directed reading
CLASSICS
®
essentialeducation
Elbow Disorders and Injuries
©2017 ASRT. All rights reserved.
American Society of Radiologic Technologists
essentialeducation
directed reading
CLASSICS
®
Elbow Disorders and Injuries
Matthew E Berry, BS, R.T.(R)(CT)
The elbow is a complex
joint that supports forearm
movement and consequently is
at risk for various injuries and
disorders. Elbow disorders can
range from chronic to acute
problems, many of which can be
debilitating. This article explains
the functional anatomy of the
elbow joint and discusses the
most common elbow disorders
and injuries. It also presents
the most common diagnostic
imaging choices, along with
typical acquisition methods.
This ASRT Directed Reading
Classic was originally
published in Radiologic
Technology, July/August
2013, Volume 84, Number 6.
Visit www.asrt.org/store to
purchase other ASRT Directed
Reading Classics.
Elbow Disorders and Injuries
After completing this article, the reader should be able to:
 Describe elbow anatomy.
 Identify ordinary anatomical lines on a radiograph.
 Explain the radiologic modality choices for diagnosing elbow disorders and injuries.
 Discuss the most common elbow disorders and injuries.
 Summarize the differences between pediatric and adult elbow anatomy.
T
he elbow is an essential joint for
movement of the hand and
forearm. The functionality of
the upper extremity relies on
elbow motion. If a person’s elbow
motion decreases by 50%, upper
extremity impairment increases by as
much as 80%.1
The elbow controls pronation, supination, flexion, and extension of the
forearm. Pronation positions the forearm with the palm facing down and the
arm extended. This position causes the
paths of the radius and ulna to cross at
the midpoint of the shafts. Supination
of the forearm brings the palm of the
hand face up with the forearm extended. This position brings the radius and
ulna parallel with each other.2
The elbow joint’s ability to flex and
extend depends on the articulation of
the ulna and humerus. Pronation and
supination depend on the radial head
and capitulum of the humerus.3 A fully
functioning elbow should allow the forearm to extend 145° from full extension
to full flexion and permit a 180° rotation
during pronation or supination.3
www.asrt.org
Elbow pain can be caused by a
number of issues with the joint or surrounding anatomy. Pain at the elbow
also can result from problems not related to the elbow joint, such as cervical
radiculopathy or referred shoulder pain.
Most commonly, elbow pain is due to
periarticular causes or problems specific
to the elbow joint. Polyarticular causes,
or problems affecting many joints, also
play a role in elbow disorders.4
Chronic elbow injuries can be
attributed to repetitive motion of the
joint or inflammatory processes. Acute
injuries occur from trauma, most often
from falls. 5
Anatomy
Functional Anatomy
All the elbow’s functional anatomy
must work collectively for the joint to
operate. The humerus, radius, and ulna
are the 3 bones that make up the elbow.2
Each bone is designed to allow the
elbow to act as a hinge joint. The distal
humerus contains the trochlea, capitulum, coronoid fossa, olecranon fossa,
radial fossa, medial epicondyle, and
1
directed reading
CLASSICS
essentialeducation
lateral epicondyle. The proximal radius includes the radial head, radial neck, and radial tuberosity. The proximal
ulna comprises the olecranon process, coronoid process,
radial notch, and trochlear notch (see Figure 1).6
Within the elbow are the ulnohumeral, radiocapitellar, and radioulnar joints, all of which lie within the
same joint capsule.7,8 The capsule has an internal synovial layer and a superficial fibrous layer. Within these
layers are 3 fat pads. The coronoid fossa and radial fossa
both contain an anterior fat pad, and the olecranon
fossa has a posterior fat pad.8
The largest of the elbow joints is the ulnohumeral
articulation, which is a modified hinge joint.2,6 The
trochlear groove of the humerus holds the ulnohumeral
articulation, which allows movement between the ulna
and the humerus. 3
The radiocapitellar joint is a ball and socket joint
composed of the radial head and humeral capitulum.
This joint is lateral to the ulnohumeral joint and permits forearm supination and pronation.2,6
The radioulnar joint is a pivot type of synovial joint
(a freely movable joint that contains fibrocartilage and
hyaline cartilage layers and synovial fluid) divided into
superior and inferior sections. The superior section
contains the articulation between the radial head and
the radial notch of the ulna; the joint rotates within the
annular ligament during pronation or supination. The
inferior section articulates with the ulnar notch of the
radius and swivels around the head of the ulna during
pronation or supination. 6
The olecranon process is the bony prominence of
the ulna and also is where the triceps muscle attaches
to the elbow joint. 6,9 The olecranon bursa is a fluidfilled sac that serves as a cushion between the bone
and the slack skin directly over the olecranon process.9
The bicipitoradial bursa, or cubital bursa, lies between
the radial tuberosity and the biceps tendon.10 The
interosseous medial bursa lies medially between the
bicipitoradial bursa and the interosseous membrane of
the forearm.
Below the neck of the radius, the radial tuberosity
lies at the insertion point of the biceps tendon. The
brachialis muscle attaches at the coronoid process,
whereas the radial notch articulates with the radial head
to provide radial head stabilization. The trochlea of the
humerus is held at the trochlear notch. 6
Elbow Disorders and Injuries
www.asrt.org
®
Humerus
Coronoid
fossa
Olecranon
fossa
Radial
fossa
Medial
epicondyle
Olecranon
process
Lateral
epicondyle
Trochlea
Capitulum
Trochlear
notch
Coronoid
process
Radial
head
Radial neck
Radial notch
Radial tuberosity
Radius
Ulna
Figure 1. Elbow anatomy. Image courtesy of Pioneer Memorial
Hospital & Health Services, Viborg, SD.
Elbow Ligaments
Ligaments provide stability for the elbow joint. The
medial and lateral collateral ligaments supply most of
the stabilization. The medial collateral ligament (MCL)
attaches the ulna to the medial epicondyle of the
humerus. The annular ligament loops around the radial
head. The lateral ligament attaches the lateral epicondyle to the annular ligament.3
The MCL, also called the ulnar collateral ligament,
has 3 separate bundles and is essential to stabilizing
the ulnohumeral articulation of the elbow. The ligament bundles are the anterior, transverse, and posterior
bundles. 6 The most important of the elbow stabilizing
ligament bundles is the anterior bundle (see Figure 2).11
The anterior bundle originates at the inferior medial
epicondyle site and attaches to the coronoid process
medially. The anterior bundle also contains the anterior
and the posterior bands. The posterior band stretches
tight during flexion and becomes slack during extension. The anterior band is firm during extension and
relaxed when the elbow is flexed. 6
The transverse bundle originates at the medial
olecranon and attaches to the coronoid process. The
2
essentialeducation
directed reading
CLASSICS
®
muscles.11 The brachial muscle stimuHumerus
lates the arm for flexion. The biceps
Humerus
Medial
epicondyle
brachii usually is felt and seen during a
Lateral epicondyle
flexed pose of approximately 90°.3
Ulnar collateral
ligament
The biceps brachii inserts at the
Posterior ligament
Olecranon
radial tuberosity and forearm flexor
process
Anterior
ligament
Olecranon
Posterior
fascia. The brachialis is deeper than the
process
portion
biceps; it attaches to the coronoid proAnnular
Radial collateral
Anterior portion
ligament
ligament
cess of the ulna and originates from the
Coronoid process
Lateral ulnar
distal humerus. 5
Radius
collateral ligament
The extensor group contains the
Annular
ligament
Accessory lateral
triceps
and anconeus muscles. 6 The
collateral ligament
triceps muscle and part of the anconeus
Ulna
muscle control forearm extension. 3,5
Radius
The extensor supinator group contains
Ulna
the brachioradialis, supinator, extensor
digitorum, extensor carpi radialis lonFigure 2. Ligaments of the elbow.
gus and brevis, extensor carpi ulnaris,
and extensor digiti minimi. The flexor
posterior bundle rises at the medial epicondyle and
pronator group includes the pronator teres, flexor carpi
attaches to the medial olecranon. The transverse bunradialis, palmaris longus, flexor carpi ulnaris, and flexor
dle also stretches tightly when the elbow is flexed. 6
digitorum superficialis. 6
The lateral collateral ligament has 4 separate strucBlood Supply and Elbow Nerves
tures: the annular ligament, the accessory lateral
The blood supply through the elbow is extensive,
collateral ligament, the lateral ulnar collateral ligament,
and the major arteries associated with the elbow are
and the radial collateral ligament. 6
the brachial artery, radial artery, and ulnar artery. The
The annular ligament encompasses the radial head
brachial artery is lateral to the median nerve and lies
and stabilizes the radial notch of the ulna by band6,11
within the cubital fossa of the elbow. Several small
ing the proximal radius to the proximal ulna. The
branches exit off the brachial artery to supply blood to
accessory lateral collateral ligament derives from the
the surrounding elbow structures. Within the cubital
inferior portion of the annular ligament and connects
fossa, the brachial artery then bifurcates into the radial
to the supinator crest of the ulna. The lateral ulnar coland ulnar arteries. These arteries continue into the forelateral ligament begins at the lateral epicondyle and also
arm to supply blood distally.12
attaches to the ulna’s supinator crest. The radial collatFour nerves control elbow function and sensation.
eral ligament begins at the lateral epicondyle and inserts
6
They
are the musculocutaneous nerve, median nerve,
into the annular ligament.
ulnar nerve, and radial nerve.5,6 The brachial plexus
of the elbow is very complex, filled with a network of
Elbow Muscles
peripheral nerves. The most accessible nerve is the
Four muscle groups, as well as the tendons, work
ulnar nerve. This nerve sits along the olecranon groove
together to move the elbow joint. The muscle groups
and crosses the elbow through the cubital tunnel of the
are flexors, extensors, the extensor supinator group,
humerus.3,5 Because of its location, the ulnar nerve is
and the flexor pronator group (see Figure 3). 6 Three
the elbow nerve injured most often. It most commonly
muscles within the flexor group primarily act upon the
is compressed during direct trauma. 3
elbow. They are the biceps brachii, the brachioradialis,
and the brachialis muscles. 6 The brachialis muscle and
The radial nerve crosses the elbow forward of the
lateral epicondyle.5 Radial nerve compression also is
the biceps brachii are the most powerful elbow flexor
Elbow Disorders and Injuries
www.asrt.org
3
directed reading
CLASSICS
essentialeducation
Biceps
brachii
®
Triceps brachii
Brachialis
Brachioradialis
Pronator
teres
Palmaris
longus
Brachioradialis
Extensor carpi
radialis longus
Flexor carpi
radialis
Anconeus
Flexor
carpi
ulnaris
Extensor carpi
ulnaris
Extensor
digitorum
Extensor carpi
radialis brevis
Flexor
digitorum
superficialis
Extensor digiti
minimi
Figure 3. Muscles of the elbow.
possible because the nerve is susceptible to tightening
of the fibrous band that surrounds it. This tightening is
common during repeated contraction of the extensor
muscles during radial and ulnar deviation, as well as
finger extension. 3
The median nerve runs medially to the biceps tendon
and crosses the elbow from within the antecubital fossa.
