13. Upper Limb II Flashcards
Which bones articulate with the Carpal Bone?
Only the Radius articulates with the Carpal Bone,
Not the Ulna.
What is a consequence of only the Radius
articulating with the Carpal Bones?
Forces e.g. Fall on outstretched hand are transmitted through the Radius only,
Making it more likely to Fracture from these forces compared to the Ulna.
What are the main bony features of the Radius?
- Head of Radius
- Neck of Radius
- Radial Tuberosity
- Oblique Line
- Interosseous Border
- Dorsal Tubercle
- Styloid Process of Radius
What are the 2 Articular surfaces on the Radius?
Articular Surface to Scaphoid Bone (lateral)
Articular Surface to Lunate Bone (medial)
What is the purpose of the Interosseous Border?
Attachment for Interosseous Membrane
Membrane between Radius and Ulna
What does the Head of the Radius Articulate with?
Capitulum of Humerus
“CAP ON HEAD”
What is the main structural difference between the
Radius and the Ulna? Why?
Radius: Distal End is Larger than its Head.
Ulna: Distal End is Smaller than its Head.
So the two bones articulate (fit) together well.
What is the Proximal Radial - Ulnar Joint?
Located near the Elbow,
An Articulation between the Head of the Radius,
And the Radial Notch of the Ulna.
What is the importance of the
Proximal Radial - Ulnar Joint?
This joint is classified as a Pivot Joint,
Responsible for Pronation and Supination of the Forearm.
What is the Anular Ligament?
AKA: Orbicular Ligament
Is a Strong Band of Fibers that encircles the head of the Radius,
And retains it in contact with the Radial Notch of the Ulna.
Prevents Radial Head Disloation
What are the main features of the Ulna?
- Olecranon Process
- Coronoid Process
- Trochlear Notch
- Radial Notch
- Ulnar Tuberosity
- Interosseous Border
- Styloid Process of Ulna
Which segements of the Ulna help to form the
Elbow Joint?
Olecranon Process
Coronoid Process
Trochlear Notch
What movement does the Trochlear Notch limit?
Extension of the Elbow.
Which Nerve is risk of injury with an
Olecranon Fracture?
Ulnar Nerve
However it can grow back.
What is the Distal Radial - Ulnar Joint?
Located near the Wrist,
An Articulation between the Head of the Ulna,
And the Ulnar Notch of the Radius.
Where are the Styloid Processes found?
At the Distal End of both Radius and Ulna
What attaches to the Ulnar Styloid Process?
Ulnar Ligament
What type of joint is formed by the
Interosseuous Membranes?
Syndesmosis
A Fibrous Joint between Two Bones
Which other long bones have a Syndesmosis?
Tibia and Fibula
What is the most common Fracture of the Forearm?
Colles Fracture:
Fracture of the Distal End of the Radius.
A complete Transverse Fracture within the Distal 2cm of the Radius.
The Distal Fragment is displaced Dorsally and is often Comminuted (broken into pieces).
How does Colles Fracture happen?
The Fracture results from Forced Dorsiflexion of the Hand,
Usually as the result of trying to ease a fall by outstretching the Upper Limb.
Which Nerve can be damaged by a Radial Fracture
and what does this lead to?
Radial Nerve:
Leads to a Wrist Drop
How is the Deformity from Colles Fracture described?
The deformity is referred to as a dinner fork deformity,
Because a “jog” occurs just Proximal to the Wrist,
Which is produced by the Posterior Displacement and Tilt of the Distal Fragment of the Radius.
Who is more susceptible to Fractures?
The most Common Fracture in Adults over 50.
Occurs more frequently in women,
Because there bones are often weakened by Osteoporosis.
List the Proximal Row of Carpal Bones
(Lateral To Medial):
- Scaphoid
- Lunate
- Triquetrum (Triquetral)
- Pisiform
List the Distal Row of Carpal Bones
(Lateral To Medial):
- Trapezium
- Trapezoid
- Capitate
- Hamate
Why is fracture of the Scaphoid commonly associated with
Avascular Necrosis of the Proximal Fragment?
The Scaphoid has its own Blood Flow unlike other Carpal Bones.
It receives its own Blood Supply primarily form Lateral and Distal Branches of the Radial Artery.
Blood flows from the Distal End of the Bone in a retrograde fashion down to the Proximal End.
Disruption to this Blood Flow may cause the Bone not to heal.
