A&P L.9 (ANATOMY AND POSITIONING OF THE FOREARM AND ELBOW)
Distal Radioulnar Joint
Distal Radioulnar Joint
Axiolateral is performed in place of
External Oblique Elbow for demonstration of the Radial Head and Capitellum free of superimposition
LATERAL PROJECTION
Flex the patient's elbow 90 degrees with the Thumb up, resting the Forearm on the Ulnar surface
45 DEGREE LATERAL OBLIQUE
Instruct the patient to lean laterally with their palm up Externally rotate the hand to place the Elbow Joint and Humeral Epicondyles at a 45 degree angle with plane of the Image Receptor
Central Ray may have to be angled slightly toward the hand (trauma elbow)
if the patient's elbow is flexed at almost 90 degrees
Bursae
Located over the Olecranon Process and Humeroradial Joint (Between the Head of the Radius and Capitellum of the Humerus)
AP ELBOW positioning
Long axis of arm should be aligned with the long axis of the Image Receptor No rotation is evidenced by appearance of Humeral Epicondyles in profile Radial Head and Tuberosity slightly superimposed over Ulna Olecranon Process of Ulna within the Olecranon Fossa of Humerus Elbow Joint space appears open
When performing the Lateral Projection in trauma
it will be necessary at times to have the patient hold the Image Receptor if the patient is able
ROUTINE PROJECTIONS OF THE ELBOW
Anteroposterior Bilateral Oblique Positions 45 Degree Medial (Internal) Oblique 45 Degree Lateral (External) Oblique Lateral Axiolateral - Radial Head Capitellum
ROUTINE PROJECTIONS OF THE FOREARM
Anteroposterior Lateral
JONES METHOD
Center the Olecranon Process to the center of the Image Receptor Direct the Central Ray perpendicular to 2 inches superior to the Olecranon Process
Axiolateral Projection of the Elbow is the same positioning as a Lateral Elbow with
Central Ray angle of 45 degrees toward the Shoulder Joint
Coyle Method
Central Ray is angled 45 degrees toward the shoulder
PROXIMAL FOREARM
Depending upon the degree of partial extension, the Central Ray may have to be angled 10-15 degrees into the Elbow Joint (toward the shoulder)
Lateral Epicondyle
small process above the Capitellum on the lateral side of the distal Humerus
Capitellum or Capitulum
small rounded process located on the lateral side of the Humerus which articulates with the Head of Radius in extension
Semilunar Notch or Trochlear Notch
two processes are separated by a half-moon shaped notch
Supinator Fat Pad
within the Radial Fossa above the Capitellum of the distal Humerus
Radial Fossa
A ditch or depression on the anterior surface of distal Humerus above the Capitellum Accommodates the Head of Radius in Flexion
X-TABLE AXIOLATERAL ELBOW TRAUMA
place the Image Receptor between the patient's body and the lateral Elbow Direct a horizontal Central Ray 45 degrees medially toward the Shoulder Joint
Trochlear Sulcus or Groove
the smooth depressed center portion of the Trochlea
Manual Exposure Factors for elbow
50-60 kV 4 -6 mAs (depends upon Analog or Computed Radiography imaging) May Increase exposure factors for Lateral / Axiolateral Projections
Manual Exposure Factors
50-60 kV 4 mAs (depends upon Analog or Computed Radiography imaging)
Styloid Process of Ulna
A small pointed process superior to the head
Central Ray angulation Image Receptor position
Adapt the positioning to the patient with X-ray equipment
Radial Tuberosity
As the shaft of the Radius ascends to the proximal end, there is a roughened, raised area on the medial, anterior surface attachment site for the Biceps Tendon
Neck of the Ulna
Below the head it narrows
45 DEGREE LATERAL OBLIQUE ELBOW positioning
Complete separation between the Radius and Ulna Radial Notch of Ulna open Lateral Epicondyle and Capitellum elongated
the Elbow flexed at an 80 degree angle and the hand pronated (coyle)
Coronoid Process is best demonstrated
LATERAL ELBOW structures
Elbow joint open and flexed 90 degrees Semilunar / Trochlear Notch demonstrated in profile Olecranon Process in profile Fat pads of the Elbow Joint if injury is present
Trochlea of Humerus
In extension, the Coronoid Process articulates with
Coronoid Fossa of the distal Humerus
In flexion, the Coronoid Process articulates with
ACUTE FLEXION OF THE ELBOW JONES METHOD
In the event that the patient's condition presents with the Elbow Joint in acute flexion, the lateral projection is performed as a X-Table Lateral
Biceps Tendon
It attaches to the Brachialis Muscle and to the Radial Tuberosity allowing the flexion of the Forearm at the Elbow Joint
Triceps Muscle
It attaches to the Olecranon Process of the Ulna to extend the Forearm at the Elbow Joint
AXIOLATERAL ELBOW structures
Joint space between Radial Head and Capitellum open Radial Head, Neck and Tuberosity in profile
Neck of Radius
Just distal to the Radial Head is a constricted area
Positioning for AP
Long axis of the Forearm should be aligned with the long axis of the Image Receptor True AP projection as evident by no Radial Cross-over of the shafts of the Forearm No rotation as evident by the appearance of the Humeral Epicondyles Radial Head and Tuberosity will be slightly superimposed on the Ulna Wrist and Elbow Joints are open
Anatomical Structures for Lateral
Lunate - Carpal Bone to Lateral and Medial Epicondyles superimposed
45 DEGREE MEDIAL OBLIQUE ELBOW structures
Medial Epicondyle of Humerus and Semilunar Notch of Ulna elongated and in partial profile Coronoid Process and Semilunar Notch in profile