At the elbow, the posterior interosseous nerve branches
off the radial nerve. The musculocutaneous nerve traverses the elbow through the lateral antecubital fossa.5
Bone Development
Bones develop in 3 distinct stages during childhood,
adolescence, and young adulthood. Bone development
begins during childhood, and this stage ends with the
appearance of secondary ossification centers, signaling
the beginning of the adolescent stage. The adolescent
stage of bone growth concludes once the secondary
ossification centers have fully fused with the corresponding long bones. This period begins the time of
young adult bone growth, which extends to the point
when all new bone is developed and final adult skeletal
structures are complete.13
When viewing a radiograph of a pediatric patient’s
elbow, it is important to understand the ossification
Elbow Disorders and Injuries
www.asrt.org
centers and the order in which the elbow joint and
bones begin to develop. The order of bone growth is
the same for all pediatric patients, and the commonly
accepted mnemonic for this sequence is CRITOE
(capitulum, radial head, internal [medial] epicondyle,
trochlea, olecranon process, and external [lateral] epicondyle) (see Table 1). Ossification centers typically
appear in girls 1 to 2 years before they appear in boys.14
The age at which the elbow joint completes the
growth process varies and tends to be later in boys than
girls. Generally, the capitulum, trochlea, and olecranon
process completely fuse by about the age of 14. At the age
Table 1
15,16
Elbow Ossification Sequence
Area of Ossification
Typical Age for
Ossification (Years)
Capitulum
1-2
Radial head
3-6
Internal (medial) epicondyle
4-6
Trochlea
7-8
Olecranon process
6-12
External (lateral) epicondyle
10-12
4
essentialeducation
directed reading
CLASSICS
®
of 15, the medial epicondyle fuses, and the lateral epicondyle and radial head unify at about 16 years of age.13
Radiographic Anatomy
The cause and treatment of elbow conditions differ
significantly, but there is little variation in the recommendation to use medical imaging for diagnosis and
to improve the outcome for patients with elbow conditions.17 Radiographically, several anatomical lines
are essential in assessing possible elbow damage. The
radiocapitellar line is centered through the long axis of
the radius and extends through the radial neck to the
center of the capitulum. Because the radius articulates
with the capitulum, this line should remain straight
regardless of the elbow’s position or the radiographic
projection (see Figure 4).14
A lateral radiograph also should display the anterior
humeral line. This line begins at the anterior portion of
the humerus and extends vertically through the middle
third of the capitulum (see Figure 5).14 The coronoid
line also can be seen on the lateral image. This line proceeds from the top of the coronoid process of the ulna
and intersects the anterior portion of the capitulum and
trochlea proximally (see Figure 6).5
The lateral projection of the elbow is essential in
evaluating the fat pads. The distal humerus contains
2 fat pads that make contact with the joint capsule
on the anterior and posterior portion of the joint.
Radiographically, this fat pad appears as a darker
density next to the bone with a grayer density of tissue surrounding the edges. The anterior fat pad is
visible on most lateral projections of the elbow. It is
not common to see the posterior fat pad, however.
If the radiologist notes the posterior fat pad, this
observation is known as a positive “fat pad sign” and
indicates a probable fracture in approximately 90% of
fracture cases.14,18
Fat pads appear in the presence of a joint effusion
when the capsule that holds the fat pads distends. The
distended capsule displaces the fat pads farther away
from the bone. During this change, the anterior fat pad
often takes the shape of a sail while making the posterior fat pad visible (see Figure 7).18
Correctly positioning the patient’s elbow at 90° is
imperative when imaging fat pads. A minor extension
of the arm can increase the pressure on the posterior fat
Elbow Disorders and Injuries
www.asrt.org
Figure 4. Radiograph of the radiocapitellar line. Image courtesy of
Pioneer Memorial Hospital & Health Services, Viborg, SD.
Figure 5. Radiograph of the anterior humeral line. Image courtesy of
Pioneer Memorial Hospital & Health Services, Viborg, SD.
Figure 6. Radiograph of the coronoid line. Image courtesy of
Pioneer Memorial Hospital & Health Services, Viborg, SD.
5
essentialeducation
directed reading
CLASSICS
®
pad, making the fat pad appear on the image and leading to a false-positive diagnosis.19
Diagnostic Imaging Modalities
Radiography
Radiography helps detect many elbow disorders
and injuries. The most common findings are fractures,
arthritis, loose bodies, and destructive processes.15
Radiologic technologists should obtain a minimum of
2 projections with 90° of differentiation because the
elbow anatomy appears normal in some projections
even when the patient has a disorder or injury in the
area. For the elbow, an anteroposterior (AP) projection and a lateral projection should be taken.20 Other
common elbow projections include the medial and
lateral oblique, axial lateromedial (Coyle), and the
Jones method, also known as the distal humerus acute
flexion projection.
In the AP projection, the patient’s elbow is extended
over the image receptor (IR). Supination of the hand
prevents the forearm bones from crossing. A slight
lateral tilt of the forearm can place the anatomy in the
correct position. The x-ray beam is perpendicular and
centered to the elbow joint (see Figure 8).19
When the patient cannot completely straighten the
elbow, 2 images replace the AP projection. Positioning
for both projections is similar to the AP projection,
in that the central ray is perpendicular to the joint.
However, the first projection places the posterior
surface of the humerus flat and parallel to the image
receptor. For the second projection, the technologist
places the patient’s arm so that the posterior forearm is
flat and parallel to the IR (see Figure 9).19
Lateral images of the elbow require the patient to
flex the elbow 90°. Both the forearm and the humerus
should be parallel to the surface of the IR during contact, and the radiologic technologist should rotate the
patient’s hand into a true lateral position. The central
ray should be directed perpendicular to the elbow joint
(see Figure 10).19
The medial oblique projection requires the patient
to extend the elbow over the IR as in the AP projection
but with the arm and hand in a pronated position. The
internal oblique projection is positioned similarly, but
the arm should be rotated laterally until the elbow is at a
45° angle to the IR (see Figures 11 and 12).19
Elbow Disorders and Injuries
www.asrt.org
Figure 7. Posterior fat pad and elevated anterior fat pad with the typi-
cal sail appearance seen in probable fracture cases. Image courtesy of
Avera Health, Sioux Falls, SD.
Figure 8. Anteroposterior (AP) elbow. Image courtesy of Pioneer
Memorial Hospital & Health Services, Viborg, SD.
The axial lateromedial (Coyle) projection requires
the elbow to be flexed 90° if possible, with the hand
pronated.21 The x-ray beam is angled 45° toward the
shoulder, centering on the elbow joint. This projection
shows an oblique angle of the lateral elbow separating
the proximal radius and ulna (see Figure 13).20
The Jones method acquires images of the elbow in
complete flexion. The posterior aspect of the humerus
6
essentialeducation
directed reading
CLASSICS
®
A
Figure 10. Lateral elbow. Image courtesy of Pioneer Memorial
Hospital & Health Services, Viborg, SD.
B
Figure 9. A. AP elbow, with the humerus flat against the image receptor and bent elbow. B. AP projection of the elbow with the radius and
ulna flat against the IR with elbow bent. Images courtesy of Pioneer
Memorial Hospital & Health Services, Viborg, SD.
Elbow Disorders and Injuries
www.asrt.org
Figure 11. Medial oblique elbow. Image courtesy of Pioneer Memorial
Hospital & Health Services, Viborg, SD.
7
essentialeducation
directed reading
CLASSICS
®
Figure 14. Axial or Jones method. Image courtesy of Pioneer
Memorial Hospital & Health Services, Viborg, SD.
Figure 12. Lateral oblique elbow. Image courtesy of Pioneer
Memorial Hospital & Health Services, Viborg, SD.
Figure 13. Axial lateromedial (Coyle) elbow. Image courtesy of
Pioneer Memorial Hospital & Health Services, Viborg, SD.
Elbow Disorders and Injuries
www.asrt.org
lies on the IR with the forearm superimposed over the
top. The x-ray beam should be perpendicular to the IR
and centered approximately 2 inches above the olecranon process (see Figure 14).19
Magnetic Resonance Imaging
Magnetic resonance (MR) imaging is useful in evaluating anatomical elbow structures. In particular, MR
helps display the joint’s muscle and tendon attachments.8
The ability to evaluate much of the elbow anatomy
would make MR an optimal imaging choice except that
positioning the elbow is difficult using MR equipment.22
For elbow MR, the patient can lie in a prone position
with the arm positioned above the head. This position
helps maintain the homogeneity of the magnetic field
but can compromise image quality because of motion
artifacts. Patients do not tolerate this position well;
therefore, the supine position is used more frequently.
In the supine position, the patient lies on his or her back
with the arms placed at the sides.8
The classic MR acquisition for the elbow involves
axial, coronal, and sagittal images with T1- and T2weighted sequences. Axial images of the radial tuberosity
are required to evaluate the biceps tendon attachment.8
Biceps brachii positioning can produce a partial volume artifact. The error occurs when different tissues
8
directed reading
CLASSICS
essentialeducation
are averaged and provide inconsistent data. Multiple
images generally are needed to overcome the averaging
effect. Images of the elbow using an abducted shoulder,
supinated forearm, and flexed elbow often can display
the biceps brachii fully.8
MR imaging cannot clearly define the posterior or
transverse bundles of the medial collateral ligament.
However, coronal images display the anterior bundle.
The annular ligament bundle displays better on axial
scans acquired while imaging the lateral collateral
ligament, and the radial collateral ligament is best
demonstrated with coronal imaging. The lateral ulnar
collateral ligament is displayed well on both coronal and
sagittal imaging.8
Axial images show the path of the muscles throughout the elbow in excellent detail. Sagittal images best
display longitudinal views of the anterior or posterior
muscle sections, and coronal imaging best displays the
medial and lateral segments.8
MR images of the 3 major nerves of the elbow generally appear the same intensity as muscle on T1-weighted
imaging. The signal intensity is slightly higher with
T2-weighted images, but outlining and visualizing the
nerves depend somewhat on adjacent fat. Axial images
characteristically allow better display of the nerves as
they pass through the distal humerus.8
MR images of an injured ligament might show
thickening or thinning of the ligament, increased signal
intensity, hemorrhage, slackness, and other abnormalities. Muscle injuries on MR scans demonstrate
morphological changes, atrophy, fatty changes, and
edema. Joint fluids increase with diseases that produce
synovial inflammatory changes. MR using gadolinium
contrast enhances the tissue’s signal intensity.22
Overall, MR of the elbow remains an excellent imaging choice for many elbow disorders and injuries. The
most common elbow conditions found on MR are listed
in Table 2. More than half of MR results can be categorized as normal findings or osseous lesions (54%);
synovial abnormalities are the next most frequent
finding (38.7%); and musculotendinous abnormalities
represent almost a quarter of the results (24.9%).22
Computed Tomography
The rapid scanning and helical imaging of modern
computed tomography (CT) scanners make accurate
Elbow Disorders and Injuries
www.asrt.org
®
and prompt imaging of elbow trauma possible. Planning
for elbow surgery also benefits from CT’s ability to
reformat images in any plane required and to provide
3-D volume renderings.17 These renderings model the
appearance of the outside of the bone (see Figure 15).