How common is Avascular Necrosis in Scaphoid Fractures?
Avascular Necrosis happens in approximately 13 - 50% of Scaphoid Fractures.
Which Nerve is related to the pain on the Wrist Fractures?
Median Nerve
What is the Main Branch of the Median Nerve?
Anterior Interosseous Branch
What is a Sesamoid Bone?
A Bone located within a Tendon
e.g. The Patella
Which Carpal Bone is a Sesamoid Bone?
Pisiform
Within which Tendon is the Pisiform bone located?
Flexor Carpi Ulnaris Muscle
What Bones come Distal to the Carpals?
Metacarpals (1 - 5)
What Bones come Distal to the Metacarpals?
Phalanges (1 - 5)
What can Phalanges be subdivided into?
- Proximal
- Middle
- Distal
What is unique about the Pollux (Thumb)?
It doesn’t have a Middle Phalanx
Only has Proximal and Distal Phalanges
What is the Joint between the Radius and Carpals called?
Radiocarpal Joint
What is the Joint between the Carpals and Metacarpals called?
Carpometacarpal Joint
What is the Joint between the Metacarpals and Phalanges called?
Metacarpophalangeal Joint
What is the Joint between Phalanges called?
Interphalangeal Joint
What type of joint is the first Carpometacarpal Joint?
Saddle Joint
This is the Pollux (Thumb)
What movements is the Pollux (Thumb) capable of?
Flexion
Extension
Abduction (palmar and radial)
Adduction
What does the arrangement of the Carpals form?
Carpals are arranged in such a way as to form an Anterior Concavity.
What is found within the Anterior Concavity?
This Anterior Concavity is bridged by the Flexor Retinaculum to form the Carpal Tunnel.
What is the Radiocarpal (Wrist) Joint?
The Wrist (Radiocarpal) Joint is the Synovial Articulation of the Concave Distal End of the Radius with the Scaphoid and Lunate Bones
What actions occur at the Wrist?
Abduction (Radial Deviation),
Adduction (Ulnar Deviation),
Palmar Flexion
Extension
What movements occur within the Distal Radioulnar Joint?
Supination and Pronation
What are the main contents of the Cubital Fossa?
- Distal Tendon of Biceps Brachii
- Median Cubital Vein
- Median Antebrachial Vein
- Median Nerve: at this level no branches are given off
- Brachial Artery
- Bicipital Aponeurosis
What is the Bicipital Aponeurosis?
Broad Aponeurosis of the Biceps Brachii
Originates from the Distal Insertion of the Biceps Brachii
Located in the Cubital Fossa
Separates Superficial from Deep Structures
Which structures are Deep to the Bicipital Aponeurosis?
Median Nerve
Brachial Artery
Which structures are Superficial to the Bicipital Aponeurosis?
Median Cubital Vein
Median Antebrachial Vein
How does the Bicipital Aponeurosis facilitate taking Blood?
When taking Blood (venepuncture) from the Median Cubital Vein,
The Bicipital Aponeurosis would help protect the Brachial Artery and Median Nerve
From a Needle being placed too Deeply.
What are the Three sections of the Anterior (Flexor) Compartment
Muscles of the Forearm?
SUPERFICIAL
INTERMEDIATE
DEEP
List the Superficial Muscles of the Anterior (Flexor) Compartment
from from Lateral to Medial?
- Pronator Teres
- Flexor Carpi Radialis
- Palmaris Longus
- Flexor Carpi Ulnaris
What is the Intermediate Muscle of the Anterior (Flexor) Compartment?
- Flexor Digitorum Superficialis
List the Deep Muscles of the Anterior (Flexor) Compartment
from from Lateral to Medial?
- Flexor Pollicis Longus
- Flexor Digitorum Profundus
- Pronator Quadratus
What is the principal movement the Anterior (Flexor) Compartment?
Wrist Flexion
Pronation
What is the innervation of the of the Anterior (Flexor) Compartment?
Median (C6-T1), Ulnar (C8-T1).
How would you test Flexor Digitorum Superficialis
and Flexor Digitorum Profundus function independently of each other?
Distal vs. Proximal Interphalangeal Flexion:
No Proximal Interphalangeal (PIP) Flexion: problem with Flexor Digitorum Superficialis.
No Distal Interphalangeal (DIP) Flexion: problem with Flexor Digitorum Profundus.
