MDx UE Elbow

Biceps muscle lies superficial to the brachialis and has a long tendon that inserts on the radial tuberosity. A complete biceps tendon rupture is the most common rupture at the elbow (although >90% of biceps tendon ruptures occur at the long head proximally in the shoulder). A complete tear is identified as a gap between the two retracted tendon ends. Partial tears are identified by changes in the tendon firth and an abnormally high signal within the tendon on a T2 weighted image. The bicipital bursa is located between the tendon and its insertion on the radial tuberosity to reduce friction. Assess this teardrop-shaped bursa for inflammation.

Soft tissue anterior compartment of elbow MRI

Oblique external rotation

You are trying to assess for an impaction fracture of the radial head, but the lateral projection did not show the radial head without superimposition. What projection would you use

Oblique external rotation*

You are trying to assess the quality of the radial neck. What projection would you use?

Second look at radiographically occult fractures Bony disruption at sites of tendon attachment Bony injury that occurred during dislocation or trauma

Alignement MRI of elbow

Deviations in geography of the bone or joint articulations signal fracture, dislocation, or bone destruction. Axial views can evaluate the humeroulnar and humeroradial articulations, as well as the PRUJ articulation. Sagittal oblique views assess the configuration of the ulnar trochlear notch and trochlea. Assess the radial head and its articulation with the capitulum. Is the anatomy intact with proper articulation relationship?

Alignment CT of elbow

3 joints! - articulation between the trochlea on the humerus and the ulna = humeroulnar joint. - capitulum on the distal humerus and the radius =humeroradial joint. - elbow is the proximal radioulnar joint (often called the PRUJ)

At the elbow we have ______ separate synovial articulations within one joint capsule. Whenever we have ____ joints in one capsule, there are unique challenges to identifying the results of the trauma

Bicep muscle + tendon seen in cross section as it inserts into radial tubersity Tricep tendon Annular ligament of radial head Brachial artery and radial nerve in cubital fossa Ulnar nerve, deep to the tricep, in cubital tunnel

Axial plane MRI; what structures should you see

The decision for the arm in internal or external rotation is determined by which structures are needed to be seen. The elbow should be in full extension for either projection

Oblique projection of elbow: how to decide if to do internal or external rotation

Cortical bone is most dense, cancellous bone is less dense. Assess for any bony destruction signifying disease or infection. Degenerative osseous cysts, cortical hypertrophy, and sclerosis may occur in the humeral head due to the mechanical alterations caused by impingement or rotator cuff tear. Is cortical bone definitive on margins and shafts? Are trabeculae in organized patterns? Are osseous cysts, cortical hypertrophy, or sclerosis present?

Bone density CT of elbow

Assess for bone bruises Assess for marrow edema, stress fractures, osteochondral injuries, ambiguous fractures

Bone signal MRI of elbow

A B + C

Which of the following projections are the minimum recommended projections for radiographic evaluation of trauma at the elbow? a. AP elbow b. AP forearm c. Lateral elbow d. Lateral forearm e. Oblique external rotation f. Oblique internal rotation

Assess the joint surfaces for smooth chondral surfaces Osteochondral lesions are most common in at the capitulum and radial head. Identify any free fragments that may have migrated into the space from a fracture. Are there any defects present in the cartilage or subchondral bone? Any loose bodies present?

Cartilage CT of elbow

Assess for articular cartilage abnormalities at each joint surfaces The capitulum is frequenly a site of an osteochondral lesion.

Cartilage MRI of elbow

MCL and LCL Medial and lateral muscle groups Common flexor tendon and common extensor tendon Medial and lateral epicondyles Bicipitoradial bursa b/w bicep tendon and radial tuberosity Proximal radioulnar joints

Coronal plane MRI: what structures should you see

This is the "footprint' of injury on MRI, meaning that if you see edema, an injury has occurred at that spot. Be sure to look for edema on sequences that are fluid-sensitive, such as T2-weighted

Edema MRI of elbow

medial medial epicondylitis

Golfers elbow = _______ elbow

UCL tear tommy john surgery

If a younger baseball player has an injury to the medial elbow, what would you likely think it is?