CT displays fractures, loose bodies, osteochondral
lesions, and other bony abnormalities well. Aside from
fracture fragment evaluation, CT with IV contrast
also is beneficial for blood vessel evaluation following trauma.17,23 CT arthrography also can play a role in
diagnosing elbow disorders. Similar to conventional
arthrography of the elbow (see Figure 16), CT arthrography highlights the joint capsule and filling defects
from synovitis or loose bodies. CT arthrography also is
Table 2
MR Abnormality Findings (Allowing for
22
Multiple Injuries)
Normal findings or osseous lesions
54%
Synovial abnormalities
38.7%
Musculotendinous abnormalities
24.9%
Nerve abnormalities
14.9%
Soft-tissue abnormalities
12.7%
Ligament abnormalities
5.8%
Miscellaneous
3.3%
Figure 15. Computed tomography 3-D volume rendering of the elbow
joint. Image courtesy of Sanford Health, Sioux Falls, SD.
9
directed reading
CLASSICS
essentialeducation
®
guiding aspiration needles or during therapeutic procedures for the elbow.17
Elbow Disorders
Figure 16. Arthrogram of
the elbow showing a small
defect on the lateral radial
head likely indicating an
interarticular loose joint
body. Image courtesy of
Sanford Health, Sioux
Falls, SD.
helpful in evaluating medial collateral ligament tears. A
1- to 2-hour delay following contrast injection can help
delineate periarticular masses of the elbow, including
ganglion and synovial cysts, and aid the assessment of
the elbow joint in relation to the masses.17
Ultrasonography
Ultrasonography is not a typical choice for imaging
the elbow, but the modality offers a less-expensive alternative for evaluating tendons, ligaments, and nerves.
Ultrasonography is useful in diagnosing soft-tissue
diseases of the elbow.23 It is also a good choice when imaging infants and young patients to evaluate unossified
epiphyses that might not be noticeable on radiographs.24
The sonographer can manipulate the elbow joint
during image acquisition, which can prove diagnostically helpful.23 For example, common manipulations of the
elbow using valgus stress (ie, applying stress to force the
hand and forearm away from the body while the elbow
is counter-forced) and ultrasonography techniques can
help assess cases of medial collateral ligament instability. Tendon motion demonstrated on ultrasonography
is one of the most important features used to diagnose
elbow tendinopathy.25 The ulnar nerve also can be
evaluated during flexion and extension.17
Color-flow Doppler imaging highlights soft-tissue
inflammation by showing increased blood flow to areas
of the elbow. Doppler imaging also can help distinguish
cystic from solid masses by displaying the vascular
components of the mass. Ultrasonography is useful for
Elbow Disorders and Injuries
www.asrt.org
Olecranon Bursitis
Inflammation of the olecranon bursa is called olecranon bursitis.9 It is also referred to as student’s elbow
because the condition can be caused by leaning excessively on the elbow.26 Inflammation builds slowly over
time and becomes a chronic condition, or it can develop
in acute situations.9 Chronic olecranon bursitis is seen
in people who throw repetitively, such as baseball pitchers; acute cases usually occur after a direct fall onto a
hard surface.5 Acute cases also can be attributed to a
sudden attack of gout, rheumatoid arthritis, or other
inflammatory diseases.11,27
Patients with bursitis are easily identified by the
large amount of swelling and masslike appearance of
the elbow. Other classic symptoms include redness and
heat in the area, often seen in trauma cases, and small
painful lumps that remain after the swelling ebbs.9,11
Bursitis does not routinely result in loss of motion, and
the pain is generally minimal.27
In nontraumatic situations, imaging may not be
required if the bursa fluid can be aspirated. In traumatic
cases, however, the bursa can become inflamed because
of an olecranon fracture.9 Fluid aspiration sometimes
leads to infection, and continued pain should be investigated with further imaging studies (see Figure 17).
Cubital Bursitis
Most frequently, cubital bursitis coexists with other
inflammatory processes such as rheumatoid arthritis.
Occasionally, it appears in cases of overuse, trauma, or a
distal biceps tear. Cubital bursitis also is known as bicipitoradial bursitis, and symptoms include antecubital fossa
swelling and tenderness. Patients with cubital bursitis
usually have limited pronation of the elbow joint.27
Cases of cubital bursitis are routinely diagnosed
using MR or ultrasonography.27 Some radiographic
images may show an abraded surface of the radial tuberosity or slight calcifications nearby.10
MR imaging of cubital bursitis demonstrates high-signal fluid that emerges between the radial tuberosity and
biceps tendon distally. The fluid normally appears on
T2-weighted images, which can lead to a misdiagnosis
10
essentialeducation
Figure 17. CT image showing air present within the bursa, possibly
related to active infection. Image courtesy of Sanford Health, Sioux
Falls, SD.
of a soft-tissue tumor. In questionable cases, IV contrast
assists in the diagnosis. If the fluid collection does not
enhance, bursitis is the likely diagnosis.22
During ultrasonography, elbow extension is routine.
The transducer should be placed at the lower edge of
the antecubital fossa.10 Sonograms of cubital bursitis
can show fluid or hypoechoic tissue that causes active
distention of the bicipitoradial bursa. Doppler imaging demonstrates an increase in blood flow to the area,
which is symptomatic of active inflammation.10
Tendonitis and Tendon Tears
Tendonitis of the elbow is due to inflammation of
the tendons. Tendonitis of the biceps muscle can lead to
rupture on either end. This condition commonly occurs
after lifting heavy objects and causes tenderness near
the biceps rupture site.11
Younger people do not usually experience tendonitis
of the biceps muscle, but those who lift weights are at
higher risk for ruptures. On average, tendonitis of the
biceps occurs in men aged 45 to 60 years.11
When the distal end of the biceps muscle ruptures,
symptoms include proximal elbow pain and weakness, especially during supination. When the rupture
occurs, the patient can experience a snapping sensation
followed by the appearance of a bulbous deformity, or
“Popeye sign,” near the distal bicep.11
Elbow Disorders and Injuries
www.asrt.org
directed reading
CLASSICS
®
Radiographs may show an avulsion fracture of the
radial tuberosity in cases of complete tears, but enlargement or abnormality of the radial tuberosity is the most
common finding.28 MR imaging is useful to assess a
possible tear or degeneration of the biceps tendon.
Distal ruptures routinely appear at the radial bicipital
tuberosity.11 Ultrasonography may be helpful in determining the extent of any tears.28
Triceps tendonitis is common with repetitive elbow
use in young athletes. The individual often experiences
a sensation on the medial border of the elbow that
patients describe as something snapping into place. In
addition, posterior elbow pain overlying the olecranon
process can indicate triceps tendonitis.5
Although triceps rupture is rare in adolescents and
children, untreated cases of triceps tendonitis can lead
to a rupture or tear of the tendon.5 Infrequent cases
have shown that anabolic steroid use or corticosteroid
injections of the olecranon bursa can increase the risk of
a triceps tendon rupture.27
Radiographic evidence of a triceps avulsion fracture
is referred to as a “flake or fleck sign” because a small
piece of bone avulsed from the olecranon process can
be seen on the lateral radiograph.29 As with biceps tears,
MR and ultrasonography images can help physicians
distinguish tears from other pathology.28
Lateral Epicondylitis
Lateral epicondylitis is the most common sportsrelated injury of the elbow and a primary cause of elbow
pain.5,30 It often develops in individuals who overuse
the elbow joint.9 The mechanism of injury depends
on repeated, forceful contraction of the wrist extensor muscles; contraction occurs with frequent forearm
pronation and supination, along with wrist extension. 3,31
The abuse of the extensor muscles causes inflammation
at the lateral epicondyle.3
Lateral epicondylitis is frequently referred to as
tennis elbow. Approximately 20% of injuries in tennis
players occur at the elbow.32 Although the condition is
associated with tennis, many other repetitive motions
can cause epicondylitis. Estimates show that 90% of
lateral epicondylitis patients develop the disorder from
activities other than tennis.23 Some examples include
painting on a frequent, regular basis (such as someone
in the painting profession), playing other racquet sports,
11
essentialeducation
and frequently using a screwdriver. The problem is normally seen in middle-aged patients with an average age
in their 40s.9 Smoking and obesity also seem to increase
risk for developing lateral epicondylitis.32
As the name suggests, the condition appears to be a
form of tendonitis in the area of the lateral epicondyle.
The inflammation process is not actually seen, but
increased tissue degeneration in the area of the common extensor tendon can be found. Therefore, lateral
tendinosis and angiofibroblastic tendinosis are alternative terms for this condition.9,27
The pain associated with this condition normally
occurs at the lateral epicondyle or slightly outside the
elbow. Pain can spread to the posterior portion of the
upper forearm and increases with the lifting of heavy
objects.9 Gripping items can become difficult because
of weakness and increased pain within the forearm.
This problem is known as the “coffee cup sign.”31
Radiographic evidence of lateral epicondylitis is rarely found. Occasionally, the radiologist sees calcification
at the extensor muscle and lateral epicondyle attachment, but the actual joint is characteristically normal.
In any case, radiographs differentiate lateral epicondylitis from other disease processes of the elbow such as
arthritis or loose bodies.9
Regardless of whether the tendinosis is located
medially or laterally, MR imaging demonstrates
the same epicondylitis features on either side.
T1-weighted images show tendon thickness and signal intensity changes. Abnormalities of the tendon
and signal changes are highlights of MR tendon
pathology.22,33 Ultrasonography can demonstrate
calcifications or hypoechoic areas in the lateral
epicondyle region and may be useful in diagnosing
tendinosis (see Figure 18).
In cases of chronic lateral epicondylitis, the capsule
below the extensor carpi radial brevis (ECRB) tendon
should be examined for tears. There are 3 classifications
for capsule tears. A type I capsule is completely intact
but demonstrates flaying of the ECRB tendon. Type II
cases show a linear capsular tear, and type III suggests a
complete capsular tear with retraction. 34
Currently, the best modality for diagnosing capsular
tears is arthroscopic techniques. Arthroscopy can help
definitively diagnose capsular tears, but diagnostic
imaging generally is desirable because it is less invasive.
Elbow Disorders and Injuries
www.asrt.org
directed reading
CLASSICS
®
Figure 18. Longitudinal sonogram of the common extensor tendon
(CET) at the insertion of the lateral epicondyle (LAT EPI). The
radius is labeled RAD, and LT stands for left. The tendon shows
hypoechoic areas consistent with chronic tendinosis. Areas of fluffy
calcification also are seen. Image courtesy of Sanford Health, Sioux
Falls, SD.
Unfortunately, MR images have a poor sensitivity rate
and may fail to provide a confident reading.34
Although MR falls short of accurately imaging capsular tears of the ECRB tendon, CT arthrography has
shown excellent success at displaying capsular tears. 30
The concern with CT arthrography is increased radiation exposure to the patient.
