The Elbow & Forearm
look at the HUJ dislocation with a fracture coronoid process
*remember the coronoid process moves
what is the carrying degree in males vs females?
- 10-15 degrees in males - greater than 15 degrees in females
what are the three articulations?
- Humero-Radial Joint (HRJ) - Humero-Ulnar Joint (HUJ) - Proximal Radioulnar Joint (PRUJ)
UCL vs Medial Epicondyle Apophyseal Fracture
- Medial Epicondyle Apophyseal Fracture usually seen in younger throwing athletes... prior to full maturation - UCL less common in younger athletes
the medial and lateral borders of the humerus terminate into...
- Medial Supracondylar ridge into the Medial Epicondyle - Lateral Supracondyler ridge into the Lateral Epicondyle
the humeral condyle includes what three fossas?
- Olencranon Fossa - Coronoid Fossa - Radial Fossa
who were the pitcher he talked about?
- Tommy John - Nolan Ryan - Randy Johnson
the posterior inferior surface of medial epicondyle on humerus is the location of what?
- Ulnar Nerve - Ulnar Groove
the radial shaft has four borders what are they?
- anterior - posterior - lateral (terminates into the radial styloid) - interosseous membrane
what are the three bands of the Ulnar (Medial) Collateral Ligament?
- anterior - posterior - transverse (oblique)
anterodistally? the notch terminates as what? and is often fractured with....
- coronoid process - posterior dislocation
the anterior capsule includes what?
- fibers oriented in 3 directions - stable in extension, varus and valgus
Radial (Lateral) Collateral Ligament receives most of stability from what?
- lateral stability from joint structure
describe the radius
- long bone (not as long as ulna) that increases in size distally - strong site for muscle attachment - helps support hand
what are the two process on the Proximal Ulna?
- olecranon - coronoid
the increase of decrease in the carrying angle can have clinical implications especailly with which type of athletes?
- over head like volleyball
what does the annular ligament allow? and what does the distal segment act as?
- pronation and supination - as a restraint to traction
Describe the proximal radioulnar joint
- radial head articulates with radial notch in ulna - pivot joint - allows pronation and supination of the forearm
what is the clinical implication of the Annular ligament?
- subluxation of the radial head AKA Nursemaid's elbow (think about swinging a child by their arms...)
the medial articular surface of the humeral condyle is called the ______ which also extends posteriorly
- trochlea articulates with the trochlear notch of the ulna
what is the lateral articular surface of the humeral condyle called?
Capitulum (or the capitellem) which articulates with their radial head
what tubercle is located in the distal radius?
Dorsal (Lister's) Tubercle - articulates with the ulna (DRUJ)
what surrounds all 3 joints of the elbow and has fibrous and synovial components?
Elbow Joint Capsule - but has to have enough flexibility to allow movement
what muscles passes medially (ulnarly) to the dorsal tubercles before heading to the thumb?
Extensor Pollicis Longus
UCL vs Medial Epicondyle Apophyseal Fracture which has better prognosis?
Medial Epicondyle Apophyseal Fracture... ligament would have required surgery
List the architectural stability for the elbow joint Primary: Secondary: Tertiary:
Primary: structural integrity (Humero-Ulnar Joint or HUJ) Secondary: good ligamentous support (especially medially) Tertiary: good muscular support
what ligament extends from lateral epicondyle to the annular ligament?
Radial (Lateral) Collateral Ligament
the Ulnar (Medial) Collateral Ligament is known as what famous ligament?
Tommy John because your UCL receives a lot of stress in throwing - especially when you think about the shoulder pathology
"medial coronoid process to medial olecranon process and courses from ULNA TO ULNA"
Transverse, unique because it goes from bone to same bone
what ligament is the primary stabilizer for valgus stress, taught throughout ROM, and includes three different bands?
Ulnar (Medial) Collateral Ligament
Radial (Lateral) Collateral Ligament resists what?