Oblique internal rotation

In which projection is the elbow in extension and pronation

Ligament disorders: sprains, partial tears, complete tears Disorders of the flexor and extensor tendon origins Distal biceps tendon disease: tendinopathy, partial, and complete tears Distal triceps tendon disease: ttendinopathy, partial, and complete tears, snapping, and subluxation Peripheral nerve disorders

Indications for MRI of the elbow: what disorders/diseases?

trochlear sulcus

Lateral view: There should be a radiodense circular image surrounded partialy by concentric arcs. This is produced by the _______ ______. The inner concentric acs are formed by the rims of the capitulum and trochlea. The outer arc is formed by the trochlear notch

All three imaging planes are evaluated. Distension of joint capsule via injection of fluid gadolinium allows identification of all intra-articular tissues.

MR arthorogram procedure

Collateral ligament defects or tears Cartilage defects Stability of osteochondral fractures of the capitulum (if radiographs non-diagnostic)

MR arthrogram is useful for accessing

prolonged, refractory, or unexplained elbow pain Sports injuries, especially in throwing athletes Elbow instability Painful elbow snapping or mechanical symptoms Refractory tennis elbow Limited or painful ROM or contracture Unexplained swelling, mass, or atrophy Neuropathy whose cause is localized to the elbow Patients with whom diagnostic or therapeutic arthroscopy or elbow surgery is planned Patients with recurrent, residual, or new symptoms following elbow surgery

MRI may be useful to evaluate

Arthritides Primary and secondary bone and soft tissue tumors Fractures and dislocations Soft tissue injuries associated with a knoen fracture

MRIs may be indicated for clarification and staging conditions diagnosed clinically and/or suggested by other imaging modalities, including:

5-15 degrees - Abnormal increases or decreases may be a sign of fracture or posttraumatic deformity

Normal carrying angle of elbow? If abnormal this could indicate?

The forearm is fully supinated. This is the best view of the radial head, neck, and tuberosity because they are free of any superimposition.

Oblique external rotation: what is the position of the arm? what is this best to view?

The arm is in a pronated position, so the proximal radius crosses over the ulna. Most of the structures are superimposed. This is the BEST position for viewing the coronoid process without superimposition.

Oblique internal rotation : what is the position of the arm? what is this best to view?

Muscle and myotendinous injuries Occult fractures Osteochondral lesions: osteochondral fractures and osteochondritis dessicans Cartilage lesions: chondral fractures and flaps, chondromalacia, degenerative arthritis Joint effusions and inflammatory or proliferative synovitis Intra-articular bodies Symptomatic plicase, synovial folds, and elbow menisci Olecranon and bicipitoradial bursitis: septic, traumatic, crustal-induced, inflammatory Marrow abnormalities: bone contusion, osteonecrosis, marrow edema, and stress fractures Neoplasms, masses, and cysts of the bone, joint, or soft tissue Infection of bone, joint, or soft tissue Congenital and developmental conditions, including dysplasia and normal variants Abnormalities of the proximal forearm interosseous membran and neuromuscular structures

Other reasons to do MRI of elbow

Bicep and tricep tendon seen longitudinally Anterior and posterior muscle groups Radial head assessed for radiographically occult fractures Humeroradial and humeroulnar joints

Sagittal plane MRI; what structures should you see

Identify the soft tissues by location Identify any effusions of the subtendionous or subcutaneous olecranon bursae, bicipitoradial or radioulnar bursae. Identify any masses or atrophy in the muscular compartments.