What are the Two sections of the Posterior (Extensor) Compartment
Muscles of the Forearm?
SUPERFICIAL
DEEP
List the Superficial Muscles of the Posterior (Extensor) Compartment
from from Lateral to Medial?
- Brachioradialis
- Extensor Carpi Radialis Longus
- Extensor Carpi Radialis Brevis
- Extensor Digitorum
- Extensor Digiti Minimi
- Extensor Carpi Ulnaris
- Anconeus
List the Deep Muscles of the Posterior (Extensor) Compartment
from from Lateral to Medial?
- Supinator
- Abductor Pollicis Longus
- Extensor Pollicis Brevis
- Extensor Pollicis Longus
- Extensor Indicis
What is the principal movement the Posterior (Extensor) Compartment?
Wrist Extension
Supination
What is the innervation of the of the Posterior (Extensor) Compartment?
Radial Nerve (C5-T1)
Which of the Posterior Muscles bound the “Anatomical Snuffbox?
- Extensor Pollicis Longus: extends Thumb
- Extensor Pollicis Brevis: extends Thumb
- Abductor Pollicis Longus: abducts Thumb
The latter two run together.
Supination:
Supinator
Biceps Brachii
Pronation:
Pronator Quadratus
Pronator Teres
Wrist Flexion:
Flexor Digitorum Superficialis/Profundus Flexor Carpi Radialis Flexor Carpi Ulnaris Plamaris Longus Flexor Pollicis Longus
Wrist Extension:
Extensor Carpi Radialis Longus/Brevis Extensor Carpi Ulnaris Extensor Digitorum Extensor Pollicis Longus Extensor Indicis Extensor Digiti Minimi
Wrist Ulnar Deviation (Adduction):
Flexor Carpi Ulnaris
Extensor Carpi Ulnaris
Wrist Radial Deviation (Abduction):
Flexor Carpi Radialis
Extensor Carpi Radialis Longus/Brevis
Abductor Pollicis Longus
Extensor Pollicis Longus/Brevis
Proximal Interphalangeal Flexion:
Flexor Digitorum Superficialis
Distal Interphalangeal Flexion:
Flexor Digitorum Superficialis/Profundus
When can a Fist be made?
Wrist must be extended in order that the hand can grip effectively.
Making a Fist with Wrist Flexed is not possible.
When can the Distal Interphalangeal (DIP) Joint not be flexed?
When the Proximal Interphalangeal (PIP) Joint is fully Flexed,
You cannot flex the Distal Interphalangeal (DIP) Joint,
The Distal Phalanx is completely lax.
When can the fingers not be Abducted?
Fingers are easily Abducted in the Neutral Position.
However this is much more difficult with the Wrist fully flexed.
What would be the clinical presentation of injury to Radial Nerve?
Radial: Radial Nerve Palsy (Saturday Night palsy)
Loss of Wrist Extension (wrist drop)
Through which Muscles does the Median Nerve enter the Forearm?
- Passes between the Two Heads of Pronator Teres,
- Travels between Flexor Digitorum Superficialis,
- And Flexor Digitorum Profundus,
- Before emerging between Flexor Digitorum Superficialis and Flexor Pollicis Longus.
Through which Muscles does the Ulnar Nerve enter the Forearm?
- Enters forearm through the two heads of Flexor Carpi Ulnaris,
- And runs alongside the Ulna,
- It then joins with the ulnar artery,
- And travels deep with it to the Flexor Carpi Ulnaris.
Through which Muscles does the Radial Nerve enter the Forearm?
Under the Brachioradialis it reaches the Lateral Epicondyle where it divides into a Deep (Motor) Branch and a Superficial (Sensory) Branch.
Where do the Interosseous Nerve Branches arise from?
Anteriorly the Median Nerve gives an Anterior Interosseous Branch,
Posteriorly the Radial Nerve gives a Posterior Interosseous Branch.
What Branches does the Radial Artery give in the Forearm?
Radial Artery gives no major branches, in the Forearm.
What Branches does the Ulnar Artery give in the Forearm?
Ulnar Artery gives a Common Interosseous Branch
Which divides into Anterior and Posterior Interosseous Branches.
List the Main Ligaments and Fibrous structures at the Wrist/Hand:
- Palmar Aponeurosis
- Palmar Carpal Ligament
- Flexor Retinaculum (Transverse Carpal Ligament)
- Extensor Retinaculum (Thickening Of Posterior Antebrachial Fascia)
What structures form the boundaries of the Anatomical Snuffbox?
