament
What is the common source of pain in a radial head subluxation or dislocation?
A pinched anular ligament
What do we call a fracture to the distal end of the radius?
Colles fracture
What is Bull rider’s thumb?
A sprain of the radial collateral ligament, and an avulsion fracture of the lateral part of the proximal phalanx of the thumb
What is skier’s thumb? or game-keeper’s thumb?
Rupture or chronic laxity of the collateral ligament of the 1st MP joint
What causes skier’s thumb?
hyperabduction of the MP joint of the thumb.
In severe injuries the head of the metacarpal has an avulsion fracture