Soft tissue CT of elbow

The extensor-supinator group of muscles arises from the lateral epicondyle to form the common extensor tendon; these tissues suffer from overuse injuries, usually related to sports or repetitive movements during work. This is sometimes called "Tennis Elbow." MRI findings are similar to that of medial epicondylitis. Refer to your book for more detailed information. Tears of the radial (lateral) collateral ligament complex are less frequently seen compared to ulnar collateral ligament tears. They can be seen in association with lateral epicondylitis or elbow dislocations. Sprains will appear as a thickened or thinned ligament with a high signal in and around the structure. Complete tears will show discontinuity of fibers. Avulsions at the attachment sites will show edema and hemorrhage extending into the defect.

Soft tissue lateral compartment tissues MRI

The flexor-pronator group of muscles arises from the medial epicondyle as the common flexor tendon, and can suffer from overuse injuries. This is often referred to as "Little Leaguer's Elbow." MRI findings in medial epicondylitis include tendon degeneration, tendon disruptions, partial tears, and muscle strain. Coronal and axial imaging will show possible alterations in tendon thickness, discontinuity of torn fibers, and a high signal from associated inflammation. Ulnar (medial) collateral ligament tears are associated with throwing athletes, who frequently sustain midsubstance tendon ruptures or avulsions. Coronal views are best to identify torn fibers and abnormal signal in the normally linear, low-signal ligament.

Soft tissue medial compartment tissues MRI

Triceps tendon ruptures are less common. Normal triceps tendon may appear wavy on a sagittal slice due to the lack of tension if the elbow is in extension. Snapping triceps tendon refers to slipping of the medial head of the triceps over the medial epicondyle, which might cause the ulnar nerve to dislocate. To diagnose this, imaging is done with the elbow in flexion and extension to compare the tissue. Olecranon bursitis is recognized as a high signal focal collection of fluid over the olecranon process and may be associated with gout or triceps tears or be due to repetitive pressure on the bone.

Soft tissue posterior compartment of elbow MRI

lateral lateral epicondlyitis

Tennis elbow = ______ elbow

THREE - coronoid fossa - radial fossa - olecranon fossa

The distal humerus has _____ depressions, or fossae

coronoid and radial = sail sign

The fat pads of the _________ and ______ fossae are usually superimposed and appear as a thin triangular lucency. A fracture will displace these fat pads, giving them a triangular appearance. Remember this is called a "____ ____"

the olecranon processes at the proximal end, and the coronoid process on the anterior surface.

The proximal ulna has 2 beadlike processes...

medial and lateral epicondyle superimposed on each other - if you do not see tear drop = misalignment (think fracture)

What is the tear drop shape on the distal humerus

biceps and brachialis muscles and tendons

What should be in anterior compartment soft tissue of elbow

Common flexor tendon originating on the medial epicondyle, the flexor-pronator group of muscles.

What should be in the medial compartment soft tissue CT of elbow

triceps and anconeusLateral tissues: common extensor tendon originating in the lateral epicondyle, the extensor-supinator muscle group, and the brachioradialis muscle

What should be in the posterior compartment soft tissue CT of elbow

The olecranon process should be articulated with the olecranon fossa in this position. Therefore, the olecranon process should be seen, but superimposed behind the trochlea of the humerus. Part of the radius is superimposed on the ulna. The humeroradial and humeroulnar joint spaces are well preserved

Things to check for in AP of elbow

The forearm is in the anatomic position. Note any bowing and contour of the shafts. The olecranon is articulating in the olecranon fossa and is superimposed on the trochlea. Both the proximal and distal articulations of the forearm are visible

Things to check for in AP projection of forearm

The coronoid process is visualized free of superimposition. The olecranon process is articulated in the olecranon fossa. The joint space between the trochlear notch and trochlea is visible.

Things to check for in an oblique of the elbow

The radioal head, neck, and tuberosity are free of superimposition. The capitulum and lateral epicondyle are viewed in profile. The humeroulnar and humeroradial joint spaces are visible

Things to check for in oblique external rotation view

Elbow structures should have the same alignment as the lateral view of the elbow. Note any bowing and contour of the shafts. The radial head is superimposed on the coronoid process. Both the proximal and distal articulations of the forearm are visible.

