Elbow Flashcards
What ligament is responsible for posterolateral rotatory instability and a positive pivot shift test in the elbow?
Lateral Ulnar Collateral Ligament
What does the microhistopathology of lateral epicondylitis reveal?
angiofibroblastic hyperplasia, disorganized collagen, and lacks inflammatory cells
During what phase of throwing is valgus load on the elbow the highest?
Late cocking, early acceleration
What are the two bands of the anterior oblique ligament of the MUCL? And what are their function?
anterior band - primary restraint to valgus stress; isometric strain throughout elbow ROM
posterior band - increasing strain during elbow flexion
What are the three components of the MUCL? And which is the primary restraint to valgus stress?
Anterior oblique ligament; posterior ligament, transverse ligament; the anterior oblique band (specifically the anterior band) is the primary restraint to valgus stress
What is the origin and the insertion of the anterior oblique ligament of the MUCL?
O: anteroinferior ridge on medial epicondyle
I: sublime tubercle
During what degrees of elbow ROM is the UCL the primary restraint to valgus stress?
30 to 120 degrees
What are the risk factors for little league elbow?
> 85 mph pitching speed, more than 8 months of pitching per year, >80 pitches per game, continued pitching despite arm fatigue and pain, participating in showcases
What is the orientation of the distal insertion of the long head and short head of the biceps tendon?
The long head of the biceps inserts more proximally while the short head inserts distally at the tuberosity.
Where does the anterior oblique bundle of the ulnar collateral ligament insert?
sublime tubercle
Which muscle is thought to be the instigator of lateral epicondylitis?
ECRB
Where does ECRL originate?
lateral supracondylar ridge
What muscles originate on the lateral epicondyle?
extensor carpi radialis brevis, extensor carpi ulnaris, extensor digitorum, extensor digiti minimi, anconeus (shares same attachment site as ECRB)
What is the origin and the insertion of ECRB?
anterior aspect of the lateral epicondyle and inserts on the third metacarpal
A patient develops posterolateral rotatory instability after arthroscopic debridement for lateral epicondylitis, which structure was injured?
lateral ulnar collateral ligament
What is the origin and the insertion of the lateral ulnar collateral ligament?
originates on the lateral epicondyle of the humerus and inserts upon the supinator crest of the ulna.
What is the survival rate of total elbow arthroplasty in patients with rheumatoid arthritis at 15 years?
upwards of 90% survival rate at 15 years
What is the most common mode of failure of the lateral ulnar collateral ligament associated with an elbow dislocation?
Avulsion off the humeral origin
What is the origin of the LUCL?
lateral epicondyle
What are the primary static stabilizers of the elbow joint?
ulnohumeral joint, anterior bundle of the MCL, LCL complex (including the LUCL)
What are the secondary static stabilizers of the elbow joint?
radiocapitellar joint, the capsule, origins of the common flexor and extensor tendons
What are the dynamic stabilizers of the elbow?
muscles that cross the joint - brachialis, anconeus, triceps
In extension and axial loading, how much weight is carried through the ulnohumeral joint? and the radiocapitellar joint, respectively?
40% through ulnohumeral joint; 60% through radiohumeral joint
Where does the anterior bundle of the medial ulnar collateral ligament attach distally?
Sublime tubercle on the ulna
Microtrauma from repetitive valgus stress leads to rupture of the […] band of the medial UCL
anterior
Baseball pitchers place significant valgus stress on the elbow in the […] and […] phase of throwing
late cocking; early acceleration
The UCL primary restraint to elbow valgus stress from […] degrees of flexion
30 to 120
In elbow UCL anterior band reconstructions, […] technique is associated with better patient outcomes and lower complication rate compared to figure-of-8 fixation
humeral docking
The […] autograft most common graft used for UCL reconstruction surgery.
palmaris longus
What is the blood supply to palmaris longus?
posterior ulnar recurrent artery
What is the innervation of palmaris longus?
median nerve
Patients undergoing UCL reconstruction should avoid valgus stress until […] months post op
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What is the most common complication following elbow UCL reconstruction?
ulnar n. neuropraxia
Lateral collateral ligament complex of the elbow most commonly fails at […]
humeral origin (lateral epicondyle)
[…] is the primary stabilizer to varus & ER stress at the elbow
LUCL
What is the insertion of the LUCL?
the tubercle of the supinator crest of the ulna
During flexion of the elbow on the lateral pivot shift test the […] reduces the radial head
triceps tension
What is the intermuscular plane of the Kocher approach to the elbow?
ECU and anconeus
During the Kocher approach to the elbow, the forearm should be kept in […] to avoid injury to the PIN
pronation
During the Kocher approach to the elbow, the PIN is not in danger as long as dissection remains proximal to […].
annular ligament
What is the inter-nervous plane in the Kocher approach to the elbow?
