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Plain Films - Lower Extremities

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Femur AP and Lateral
If # include both joints on at least one view
Standing long leg
Leg Length or varus/valgus measurement
Use patella markers. Mid patella
Block under short leg if requested
Use Anode heel effect
AP and Lateral both legs
Adults: always do both AP legs on one image, similarly weight bearing, acetabulum to talus. Lateral only if specifically requested.
Knee
Horizontal ray for any injury
No more than 15deg flexion for lateral
AP and Lateral
Tibia and Fibula
Trauma/?Toddlers #
Include both Joints
AP and Lateral knee to ankle
If ?toddlers # also do oblique
Ankle AP radiographic
AP anatomic and lateral for all initial injury
AP radiographic and lateral only for follow up
Foot
Club Foot (Talipes)
Dorsi plantar and oblique routinely
Lateral for all trauma and FB
Forced Dorsi-flexion lateral foot and ankle
Calcaneum
Trauma
Calcaneal spurs
Lateral
Half axial
Lateral views both ankles

Femur

  • AP and lateral
  • If fractured, must see both joints in at least one view

Standing Long Legs

(for leg length or varus/valgus measurement)

  • Rotate tube so (cathode -ve) end of tube is up (anode down); anode heel effect
  • Adjust position until both patellas facing forward
  • Tape Ball Bearing patella markers in centre of each patella.
  • Place an appropriately sized block(s) under short leg if needed to straighten pelvis. If you do this, annotate film with size of block
  • AP and lateral both legs - use stitching device if needed.
  • CT scanogram is a more accurate way of measuring leg length but some orthopods want standing legs.
  • Adults : Both AP on one image. Acetabulum to talus

Knee

  • AP and Horizontal ray lateral for any injury - to see fluid levels
  • Lateral: knee no more than 15deg flexion

Rickets

  • L knee AP
  • L wrist AP

Intercondylar views:

Osteochondritis Dissecans / loose bodies

  • Either: AP - knee flexed about 45 deg, film on foam pad as close under knee as possible, tube angled perpendicular to plane of tibia, centring on knee.
  • Ref Long and Raffert P 338

Skyline Patella

  • Knees flexed to 45 deg
  • Cassette held vertical at distal femur
  • Angle tube 15deg to tibia
  • Centre on lower margin of Patella. 

Merchant View

  • Patient supine, knee flexed 45deg over table edge
  • Cassette is held perpendicular to tibia,
  • Central beam directed caudally through patella at 60 deg angle from vertical

Tibia + Fibula

  • AP and Lateral Knee to ankle include both joints.
  • Spiral 'toddlers' fracture is common and can be very subtle. 
  • If clinically # but not seen on AP / Lateral do an oblique tib/ fib to better demonstrate spiral # .
  • If # still not seen, you can do oblique foot to include lower tibia, this will sometimes demonstrate an obscure # . See TND 1256.

Ankle

  • AP (Radiographic, Mortise) and AP (anatomic) and lateral on all initial injury views
  • AP (Radiographic) and lateral only on follow up - unless valid reason.

Club Feet

Forced Dorsi flexion lateral foot and ankle

  •  Use block or wood (R2 cupboard) to dorsi - flex foot - or standing if patient old enough.
  • Dorsi Plantar and oblique routinely
  • Lateral for all trauma and Foreign Bodies


Varus or Valgus Deformity

  • Weight bearing AP and Lateral both feet for comparison.
  • Oblique foot for affected foot.

Calcaneum

  • Injuries: Lateral
                Half axial
  • Calcaneal spurs: Lateral views both ankles

Special Foot and Ankle Views

See Long and Raffert P 375/357

Tarsal Coalition (A)

  1. Dorsi - Plantar
  2. Oblique Mid foot with 20deg tube angulation toward foot 
  3. Lateral with vertical ray coned to the tarsal bones


Tarsal Coalition (B)

  1. lateral weight bearing foot and ankle
  2. Harris 'ski jump' view (see below) 
  3. Oblique mid foot as above


Harris Ski Jump view

  • Stand patient on film (film in support cassette) on floor. Collimate to improve both feet.
  • Flex knees so tibiae form angle of approx 60 deg to cassette.
  • Angle 45 deg from behind patient towards toes, centre to include both os calci and forefeet 
  • Expose to penetrate the ankle and show the underside of the talus and 2nd metatarsal 
  • Long + Raffert p 408


Gravity stress view of ankle

  • Patient lying on affected side, foot / ankle hanging off end of table
  • Cassette positioned behind ankle, perpendicular to table
  • Central beam as for Horizontal ray AP ankle .
  • Annotate image with direction of gravity


External Fixators

  • If patient has a circular external fixator, look at previous images, and think about how to image the # or osteotomy site without the ex- fix obscuring the # site. Each situation will be different.
  • Often the request will be quite specific, you may need to try to superimpose the sides of the ex fix, You may need to angle the tube or oblique the limb position.-it depends on the type and position of ex- fix and fracture.
  • You will have a better chance of obtaining an orthogonal image with the sides of ex-fix superimposed if you use a shorter FFD - the divergent beam is less noticeable - adjust exposure accordingly.


Associated documents

  • Long and Raffert, 1995. Orthopaedic Radiography
  • Peri -Operative Planning, Baltimore Limb Deformity Course 2000

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Document Control

  • Date last published: 28 October 2017
  • Document type: Imaging Protocol
  • Services responsible: Paediatric Radiology

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