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61 Cards in this Set
- Front
- Back
In relation to the transepicondylar axis of the humerus, is the humerus retroverted or anteverted and to what degree?
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Retroverted 30 degrees
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Which is more commonly involved in fractures, the anatomic or surgical neck of the humerus?
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The surgical
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From anterior to posterior, what 3 cuff muscles attach at the greater tuberosity?
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Supraspinatus, Infraspinatus, Teres Minor
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What is the course of the radial nerve?
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Terminal branch of posterior cord.
This nerve travels along the subscapularis to join with the deep brachial artery at the triangular interval. Approximately 10-14 cm from the acromion, the nerve and artery travel along the spiral groove separating the medial and lateral heads of the triceps |
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What part of the humerus articulates with the olecranon of the ulna? What articulates with the radial head?
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The trochlea of humerus articulates with the olecranon medially.
The capitellum articulates with the radial head |
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Normal articular alignment of the distal humerus has what type of tilt and to what degree?
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A 7-degree valgus tilt (carrying angle)
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What is the axis of rotation for the elbow?
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Axis of rotation for the elbow is centered through the trochlea and capitellum and passes through a point anteroinferior on the medial epicondyle.
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In what position will patients hold their arm if they have an elbow effusion because it is the most comfortable?
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Capsule allows maximum distension at approximately 70 to 80 degrees of flexion
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Where does the anterior capsule attach at the elbow?
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Approximately 6 mm distal to the tip of the coronoid. The coronoid tip is an intraarticular structure that is visualized during elbow arthroscopy
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Where does the MCL of the elbow arise from, where does it insert, how many bundles does it have, and in what motion does it provide stability?
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Arises from the anteroinferior portion of the medial humeral epicondyle.
The anterior bundle (which is the most important) inserts 18mm distal to the coronoid tip. Made up of 3 bundles: anterior, posterior, and transverse Provides stability in valgus stress - valgus stability with the arm in pronation suggests that the anterior bundle is intact |
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What parts make up the radial collateral (lateral collateral) ligament of the elbow? Where does this ligament originate?
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Annular, Radial, and Ulnar parts. Originates on the lateral humeral epicondyle near the axis of elbow rotation
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The lateral ulnar collateral ligament (LUCL) is an essential elbow stabilizer and runs between where?
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Runs from the lateral epicondyle to the ulna supinator crest
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A deficiency of the LUCL of the elbow manifests as what?
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Posterolateral rotatory instability of the elbow
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The musculocutaneous nerves comes from the ______________________ cord of the brachial plexus, pierces the __________ muscle ____________centimeters distal to the ___________. It innervates the ____________, ___________, and ___________ then gives off a branch to the elbow joint before terminating as the ________________ which is located deep to the cephalic vein
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The musculocutaneous nerves comes from the lateral cord of the brachial plexus, pierces the coracobrachialis muscle 5-8 centimeters distal to the coracoid. It innervates the coracobrachialis, brachialis, and the biceps then gives off a branch to the elbow joint before terminating as the lateral antebrachial cutaneous nerve of the forearm which is located deep to the cephalic vein
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The radial nerve comes from the __________ cord of the brachial plexus, spirals around the humerus (medial to lateral) in the ________ at a distance of approximately ________ cm from the ________. It emerges on the lateral side of the arm after piercing the _____________ approximately __________ cm above the trochlea between the _________and __________ muscles anterior to the _____________ (where it supplies the ____________ muscle)
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The radial nerve comes from the posterior cord of the brachial plexus,spirals around the humerus (medial to lateral) in the SPIRAL GROOVE at a distance of approximately 13 cm from the TROCHLEA. It emerges on the lateral side of the arm after piercing the LATERAL INTERMUSCULAR SEPTUM approximately 7.5 cm above the trochlea between the BRACHIALIS and BRACHIORADIALIS muscles anterior to the LATERAL EPICONDYLE (where it supplies the ANCONEUS muscle)
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What vessel does the median nerve run with in the arm?
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The brachial artery. The median nerve crosses the brachial artery lateral to medial during its course
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The ulnar nerve comes from what cord of the brachial plexus? Where does it run in the arm?
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The medial cord. Passes medial to the brachial artery in the arm and then runs behind the medial epicondyle of the humerus, where it is superficial
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What structures form the cubital fossa? (3)
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Distal humerus proximally, the brachioradialis laterally, and the pronator teres medially
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The brachial artery originates at the lower border of the tendon of the _________ and continues to the elbow, where it bifurcates into the _______ and ________ arteries. It lies medial in the arm, curving laterally to enter the ________________
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The brachial artery originates at the lower border of the tendon of the TERES MAJOR and continues to the elbow, where it bifurcates into the RADIAL and ULNAR arteries. It lies medial in the arm, curving laterally to enter the CUBITAL FOSSA
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What are the principal branches of the brachial artery?