Things to check for lateral projection of forearm

The olecranon process should be seen articulating in the olecranon fossa. The coronoid process should be superimposed on the posterior portion of the radial head. Only the anterior head of the radius should be free of superimposition.

Things to check for on lateral projection of elbow

Are there any ossesous changes at the origin of the common extensor or flexor tendons The epicondyles may show irregularities due to chronic inflammation or rupture of these tendons is the articular surface of the capitulum intact? osseous leisons occur here with frequency

Things to look for in axial CT image

Humerulnar and humeroradial spaces should have smooth congruent articular surfaces The trochlear cleft is a normal groove on the medial and lateral sides of the trochlear notch that can mimic a fracture The pseudodeficit will not be present on a midline sagittal slice

Things to look for in sagittal CT image

Avulsions or irregularities due to acute or chronic stress may occur at the site of attachment of the MCL or LCL on the respective medial and lateral epicondyles - the collateral ligaments are deep to the common tendons, which also attach to the epicondyles - an imaging pitfall = "the psedodefect at the capitulum" this groove on the posterolatearl aspect of the capitulum can mimic a fracture on coronal view

Things too look for in Coronal CT image

Oblique Internal rotation view

What view is this

Oblique internal rotation view

What view is this

Oblique internal rotation*

You are suspecting a mild fracture of the coronoid process of the ulna. Which projection would you use?

In pediatric pts, the normal position of the capitulum relative to the distal humerus and proximal radius should be at the intersection of a line drawn: - along the longitudinal axis of the radius (line a) - a line along the anterior border of the humerus (line B) - these lines should intersect at the middle 1/3 of the capitulum - disruptions can indicate a bone fracture

What is pediatric clientele?

Flexed elbow, Abducted arm, Supinated forearm - It allows for a full longitudinal look at the biceps and brachioradialis tendons on MR imaging.

What is the FABS position? What imaging is it used for?

one arm overhead - position for MRI + CT so no unecessary radiation exposure to thorax

What is the mighty mouse position? What imaging is it used for?

two arms overhead - - position for MRI + CT so no unecessary radiation exposure to thorax

What is the superman position? What imaging is it used for?

CTs

____ may be indicated to identify occult fractures, osteochondral lesions, or specific locations of loose bodies

MRIs

_____ may reveal occult fracture abnormalities of the synovium, joint capsule, ligaments, or tendons. Diagnostic ultrasound is appropriate if we want to examine biceps tendon tears, bursitis, or epicondylitis.

Severe trauma Assessment of alignments and displacement of fracture fragments Identification of loose bodies of the elbow joint Evaluation of osteochondral lesions, if MRI is unavailable or contraindicated Evaluation of any condition seen by MRI if MRI is contraindicated, including use of intraarticular contrast.

indication for CT scan of the elbow

ulnar collateral ligament: broad triangle shape radial collateral ligament annular ligament: oval shaped, encloses head of the radius = stability and allows elbow to spine

ligaments of the elbow

AP and lateral views - in cases of trauma: a radiographic evaluation is NOT complete without evaluation of the entire forearm, preferably in both the AP and lateral forearm views

minimum projections for the elbow

Distal humerus: medial and lateral epicondyles, capitulum, and trochlea Ulna: Olecranon process and shaft Radius: Radial head, neck, and tuberosity Humeroulnar and humeroradial joint spaces Carrying angle of the elbow: Scroll over the term if you need to refresh your memory on what this angle is

things you should be able to identify on AP projection of elbow

Olecranon: olecranon process and coronoid process Radius: radial head, neck, and tuberosity Distal humerus: epicondyles and concentric images of the trochlear sulcus, capitulum, trochlear rims, and trochlear notch Radiolucent anterior fat pad

things you should be able to identify on lateral projection of elbow

oblique view

this projection is usually not required, but requested for the elbow