Medial Epicondylitis
Known to patients as golfer’s elbow, medial epicondylitis is common in individuals who overuse their
wrist flexors and forearm pronator but is seen far less
frequently than lateral epicondylitis. Medial epicondylitis is associated with several activities that overuse the
elbow but is common in golfers because of the position
of the arm while swinging a club.5
Medial epicondylitis primarily affects the insertion
point of the flexor carpi radialis.27 The patient presents
with pain at the medial aspect of the elbow. 5 Attempting
to stop wrist flexion can worsen the pain.27
As with lateral epicondylitis, radiographic evidence
of medial epicondylitis can be difficult to find, but
small calcifications or spurs next to the medial epicondyle are common. MR imaging most often is used for
diagnosis; T1- and T2-weighted images demonstrate
increased signal intensity and thickening of the common flexor tendon.27,35
12
essentialeducation
Arthritis
Arthritis is a disorder that produces inflammation
in the joints of the body. There are several kinds of
arthritis, each exhibiting different causes and symptoms. Regardless of the type of elbow arthritis, initial
pain management includes pain medication and physical therapy. Occasionally, corticosteroid injections are
used for pain management, but physicians must ensure
that the injections do not lull patients into a false sense
of well-being and overuse of the elbow joint, causing
further deterioration.7
Rheumatoid Arthritis
Rheumatoid arthritis is a severe form of arthritis
that progressively affects the body’s joint tissues. Joint
erosion and destruction are common because of the
severity of rheumatoid arthritis.36
When rheumatoid arthritis affects the elbow,
it is not uncommon to see recurring effusions. As
the disease progresses, the joint surfaces begin to
deteriorate, leaving little articular cartilage. This
deterioration can cause loss of motion and pain during movement.11
Rheumatoid arthritis commonly begins in the radiocapitellar joint. The radial head may move out of its
regular position and cause problems with other elbow
anatomy. The radial head’s movement can press on the
ulnar nerve, causing increased pain.26
Radiographs monitor structural changes caused by
rheumatoid arthritis, but radiography is not the preferred
method for early disease assessment.37 Bone erosion from
rheumatoid arthritis is better displayed on CT images
than on MR images or radiographs.38 Ultrasonography
can show inflammation related to rheumatoid arthritis
and document destructive changes.37
MR images of the elbow in patients with rheumatoid arthritis demonstrate the same signal intensity as
fluid-filled masses. Therefore, it is important to use
gadolinium contrast, which indicates inflammation by
enhancing the exterior portion of the arthritic area.22
Osteoarthritis
Arthritic conditions of the elbow are not uncommon,
but osteoarthritis of the elbow is rare. Osteoarthritis is
much more prevalent in weight-bearing joints, such as
knees and hips, and in the interphalangeal joints of the
Elbow Disorders and Injuries
www.asrt.org
directed reading
CLASSICS
®
hand. Most often, osteoarthritis of the elbow occurs in
middle-aged male laborers.7
Patients with osteoarthritis affecting the elbow
experience the most pain during terminal flexion and
extension of the joint. In some cases, however, osteoarthritis limits motion because of bone protrusion into
the olecranon or coronoid fossa.7
Radiographic evidence of osteoarthritis includes
osteophyte formation. These osteophytes usually are
near the ulnohumeral joint and occasionally impinge on
the ulnar nerve. Other common features seen on radiographs of the elbow include loose bodies.7 MR and CT
images of the elbow help show the joint surfaces and
detect loose bodies or spurs.7,39
Gout
Elevated uric acid levels can produce monosodium
urate crystals that infiltrate the synovial fluid of joint
spaces and lead to gout. Gout usually is found in the
joint spaces of the toes but can appear at the elbow. The
difference is that elbow gout tends to affect the olecranon bursa instead of the joint space. 40
Evidence of gout is obvious in patients with
advanced disease but is not often apparent on images
of early cases. Both MR and CT are excellent modalities for diagnosing and monitoring gout. MR images
are better for evaluating synovial involvement, and
CT is better for displaying intraosseous lesions.
Ultrasonography also can highlight thickening of the
synovial fluid, along with inflammation. 38
Overuse Conditions in Children
Children can have elbow injuries and conditions
related to overuse of the elbow joint. Examples of these
problems, sometimes referred to as Little League elbow,
include traction apophysitis of the medial epicondyle,
Panner disease, and osteochondritis dissecans.
Traction Apophysitis of the Medial Epicondyle
Traction apophysitis of the medial epicondyle is
inflammation of the medial epicondyle due to an
avulsion tear or trauma.9,14 Because of the timing of
ossification in children, traction apophysitis is the
most common elbow injury in young children. It is less
common in older children who have begun to grow secondary ossification centers.
13
essentialeducation
Overhand throwing places extreme valgus force on
the medial epicondyle. Approximately 97% of elbow
problems in baseball pitchers are associated with symptoms of the medial elbow.41 The throwing mechanics of
young athletes places direct strain on the elbow, causing medial, lateral, and posterior symptoms. The main
symptom of apophysitis of the medial epicondyle is pain
immediately after a repetitive motion such as throwing.
This pain is unremitting and tends to get worse.5
Radiographs of the elbow might show slight widening of the apophysis, but this can be missed easily
if the radiologist does not review comparison radiographs of the opposite elbow.13 MR imaging can show
edema of the bone marrow around the medial epicondylar area. MR also can demonstrate signal changes in
areas of fragmentation. 39
Panner Disease
Osteochondrosis affects the ossification centers of
children when the bone degenerates and then begins to
regenerate, producing excessive calcification in some
areas. Panner disease is a form of osteochondrosis that
affects the capitulum of the elbow.5
Panner disease is most common in preadolescent
boys and children younger than 10, and it is the most
frequent reason for lateral elbow pain in young children,
routinely affecting the dominant arm. 5,13
Children with Panner disease often complain of
a dull ache and may experience acute swelling and
tenderness at the lateral elbow. The pain can be accompanied by an inability to extend the arm fully and
feelings of stiffness.5,13 Fluid buildup is not common
with Panner disease, but crackling sensations or sounds
often are felt or heard.13
Radiographs can display sclerosis and areas of
decreased density at the capitulum. The joint surfaces also might appear irregular.5 An MR series with
T1-weighted images might show fragmentation with
decreased signal intensity at the capitulum surface.39
Osteochondritis Dissecans
A more advanced form of osteochondrosis is
osteochondritis dissecans. 42 These lesions result
from death of the articular cartilage or subchondral
bone of the capitulum due to a lack of blood supply.5
Subchondral bone supports cartilage at articulation
Elbow Disorders and Injuries
www.asrt.org
directed reading
CLASSICS
®
sites. Occasionally, a small fracture of subchondral bone
or the neighboring cartilage can be found near the joint
space. If the subchondral bone or cartilage is slightly
fractured, it is known as osteochondritis dissecans.14
Patients with osteochondritis dissecans lesions often
have plica, an inflamed lining of the radiocapitellar
joint. Because the pain is located on the lateral side of
the elbow, radiocapitellar plica commonly is misdiagnosed as lateral epicondylitis.
Osteochondritis dissecans typically affects adolescent athletes aged 11 to 21 years.5,42 Athletes who throw
balls or other objects are at high risk for osteochondritis
dissecans, as is the case with Panner disease. However,
gymnasts also are at high risk for the condition. A gymnast’s radiocapitellar joint is subjected to up to 60% of
the total force placed on the upper extremity and the
elbow during axial loads. This force appears to interfere
with blood supply to the capitulum, directly affecting
the growth and strength of the subchondral bone.13
Osteochondritis dissecans is characterized by a dull
ache with no centralized location. The pain may disappear when the child is resting then reappear during
strenuous activities. If fragments are loose in the area,
the joint may routinely catch or cause a popping sensation.5,13 Radiographs commonly show the capitulum
surface as smooth and compressed with decreased density around the anterolateral aspect. Subchondral bone
fractures are also a common finding.13 Radiographs
typically are not very sensitive for identifying loose
bodies, and less than 30% of positive loose bodies are
found using radiography.41 In extreme cases, radial head
enlargement, osteophyte formation, and collapse of the
articular surface have been seen.13
Radiographically, osteochondritis findings are classified into 3 grades based on AP elbow images. Grade I
radiographs show a translucent shadow around the middle or lateral capitulum; grade II images demonstrate a
clear line between the lesion and subchondral bone, and
grade III images visualize loose bodies.13
There are 4 types of osteochondritis dissecans
lesions. Type I are continuous lesions, or lesions that
are in one solid piece. Type II lesions have partial
discontinuity, or areas where cartilage or bone may
be partially detached. Type III lesions have fractures
that are separated completely. Type IV lesions are
loose or dislocated.
14
directed reading
CLASSICS
essentialeducation
This classification system of lesions is often used,
but it is not standardized, which can lead to confusion.
To lessen this confusion, a grading system was created
using arthroscopy techniques that grade the lesions
using an additional standardized approach. The grading
process can be seen in Table 3. 42
CT of the elbow joint helps physicians locate and
count loose bodies found throughout the elbow compartments before the patient undergoes arthroscopic
procedures to remove the fragments. If CT is used for
this purpose, the removal procedure should follow soon
after the scan before loose bodies shift.42
On MR images, osteochondral lesions can be confused with normal osseous variants of the elbow. For
example, pseudodefects of the capitulum can appear on
coronal and sagittal MR images as a groove between
the lateral epicondyle and posterolateral aspect of the
capitulum. Another false finding on MR elbow scans is a
pseudolesion at the trochlear notch. This variant appears
as an area between the coronoid and olecranon articular
surface that is barren of any cartilage.8
Osteochondral lesions typically are encircled by areas
of edema on T2-weighted images and usually are located
more anteriorly than a pseudodefect of the capitulum (see
Figure 19). As for the trochlear notch pseudolesion, sagittal imaging may show the trochlear groove or area without
cartilage. If no bone marrow edema appears to indicate
the osteochondral lesion, a pseudolesion is suspected.8
Ultrasonographic imaging of osteochondritis dissecans is not routinely performed, although it can provide
information about elbow stability.13 Arthroscopy is used
most often because it remains a safe and effective way
to diagnose and evaluate osteochondritis dissecans or
lesions of the elbow. The benefit of arthroscopy is the
ability to immediately remove any loose bodies or deliver
other treatments.42
Table 3
Grading of Osteochondritis Dissecans Lesions
Numerous injuries can cause nerve damage to the
elbow.5 The most common nerve condition in the
elbow is ulnar neuritis. This inflammation of the nerve
causes radiating pain from the posterior medial elbow
to the hand and fingers.3 Compression of the elbow
nerves is attributed to a wide range of abnormalities.
The most common causes of nerve compression are
listed in the Box.22
www.asrt.org
42
Grade 1
Soft and smooth cartilage that is moveable
Grade 2
Fibrillation or fissuring of cartilage
Grade 3
Exposed bone with fixed osteochondral fragment
Grade 4
Loose but nondisplaced fragment
Grade 5
Displaced fragment with loose body
Figure 19. Magnetic resonance image showing small joint effusion
(arrow) with a focus of osteochondritis dissecans (with mild subchondral bone marrow edema involving the inner aspect of the capitulum).
Image courtesy of Sanford Health, Sioux Falls, SD.