Posterior:
- Extensor Pollicis Longus Tendon
Anterior:
- Extensor Pollicis Brevis Tendon
- Abductor Pollicis Longus Tendon
Proximal:
- Styloid Process of Radius
Distal:
- Apex of the Anatomical Snuffbox Triangle
- Formed by the meeting of the Tendons
Floor:
- Scaphoid
- Trapezium
Which Superficial Vein and Cutaneous Nerve lie within
the Anatomical Snuffbox?
Cephalic Vein
Dorsal Cutaneous Branch of Radial Nerve.
What is the Flexor Retinaculum?
A Strong, Fibrous Band.
It covers the Carpal Bones on the Palmar Side of the Hand near the Wrist.
It attaches to the Bones near the Radius and Ulna.
What does the Flexor Retinaculum form?
It forms the Roof of the Carpal Tunnel
Where does the Flexor Retinaculum attach on the Radial Side?
Tubercle of Scaphoid
Anterior Ridge on Trapezium
Where does the Flexor Retinaculum attach on the Ulnar Side?
Pisiform
Hook/Hamulus of Hamate
Which Structures pass Superficial to the Flexor Retinaculum?
Ulnar Artery
Ulnar Nerve
Palmaris Longus Tendon (above)
Which Tendons pass Deep to the Flexor Retinaculum?
Tendons of the:
- Flexor Carpi Radialis
- Flexor Pollicis Longus
- Flexor Digitorum Profundus
- Flexor Digitorum Superficialis
How many Tendons pass through the Carpal Tunnel?
NINE (9) Tendons:
ONE Tendon of Flexor Pollicis Longus
FOUR Tendons of Flexor Digitorum Profundus
FOUR Tendons of Flexor Digitorum Superficialis
Where is the Median Nerve in relation to the Flexor Retinaculum?
Median Nerve lies deep to Flexor Retinaculum.
How does Carpal Tunnel Syndrome occur?
Inflammation within the Carpal Tunnel may impinge on the Median Nerve,
Creating Carpal Tunnel Syndrome.
What are the Sensory Symptoms of Carpal Tunnel Syndrome?
Numbness, Tingling, or Burning in:
- Thumb Finger
- Index Finger
- Middle Finger
- Lateral half of Ring Finger.
Pain in Hands or Wrists.
What are the Motor Symptoms of Carpal Tunnel Syndrome?
Loss of Grip Strength
What is the Palmar Aponeurosis?
Central Part of the Deep Fascia of the Palm
Which is a highly specialized Thickened Structure with little mobility.
It is triangular in shape and it covers the underlying Neurovascular and Tendon Structures.
What is the function of the Palmar Aponeurosis?
- Provides firm attachment to overlying Skin.
- Helps to form the ridges in the Palm,
Which in turn help to increase friction so that we can grasp objects firmly. - Protects underlying structures.
- Provides attachment to Muscles.
How is the Palmar Aponeurosis related to the Tendon of
Palmaris Longus?
The Tendon of Palmaris Longus
Attaches to the Proximal part of the Palmar Aponeurosis.
What are the main Ateries of the Upper Limb?
- Brachial Artery
- Radial Artery
- Deep Palmar Arch
- Superficial Palmar Arch
- Ulnar Artery
- Common Interosseous Artery:
- Anterior Interosseous Arteries
- Posterior Interosseous Arteries
What are the main branches of the Radial Artery?
- Superficial Palmar Arch
- Princeps Pollicis Artery
- Deep Palmar Arch
Where does the Radial Artery enter the Palm?
Between Heads Of 1st Dorsal Interosseus Muscle.
What are the main branches of the Ulnar Artery?
- Common Interosseous Artery:
- Anterior Interosseous Arteries
- Posterior Interosseous Arteries
- Superficial Palmar Arch
Where is the Ulnar Artery located in the Wrist/Hand?
Anterior To Flexor Retinaculum
Lateral To Ulnar Nerve
Which Artery makes the major contribution to the Superficial Palmar Arch?
The Ulnar Artery.
How is the Deep Palmar Arch formed?
The Radial Artery Anastomoses with the Deep Branch of the Ulnar Artery,
Forming the Deep Palmar Arch
What is the Superficial Palmer Arch?
