Bontrager Chapter 4 - Forearm and elbow
Positioning considerations for all upper limbs
40" SID gonadal shielding collimation long axis of IR to long axis of part Patient ID and side marker visible
Elbow special projections
Trauma axial lateral (Coyle method)
Three Concentric Arcs of lateral elbow
Trochlear sulcus outer ridges of capitulum and trochlea trochlear notch of ulna
medial epicondyle
small projection on the medial edge of the distal humerus
AP elbow medial rotation xray
superimposed radius and ulna
Proximal radioulnar joint is what type of joint
trochoidal (pivot) type joint
Two Partially Flexed AP Projections(when elbow cannot be fully extended)
Humerus parallel and forearm parallel
Fracture
- Simple (closed) fx - Compound (open) fx (breaks through skin) - Comminuted fx (splintered or crushed) - Impacted fx (fragments driven into each other)
Trauma Axial Lateromedial Projections (Coyle Method) projection for radial head
1. Part position: elbow 90 degree flexion, hand pronated 2. CR: 45 degree angle toward the shoulder centered to the mid elbow joint
Lateral elbow projection
1. Patient Position: pt seated elbow flexed 90 degrees, drop shoulder 2. Part position: rotate hand and wrist into a true lateral position thumb side up, place support under hand and wrist to make sure forearm and humerus is parallel 3. CR: perpendicular to the mid elbow joint, approximately 4cm (1 ½ in ) medially to the posterior surface of the olecrenon process
AP Elbow—Fully Extended
1. Patient Position: seated with elbow fully extended 2. Part position: align w/long axis of IR, center elbow joint to center of the IR, may need pt to lean laterally to obtain a true AP, support hand to prevent motion 3. CR: perpendicular to the mid elbow joint, which is 2cm distal to the midpoint of the line between the epicondyles
Elbow oblique projection - For medial rotation
1. Patient Position: seated, shoulder and elbow on the same horizontal plane 2. Part position: pronate the hand and rotate arm until the distal humerus and the anterior surface of the elbow are rotated 45 degrees. For both positions palpate the epicondyles to determine if they are 45 degrees 3. CR: perpendicular to the mid elbow joint (2cm distal to the midpoint of the line between the epicondyles
Elbow oblique projection - for lateral rotation
1. Patient Position: seated, shoulder and elbow on the same horizontal plane 2. Part position: supinate the hand and rotate the entire arm so the distal humerus and and anterior surface of the elbow joint are 45 degrees to the cassette (pt will need to lean laterally) For both positions palpate the epicondyles to determine if they are 45 degrees 3. CR: perpendicular to the mid elbow joint (2cm distal to the midpoint of the line between the epicondyles
3 elbow fat pads
1. anterior fat pad 2. posterior fat pad 3. supinator fat pad-located anterior to the proximal radius
Elbow projections
AP Lat oblique Med oblique Lateral
Medial oblique criteria
Coronoid process in profile Trochlea and medial epicondyle in profile
Elbow joint in what type of joint
Ginglymus (hinge) type because it allows for flexion and extension
styloid process
Located at extreme distal ends of radius and ulna
The two beak-like processes on the proximal ulna
Olecranon and coronoid processes
Trauma Axial Lateromedial Projections (Coyle Method) projection for coronoid process
Part position: Elbow 80degree flexion CR: 45 degrees away from the shoulder into the mid elbow joint
Lateral oblique criteria
Radial head, neck, and tuberosity in profile Lateral epicondyle and capitulum in profile
trochlear sulcus
Smooth depressed center portion of the trochlea
coronoid tubercle
The medial margin of the coronoid process opposite the radial notch
Lateral elbow criteria
Three concentric arcs visible Olecranon process in profile Appropriate exposure factors
Trochlea
a smooth, grooved articular process shaped like a pulley
capitulum
articulates with head of radius
Radial notch
depression on the lateral side of the proximal ulna
ulnar notch
depression on the medial distal end of the radius, articulates with the head of the ulna
Criteria-AP Elbow
elbow joint visible and in center of the film, epicondyles seen in profile, olecrenon process seated in the olecrenon fossa if fully extended
Elbow Fat Pads and Stripes
only seen in the lateral position, elbow must be 90 degrees
lateral epicondyle
projection on the lateral side of the distal humerus above the capitulum
AP elbow no rotation
radias and ulna are partially superimposed
AP elbow xray
radius and ulna slightly superimposed
AP elbow, lateral rotation
separates radius and ulna
AP elbow lateral rotation xray
separates ulna and radius
AP elbow, medial rotation
superimposes the radius and ulna
Overall the elbow joint is a ---- (freely moveable) joint
synovial
Humeral condyle
the entire distal end of the humerus and includes two smooth elevations for articulation- trochlea on the medial side and capitulum on the lateral side