Elbow Flashcards
In general, who has a larger carrying angle, men v. women?
Women
Which epicondyle is more prominent?
Medial
What 3 main anatomical attachments occur at the medial epicondyle?
Flexors, ulnar collateral ligament, pronator teres
What 3 main anatomical attachments occur at the lateral epicondyle?
Extensors, radial collateral ligament, supinator
What is the attachment site for the biceps brachii?
Radial tuberosity
The radius articulates with what aspect of the humerus?
Capitellum
The ulna articulates with what aspects of the humerus?
Coronoid fossa - olecranon fossa
In what motion does the UCL become taut?
Flexion - higher the deg of flexion, the more taut the ligament
In what motion is the RCL taut?
RCL is taut throughout flexion and extension - increases even more in supination
Name the flexors of the elbow (3) and their nerve innervations:
Flexor of shoulder additionally (1)
Biceps - musculocutaneous
Brachialis - musculocutaneous
Brachioradialis - radial
Coracobrachialis - musculocutaneous
Name the extensor of the elbow (2) and their nerve innervations:
Triceps - radial
Anconeus - radial
In general, the extensor muscles (5) are innervated by what peripheral nerve?
Radial nerve - ECRL, ECRB, extensor digitorum, extensor digiti minimi, extnesor carpi ulnaris
Supinator muscle is innervated and pierced by what peripheral nerve?
Radial nerve
When the radial nerve exits supinator muscle, what does it become?
Posterior interosseous nerve
Which muscle is the primary supinator of the elbow/forearm?
Biceps - supinator assists
Which nerve innervates pronator teres?
Median nerve
Flexor muscle group is innervated by both median and ulnar nerves - distinguish between FCR / FCU / Flexor digitorum superficialis / Flexor digitorum profundus ->
FCR - median
FCU - ulnar
Flexor digitorum superificialis - median
Flexor digitorum profundus - digits 2 and 3 median // digits 4 and 5 ulnar
Posterior interosseous nerve innervates 4 thumb/index finger muscles:
1) abductor pollicis
2) extensor pollicis longus
3) extensor pollicis brevis
4) extensor indicis
After median nerve passes through pronator teres, it becomes what peripheral nerve?
Anterior interosseous nerve
Anterior interosseous nerve innervates two important muscles in making the OK sign: they are ->
Flexor pollicis longus
FDProfundus (digits 2/3 - branch of median nerve)
Which gender is more affected with lateral tendinoapthy?
Women
Does medial tendinopathy affect the dominant or non-dominant elbow?
Dominant > non-dominant
What age group and gender is most prevalent for distal biceps rupture?
Men, age 40-60 - also younger men powerlifting/body building
What are the Biceps squeeze test and Hook test?
Assessment of integrity of distal biceps tendon
Is posterolateral rotatory instability a dislocation of the radial head or humeroulnar/humeroradial joints?
ER of the ulnar away from trochlea with subluxing humeroulnar & radial joints
Define the lateral pivot shift test for the elbow:
Axillary compression down forearm shaft, starting in extension -> moving into flexion and applying vaglus force with supination to produce clunk between 40-70 deg of flexion
Who is at inc risk for UCL injury?
Overhead throwing athlete - esp younger with open physis
In Little Leaguer’s Elbow, what puts the athlete at inc risk for developing UCL injury?
Higher pitch count
With Tommy John Surgery, what is time frame for return to sport?
9-12 months - return to progressive throwing at 4 months
What loss of ROM appears to be linked with length of time immobilized after elbow dislocation?
Extension
Three sub/objective signs indicating fracture in the elbow:
1) Hx of trauma
2) presence of fat pad sign (effusion over posterior elbow)
3) inability to fully extend elbow
Cardinal signs of olecranon fracture: (3)
Loss of extension
Triceps weakness/disruption
Fragment on radiograph
Can the radial head be excised if the UCL is not intact?
NO! If UCL is intact, pronator/flexor mass can compensate
Define Monteggia fracture:
Fx of proximal third of ulan with dislocation of radial head
Define Essex-Lopresti fracture:
Fx of radial head with concurrent dislocation of distal RUJ, disruption of IOM
What nerve is affected with severe elbow flexion contracture?
Ulnar - can develop ulnar neruritis
What can develop for up to 2 months after soft tissue injury? Hallmark sign is pain with progressive loss of motion
Heterotropic ossificans
What nerve injury is the transient physiological block caused by ischemia (pressure/stretch) without Wallerian degeneration - nerve structure intact?
Neurapraxia - no positive Tinel without Wallerian degeneration
What nerve injury occurs when the axons of the nerve are badly damaged, but the architecture of the nerve remains intact - Wallerian degeneration occurs?
Axonotmesis - positive Tinels
What nerve injury occurs when the structure of the nerve is destroyed by cutting, scarring, or prolong severe compression - Wallerian degeneration occurs?
Neurotmesis - positive Tinels
What is the expected recovery of neurapraxia?
Will resolve - days to weeks
What is the expected recovery for axonotmesis?
Recovery at 1mm/day - >18 months of recovery = poorer prognosis
What is expected recovery for neurontmesis?
Incomplete recovery, surgical intervention usually required
What nerve disorder are overhead throwers most likely to develop?
Cubital tunnel syndrome; traction with extreme valgus stress on medial arm
Define Wartenburgs sign:
Place hand flat on table, passively abduct digits - inability to adduct 5th digit; indication of ulnar nerve palsy
Define Froments sign:
Attempts to remove piece of paper between thumb and index finger will result in inability to hold paper or hyperflexion of IP of thumb; indicates ulnar nerve palsy
What is the hallmark sign for Anterior Interosseous Nerve entrapment?
Inability to make OK sign - decreased motor function of flexor pollicis longus/flexor digitorum profundus (2/3)
What is a distinguishing feature between AIN entrapment and pronator teres syndrome?
In AIN syndrome, there are no sensory sxs in the fingers - pronator teres may have sensory component like CTS
What are distinguishing tests for pronator teres syndrome versus CTS?
Tinels and prolong wrist flexion - do no reproduce sxs in pronator teres syndrome
What nerves are seen commonly affected in Parsonage Turner Syndrome?
Commonly affects axillary nerve, upper trunk of brachial plexus (suprascapular and long thoracic nerve)
Does Posterior Interosseous Nerve syndrome have sensation loss?
No
PIN syndrome causes weakness in what muscle group?
Finger extensors
What diagnosis causes pain with resisted supination, repetitive wrist flexion but has no motor or sensory loss?
Radial tunnel syndrome
What population is more greatly affected by Osteochondritis Dissecans?
Adolescents - male 12-17 y.o. - esp pitchers
What disease consists of epicondyle apophysitis in children 7-10 y.o. with non-traumatic development?
Panner’s disease
Which arthritis has best outcomes for Total elbow arthroplasty?
RA > OA (traumatic)
What is the MCID for the DASH?
10-17
What is the MCID for the quickDASH?
19