The Superficial Palmar Arch is Superficial to the Deep Palmar Arch
And the Apex of this Arch runs more Distally than the Deep Palmar Arch.
Which of the two Arches is larger?
Superficial Arch is much larger and more important than the Deep Arch
Where does Venous Drainage of the Hand occur from?
Note that Venous drainage occurs on the Dorsal Aspect of the hand.
How are Veins arranged on the Hand?
The arrangement of the Veins is very variable.
What are the main Veins of the Hand?
- Basilic Vein (Ulnar Side)
- Cephalic Vein (Radial Side)
- Dorsal Venous Arch
- Median Antebrachial Vein
- Median Cubital (Median Basilic) Vein
What are the 5 Compartments of the Intrinsic Muscles of the Hand?
- Hypothenar Compartment:
- Relating to the prominent part of the palm of the hand above the base of the little finger.
- Thenar Compartment:
- Relating To The Thumb
- Central Compartment:
- Short Muscles And Long Flexor Tendons
- Adductor Compartment:
- Interosseous Compartment:
- Between Metacarpals
What are the Muscles of the Hypothenar Eminence?
- Flexor Digiti Minimi
- Abductor Digiti Minimi
- Opponens Digiti Minimi
What are the Muscles of the Thenar Eminence?
- Opponens Pollicis
- Abductor Pollicis Brevis
- Flexor Pollicis Brevis
- Palmaris Brevis
What are the Other Intrinsic Muscles of the Hand?
- Adductor Pollicis
- Lumbricals
- Palmar Interossei
- Dorsal Interossei
What is the Function of the Adductor Pollicis?
Adduction and aids in Flexion of the Thumb.
Supplies 50% of the Adduction force to First Metacarpal.
What is the Function of the Lumbricals?
Flex Metacarpophalangeal Joints
Extends Interphalangeal Joints
What is the Function of the Palmar Interossei?
Adduct Fingers towards Middle Finger.
PAD (Palmar Adduct)
What is the Function of the Dorsal Interossei?
Abduct the Fingers away from Middle Finger.
DAB (Dorsal Abduct)
Where are the Intrinsic Muscles found?
The Intrinsic Muscles are wholly contained within the Hand.
From which Spinal Segment are the Intrinsic Muscles innervated?
T1
How can Extrinsic Muscles have an impact on the Hand?
The Extrinsic Muscles arise in the Arm or Forearm
And attach to Bones in the hand where they have their effect.
How are the Flexor Digitorum Superficialis and Flexor Digitorum Profundus
related to each other and to the Phalanges?
- Flexor Digitorum Superficialis (FDS) runs Superficial to Flexor Digitorum Profundus (FDP).
- At the base of the Proximal Phalanx,
The FDS Tendon splits to surround the FDP Tendon. - The two halves of the FDS Tendon,
Are attached to the sides of the Middle Phalanx, - Whilst the FDP passes through the centre to reach the Distal Phalanx.
Why may Radial Nerve Palsy lead to weak grip?
Radial Nerve Palsy causes a 42% loss of power across the wrist.
This is due to an inability to stabilise the wrist and lack of Flexor Tendon stretching.
What is the distribution of the Ulnar Nerve to the Skin of the hand?
Skin:
- Ulnar Side of the hand.
- Little finger and Half of Ring Finger.
What is the distribution of the Ulnar Nerve to the Muscles of the hand?
Muscles:
- Superficial Branch supplies Palmaris Brevis
- Deep Branch supplies Hypothenar Muscles
- All Interosseous Muscles
- 3rd Lumbrical
- 4th Lumbrical
- Flexor Pollicis Brevis
- Adductor Pollicis
What is the distribution of the Median Nerve to the Skin of the hand?
Skin:
- Palmar Side of the Thumb
- The Middle Finger
- The Index Finger
- Half the Ring Finger
- Nailbed of these Fingers
- Lateral Part of Palm
What is the distribution of the Median Nerve to the Muscles of the hand?
Muscles:
- 1st Lumbrical
- 2nd Lumbrical
What is the distribution of the Radial Nerve to the Skin of the hand?
Skin:
- Superficial Radial Branch supplies Radial Side of Thumb
- Posterior aspect of Hand and Fingers to Nailbed.
What is the distribution of the Radial Nerve to the Muscles of the hand?
Muscles:
- No motor supply to Muscles on Hand.
