Normal Variants of the Normal Variants of the ElbowElbow

Olecranon Olecranon ForamenForamen

aka aka Supratrochlear Supratrochlear

ForamenForamen

Olecranon Olecranon ForamenForamen

Radioulnar SynostosisRadioulnar Synostosis

• usually bilateral• may decrease supination or

pronation

Supracondylar ProcessSupracondylar Process

• An osseous projection on the anteromedial aspect of the distal humerus

• Struther’s ligamentStruther’s ligament may extend inferior from this process to the medial epicondyle

• may cause neurovascular signs or symptoms

Fracture of Supracondylar ProcessFracture of Supracondylar Process

Ununited Ununited Secondary Secondary OssificatioOssification Center - n Center -

Medial Medial EpicondyleEpicondyle

Pseudotumor Pseudotumor appearance of appearance of

the Radial the Radial TuberosityTuberosity

The WristThe Wrist

Standard Wrist SeriesStandard Wrist Series

• PA Wrist

• Medial Oblique Wrist

• Lateral Wrist

PA PA Wrist Wrist

Note the overlap between the trapezium and the trapezoid

PA WristPA Wrist

Medial Medial Oblique Oblique

WristWrist

• No overlap between the trapezium and the trapezoid

Lateral WristLateral Wrist

Lateral WristLateral Wrist

-the third metacarpal, capitate, lunate and radius should form a straight line

Age of Carpal Appearance

• Capitate and Hamate: at birth-6 mo

• Triquetrum: .5 yr-3.5yrs

• Lunate: 1.5-4.5yrs

• Scaphoid: 3-9yrs

• Trapezium: 3-9yrs

• Trapezoid: 3-9yrs

• Pisiform 7-13yrs

• Distal radial epiphysis: .5-2yrs (19)

• Distal ulnar epiphysis: 5.5-9.5yrs(18)

Pronator Quadratus Fat Pronator Quadratus Fat StripeStripe

• Not visualized or may be displaced following trauma

Accessory Views of the Accessory Views of the WristWrist

PA Wrist with Ulnar PA Wrist with Ulnar DeviationDeviation

Carpal Carpal Tunnel Tunnel

ProjectionProjection

Three Arcs of Carpal Three Arcs of Carpal AlignmentAlignment

• Along proximal aspect of proximal row

• Along distal aspect of proximal row

• Along proximal aspect of distal row

Intercarpal DistancesIntercarpal Distances

• The joint spaces between the carpal bones should not exceed 2mm2mm

• the distal radioulnar joint space should not exceed 2mm2mm

Normal VariantsNormal Variants

Carpal CoalitionCarpal Coalition

• Fusion between the capitate and hamate possibly involving the triquetrum and pisiform

Carpal CoalitionCarpal Coalition

Accessory Ossicle Distal to Accessory Ossicle Distal to UlnaUlna

• Ununited secondary ossification center of the ulnar styloid process. Most likely represents old un-united fracture.

Pie SignPie Sign

Negative Ulnar VarianceNegative Ulnar Variance

• Normally the ulna should be no more than 1-2mm 1-2mm shorter shorter than the radius

• predisposes lunate to avascular necrosis

Madelung’s DeformityMadelung’s Deformity

• Delayed growth of medial distal radius

• may result in a posterior subluxation of the ulna and the “bayonette” appearance.

• Carpal angle >117°.

Madelung’s DeformityMadelung’s Deformity

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