Box
Causes of Elbow Nerve Compression
Nerve Damage
Elbow Disorders and Injuries
®
22
Ectopic calcification
Ectopic ossifications
Ganglion
Hematoma
Inflammatory pannus
Lipoma
Loose bodies
Osteophytes
15
directed reading
CLASSICS
essentialeducation
The median and radial nerves can be injured in cases
of supracondylar fractures when the arm is hyperextended. An ulnar nerve injury typically is associated
with supracondylar fractures when the arm is in hyperflexion, but most ulnar nerve injuries occur because of
direct blows to the nerve.24
Damage to the ulnar nerve can lead to numbness and
tingling of the hand. Most often, these sensations occur
in the medial area of the palm, including half of the
fourth finger and all of the fifth. 3 The fifth finger also
may be weak during abduction or flexion and the entire
arm can feel heavy.27,41
The ulnar nerve is so sensitive that severe swelling
can affect this nerve to the point that it causes numbness in the fingers.9,43 In severe cases of ulnar nerve
injury, symptoms can last for years after the trauma.
This is commonly known as tardy ulnar palsy. 44
Symptoms of median nerve compression syndrome
include pain at the anterior proximal forearm. This
pain is frequently noted during repetitive pronation
of the arm. 5 Several tests can be performed to evaluate this condition; for example, the patient’s hand can
be rested on the forehead for approximately 1 minute.
After 1 minute, positive ulnar nerve damage causes
a tingling sensation. The same effect is achieved by
tapping the ulnar nerve at the elbow. The tingling sensation is known as a positive “Tinel sign.”27,43
The interosseous medial bursa can become
enlarged and press on both the median nerve and
the bicipitoradial bursa. The bicipitoradial bursa
then compresses the posterior interosseous nerve,
producing pain.10
Radiography of the elbow for nerve damage typically is not useful. In ulnar neuritis, however, medial
osteophyte development might be seen on a radiograph. 5 MR imaging is the best modality to show nerve
damage and edema; the nerve damage appears as signal intensity changes on the T2-weighted images.22
Cubital Tunnel Syndrome
Cubital tunnel syndrome is another term for ulnar
nerve entrapment. The ulnar nerve is particularly vulnerable to injury at a point behind the medial epicondyle
within the cubital tunnel. Hitting this area produces the
recognizable sensation of tingling and pain, commonly
referred to as hitting the “funny bone.”30
Elbow Disorders and Injuries
www.asrt.org
®
During normal elbow flexion, pressure on the ulnar
nerve at the cubital tunnel increases by 3 to 9 times.41
The ulnar nerve can become entrapped within the cubital tunnel from diseases such as diabetes and arthritis or
simply from repetitive activities and bending the elbow.30
MR imaging shows ulnar nerve entrapment as an
increased thickness of the nerve above and within the
cubital tunnel. This thickness usually diminishes with
increasing distance from the cubital tunnel.22
Radial Tunnel Syndrome
In some cases, the posterior interosseous nerve that
branches off at the radial nerve becomes entrapped. This
condition is known as radial tunnel syndrome and can
be difficult to diagnose.11 Common causes of entrapment include compression from fractures or dislocations
of the radial head or ganglia, and rheumatoid arthritis.26
Repetitive pronation of the forearm and extension of the
wrist can directly cause radial tunnel syndrome.11
Symptoms of radial tunnel syndrome include dull
pain on the lateral elbow, with direct pressure replicating the pain. The pain is similar to lateral epicondylitis,
but radial tunnel syndrome typically exerts pain more
distally than the lateral epicondyle location. Repeated
extension of the middle finger can cause weakness
and pain and might indicate nerve entrapment.11,26
Eventually, uncorrected nerve entrapment can lead to
inability to extend the fingers and thumb.26
Medical imaging is not particularly useful in diagnosing radial tunnel syndrome. However, imaging
can help distinguish radial tunnel syndrome from
other processes.12
Elbow Injuries
Ligament or Tendon Injury
About 50% of the medial and lateral plane of the elbow
is stabilized by ligaments.45 If the anterior bundle of the
medial collateral ligament is injured, the elbow becomes
extremely unstable except when fully extended. A disturbed or compromised lateral ligament complex can
result in loss of the ability to pronate or supinate the arm.6
Radiography can assess ligament tears and joint stability, particularly with valgus or varus stress applied
during a fluoroscopic examination. However, this
examination can be painful and usually is conducted
with the patient under anesthesia.23
16
essentialeducation
Gadolinium contrast often is used during MR imaging to help enhance MCL injuries.7 Partial tears appear
as a thinning of the ligament and exhibit high signal
intensity during T2-weighted acquisition. Complete
tears can be seen by following the ligament and noting
a disruption or separation; they also are seen best on
T2-weighted images.22
Full tears of the MCL can be evaluated using MR
imaging with intra-articular contrast. 5 Although
MR imaging is highly sensitive for complete tears of
the MCL, it is not the method of choice for viewing
partial tears. CT arthrography has a higher rate of
identifying partial tears.12 In either modality, a sagittal projection is the best choice for determining the
size of a ligament injury. 22
Dislocations
The elbow is the joint that is dislocated most often
among pediatric patients. It is the second most dislocated joint in adult patients, with 50% of cases resulting
from sports activities.9 Dislocations represent 10% to
30% of all elbow injuries.45
Elbow dislocations occur as a result of many situations but most often arise from a fall on an outstretched
hand. 46 The instinct to protect against a fall with an
outstretched arm leads to posterior or anterior dislocations. Posterior dislocations are much more common;
only 2% of dislocation cases are anterior dislocations.9
The most common dislocation involves displacement of
both the ulna and radius (see Figure 20). It is possible
to displace the ulna while the radius remains stable.
Alternately, radial displacement without ulna displacement is extremely rare in adults but can happen.14
Elbow dislocations often present with other injuries.
Dislocations are also associated with 10% to 15% of
coronoid process fractures and 10% of radial head fractures that occur during the same injury.1,47 Other elbow
anatomy at risk during dislocations includes neurovascular structures such as the median nerve or brachial
artery. Dislocations require an assessment of radial
pulse and nerve sensation to assess for the possibility of
these neurovascular injuries.9
The medial collateral ligament is routinely compromised in elbow dislocation. With MCL damage, the
elbow joint might remain unstable unless the ligament
heals or is surgically repaired.2
Elbow Disorders and Injuries
www.asrt.org
directed reading
CLASSICS
®
Figure 20. Posterior disloca-
tion of the elbow involving
the radius and ulna. Image
courtesy of Sanford Health,
Sioux Falls, SD.
A patient with an elbow dislocation most often
experiences extreme pain and swelling. A deformity
may or may not be clearly seen. The patient may not
be able to bend the elbow following a fall on the outstretched hand.9
An AP and lateral radiograph elbow series is sufficient
to diagnose an elbow dislocation.9 Once diagnosed, it is
important that a physician reduce the dislocation as soon
as possible. If the elbow has been dislocated for a long
time, swelling and muscle spasms can make it difficult to
correct the dislocation without general anesthesia.9
An elbow reduction most often is performed by
holding the patient’s upper arm in place while steadily
pulling on the forearm and hand. This counter-traction
should be made with the long axis of the upper arm.
Once the dislocation is reduced, the elbow should be
tested for mobility and examined with radiography to
ensure satisfactory reduction of the joint and exclude
any further bone injury.9
A neurovascular examination should be performed
and results noted before and after reducing the dislocation. 45 Once an elbow dislocation has been reduced,
the patient still might have problems with the arm as a
result of the trauma. Following an elbow dislocation,
extension can become compromised, and the elbow
may be unstable.9 Six weeks after a simple dislocation,
instability is rare (< 1% to 2% of cases). 45 Over time,
some patients might develop arthritis or ectopic bone.9
17
directed reading
CLASSICS
essentialeducation
Heterotopic Bone Formation
Formation of bone or calcification that is not in the
normal bone growth area is called heterotopic bone
formation. Heterotopic bone growth at the elbow can
be associated with traumatic injury of the elbow, but it
also can be caused by central nervous system trauma or
excessive burns.1 The reasons for heterotopic bone formation after brain and spinal cord injuries is unknown,
however, making it difficult to predict or manage.1,11
Heterotopic bone formation of the elbow tends to
develop more often in the deep posterior sections of the
triceps from the epicondyle to the olecranon process.
At the anterior location, it is more often noted at the
brachialis muscle. Bone formations also grow between
the radius and ulna, causing a fusion.1
The formation of juxta-articular bone at the elbow
joint can cause problems because of decreased range of
motion.11 Once elbow motion has been compromised by
heterotopic bone formation, the only treatment for restoring motion is surgical resection of the bone.1 Classes of
heterotopic bone of the elbow are listed in Table 4.
®
Table 4
Classification of Heterotopic Bone Formation of
1
the Elbow
Class I
Radiographic evidence of heterotopic bone
formation with no loss of functionality
Class IIA
Radiographic evidence of heterotopic bone
formation with some functional loss of flexion
and extension
Class IIB
Radiographic evidence of heterotopic bone
formation with some functional loss of pronation
and supination
Class IIC
Radiographic evidence of heterotopic bone
formation with some functional loss of flexion/
extension and pronation/supination
Class IIIA
Ectopic bone with joint fixation in flexion
or extension
Class IIIB
Ectopic bone with joint fixation in pronation
or supination
Class IIIC
Ectopic bone with joint fixation in either flexion/
extension and pronation/supination
Fractures
The proximity of nerves, arteries, tendons, muscle,
and bones in the elbow contributes to the joint
being considered one of the most complex fracture
sites.20 Clinical examination begins by observing the
patient’s arm. When both arms hang normally at the
patient’s sides, there should be a 5° to 15° separation
of the forearms and hands from the body. Women
normally have a greater separation than men. This
arm-to-body separation is known as “the carrying angle.” If the patient’s arms and hands are not
observed within the acceptable ranges, it could indicate an elbow fracture. 5,44 Any variation of the angle
that is more than 15° is known as cubitus valgus.
Angles less than 5° are called cubitus varus. 44
All fractures are serious and should be treated as
such, although open fractures are at higher risk for
adverse complications. An open site can become a host
for osteomyelitis (bone infection), wound infections,
and other diseases. In many cases of open fractures, the
bone retreats into the skin and cannot be seen.20
There are 3 distinct phases in the healing process
of bones. In the first phase, fractures begin healing in a
state of inflammation that can last approximately 10% of
Elbow Disorders and Injuries
www.asrt.org
the entire healing process. Once the inflammation at the
fracture site has subsided, the second phase begins with
the process of bone repair. This phase can last up to several weeks and is continued into the remodeling phase.
Complete fracture healing can last for months or years.18
Distal Humerus Fractures
Distal humerus fractures represent only 2% of adult
fractures. These fractures can appear in both condyles
and often continue into the joint space. The lateral condyle is more commonly affected (see Figures 21 and 22).9
Location determines the classification of distal
humerus fractures. A fracture above the condyles
is called a supracondylar fracture (see Figure 23).
Fractures on the same plane as the condyles are called
transcondylar fractures. Fractures through a condyle
are known as condylar fractures. Fractures that occur
between condyles are known as intercondylar fractures
and have distinct classifications (see Table 5).20
Patients with distal humerus fractures experience
extensive swelling, deformities, and pain. These fractures
also can bruise the skin. Flexion of the arm can produce
crackling or popping sounds from bone fragments.9
18
directed reading
CLASSICS
essentialeducation
®
Figure 21. Radiograph
showing a severe fracture
of the lateral epicondyle.
