Ch 4 - MSK: Elbow

Question 1

Describe elbow ROM.

Answer 1

• Elbow flexion: 135°
• Elbow extension: 0° to 5°
• Forearm supination: 90°
• Forearm pronation: 90°

Question 2

Describe muscles and innervation involved with elbow flexion.

Answer 2

– Brachialis (musculocutaneous n, lateral cord: C5, C6, C7)
– Biceps brachii (musculocutaneous n, lateral cord: C5, C6)
– Brachioradialis (radial n, posterior cord: C5, C6, C7)
– Pronator teres (median n, lateral cord: C6, C7)

Question 3

Describe muscles and innervation involved with Elbow extension.

Answer 3

– Triceps (radial n, posterior cord: C6, C7, C8)

– Anconeus (radial n, posterior cord: C7, C8, T1)

Question 4

Describe muscles and innervation involved with forearm supination.

Answer 4

– Supinator (PIN, posterior cord: C5, C6)

– Biceps brachii (musculocutaneous n, lateral cord: C5, C6)

Question 5

Describe muscles and innervation involved with forearm pronation.

Answer 5

– Pronator quadratus (AIN: C7, C8, T1)
– Pronator teres (median n, lateral cord: C6, C7)
– Flexor carpi radialis (median n, lateral cord: C6, C7)

Question 6

What does the annular ligament do?

Answer 6

Holds the radial head in proper position

Question 7

What is the normal carrying angle?

Answer 7

– Males: 5° of valgus
– Females: 10° to 15° of valgus
– >20° is abnormal

Question 8

What are indications for elbow arthrodesis?

Answer 8

– Arthritis

– Failed surgical procedure

Question 9

Describe the fusion position of elbow arthrodesis.

Answer 9

– Unilateral: Flexion—90°

– Bilateral: Flexion—110° in one arm and 65° for the other

Question 10

What causes medial epicondylitis?

Answer 10

Repetitive valgus stress to the elbow

Question 11

Who is typically affected by medial epicondylitis?

Answer 11

Baseball pitchers

Golfers

Question 12

What phase of throwing causes medial epicondylitis?

Answer 12

Late cocking and acceleration phase

Question 13

What phase of a golf swing causes medial epicondylitis?

Answer 13

Backswing and downward follow-through swing just prior to ball impact

Question 14

What is Little Leaguer’s elbow?

Answer 14

Hypertrophy of the medial epicondyle leading to microtearing and fragmentation of the medial epicondylar apophysis

Question 15

What can Little Leaguer’s elbow lead to?

Answer 15

Osteochondritis dissecans of the capitellum

Question 16

What reproduces symptoms of medial epicondylitis on exam?

Answer 16

Resisted wrist flexion and pronation

TTP over common flexor tendon origin

Question 17

What is the MOI of lateral epicondylitis?

Answer 17

Activities that require repetitive wrist extension and/or forearm supinatio

Question 18

What types of poor technique with racquet sports can lead to lateral epicondylitis?

Answer 18

– Improper technique for backhand swings
– Inappropriate string tension
– Inappropriate grip size

Question 19

What tendon is inolved in lateral epicondylitis?

Answer 19

Extensor carpi radialis brevis (ECR-B)

Question 20

Describe Cozen’s test.

Answer 20

Pain in the lateral epicondyle with making a fist, pronating forearm, radially deviating and extending the wrist against resistance

Question 21

Describe Mill’s test.

Answer 21

Passive extension of the elbow with forced flexion of the wrist with radial deviation may precipitate pain at the lateral epicondyle

Question 22

Describe posttreatment RTP for lateral epicondylitis.

Answer 22

– Dec string tension to <55 lb

– Inc grip size

Question 23

What is the mechanism of olecranon bursitis?

Answer 23

Repetitive trauma
Inflammatory  disorder  (gout, pseudogout, RA)

Question 24

Who is typically affected by elbow dislocation?

Answer 24

2nd MC dislocation in children and adults

25-30 yo most affected and sports activities account for almost 50% of injuries

Question 25

What is the MOI of elbow dislocation?

Answer 25

FOOSH

Question 26

What is the MC direction of elbow dislocation?

Answer 26

98% posterior

Question 27

What are associated injuries of elbow dislocation?

Answer 27

Radial head fx Brachial artery Median nerve

Question 28

What are treatments of elbow dislocation?

Answer 28

* Reduce dislocation as soon as possible after injury * Splint for 10 days * ROM exercises * NSAIDs

Question 29

What is the cause of distal biceps tendonitis?

Answer 29

Repetitive elbow flexion and supination or resisted elbow extension

Question 30

What is the cause of distal triceps tendonitis?

Answer 30

Overuse syndrome secondary to repetitive elbow extension

Question 31

What is the cause of distal triceps avulsion?

Answer 31

Decelerating counterforce during active elbow extension

Question 32

What is valgus extension overload (VEO) syndrome?

Answer 32

Overuse elbow injuries in baseball players caused by repetitive valgus forces during the throwing motion, esp cocking and acceleration phases

Question 33

What is the cause of valgus extension overload (VEO) syndrome?

Answer 33

Valgus forces cause tensile stress in the medial elbow and lateral shear stress in the posterior aspect of the elbow (posteromedial olecranon)

Question 34

Describe the VEO test.

Answer 34

Flex elbow to 30° and repeatedly extend the elbow fully while applying a valgus stress

Question 35

What indicates a (+) VEO test?

Answer 35

Pain elicited at the last 5° to 10° of extension

Question 36

Why should a valgus stress test be done in VEO syndrome?

Answer 36

Performed >90° to rule out MCL injury

Question 37

What is the cause of MCL/UCL sprain?

Answer 37

A repetitive valgus stress occurring across the elbow most prominently during the acceleration phase of throwing

Question 38

What indicates a torn UCL on exam?

Answer 38

Medial pain or instability on valgus stress with the elbow, flexed 20° to 30°

Question 39

What indicates UCL on injury on x-ray?

Answer 39

Valgus stress radiographs demonstrate a 2-mm joint space

Question 40

What is the cause of a LCL/RCL sprain?

Answer 40

Elbow dislocation from a traumatic event

Question 41

What indicates a torn LCL on exam?

Answer 41

Lateral pain or instability on varus stress with the elbow flexed 20° to 30°

Question 42

What indicates LCL on injury on x-ray?

Answer 42

Varus stress radiographs demonstrating a 2-mm joint space

Question 43

What is pronator teres syndrome?

Answer 43

Median nerve compression at the elbow by: – Ligament of Struthers or supracondylar spur – Lacertus fibrosus – Pronator teres muscle – B/W 2 heads of the FDS

Question 44

What causes ulnar entrapment in cubital tunnel syndrome?

Answer 44

– Arcade of Struthers – Hypermobility of the ulnar nerve – Excessive valgus force at the elbow – Impingement from osteophytes or loose bodies

Question 45

What is Panner's disease?

Answer 45

Osteochondrosis of the elbow | Epiphysial aseptic necrosis of the capitellum

Question 46

What is the cause of Panner's disease?

Answer 46

Interference in blood supply to epiphysis> resorption of the ossification center> repair/replacement

Question 47

Which elbow is typically affected by Panner's disease?

Answer 47

Dominant elbow of young boys

Question 48

What is the clinical presentation of Panner's disease?

Answer 48

* Sx relieved by rest and aggravated by activity * Tender/ swelling of lateral elbow * Limited extension

Question 49

What is seen on radiographs of Panner's disease?

Answer 49

Sclerosis, patchy areas of lucency with fragmentation