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▪ Deep brachial (also known as the profunda, this artery accompanies the radial nerve posteriorly in the triangular interval)
▪ Superior and inferior ulnar collateral arteries ▪ The nutrient and muscular branches ▪ The supratrochlear artery (the least flexible branch) |
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What is the interval for the proximal approach to the anterior humerus and what structures are at risk?
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Deltoid (axillary nerve) and pectoralis major (medial and lateral pectoral nerves).
Risk: the anterior circumflex humeral vessels may need to be ligated |
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What is the interval for a distal anterior approach to the humerus?
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Distal approach: between the biceps (musculocutaneous) and brachialis (musculocutaneous/radial) laterally, or the brachialis can be split because of its dual innervation.
The radial and axillary nerves could be at risk mostly due to traction |
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What is the interval for the posterior approach to the humerus? Describe the superficial and deep approaches.
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None, it is triceps splitting (radial nerve).
Superficial approach: Dissect between the lateral and long heads of the triceps. Deep approach: Split the medial head of the triceps. |
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What structure would be at risk with proximal extension of the posterior approach to the humerus?
What structure is at risk if a subperiosteal dissection is not performed meticulously? |
The Radial nerve: limits proximal extension of approach
Identify and protect the radial nerve as it passes from medial to lateral in the proximal part of the exposure. Ulnar nerve: jeopardized unless subperiosteal dissection of the humerus is performed meticulously |
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In the posterior approach to the elbow, how is predrilling of the olecranon osteotomy best performed?
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With a chevron cut 2cm distal to the tip
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What is the interval for the proximal medial approach to the elbow? What is at risk?
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between the brachialis (musculocutaneous nerve) and the triceps (radial nerve) proximally. Incise the anterior third of the flexor pronator mass to reach the anterior elbow capsule
Risks: The ulnar and medial antebrachial cutaneous nerves are in the field and must be protected |
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What is the interval for the distal medial approach to the elbow?
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Between the brachialis (musculocutaneous) and pronator teres (median nerve) distally.
Risks: The ulnar and medial antebrachial cutaneous nerves are in the field and must be protected |
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What is the interval for the lateral or posterolateral (Kocher's) approach to the elbow? How would you protect the PIN from injury?
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Interval: between the anconeus (radial nerve) and the origin of the main extensor (extensor carpi ulnaris, posterior interosseous nerve [PIN]).
Dissection: Pronate the arm to move the PIN anteriorly and radially, and approach the radial head through the proximal supinator fibers |
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What is the interval to proximally extend the lateral approach to the elbow?
Why should you place a retractor under the brachialis anteriorly? |
Interval: along lateral intercondylar ridge, between triceps and extensor carpi radialis longus (ECRL) (brachioradialis nerve)
Dissection: Subperiosteally expose the anterior humerus and lateral column. Risks: retractor placed under brachialis anteriorly to protect radial nerve, distally limited by PIN |
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What are the 3 portals for elbow arthroscopy and what structures are at risk when placing them?
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1. Anterolateral portal (risk for injury to the radial nerve)
2. Anteromedial portal (risk for injury to the medial antebrachial cutaneous and median nerves) 3. Posterolateral portals |
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What is the origin, insertion, action, and innervation of the following muscle?
Coracobrachialis |
Origin: Coracoid
Insertion: Medial mid-humerus Action: Flexion, adduction Innervation: Musculocutaneous |
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What is the origin, insertion, action, and innervation of the following muscle?
Brachialis |
Origin: Anterior humerus
Insertion: Anterior ulnar tuberosity Action: Flexes forearm Innervation: Musculocutaneous, Radial |
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What is the origin, insertion, action, and innervation of the following muscle?
Biceps brachii |
Origin: Coracoid (short); Supraglenoid (long)
Insertion: Radial tuberosity Action: Supination, flexion Innervation: Musculocutaneous |
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What is the origin, insertion, action, and innervation of the following muscle?
Triceps brachii |
Origin: Infraglenoid (long), Posterior humerus (lateral & medial heads
Insertion: Olecranon Action: Elbow extension Innervation: Radial |
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What are the sites of compression of the median nerve?
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Supracondylar process of humerus & ligament of Struthers
Lacertus fibrosis (bicipital aponeurosis) Pronator teres Arch of flexor digitorum superficialis |
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What are the possible compression sites of the AIN
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Deep head of pronator teres
Flexor digitorum superficialis Aberrant vessels Accessory muscles (i.e., Gantzer's muscles, which is an accessory head of the FPL) |
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What are the possible sites of compression of the ulnar nerve?
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1. Arcade of Struthers
2. Medial intermuscular septum 3. Medial epicondyle 4. Cubital tunnel 5. Proximal edge of FCU (Osborne fascia) 6. Deep flexor pronator aponeurosis |
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What is the arcade of struthers?
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A thin aponeurotic band extending from medial head of triceps to the medial intermuscular septum; it lies approximately 8 cm proximal to the medial epicondyle
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What is the ligament of struthers?