Image courtesy of Sanford
Health, Sioux Falls, SD.
Figure 22. CT image showing a severe fracture of the lateral epicondyle. Image courtesy of Sanford Health, Sioux Falls, SD.
Table 5
Classification Criteria for Intercondylar Fractures
22
Type I
Involves nondisplaced fracture lines between the
capitulum and trochlea
Type II
Separation of fracture lines exist but no rotation of
fracture is seen in the frontal plane
Type III
Separation of fracture lines are seen with marked
rotation of fragments
Type IV
Involves severe comminution of the articular
surface with large separation of fragments
Elbow Disorders and Injuries
www.asrt.org
Figure 23. Radiograph showing a supracondylar fracture. Image
courtesy of Avera Health, Sioux Falls, SD.
A 2-projection radiographic examination usually is
sufficient to evaluate distal humerus fractures. A positive fat pad sign occasionally indicates bleeding from
a small occult fracture.9 A lateral oblique projection
is helpful for diagnosing lateral condyle fractures or
displacement.24 In pediatric patients who have little
ossification of the bones, nondisplaced fractures of the
condyle can easily be missed. An oblique radiograph of
the elbow might help identify nondisplaced fractures of
the condyle in children.9
Posterior displacement of the humerus, often seen
in fractures, affects the orientation of the anterior
humeral line seen on the lateral image. If the anterior
humeral line passes through the anterior portion of the
capitulum or does not meet the capitulum at all, a fracture is possible.24
Displaced fractures are generally stabilized with surgery. Splinting is sufficient in nondisplaced fractures. It
is important to retake radiographs of the elbow after several days of splinting to ensure adequate positioning.9
Olecranon Process Fracture
The olecranon process is at high risk for fracture
because of its prominent position directly under the surface of the skin.9 These fractures generally occur when
an individual falls directly onto the flexed elbow, resulting in a comminuted break.14,20 A fall on an outstretched
hand also can produce proximally displaced oblique
fractures.9,20 Other fractures of the olecranon process
include avulsion, nondisplaced transverse and nondisplaced oblique fractures, and fracture-dislocations.9,18
19
essentialeducation
Swelling and extensive bruising often are noted following an olecranon process fracture.9 Range of motion can
be limited, and extension can be difficult because of
possible triceps injury.20
AP and lateral radiographs can usually demonstrate
olecranon process fractures,9 with a lateral projection
providing the best view of the fracture (see Figure 24).14
If an olecranon process fracture is nondisplaced,
a posterior splint to flex the elbow 90° usually is the
first step in treatment. Follow-up for this treatment
includes radiography to ensure that the fracture
remains nondisplaced. Displaced fractures require
internal fixation with plates, screws, pins, or wires to
align the bone properly.9
Even after healing, an olecranon process fracture
can limit motion regardless of treatment. If fixating
hardware is used, the hardware can irritate the tissues
around the fracture site, causing more pain.9
Coronoid Process Fracture
Fractures of the coronoid process typically occur
in conjunction with posterior elbow dislocations.14
An avulsion fracture of the coronoid is possible if the
brachialis muscle is subjected to forceful contraction.
Antecubital fossa tenderness and swelling are common
symptoms of coronoid fracture.20
Coronoid fractures are divided into 3 classifications.
Type I fractures only involve the tip of the coronoid.
Less than 50% of the coronoid is involved in type II
fractures. Type III fractures involve more than 75% of
the coronoid. Type II and III fractures regularly result
in joint instability.45
The radial head or oblique projection of the elbow
highlights possible fractures of the coronoid. The lateral
projection best demonstrates coronoid fractures, however, and also highlights avulsion fractures.14,20
Radial Head Fracture
The radial head is believed to be the secondary stabilizing source for the elbow during valgus stress. 45 As a
result, radial head fractures tend to occur when patients
fall with a forearm turned inward and land on an outstretched hand. These are the most common elbow
fractures among adults.9,48 Although less common,
radial head fractures can occur from a direct blow to
the elbow or from hyperflexion injuries. 49 Because there
Elbow Disorders and Injuries
www.asrt.org
directed reading
CLASSICS
®
Figure 24. Lateral radiograph of the elbow showing a severe fracture
of the olecranon process as well as the proximal ulna and coronoid
process. Image courtesy of Custer Regional Hospital, Custer, SD.
is no subchondral bone on the anterolateral portion of
the radial head, this site is more vulnerable to fracture,
accounting for 17% to 19% of trauma to elbows.29,49
Radial head fractures occur with elbow dislocations in approximately 10% of cases.9,49 Other injuries
associated with radial head fractures include fractures
of the distal radius, coronoid, and capitulum. In some
instances, medial and lateral collateral ligaments also
are injured. 49
There are 3 classifications for radial head fractures.
Type I fractures are nondisplaced. Type II fractures are
displaced but only slightly. Type III fractures involve
the entire radial head and are comminuted.9 Stability of
the elbow can usually be maintained in radial head fractures if the fracture involves less than 30% of the radial
head and an intact medial collateral ligament. 45
Patients who have radial head fractures experience
pain on the outer surface of the elbow and may not be
able to pronate or supinate the forearm. The elbow can
show signs of swelling, limiting the amount of flexion
and extension.9
Standard 2-projection radiographs of the elbow are
routine for suspected radial head fractures because these
breaks usually produce a positive posterior fat pad sign
on radiographs. In cases of diffusion, the anterior fat pad
may be displaced, giving the appearance of a sail.14,49
20
essentialeducation
Other radiographic projections may be helpful if the
standard projections are not sufficient. If a radial head
fracture is suspected, radiocapitellar oblique projections
should be performed in addition to the standard set.14,49
Elbow radiographs normally are adequate to identify
type II and type III fractures of the radial head, but
type I fractures are frequently missed. If a nondisplaced
fracture is suspected, another set of radiographs should
be taken 3 weeks following the injury to see if any healing fractures can be noted.9 With type III fractures, a
CT scan may be performed for surgical planning.20
Capitulum Fractures
Fractures of the capitulum are not very common,
but when they occur, they share a similar mechanism
of injury as radial head fractures because of the axial
alignment of the capitulum. 49 In fact, nearly 50% of
capitulum fractures are accompanied by a radial head
fracture. 47 People who are middle-aged and elderly are
most likely to suffer capitulum fractures. 49
Capitulum fractures cause pain, tenderness, and
swelling over the lateral aspect of the elbow. A grating or crackling sound can be heard during flexion or
extension, and range of motion may be limited. 49
Results of routine radiography often are misleading in cases of this fracture. The AP projection can
hide a fracture fragment behind the humerus, and any
rotation or a slight oblique lateral positioning often
obscures the fracture. 47,49 Radiographs of the elbow
consistently show a positive fat pad sign on the lateral
projection, but radiographers should acquire an axial
lateromedial (Coyle) projection to better demonstrate
any fracture fragments. 49
If the trochlea is involved, lateral projections might
show what is known as the “double arc sign.”49 This sign
is a characteristic finding that represents the subchondral bone of the capitulum and the lateral trochlear
ridge, both of which appear as an arc.50
Capitulum fractures are classified into 3 types. The
most common capitulum fractures are type I fractures,
which include most of the osseous capitulum and some
of the trochlea. Type II fractures involve the capitulum
articular cartilage and a limited amount of subchondral bone. Type III fractures are routinely impacted
or comminuted and occasionally are seen with radial
head fractures. 49
Elbow Disorders and Injuries
www.asrt.org
directed reading
CLASSICS
®
Determining the degree of displacement in capitulum fractures is difficult with radiographs. CT images
can show precise details of the fracture. 49
Avulsion Fracture
Stress to the elbow joint can create avulsion fractures.
For instance, a rapid baseball pitch can cause enough
stress to produce an avulsion fracture of the medial
epicondyle. Avulsion fractures frequently are found in
adolescents aged 9 to 12 years, and they are the most
common type of elbow fracture in adolescent athletes
who participate in throwing as part of their sport.9,13
Avulsion fractures most often are found before the
secondary ossification centers fuse.5 A common symptom of avulsion fractures is an acute popping sensation
in the elbow followed by pain. The pain often is felt
immediately after making a hard pitch or throw.5,13
Tenderness with pressure applied to the medial epicondyle is common, along with swelling or bruising.13
A radiographic examination with AP and lateral
projections usually provides diagnostic information for
avulsion fractures. Images obtained following the injury
might show a disconnection of the medial epicondyle
apophysis or subtle displaced fractures.5,13 Occasionally,
a gravity stress test or manual stress projections of the
elbow also are ordered.13
Classification of medial epicondyle fractures is
based on the patient’s age and degree of fracture. Type
I injuries affect patients aged 14 years or younger and
routinely involve the apophysis. Type II injuries occur
in patients older than 15 years who have large fragments
with an injury that might involve the medial collateral
ligament. Type III injuries occur in patients older than
15 years but consist of smaller fractures.13
Combined Fractures and Dislocations
Monteggia fracture-dislocations involve a fracture
of the ulnar shaft and displacement of the radial head.14
If the alignment of the radiocapitellar line does not
point to the capitulum on all radiographic projections, a
Monteggia fracture or lateral condyle fracture is likely.24
Galeazzi fracture-dislocations combine a distal radial
head disruption and a distal radial fracture. EssexLopresti fracture-dislocation consists of a radial head
fracture that is comminuted and a distal subluxation or
dislocation of the radioulnar joint.14
21
essentialeducation
directed reading
CLASSICS
®
The “terrible triad” is a devastating elbow injury
that includes a radial head fracture, a medial collateral
ligament injury, and a coronoid process fracture. This
injury makes the elbow extremely unstable because the
affected anatomy generally helps stabilize the joint. 49
Another triad injury of the elbow includes a triceps
rupture, radial head fracture, and an MCL rupture.
Distal triceps ruptures are extremely rare, accounting for
less than 1% of tendon problems in the upper extremity.29
Arterial Injuries
Although most types of fractures rarely lead to
arterial injury, it is not uncommon for dislocations
and displaced fractures of the elbow to cause trauma
to the arteries. Specific traumas, such as supracondylar fractures, carry such a high risk for arterial injury
that it should be suspected in most cases. Arterial
injuries are very serious and can lead to contracture
or loss of the affected limb.20 If the brachial artery
is damaged, the patient may have a decreased pulse,
radiating pain, decreased skin temperature, and the
skin of the affected arm may appear pale. 5 A pulse
should be detectable distal to the fracture. If the skin
appears pale or the pulse is noticeably low or absent,
arterial injury is likely.20 A CT examination with IV
contrast can display any occlusions or hematomas
(see Figures 25 and 26).
