Ch 4 - MSK: Elbow Flashcards
Describe elbow ROM.
- Elbow flexion: 135°
- Elbow extension: 0° to 5°
- Forearm supination: 90°
- Forearm pronation: 90°
Describe muscles and innervation involved with elbow flexion.
– 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)
Describe muscles and innervation involved with Elbow extension.
– Triceps (radial n, posterior cord: C6, C7, C8)
– Anconeus (radial n, posterior cord: C7, C8, T1)
Describe muscles and innervation involved with forearm supination.
– Supinator (PIN, posterior cord: C5, C6)
– Biceps brachii (musculocutaneous n, lateral cord: C5, C6)
Describe muscles and innervation involved with forearm pronation.
– Pronator quadratus (AIN: C7, C8, T1)
– Pronator teres (median n, lateral cord: C6, C7)
– Flexor carpi radialis (median n, lateral cord: C6, C7)
What does the annular ligament do?
Holds the radial head in proper position
What is the normal carrying angle?
– Males: 5° of valgus
– Females: 10° to 15° of valgus
– >20° is abnormal
What are indications for elbow arthrodesis?
– Arthritis
– Failed surgical procedure
Describe the fusion position of elbow arthrodesis.
– Unilateral: Flexion—90°
– Bilateral: Flexion—110° in one arm and 65° for the other
What causes medial epicondylitis?
Repetitive valgus stress to the elbow
Who is typically affected by medial epicondylitis?
Baseball pitchers
Golfers
What phase of throwing causes medial epicondylitis?
Late cocking and acceleration phase
What phase of a golf swing causes medial epicondylitis?
Backswing and downward follow-through swing just prior to ball impact
What is Little Leaguer’s elbow?
Hypertrophy of the medial epicondyle leading to microtearing and fragmentation of the medial epicondylar apophysis
What can Little Leaguer’s elbow lead to?
Osteochondritis dissecans of the capitellum
What reproduces symptoms of medial epicondylitis on exam?
Resisted wrist flexion and pronation
TTP over common flexor tendon origin
What is the MOI of lateral epicondylitis?
Activities that require repetitive wrist extension and/or forearm supinatio
What types of poor technique with racquet sports can lead to lateral epicondylitis?
– Improper technique for backhand swings
– Inappropriate string tension
– Inappropriate grip size
What tendon is inolved in lateral epicondylitis?
Extensor carpi radialis brevis (ECR-B)
Describe Cozen’s test.
Pain in the lateral epicondyle with making a fist, pronating forearm, radially deviating and extending the wrist against resistance
Describe Mill’s test.
Passive extension of the elbow with forced flexion of the wrist with radial deviation may precipitate pain at the lateral epicondyle
Describe posttreatment RTP for lateral epicondylitis.
– Dec string tension to <55 lb
– Inc grip size
What is the mechanism of olecranon bursitis?
Repetitive trauma Inflammatory disorder (gout, pseudogout, RA)
Who is typically affected by elbow dislocation?
2nd MC dislocation in children and adults
25-30 yo most affected and sports activities account for almost 50% of injuries
What is the MOI of elbow dislocation?
FOOSH
What is the MC direction of elbow dislocation?
98% posterior
What are associated injuries of elbow dislocation?
Radial head fx
Brachial artery
Median nerve
What are treatments of elbow dislocation?
- Reduce dislocation as soon as possible after injury
- Splint for 10 days
- ROM exercises
- NSAIDs
What is the cause of distal biceps tendonitis?
Repetitive elbow flexion and supination or resisted elbow extension
What is the cause of distal triceps tendonitis?
Overuse syndrome secondary to repetitive elbow extension
What is the cause of distal triceps avulsion?
Decelerating counterforce during active elbow extension
What is valgus extension overload (VEO) syndrome?
Overuse elbow injuries in baseball players caused by repetitive valgus forces during the throwing motion, esp cocking and acceleration phases
What is the cause of valgus extension overload (VEO) syndrome?
Valgus forces cause tensile stress in the medial elbow and lateral shear stress in the posterior aspect of the elbow (posteromedial olecranon)
Describe the VEO test.
Flex elbow to 30° and repeatedly extend the elbow fully while applying a valgus stress
What indicates a (+) VEO test?
Pain elicited at the last 5° to 10° of extension
Why should a valgus stress test be done in VEO syndrome?
Performed >90° to rule out MCL injury
What is the cause of MCL/UCL sprain?
A repetitive valgus stress occurring across the elbow most prominently during the acceleration phase of throwing
What indicates a torn UCL on exam?
Medial pain or instability on valgus stress with the elbow, flexed 20° to 30°
What indicates UCL on injury on x-ray?
Valgus stress radiographs demonstrate a 2-mm joint space
What is the cause of a LCL/RCL sprain?
Elbow dislocation from a traumatic event
What indicates a torn LCL on exam?
Lateral pain or instability on varus stress with the elbow flexed 20° to 30°
What indicates LCL on injury on x-ray?
Varus stress radiographs demonstrating a 2-mm joint space
What is pronator teres syndrome?
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
What causes ulnar entrapment in cubital tunnel syndrome?
– Arcade of Struthers
– Hypermobility of the ulnar nerve
– Excessive valgus force at the elbow
– Impingement from osteophytes or loose bodies
What is Panner’s disease?
Osteochondrosis of the elbow
Epiphysial aseptic necrosis of the capitellum
What is the cause of Panner’s disease?
Interference in blood supply to epiphysis> resorption of the ossification center> repair/replacement
Which elbow is typically affected by Panner’s disease?
Dominant elbow of young boys
What is the clinical presentation of Panner’s disease?
- Sx relieved by rest and aggravated by activity
- Tender/ swelling of lateral elbow
- Limited extension
What is seen on radiographs of Panner’s disease?
Sclerosis, patchy areas of lucency with fragmentation
