Blue Boxes 1: Joints of the Upper Limb

Question 1

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?

Answer 1

Because the blow of most forces are usually transmitted along the length of the clavicle

Question 2

What is an ankylosis?

Answer 2

Stiffening or fixation of a joint

Question 3

When ankylosis of the SC joint occurs, what is surgically done to maintain shoulder movement?

Answer 3

A section of the center of the clavicle is removed, creating a pseudojoint or flail joint to permit scapular movement

Question 4

Which joint is weaker, AC or SC?

Answer 4

AC?

Question 5

What is an AC joint dislocation often called?

Answer 5

shoulder separation

Question 6

What is the name of the extrinsic ligament supporting the AC joint?

Answer 6

coracoclavicular ligament

Question 7

What happens when the coracoclavicular ligament tears?

Answer 7

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.

Question 8

What is calcific scapulohumeral bursitis?

Answer 8

Inflammation and calcification of the subacromial bursa resulting in pain, tenderness, and limitation of movement of the glenohumeral joint

Question 9

What rotator cuff tendon commonly has a deposition of calcium?

Answer 9

Supraspinatus tendon

Question 10

What is subacromial bursitis?

Answer 10

when a calcium deposit of the supraspinatus tendon irritates the overlying subacromial bursa, producing an inflammatory reaction

Question 11

What is painful arc syndrome?

Answer 11

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

Question 12

Why do people with subacromial bursitis usually not feel pain as long as the glenohumeral joint is adducted?

Answer 12

Becuase in this position the painful lesion is away from the inferior surface of the acromion

Question 13

What is commonly injured during repetitive use of the upper limb above the horizontal?

Answer 13

The rotator cuff

Question 14

How does degenerative tendonitis of the rotator cuff develop?

Answer 14

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

Question 15

How would you test for degenerative tendonitis of the rotator cuff?

Answer 15

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

Question 16

The deltoid starts to help with arm abduction at what degree?

Answer 16

15 degrees

Question 17

Most dislocations of the glenohumreal joint occur in what direction?

Answer 17

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

Question 18

What often occurs after an avulsion fracture of the greater tubercle of the humerus?

Answer 18

Inferior dislocation of the glenohumeral joint

There is an absence of the upward and medial pull produced by muscles attaching tot he tubercle

Question 19

What nerve may be injured when the glenohumeral joint dislocates? Head of humerus moves into quadrangular space

Answer 19

Axillary nerve

Question 20

What is adhesive capsulitis?

Answer 20

“frozen shoulder”by elevating and rotating the scapula

Can’t abduct the arm and can obtain an apparent abduction of up to 45 degrees

Question 21

What causes adhesive capsulitis?

Answer 21

adhesive fibrosis and scarring between the inflamed joint capsule of the glenohumeral joint

Question 22

What is subcutaneous olecranon bursitis commonly called?

Answer 22

student’s elbow
dart thrower’s elbow
miner’s elbow

Question 23

What does subtendinous olecranon bursitis result from?

Answer 23

excessive friction between the triceps tendon and olecranon

Question 24

When is pain from subtendinous olecranon bursitis most severe?

Answer 24

Durnig flexion of the forearm because of pressure exerted on the inflamed bursa by the triceps tendon

Question 25

When would someone experience pain from bicipitoradial bursitis?

Answer 25

when the forearm is pronated because this action compresses the bicipitoradial bursa against the anterior half of the tuberosity of the radius

Question 26

Avulsion of the medial epicondyle is much more common in children than adults because?

Answer 26

The epiphysis fro the medial epicondyle may not fuse with the distal end of the humerus until up to age 20

Question 27

What nerve is commonly injured by a avulsion of the medial epicondyle?

Answer 27

Ulnar

Question 28

What is the Tommy John procedure?

Answer 28

Reconstruction of the ulnar collateral ligament

Question 29

Where do they commonly take a tendon to replace the UCL in tommy john surgery?

Answer 29

palmaris longus or plantaris

Question 30

What ligament is often torn in elbow dislocations?

Answer 30

Ulnar collateral ligament

Question 31

What is subluxation?

Answer 31

Incomplete dislocation

Question 32

What ligament forms a socket for the radius at the elbow?

Answer 32

Anular ligament

Question 33

What is the common source of pain in a radial head subluxation or dislocation?

Answer 33

A pinched anular ligament

Question 34

What do we call a fracture to the distal end of the radius?

Answer 34

Colles fracture

Question 35

What is Bull rider’s thumb?

Answer 35

A sprain of the radial collateral ligament, and an avulsion fracture of the lateral part of the proximal phalanx of the thumb

Question 36

What is skier’s thumb? or game-keeper’s thumb?

Answer 36

Rupture or chronic laxity of the collateral ligament of the 1st MP joint

Question 37

What causes skier’s thumb?

Answer 37

hyperabduction of the MP joint of the thumb.

In severe injuries the head of the metacarpal has an avulsion fracture