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Struthers' ligament is a ligament that extends between the shaft of the humerus and the medial epicondyle of the humerus. It is not a constant ligament and can be acquired or congenital. Its clinical significance arises form the fact that the median nerve, passes in the space between the ligament and the humerus and can be compressed
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What are the possible compression sites of the PIN?
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1. Fibrous bands
2. Recurrent leash of Henry 3. Extensor carpi radialis brevis 4. Arcade of Frohse (proximal edge of superficial head of supinator) 5. Supinator distal margin |
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A fracture at the surgical neck of the humerus could injure what neurovascular structures?
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The axillary nerve and posterior humeral circumflex artery as they pass through the quadrangular space
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What neurovascular structures could a fracture of the humeral shaft damage?
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Radial nerve and deep brachial artery
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A supracondylar fracture is common in children and occurs when the child falls on the outstretched hand with the elbow in what position? What neurovascular structure is at risk?
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Elbow partially flexed. The median nerve is at risk
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Where does the following cutaneous nerve arise from and what does it innervate?
Supraclavicular nerve |
Arises from the cervical plexus (C3,C4) and innervates teh skin over the upper pectoral, deltoid, and outer trapezius area
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Where does the following cutaneous nerve arise from and what does it innervate?
Medial brachial cutaneous nerve |
Arises from the medial cord and innervates the medial side of the arm
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Where does the following cutaneous nerve arise from and what does it innervate?
Medial antebrachial cutaneous nerve |
From the medial cord and innervates the medial side of the forearm
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Where does the following cutaneous nerve arise from and what does it innervate?
Lateral brachial cutaneous |
From the axillary nerve and innervates the lateral side of the arm
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Where does the following cutaneous nerve arise from and what does it innervate?
Lateral antebrachial cutaneous |
Arises from the musculocutaneous nerve and innervates the lateral side of the forearm
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Where does the following cutaneous nerve arise from and what does it innervate?
Posterior brachial and antebrachial cutaneous nerves |
Arise from the radial nerve and innervate the posterior sides of the arm and forearm
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Where does the following cutaneous nerve arise from and what does it innervate?
Intercostobrachial nerve |
The lateral cutaneous branch of the second intercostal nerve and emerges from the second intercostal space by piercing the intercostal and serratus anterior muscles. May communicate with the medial brachial cutaneous nerve
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Describe the path of the radial nerve
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From the posterior cord of the brachial plexus, passes anterior to the insertion of the latissimus dorsi then dives into the triceps on the posterior surface of the humerus crossing into the radial groove approximately 10-14 cm distal to the acromion. The nerve crosses the midline about 15 cm from the distal articular surface of the elbow and pierces the lateral intermuscular septum ~ 12 cm from the lateral epicondyle. 1-3 cm distal to the lateral epicondyle, deep to the brachioradialis, the radial nerve splits into the PIN and SBRN.
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Describe the path of the superficial branch of the radial nerve
How far from the radial styloid does the SBRN become subQ? Where can this be compressed? |
The SBRN continues along the lateral border of the brachioradialis and becomes subcutaneous at its middle 1/3 innervating the skin on the radial aspect of the forearm & the dorsal aspect of the radial 3 and 1/2 digits.
Becomes subQ ~9 cm proximal to the radial styloid Compression can occur between brachioradialis and ECRL |
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Describe the path of the PIN
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After branching from the radial nerve 1-3 cm distal to the lateral epicondyle deep to the brachioradialis, the PIN continues down the forearm, diving into the supinator and providing branches to the extensors of the wrist and hand in the following order:
1) Brachioradialis 2) ECRL 3) ECRB 4) Supinator 5) EDC 6) ECU 7) EDM 8) APL 9) EPB 10) EPL 11) EIP |
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What is the terminal branch of the posterior interosseous nerve?
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This is a sensory branch to the dorsal wrist capsule and lies in the radial aspect of the floor of the fourth dorsal compartment
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Where is the first possible site of PIN entrapment?
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Distal to its origin, the PIN passes deep to fibrous bands that are confluent with the brachialis, brachioradialis, ECRB, and the superficial head of the supinator. These form the roof of the radial tunnel and may compress the PIN against the deep head of the supinator which forms the floor of the radial tunnel along with the capsule of the radiocapitellar joint
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What is the 2nd structure with the radial tunnel that can compress the radial nerve?
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The leash of Henry which is made up of recurrent vessels of the radial artery at the level of the radial neck
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What is the 3rd structure along the path of the PIN that may lead to compression?
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At the point in which the PIN encounters the ECRB, it can be compressed
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Where is the 4th and final location the PIN can be compressed?
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The arcade of Frohse, found beneath the sharp proximal edge of the supinator
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How would you reproduce pain caused by radial tunnel syndrome?
What is the main symptom of compression of the PIN? |
Provoked by resisted supination and repetitive forearm pronation or wrist flexion
Because the PIN is mainly a motor nerve, weakness is the main symptom of compression |
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Why is full strength of extension at the wrist maintained with radial tunnel syndrome?
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The mobile wad is spared because it is innervated proximal to the radial tunnel
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