RADIOGRAPH LEGENDS FOR AVIAN CLINICAL ANATOMY
Patrick T. Redig DVM, PhD
Department of Small Animal Clinical Sciences
Avian Core -- CVM 6880

  1. Normal radiographic features of the avian skeleton and major soft tissue features.
    Refer to the arrows and find the following structures:
    1. humerus: note pectoral crest
    2. scapula
    3. coracoid
    4. furcula Note glenoid cavity formed by juncture of scapula and coracoid -- this is the point of articulation of the humerus
    5. vertebral column and pelvic elements: note notarium, synsacrum, and acetabulum, and ileum
    6. keel
    7. radius
    8. ulna
    9. metacarpus
    10. alula
    11. femur
    12. tibiotarsus
    13. fibula
    14. tarsometatarsus
    15. liver shadow: differentiate from lateral wall of the proventriculus seen on left side of body
    16. heart shadow
    17. kidney shadow
    18. abdominal air sacs
    19. pubic bone
    20. Pulmonary vessels
    21. Normal "waist" between cardiac apex and liver
  2. Radiograph of a normal red-tailed hawk taken at maximal inspiration.
  3. Radiograph of a normal red-tailed hawk taken at maximal expiration. Compare the appearance of the abdominal air sacs with those in #2. Phase of the breathing cycle can produce a marked difference in the appearance of the air sacs and must be accounted for when examining radiographs for evidence of air sacculitis.
  4. Fracture of the coracoid bone (arrow).
  5. Luxation of the coracoid in great horned owl -- compare with previous
  6. Radiographic evidence of a shoulder separation (arrow). Compare with radiograph number 1 and note the change in the relationship of the head of the humerus to the coracoid and scapular process.
  7. Humeral fracture in a rough-legged hawk. This is a typical humeral fracture characterized by long spiral fragments proximally and distally. These spikes cause tremendous soft tissue damage that greatly compromise the potential for successful repair of such fractures unless stabilized immediately..
  8. Stabilization of a humeral fracture with simple intramedullary pinning
  9. Stabilization of a humeral fracture with a complex intramedullary pin-external skeletal fixator "tie-in".
  10. Healed compression fracture of proximal humerus.
  11. Elbow dislocation in a snowy owl. There is massive displacement of the radius and ulna from their respective points of articulation with the humerus.
  12. Midshaft fractures of the radius and ulna
  13. Stabilization of the forearm by intramedullary pinning of the radius and ulna. Care must be taken so that IM pin in the ulna does not penetrate the elbow joint at the point where it exits the ulna.
  14. Stabilization of an ulnar fracture with an external skeletal fixator
  15. Stabilization of an ulnar fracture with an intramedullary pin - external skeletal fixator tie-in
  17. Fusion of the radius and ulna during the healing of an ulnar fracture. Such fusion prevents the back and forth motion of the radius thereby preventing normal flexion and extension of the metacarpus. This fusion is known as a synostosis.
  18. Metacarpal fracture in a bald eagle
  19. Fracture in 18 repaired with external skeletal fixator.
  20. Femoral fracture with intramedullary pin - external skeletal fixator tie-in fixator
  21. Tibiotarsal fracture with Type II external skeletal fixator
  22. Osteomyelitis in the digits of a flamingo.
  23. Normal radiographic features of the skeleton of a nestling red-tailed hawk. Note the lack of formation of the articular structures in particular and the low density of the bones in general.
  24. Radiograph of a juvenile long-eared owl with multiple pathological fractures of all the long bones occurring as a result of an improper diet. This condition is referred to as nutritional secondary hyperparathyroidism.
  25. Radiograph of a Swan. Note the relative mass of the long bones. Swans weigh upwards of 25 pounds and are among the most powerful flying birds, hence tremendous strength is required of the bones for muscle attachment. Note also the anatomy of the trachea as it is coiled in the keel of the sternum (arrow).
  26. Radiograph of a loon. Note the fusiform body shape, the very short femurs, and the extended modification of the cnemial crest at the cranial end of the tibiotarsus. These are adaptations that give the loon the capability for swimming and diving.
  27. Radiograph of a great blue heron. Note the extreme length and lightness of the bones, especially compared to the swan in 25. The right humerus is also fractured.
  28. Radiograph of a young African Grey parrot with multiple long bone fractures.
Reference:
Smith and Smith. Atlas of Avian Radiographic Anatomy McMillan, MC. Imaging Techniques, Chapter 12 in Avian Medicine: Principles and Application (Ritchie, B. G Harrison, L Harrison, eds). Wingers Publ. Lake Worth, Florida 1994. 1384pp