AXIOLATERAL ELBOW positioning
No superimposition of Radial Head on Ulna Distortion of Humerus and Epicondyles due to the Central Ray angulation
Radial Head
On the proximal end of the Radius is a flat disc-like structure
Exposure factors (for both images)
Optimal brightness (density) and contrast with no motion Soft tissue margins and bony trabeculae should be evident
X-TABLE LATERAL PROJECTION TRAUMA
Place a radiolucent sponge under the Elbow to elevate it from the table top or cart when performing Projection with the patient lying supine
Lateral elbow
Place the patient's Elbow Joint in a lateral position flexed 90 degrees Humeral condyles placed perpendicular to the Image Receptor
45 DEGREE MEDIAL OBLIQUE
Pronate the patient's hand
anatomical structures for AP ELBOW
Proximal Shafts of Radius and Ulna to Distal Shaft of Humerus
Anatomical Structures for AP
Proximal row of Carpal Bones to Elbow Joint Space
Coyle Method are Axial Lateral Projections to demonstrate
Radial Head and Coronoid Process of the Ulna
45 DEGREE MEDIAL OBLIQUE ELBOW positioning
Radial Head and Neck superimposed and centered over Proximal Ulna Radius crossed over Ulna Olecranon Process of Ulna within Olecranon Fossa of Humerus
Elbow flexed at a 90 degree angle and the hand pronated (coyle)
Radial Head is best demonstrated
45 DEGREE LATERAL OBLIQUE ELBOW structures
Radial Head, Neck and Tuberosity free of superimposition
LATERAL ELBOW positioning
Superimposed Humeral Epicondyles Head of Radius superimposed over Coronoid Process of Ulna 3 concentric arcs of the Semilunar Notch / Trochlear Sulcus, Capitellum and Trochlea
Coronoid Process
The anterior beak-like process on the proximal ulna
Medicolegal Aspects
The appropriate anatomic side marker and Patient Identification should be included on all images
Trauma Projections of the Elbow
Two AP Projections AP Distal Humerus AP - Proximal Forearm Lateral - X-Table Projection Axiolateral Projection for the Radial Head / Capitellum
The Distal Humerus consists of
Two Condyles Two Epicondyles 3 Fossa
oblique elbow
Typically only one Oblique Position is performed
Radioulnar Joints
When pronating the hand, the Radius turns medially and crosses over the Ulna due to the pivotal movements of
Base of the Radius forms
Wrist Joint Proper with its articulations with Scaphoid and Lunate
Positioning for Lateral
Wrist in True Lateral Position - Radius / Ulna superimposed Elbow flexed 90 degrees Humeral Epicondyles superimposed Semilunar / Trochlear Notch demonstrated Elbow joint space open Radial Head superimposed over the Coronoid Process of Ulna Radial Tuberosity demonstrated
Olecranon Fossa
a deep ditch on the posterior surface of the distal Humerus
Trochlea
a spool-shaped structure which articulates with the half-moon shaped Semilunar Notch of the Ulna, allowing the Elbow Joint to flex and extend as a Hinge Joint
hand must be supinated to
avoid Radial cross-over onto the Ulna
Posterior Fat Pad
covers the largest area, lying within the Olecranon Fossa of the Humerus
The size of the Image Receptor
depends on the length of the patient's Forearm 1 14x17 Image Receptor for adults 2 projections can be performed on 1 Image Receptor 2 10X12 Image Receptors for smaller adults and pediatric patients Using a 10X12 Image Receptor placed diagonally is common
Coronoid Fossa
ditch or depression on the anterior surface of distal Humerus above the Trochlea Accommodates the Coronoid Process of Ulna in Flexion
Humerus
forms the Elbow Joint by its articulations with the Radius and Ulna
Elbow Joint
lined with synovial membrane, which secretes synovial fluid for lubrication of the joint
Base of the Radius
located on the distal end
Head of the Ulna
located on the distal end
Radius
located on the lateral (Thumb) side of the forearm in the True Anatomical Position shortest of the two bones in the Forearm It is classified as a Long Bone with a shaft and two articular extremities At the distal end, it is the only bone of the Forearm which helps form the Wrist Joint Proper
Ulna
located on the medial (5th Finger) side of the forearm in the true anatomical position longer, medial bone of the Forearm It consists of a shaft and two articular ends The articulations between the Ulna and distal Humerus form the majority of the Elbow joint
Anterior Fat Pad
located within the Coronoid Fossa above the Trochlea of the Humerus
Radius and Ulna
make up the bone that form the forearm
Medial Epicondyle
palpable and is a larger process above the Trochlea on the medial side of the distal Humerus
Direct the Central Ray
perpendicular to the Elbow Joint - 1 inch distal to the Medial Epicondyle
Direct the Central Ray
perpendicular to the mid-shafts of the Radius and Ulna
Olecranon Process
posterior knob-like process on the proximal Ulna It is the palpable tip of elbow often referred to as the "Funny Bone"
Collimate FOR ELBOW
proximal Radius and Ulna and distal Humerus, including surrounding soft tissue
Semilunar or Trochlear Notch
separates The Olecranon Process is separated from the Coronoid Process
Olecranon Process Coronoid Process
shaft of the Ulna expands as it ascends proximally into two processes
Collimate to include
the Wrist joint to the Elbow joint
Radial Notch
the lateral surface of the proximal Ulna, next to the Coronoid Process, is small depression
fat pads
three areas of fat associated with the Elbow Joint