Elbow and Forearm

Anatomy of the elbowo Ulna side is medial o Trochela notch allows for

extension and flexion Associated with distal

head of the humeruso Radial head, neck, and

tuberosityo Radial head associates with

capitulum Arthrology of the elbow

o Diarthrodial “hinge” articulation

o Humeroradial (capitulum and radial head)o Humeroulnar (trochlea and trochlea notch)

Fractures associated with the forearm (Pediatric)o Look for growth plates on child forearm o Torus (“buckle” fracture)

Not an impaction fracture Prolapse and pops back out but leaves a fracture line From falling

o Greenstick Occurs with complete fracture on cortex side Bone doesn’t brake completely through Usually caused by bending of the arm Also an early sign of child abuse

o Salter- harris Lots of classifications Fracture that involves the apophysis

Fractures associated with the forearm (adult)o Parry (nightstick)- an isolated fracture of the unla

Mid shaft of the ulna Goes completely through bone

o Monteggia- FX of the proximal 1/3 of the ulna with dislocation of the proximal radius

On outstretched armo Galeazzi- mid to distal 1/3 radius with dislocation distal radiolunar

joint On outstretched arm

AP forearmo Long bone- must include joints proximal and distal to injuryo Anode heel effect

o Arm extended and supinated- humeral epicondyles parallel to receptor

Any pronation will cross over the radias and ulna o CR is perpendicular to midshaft

Lateral Forearmo Arm flexed 90 degrees with humerus and forearm in same plane

If the table doesn’t move then you can use a sponge or ask patient to squat down

o Hand and wrist rotated into lateral positiono Humerus needs to be on the same plane o CR is perpendicular to midshaft o A perfect lateral:

You want elecronon process free of superimposition Want to see trochelar notch free of superimposition See coronoid Distal Radius and ulna is superimposed

Casted forearmo Usually satisfied with a PA approach

Elbow

50% of injuries to the adult elbow involve the radial head and neck (fall on outstretched arm with forearm pronated)

kVp around 65 Most of these types are non-displaced, making Dx more difficult to see unless

proper imaging and special projections are performed Different types of fractures that can happen to the radial head

o Mason fractures 1-4: Type 1: non-displaced fracture simple fracture of the radial

head Type 2: fracture with radial displacement Type 3: comminuted Type 4: fracture with dislocation of the proximal radius

o Type 3 and 4 usually with open reduction with internal rotation AP Elbow

o Elbow extended with hand supinationo Epicondyles must be parallel with receptor planeo Wrist has to be fully supinated o CR is perpendicular to joint

Right at the level of epicondyles o You can tell its AP:

Medial epicondyle free of superimposition Rest of it is a survey See elecronon fossa

1/3 to ½ of the proximal radius will still be superimposed by the ulna

Medial (internal) oblique o Elbow is positioned similar to AP, then entire arm is rotated medially

to place epicondyles in a 45 degree plane o CR is perpendicular to jointo Position best demonstrates the coronoid process and trochlea o Common area for an avulsion fracture

AP vs Lateral oblique o Lateral- no superimposition of the proximal radius and ulnao AP- 1/3 superimposition of the proximal radius

Lateral (external) obliqueo Elbow positioned same as APo Entire is rotated laterally to place epicondyles in a 45 degree planeo Lean patient laterallyo CR is perpendicular to joint o Best demonstrates the radial head, neck and tubercle and capitulum

Lateral elbowo Elbow is flexed 90 degrees with humerus and forearm in same planeo Hand and wrist rotated into a lateral positiono CR is perpendicular to joint o Best demonstrates olecranon process and trochlear notcho Evidence of “fat pads”

You should not see fat pads endless there is an injury You do not see the fat pads on any other position but the

lateral Posterior - elecronon fossa, distal humerus or elecronon Supernator fat pad - lies in soft tissue anterior of the proximal

radius 100% for radial head FX

Anterior - coronoid fossa, distal humerus FX

Trauma considerations:o Most elbow trauma is associated with the patient’s inability to extend

or rotate the extremityo Never force into position

Partial flexion APo Use when pt cannot extend elbowo A series of 2 positions

1st o Place humerus in same plane as receptor with epicondyles parallel o Bring humerus closer to IRo Demonstrate distal humerus o Extend eblow as much as possible then support

o CR perp distal humeruso +10 kVp from usual AP elbow make sure you penetrate through SI of

tissue and anatomy o Supracondila FX- make sure you don’t miss any o Lots of SI of tissue

2nd o Place proximal radius and ulna in contact with receptor with hand

supinated Keep epicondyles // CR perp proximal radius/ulna

o With patient standing Axiolaterals (Coyle)

o Trauma positions used as substitutes for visualization of coronoid and radial head when pt cannot extend and rotate elbow

o Can be easier than routine obliques- elbow remains in a “relaxed” lateral position

Axiolateral for Radial heado Elbow is placed in standard lateral positiono If possible rotate hand/wrist laterallyo CR @ 45 degrees toward shoulder/proximally o Parallel to long axis of humerus o CR enters approx 1 inch inferior to

elbow joint o +10 kVp from usual lateralo Excellent alternate for occult

intra-articular FX Bring elbow more towards

upper part of cassette o Supinator fat pads

Communited vs simple fx o Radius out from ulna shows proximal radius

Radial head elongated o Humeral anatomy superimposed

Axiolateral for coronoid o Elbow positioned same as standard lateralo Substitute for medial oblique o CR directed 45 from above shoulder, towards elbow o +10 kVp from usual lateralo Excellent for avulsion fx off coronoid process

Full rotation laterals “round the clock”o A series of 4 exposures with the hand and wrist in various stages of

rotationo Provides a profile of the entire radial heado Elbow is positioned in standard lateral, then wrist is rotated

Maximum supination Neutral lateral Pronation Maximum hyperpronation

o Turns radial head in a circle o By request only not routine

Tangential (acute flexion)o Used to assess olecranon process- 2nd most frequently fx region in

adult elbowo Aka “Jones Method” position o Humerus is placed in contact with receptor o Epicondyles //o Instruct pt to flex arm as much as possibleo CR perp and 2 inches distal to olecranon

Little league elbow o Medial epicondylar apophysitis- more for adult o Panner’s disease o Chronic avulsions of medial epicondyles o Twisting motion and chronic stresses

Olecranon free of superimposition= acute flexion and lateral