Fractures in Children
Fractures of the elbow are not uncommon in children, given their typical behavior. 46 Approximately 10%
of all fractures in children occur at the elbow.20 The
epicondylar elbow fracture often is seen in boys who
stop a fall with an outstretched hand.46 Supracondylar
fractures are the most common elbow fracture in the
pediatric population, however, constituting up to 60%
of cases.14,48 After the reduction of the fracture, a radiographic image using the Jones method can confirm
adequate reduction.51
Lateral condylar fractures constitute 12% to 16%
of elbow fractures in children, and medial epicondylar
fractures affect less than 2% of the pediatric population. Roughly 35% of pediatric skeletal injuries involve
a growth plate.14,51 Comparison images of the uninjured
elbow are helpful for determining the patient’s ossification status (see Figure 27).
Elbow Disorders and Injuries
www.asrt.org
Figure 25. Coronal CT image
of a gunshot victim showing
a narrowed brachial artery
that ends in an occlusion and
extravasated arterial contrast
leakage (arrow) indicating
acute arterial hemorrhage.
Image courtesy of Sanford
Health, Sioux Falls, SD.
Figure 26. Axial and coronal
CT images showing a peripherally enhancing fluid collection posterior to the proximal
radius and ulna and posterior aspect of the elbow representing a large hematoma.
Image courtesy of Pioneer
Memorial Hospital & Health
Services, Viborg, SD.
During the growth process, the long bones of
pediatric patients contain a physis or growth plate
that allows the bone to grow longitudinally. The
bone in the growth plate grows rapidly. This can
benefit fracture healing, but care must be taken
when managing any fracture that extends into the
growth plate because the bone can heal unevenly,
leading to deformities. 24
22
directed reading
CLASSICS
essentialeducation
Right
®
Left
Figure 27. Two medial epicondyle ossification centers in 1 elbow
(labeled “Right”) compared with only 1 on the opposite arm (labeled
“Left”). Projection indicates a likely avulsion of medial epicondylar
ossification center, possibly fractured off the more proximal fragment
(arrow). Image courtesy of Sanford Health, Sioux Falls, SD.
If a posterior fat pad is demonstrated on a lateral
radiograph and no other abnormality is seen, it is
likely the patient has a nondisplaced intracapsular
fracture. About 76% of follow-up radiographs of pediatric patients show healing fractures in the elbow area.
These findings support the decision to manage these
situations as though a fracture existed on the original
radiograph.52 If a hairline or small fracture is suspected
after a negative radiographic examination, pediatric
patients can return sooner than adult patients for repeat
images because children have faster callus formation.20
Radiographers and care providers should be aware
of specific elbow fractures that might indicate child
abuse. A transphyseal fracture of the humerus, common in children younger than 6 years, often indicates
child abuse. This fracture normally presents as pain in
the elbow, limited range of motion, and swelling over
the fracture site. 46
The routine 3-projection radiograph of the elbow is
not always helpful to diagnose a transphyseal fracture
because of a lack of ossification in pediatric patients.
Comparison radiographs of the opposite elbow can
assist the radiologist in diagnosing transphyseal fractures. A posterior fat pad sign is routinely seen, but it
is difficult to differentiate transphyseal fractures with
Elbow Disorders and Injuries
www.asrt.org
elbow dislocations from lateral condylar fractures. If
radiographs of the elbow are not definitive, MR imaging, ultrasonography, or arthrography may be required
to confirm a diagnosis. 46
If a transphyseal fracture is found and child abuse is
suspected, the provider might want to order additional
radiographs. Child abuse victims often have fractures
in multiple areas of their bodies.14 The types of child
abuse fractures that might be seen in addition to the
transphyseal fracture are diaphyseal or long-bone shaft
fractures. Diaphyseal fractures are the most common
type of fracture seen in abuse cases but often appear in
accidental cases as well. Other fractures associated with
child abuse include metaphyseal fractures of long bones,
posterior rib fractures, and multiple healed fractures
that were not reported.14
Congenital Radial-Ulnar Synostosis
Bones sometimes can fail to form as they should in
children. In congenital radial-ulnar synostosis, the radius and ulna fail to grow apart at their proximal locations.
This condition can be bilateral or unilateral. When the
proximal radius and ulna are not freely mobile, supination and pronation of the forearm is limited.9
Radiographs of the forearm confirm cross-synostosis
of the proximal radius and ulna. This appearance of the
bony union is easily seen by the increased bony formation (see Figure 28).9
Radial Head Subluxation
Children who have loose ligaments are at risk for
subluxation of the radial head. Radial head subluxation
sometimes is called nursemaid’s elbow and is the most
common elbow injury in younger children. Once a
child reaches the age of 7 years, the radial head appears
to be past risk for subluxation.9 Most often, radial head
subluxation affects the left arm of children who are
between the ages of 2 and 3 years. It is more prevalent in
girls than in boys.9,20,53
Problems with the radial head develop when a
young child’s arm is pulled with forearm extension and
pronation. The injury develops when pulling on the
radial head causes it to catch in the annular ligament
surrounding the neck of the radius.9 Damage often happens when a child is pulled up by the arm or suddenly
drops to the floor to tug away from being held.20
23
directed reading
CLASSICS
essentialeducation
®
Understanding the anatomy of the elbow and medical diagnostic imaging methods to best demonstrate
elbow injuries and disorders helps radiologic technologists enhance the diagnostic process and directly
benefits patient care.
Figure 28. Radiograph show-
ing a radioulnar synostosis.
Image courtesy of Sanford
Health, Sioux Falls, SD.
The radial head of children younger than age 3
is smaller than the annular ligament, making this a
common problem in this age group.20 Diagnosis of
radial head subluxation is complicated by young children’s inability to describe their symptoms in detail.54
Common signs that point to radial head subluxation
include guarding and nonuse of the affected arm.20
Radiographs of the elbow do not always show a
subluxation of the radial head. Occasionally, a displacement of the radiocapitellar line is evident, but the lack of
this displacement on images should not alter treatment
plans.53 Images are more helpful for ruling out other
injuries before attempting to manipulate the arm.9
Conclusion
Elbow disorders and injuries can be painful
and problematic for patients and complex for the
medical professionals providing imaging and care.
Elbow Disorders and Injuries
www.asrt.org
Matthew E Berry, BS, R.T.(R)(CT), earned his bachelor
of science degree from Mount Marty College in Yankton,
South Dakota. He attended the radiology program at
Avera Sacred Heart School of Radiologic Technology
in Yankton. Mr Berry is a graduate of the 2006 ASRT
Leadership Academy and a past president-elect, president,
and chairman of the South Dakota Society of Radiologic
Technologists. He previously served as an ASRT delegate
for South Dakota. Mr Berry works at Pioneer Memorial
Hospital & Health Services in Viborg, South Dakota, and
is a freelance medical writer. He has previously written
Directed Readings for Radiologic Technology.
The author would like to thank the following individuals
for their help and insight on this article: Susan Calmus,
MA, R.T.(R); Andrea Kindvall, R.T.(R)(CT), CBDT;
Annie Roggenbuck, BS, R.T.(R)(M); and Heidi Berry.
The information in this article was reviewed and
updated in July 2017. The content was generally accepted
as factual at the time the article was posted online.
However, the ASRT and the author disclaim responsibility
for any new or contradictory data that may become
available after posting. Opinions expressed in this article
are those of the authors and do not necessarily reflect the
views or policies of the ASRT.
© 2013, 2017 American Society of Radiologic
Technologists
References
1. Dodds SD, Hanel DP. Heterotopic ossification of the elbow.
In: Trumble TE, ed. Wrist and Elbow Reconstruction &
Arthroscopy. Rosemont, IL: American Society for Surgery of
the Hand; 2006:425-438.
2. Gross JM, Fetto J, Rosen E. Musculoskeletal Examination. 3rd
ed. Oxford, UK: Wiley-Blackwell Publishing; 2009:197-234.
3. Cailliet R. Medical Orthopedics: Conservative Management
of Musculoskeletal Impairments. Chicago, IL: AMA Press;
2004:102-108.
24
essentialeducation
4. Anderson, BC, Anderson RJ. Evaluation of elbow pain
in adults. In: Basow DS, ed. UpToDate:Clinical Reference.
Waltham, MA: UpToDate Inc; 2012.
5. Chorley J. Elbow injuries in the young athlete. In: Basow DS,
ed. UpToDate:Clinical Reference. Waltham, MA: UpToDate
Inc; 2012.
6. Jackson MD, McKeag DB. Anatomy and biomechanics of the
elbow and forearm. In: Sallis RE, Massimino F, eds. Essentials
of Sports Medicine. St Louis, MO: Mosby; 1997:294-297.
7. Edwards SL, Bell JE, Levine WN, et al. Upper extremity
considerations: Osteoarthritis of the shoulder. In: Moskowitz
RW, Altman RD, Hochberg MC, et al, eds. Osteoarthritis
Diagnosis and Medical/Surgical Management. 4th ed.
Philadelphia, PA: Lippincott Williams & Wilkins; 2007:366.
8. Stein JM, Cook TS, Simonson S, Kim W. Normal and variant
anatomy of the elbow on magnetic resonance imaging. Magn
Reson Imagin Clin N Am. 2011;19(3):609-619.
9. Snider RK, ed. Essentials of Musculoskeletal Care. Rosemont,
IL: American Academy of Orthopaedic Surgeons; 1997:133159,582-587,654-657.
10. Sofka CM, Adler RS. Sonography of cubital bursitis. AJR Am
J Roentgenol. 2004;183(1):51-53.
11. Hotchkiss RN. Elbow pain. In: Paget SA, Gibofsky A, Beary
JF, Sculco TP, eds. Hospital for Special Surgery Manual of
Rheumatology and Outpatient Orthopedic Disorders: Diagnosis
and Therapy. 5th ed. Philadelphia, PA: Lippincott Williams &
Wilkins; 2005:158-164.
12. Sellards R, Kuebrich C. The elbow: diagnosis and treatment
of common injuries. Prim Care. 2005;32(1):1-16.
13. Rudzki JR, Paletta GA Jr. Juvenile and adolescent elbow injuries in sports. Clin Sports Med. 2004;23(4):581-608.
14. Weissleder R, Wittenberg J, Harisinghani MG. Primer
of Diagnostic Imaging. 3rd ed. Philadelphia, PA: Mosby;
2003:387,845-846.
15. DeFroda SF, Hansen H, Gil JA, Hawari AH, Cruz AI.
Radiographic evaluation of common pediatric elbow injuries. Orthop Rev (Pavia). 2017;9(1):7030. doi: 10.4081/
or.2017.7030. https://www.ncbi.nlm.nih.gov/pmc/articles/
PMC5337779/. Accessed June 26, 2017.
16. Hodler J, Kubik-Huch RA, von Schulthess GK, eds.
Musculoskeletal Diseases 2017-2020: Diagnostic Imaging.
Cham, Switzerland: Springer International Publishing; 2017.
17. Fritz RC, Breidahl WH. Radiographic and special studies:
recent advances in imaging of the elbow. Clin Sports Med.
2004;23(4):567-580.
18. Raby N, Berman L, de Lacey G. Accident & Emergency
Radiology: A Survival Guide. 2nd ed. Philadelphia, PA:
Elsevier Saunders; 2005:90-107.
Elbow Disorders and Injuries
www.asrt.org
directed reading
CLASSICS
®
19. Ballinger PW, Frank ED. Upper limb. In: Merrill’s Atlas of
Radiographic Positions & Radiologic Procedures. 10th ed. Vol 1.