Varus force at elbow (rare)
what are the clinical implications of the HRJoint?
absorbs lateral compression and rotational forces with rapid forearm movements (like throwing a baseball) - also susceptible to articular cartilage damage - hypertrophy of radial head *little league throwers at risk
what is a big purpose of the interosseous membrane?
allows for weight transfer between ulna/radius and holds everything together
the proximal head of the radius is held in place by what ligamnet?
annular
which ligament holds the radial head against ulna?
annular ligament
"medial epicondyle to coronoid process" which band?
anterior
where is the elbow joint capsuel thicker?
anteriorly than posteriorly
the distal end of the radius rotates what during pronation, supination?
around the ulna... afforded at the HRJ, PRUJ, and DRUJ - requires 3 different joint, not as easy as you would think
the Humeroradial Joint (HRJ) is anatomically what type of joint?
ball and socket
the anterior surface of the proximal radius is the radial tuberosity which is the insertion of what?
biceps brachii muscle
what is the HRJoint acts as a "bustress" (structural support) to lateral compression?
capitellum of the humerus - especially with valgus forces
angulation of ulna laterally (valgus)
carrying angle
the dital end of the humerus expands in the...
condyle - articular surfaces and concavities
the radial shaft is convex or concaved?
convex laterally
where does the annular ligament originate and insert?
coronoid process for both
what is unique about the Radial (Lateral) Collateral Ligament?
does not course from bone to bone... - connects form lateral epicondyle to annular ligament
what doe the HUJoint allow?
flexion and extension of the elbow, this is a very stable joint architecturally
The Humero-Radial Joint (HRJ) allows what to happen?
flexion/extension and pronation/supination of elbow
the HUJ is typically classified as wha type of joint?
humeral-ulnar Joint typically classified as a hinge joint (some say saddle due to shape)
what are the three bones in the elbow joint?
humerus ulna radius
the lateral border of the ulnar shaft is the attachment of what?
interosseous membrane
the Lateral (ulnar) Collateral Ligament courses from what to what?
lateral epicondyle to lateral aspect of the olecranon
the elbow joint capsule is strengthen by what
medial and lateralt collateral ligaments
what is the interosseous membrane?
mid shaft connection AKA third radioulnar articulation
the posterior surface of the humeral condyle has a depression called the
olecranon fossa which receives the olecranon process
what is proximal to capitellum on the humeral condyle?
radial fossa which receives the radial head
Lateral (ulnar) Collateral Ligament acts as a "sling" to support what?
radial head
which notch is lateral to the trochlear notch on the proximal ulna?
radial notch which articulates with radial head of the radius to form the Proximal Radioulnar Joint
the radius expands distally into what?
radial styloid process on the lateral side - palpate in proximal part of the anatomical snuff box
the interosseous membrane also guides movement of what during pronation and supination?
radius (only thing that moves during this action. ulna stays put
what shape is the trochlear notch on the proximal ulna?
saddle, and it articulates with the trochlea of humerus
what is the function of the Radial (Lateral) Collateral Ligament?
supports annular ligament
what is proximal to the trochlea on the humeral condyle and receives the coronoid process of ulna?
the coronoid fossa
the distal end of the ulna terminates into what
the head of the ulna with expanded ulnar styloid process
what articulates with the capitellum on the Humeral Condyle?
the radial head... Humeral-Radial Joint (HRJ)
what structure is asymmetrical to the HUJoint?
the trochlea of the humerus - this results in the carrying angle
what is the purpose of the interosseous membrane?
transmits forces from distal to proximal and increases surfaces are for msucles attachment
the smooth distal end of the ulna is separated by the carpal bone by what?
triangular fibrocartilage complex
what articulates with the trochlea on the humeral condyle
trochlear notch of ulna (HUJ)
:site of attachment of arm and forearm muscles and supports hand
ulna
what bone of the forearm decreases in size distally
ulna
the distal end of the ulna is smooth and convex laterally and articulates with
ulnar notch of the radius (DRUJ)
what is distal to the coronoid process on the proximal ulna?
ulnar tuberosity, the insertion of the brachialis
give examples of valgus and varus
valgus: knock knee varus: bo leg
what is the shoulder pathology?
weakness, IR ROM limit, Instability - more external rotation than internal. - in throwing athletes glenoid fossa can be different than other type of athletes