Radial n (anconeus); PIN (ECU)
After reconstruction of the LUCL complex, it is important to keep forearm in full […] during ROM until after 6 weeks
pronation
Partial distal biceps tendon tears occur primarily on the […] side of the tuberosity footprint.
radial
What is the most medial structure in the antecubital fossa?
median nerve
What is the most lateral structure in the antecubital fossa?
radial nerve
In the antecubital fossa, the […] vessels lie superficial to biceps tendon.
radial recurrent
The short head of the distal biceps attaches […] and […] on the radial tuberosity.
distal; anterior
The long head of the distal biceps attaches […] and […] on the radial tuberosity.
proximal; posterior
Which is a better supinator, the long head or short head of the biceps?
Long head
The lacertus fibrosis originates from the distal […] head of the biceps tendon
short
In a distal biceps rupture, is more supination or flexion strength lost?
supination (note: 50% loss in sustained supination; 40% loss in supination; only 30% flexion strength lost)
In an anterior single incision technique for distal biceps repair, the intermuscular interval is between the […] and […].
Brachioradialis (radial n) and pronator teres (median n)
In a single incision approach to a distal biceps repair, the lateral antebrachial cutaneous nerve (LABCN) is identified as it exits between the […] and […] muscles at antecubital fossa.
biceps; brachialis
The lateral antebrachial cutaneous nerve (LABCN) originates from […] cord of brachial plexus
lateral
The lateral antebrachial cutaneous nerve (LABCN) is the terminal branch of […] nerve.
musculocutaneous
In a single incision distal biceps repair, protect PIN by limiting forceful lateral retraction and maintaining forearm […].
Supination
What is the most common complication following a single-incision distal biceps repair?
Injury to LABCN
There is a higher rate of LABCN injury in the […]-incision distal biceps repair technique.
single (most retraction)
In a dual-incision distal biceps repair, the posterior interval is between […] and […]
ECU; EDC
What is the most common complication following a dual-incision distal biceps repair?
LABCN injury
What is the overall most common complication to a distal biceps repair?
LABCN injury (higher in single incision technique)
What is the 2nd most common cutaneous nerve injured in distal biceps repair?
superficial radial nerve
Bone tunnels […] to the radial tuberosity can increase the risk of proximal radius fracture following a distal biceps tendon repair.
proximal
Which muscles shares same attachment site as ECRB?
Anconeus
What is Maudsley’s test?
resisted extension of the 3rd digit of the hand leads topain over the lateral epicondyle
ECRB located […] and […] to ECRL
deep; posterior
What is the most frequent site of PIN entrapment?
tendinous edge of the supinator (arcade of Frohse)
What vessels can cause PIN entrapment?
radial recurrent vessels (Leash of Henry)
The PIN passes over […] muscle origin to reach interosseous membrane
abductor pollicis longus
Longest survivorship of TEA is seen when performed for […] compared to other indications
rheumatoid arthritis
[…] designs TEA requires competent collateral ligaments
Unconstrained (unlinked)
What is the most common complication of unconstrained (unlinked) TEA?
instability
Semiconstrained or linked TEA […] stress on bone-cement interface, which […] incidence of component loosening
reduces; reduces
Which TEA design has the best results?
Semi-constrained
Which TEA design has the highest rates of loosening?
Constrained
In elbow arthroscopy, the […] portal usually avoided due to proximity to ulnar nerve
posterior medial
What is the most common nerve palsy seen after elbow arthroscopy?
transient ulnar nerve palsy
The radial nerve is at risk during placement of which elbow arthroscopy portal?
proximal anterolateral
In elbow arthroscopy, the […] muscle provides protective layer between anterior capsule and radial nerve proximal to the radial neck
brachialis
In elbow arthroscopy, the medial antebrachial cutaneous nerve is at risk from […] portal
anteromedial
In elbow arthroscopy, the median nerve is at risk fromthe […] portal
anteromedial
In elbow arthroscopy, the PIN is at risk with the […] portal
distal anterolateral
What is a known complication from intra-articular steroid injection at the time of elbow arthroscopy?
infection
What is the MOA of penicillin?
Binds to the transpeptidase enzyme and inhibits cell wall synthesis
The medial UCL is subjected to near-failure tensile stresses during the […] phase of throwing.
late cocking/early acceleration
Which structure is the most important static stabilizer to valgus forces at the elbow in a throwing athlete?
anterior band of the anterior bundle of the UCL
TEA for rheumatoid arthritis has been shown to have very positive survival analysis up to […] years, with studies showing rates of survival rates of over 90%.
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What is the origin of ECRL?
Lateral supracondylar ridge
What is the origin of ECRB?
Anterior aspect of lateral epicondyle (note: same origin as anconeus)