Philadelphia, PA: Mosby; 2003:140-148.
20. Eiff MP, Hatch RL, Calmbach WL. Fracture Management for
Primary Care. 2nd ed. Philadelphia, PA: Saunders; 2003:4173.
21. Lampignano, JP, Kendrick, LE. Bontrager’s Textbook of
Radiographic Positioning and Related Anatomy. 9th ed. St
Louis, MO: Elsevier; 2017.
22. Melloni P, Valls R. The use of MRI scanning for investigating soft-tissue abnormalities in the elbow. Eur J Radiol.
2005;54(2):303-313.
23. Stevens KJ, McNally EG. Magnetic resonance imaging of the
elbow in athletes. Clin Sports Med. 2010;29(4):521-533.
24. Ryan LM. Elbow anatomy and radiographic diagnosis of elbow fracture in children. In: Basow DS, ed.
UpToDate:Clinical Reference. Waltham, MA: UpToDate Inc;
2012.
25. Chuang BI, Hsu JH, Kuo LC, Jou IM, Su FC, Sun YN.
Tendon-motion tracking in an ultrasound image sequence
using optical-flow-based block matching. BioMed Eng Online.
2017;16(1):47. doi: 10.1186/s12938-017-0335-x. https://
biomedical-engineering-online.biomedcentral.com/articles/10.1186/s12938-017-0335-x. Accessed June 26, 2017.
26. Qureshi F, Stanley D. The painful elbow. Surgery.
2006;24(11):368-372.
27. Klippel JH, Stone JH, Crofford LJ, White PH. Primer on
the Rheumatic Diseases. 13th ed. New York, NY: Springer;
2008:73-74.
28. Vidal AF, Drakos MC, Allen AA. Biceps tendon and triceps
tendon injuries. Clin Sports Med. 2004;23(4):707-722.
29. Yoon MY, Koris MJ, Ortiz JA, Papandrea RF. Triceps avulsion, radial head fracture, and medial collateral ligament
rupture about the elbow: a report of 4 cases. J Shoulder Elbow
Surg. 2012;21(2):e12-e17. doi:10.1016/j.jse.2011.06.017.
30. De Fer TM, Brisco MA, Mullur RS. The Washington Manual
of Outpatient Internal Medicine. Philadelphia, PA: Lippincott
Williams & Wilkins; 2010:606.
31. Dunphy LM, Winland-Brown JE, Porter BO. Primary Care:
The Art and Science of Advanced Practice Nursing. 2nd ed. FA
Davis; 2007:735.
32. Jayanthi N. Epicondylitis (tennis and golf elbow). In:
Basow DS, ed. UpToDate:Clinical Reference. Waltham, MA:
UpToDate Inc; 2012.
33. Chew ML, Giuffrè BM. Disorders of the distal biceps brachii
tendon. Radiographics. 2005;25(5):1227-1237.
34. Sasaki K, Tamakawa M, Onda K, et al. The detection of the
capsular tear at the undersurface of the extensor carpi radialis
brevis tendon in chronic tennis elbow: the value of magnetic
25
essentialeducation
resonance imaging and computed tomography arthrography.
J Shoulder Elbow Surg. 2011;20(3):420-425.
35. Walz DM, Newman JS, Konin GP, Ross G. Epicondylitis:
pathogenesis, imaging, and treatment. Radiographics.
2010;30(1):167-184.
36. Weisman MH. Total joint replacement for severe rheumatoid
arthritis. In: Basow DS, ed. UpToDate:Clinical Reference.
Waltham, MA: UpToDate Inc; 2012.
37. Ostergaard M, Szkudlarek M. Imaging in rheumatoid
arthritis — why MRI and ultrasonography can no longer be
ignored. Scand J Rheumatol. 2003;32(2):63-73.
38. Perez-Ruiz F, Dalbeth N, Urresola A, de Miguel E,
Schlesinger N. Imaging of gout: findings and utility. Arthritis
Res Ther. 2009;11(3):232. doi:10.1186/ar2687.
39. Blease S, Stoller DW, Jafran MR, et al. The elbow. In: Stoller
DW, ed. Magnetic Resonance Imaging in Orthopaedics and
Sports Medicine. 3rd ed. Balimore, MD: Lippincott Williams
& Wilkins; 2007:1463-1622.
40. Roberts CC, Bancroft LW, Pope Jr. TL. Musculoskeletal system. In: Pope TL, ed. Aunt Minnie’s Atlas and Imaging-Specific
Diagnosis. 3rd ed. Philadelphia, PA: Lippincott Williams &
Wilkins; 2009:103.
41. Hsu JW, Gould JL, Fonseca-Sabune H, Hausman MH. The
emerging role of elbow arthroscopy in chronic use injuries
and fracture care. Hand Clin. 2009;25(3):305-321.
42. Nguyen D. Loose body, plica, and osteochondritis dissecans.
Oper Tech Orthop. 2009;19:220-227.
43. Williams RJ, Wickiewicz TL. Sports injuries. In: Paget SA,
Gibofsky A, Beary JF, Sculco TP, eds. Hospital for Special
Surgery Manual of Rheumatology and Outpatient Orthopedic
Disorders: Diagnosis and Therapy. 5th ed. Philadelphia, PA:
Lippincott Williams & Wilkins; 2005:186.
44. Magee DJ. Orthopedic Physical Assessment. 5th ed. St Louis,
MO: Saunders Elsevier; 2008:361-395.
45. Plancher KD, Lucas TS. Fracture dislocations of the elbow in
athletes. Clin Sports Med. 2001;20(1):59-76.
46. Ryan LM. Epicondylar and transphyseal elbow fractures
in children. In: Basow DS, ed. UpToDate:Clinical Reference.
Waltham, MA: UpToDate Inc; 2012.
47. Kuntz Jr DG, Baratz ME. Fractures of the elbow. Orthop Clin
N Am. 1999;30(1):37-59.
48. Kahan S, Miller R, Smith EG. In A Page Signs and Symptoms.
2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins;
2009:199.
49. Rizzo M, Nunley JA. Fractures of the elbow’s lateral column
radial head and capitellum. Hand Clin. 2002;18(1):21-42.
50. Kozin SH. Capitellum fractures. In: Mirzayan R, Itamura
JM, eds. Shoulder and Elbow Trauma. New York, NY: Thieme
Medical Publishers Inc.; 2004:39.
Elbow Disorders and Injuries
www.asrt.org
directed reading
CLASSICS
®
51. Goodwin RC, Kuivila TE. Pediatric elbow and forearm fractures requiring surgical treatment. Hand Clin.
2002;18(1):135-148.
52. Skaggs DL, Mirzayan R. The posterior fat pad sign in association with occult fracture of the elbow in children. J Bone Joint
Surg Am. 1999;81(10):1429-1433.
53. Moore BR, Bothner J. Radial head subluxation (nursemaid’s
elbow). In: Basow DS, ed. UpToDate:Clinical Reference.
Waltham, MA: UpToDate Inc; 2012.
54. Dusenbery SM, White AJ. The Washington Manual of
Pediatrics. Philadelphia, PA: Lippincott Williams & Wilkins;
2009:52.
26
directed reading
CLASSICS
essentialeducation
®
Directed Reading Classic Continuing Education Quiz
2.5 Category A+ credits
Elbow Disorders and Injuries
To earn continuing education credit:

Read the article and choose the answer that is most correct based on the text.

Take the continuing education quiz online at asrt.org/drquiz.
1. Which of these bones make up the elbow joint?
1. humerus
2. ulna
3. radius
a.
b.
c.
d.
1 and 2
1 and 3
2 and 3
1, 2, and 3
2. What is the most important stabilizing bundle of
the medial collateral ligament (MCL)?
a. anterior
b. transverse
c. posterior
d. accessory
3. Which elbow nerve is injured most frequently
because of its location?
a. musculocutaneous
b. median
c. radial
d. ulnar
4. What percentage of fracture cases shows a positive
“fat pad sign” on a radiograph?
a. 60
b. 70
c. 80
d. 90
5. Which radiographic projection or method shows
an oblique angle of the lateral elbow separating the
proximal radius and ulna?
a. anteroposterior
b. lateral
c. Coyle
d. Jones
6. Which elbow disorder is commonly referred to as
student’s elbow?
a. olecranon bursitis
b. tendonitis
c. lateral epicondylitis
d. medial epicondylitis
continued on next page
Elbow Disorders and Injuries
asrt.org
I
essentialeducation
directed reading
CLASSICS
®
Directed Reading Classic Continuing Education Quiz
7.
What is the most common sports-related elbow
injury?
a. medial epicondylitis
b. lateral epicondylitis
c. dislocation
d. fracture
8. Which of the following diagnostic imaging modalities is excellent at displaying capsular tears?
a. MR imaging
b. ultrasonography
c. computed tomography (CT) arthrography
d. radiography
9. Medial epicondylitis affects the:
a. insertion point of the flexor carpi radialis.
b. anterior bundle.
c. olecranon process.
d. radial notch.
10. Which elbow joint does rheumatoid arthritis generally affect first?
a. ulnohumeral
b. radioulnar
c. radiocapitellar
d. ulnoradial
11. Osteophyte formation seen near the ulnohumeral
joint on radiographs is typical in individuals with
which disease?
a. rheumatoid arthritis
b. gout
c. pseudogout
d. osteoarthritis
12. Which imaging modality is best for discovering
intraosseous lesions with gout?
a. magnetic resonance (MR) imaging
b. CT
c. ultrasonography
d. conventional radiography
13. Which of the following elbow disorders is most
common in preadolescent boys and children
younger than 10 years old?
a. Panner disease
b. traction apophysitis
c. osteochondritis dissecans
d. gout
14. Which of the following elbow problems is commonly misdiagnosed as lateral epicondylitis?
a. Panner disease
b. traction apophysitis
c. radiocapitellar plica from osteochondritis dissecans
d. gout
15. What is the best imaging modality for displaying
nerve damage?
a. radiography
b. MR imaging
c. CT
d. ultrasonography
16. Which imaging modality best displays partial tears
of the medial collateral ligament (MCL)?
a. MR
b. MR with arthrography
c. CT
d. CT arthrography
17. Considered the most common elbow fracture
among adults, _____ fractures often occur when a
person falls with his or her forearm turned inward
and lands on an outstretched hand.
a. distal humerus
b. olecranon process
c. coronoid process
d. radial head
continued on next page
Elbow Disorders and Injuries
asrt.org
II
essentialeducation
directed reading
CLASSICS
®
Directed Reading Classic Continuing Education Quiz
18. Which kind of fracture has a high risk of arterial
involvement?
a. olecranon process
b. supracondylar
c. radial
d. ulnar
19. What type of fractures are the most common elbow
fractures in the pediatric population?
a. olecranon process
b. supracondylar
c. diaphyseal
d. coronoid process
20. What does a transphyseal fracture of the humerus
in young children often indicate?
a. a fall on an outstretched hand
b. poor ossification of the humerus
c. overuse of the elbow joint
d. child abuse
Elbow Disorders and Injuries
asrt.org
III