Set 6 Flashcards
Describe carpal tunnel syndrome:
- Median nerve compression in carpal tunnel located on the volar wrist.
- Sensory deficits—paresthesias (numbness and tingling) involving the radial side of hand (radial 4 ½ digits).
- Motor deficit—weakness and atrophy of thenar muscles (surrounding thumb).
- Symptoms typcially worse at night and often disrupt sleep.
Most common compressive neuropathy of the upper extremity:
Carpal tunnel syndrome—median nerve
Describe ulnar tunnel syndrome:
- Ulnar nerve compression at Guyon’s canal at the ulnar aspect of the volar wrist.
- Proximal border—pisiform bone.
- Distal border—hook of hamate.
- Commonly referred to as handlebar palsy (common in cyclists).
- Presentation based on site of compression—ulnar nerve bifurcates into motor and senory branch in Guyon’s canal.
- Pure motor—weak intrinsic hand muscles.
- Pure sensory—paresthesias in ulnar 1 /1/2 digits
- Mixed—both motor and sensory.
Identify the structures labeled in the transverse image of the anterolateral elbow:
- Brachioradialis
- Superficial radial nerve (sensory)
- Deep radial nerve (motor)
- Brachialis
- Biceps brachii tendon
- Capitellum (lateral distal humerus)
- Trochlea (medial distal humerus)
Identified the structures labeled in this transverse image of the anteromedial elbow:
- Brachialis
- Biceps brachii tendon
- Brachaial artery
- Median nerve
- Pronator teres
- Trochlea (medial distal humerus)
- Capitellum (lateral distal humerus)
Identify the structures labeled in the longitudinal image of the anterolateral elbow:
- Capitellium (distal humerus)
- Radial head
- Radial neck
- Brachialis
Identify the labeled structures in this longitudinal image of the lateral elbow:
- Lateral epicondyle
- Common extensor tendon**
- Radial collateral ligament**
- Capitellium
- Radial head
**The boundary between the common extensor tendon and radial collateral ligament is often difficult to discern. The common extensor tendon is the more superficial 2/3 and the radial collateral ligament is the deeper 1/3.
Identify the labeled structures in this longitudinal view of the anterior elbow:
- Brachialis
- Biceps brachii tendon with anisotropy (anterior view)**
- Radial tuberosity
**The distal biceps brachii tendon is difficult to image anteriorly because its oblique course results in anisotropy. Often the lateral or medial windows provide better visualization of the tendon.
Identify the structures labeled in the transverse view of the lateral aspect of the proximal forearm:
- Brachioradialis
- Common extensors
- Supinator
- Radial tuberosity (biceps tendon insertion**)
- Biceps brachii tendon
**This is the lateral window used to image the biceps brachii tendon insertion. With the elbow flexed 90 degrees, the probe is positioned transversely over the lateral aspect of the proximal forearm just distal to the elbow joint.
Identify the structures labeled in the transverse view of the medial aspect of the proximal forearm:
- Pronator teres muscle
- Common flexor muscles
- Brachial artery
- Biceps brachii tendon (pronator window**)
- Supinator muscle
- Radial tuberosity
**This is the medial (pronator) window used to image the biceps brachii tendon insertion. With the elbow flexed 90 degrees, the probe is positioned transversely over the medial aspect of the proximal forearm just distal to the elbow joint
Identify the labeled structures in this longitudinal view of the medial elbow:
- Medial epicondyle
- Common flexor tendon (posterior edge)
- Ulnar collateral ligament (UCL) (anterior band)**
- Trochlea
- Coronoid process (sublime tubercle)
**The anterior band of the UCL is deep to the common extensor tendon.
Identify the structures labeled in this transverse view of the posteromedial elbow (cubital tunnel):
- Medial epicondyle
- Olecranon process
- Cubital retinaculum
- Ulnar nerve
- Common flexor tendon
Identify the labeled structures in this transverse view of the posteromedial elbow (distal aspect of cubital tunnel):
- Ulna
- Ulnar nerve
- FCU—humeral head
- FCU—ulnar head
- Arcade of Osborne (connective tissue sling between the 2 heads of the FCU)
- Common flexor muscles
Identify the labeled structures in the transverse view of dorsal wrist:
- Radius
- Listers tubercle
- ECRB (2nd EC)
- EPL (3rd EC)
- ED and EI (4th EC)
- EDM (5th EC)
- Distal radioulnar joint
- Ulna
Identify the labeled structures in this transverse view of the ulnar side of the dorsal wrist:
- Ulna
- ECU
Identify the labeled structures in this transverse view of the proximal carpal tunnel:
- Scaphoid
- Pisiform
- FCR tendon
- FPL tendon
- FDS (4) and FDP (4) tendons
- FCU tendon
- Transverse carpal ligament
- Median nerve
- Guyon’s canal (ulnar never and artery)
Identify the labeled structures in this transverse view of the distal carpal tunnel:
- Triquetrium
- Hook of hamate
- FCR tendon (with anisotropy)
- FPL tendon
- FDS and FDP tendons (with anisotropy)
- Transverse carpal ligament
- Median nerve
- Guyon’s canal (ulnar artery and nerve)
Identify the labeled structures in this longitudinal view of the volar radial aspect of the wrist:
- Distal radius
- Scaphoid
- Trapezium
- FCR tendon (with anisotropy distally)**
- Radiocarpal (wrist) joint
**The FCR is superfical to the peanut shaped scaphoid bone. The FCR takes a sharp bend at the distal aspect of the scahoid and itenters the fiberoseous tunnel in the trapezium. This is a potential site of overuse injury involving the FCR.
Identify the labeled structures in this longitudinal view over the dorsal wrist (3rd ray):
- Distal radius
- Lunate
- Capitate
- 3rd Metacarpal
- Extensor digitorum tendon (3rd digit)
- Radiocarpal (wrist) joint
- Intercarpal joint
- Carpometacarpal joint
