1. Small Animal Forelimb
RVT: Chapter 20

2. Objectives: Small Animal Forelimb
ID common concerns associated with radiographing the small animal forelimb
Safely and appropriately position a patient for various common forelimb positions.
Know where to measure & center the beam
Include appropriate margins
Position properly
Use non-manual restraint where possible
Understand alternative views
Distinguish & identify normal forelimb anatomy

3. Anatomy Review: Forelimb

4. Terminology Review Dorsal Recumbency Sternal Recumbency
Used for: distal forelimb
Dorsal Recumbency
Used for: proximal forelimb (scapula, shoulder, and humerus)

5. Radiographic Concerns: Forelimb
Field of view:
Long bones – include proximal AND distal joints
Joints – Include _______ of the bones proximal & distal
Most views done via tabletop
Collimate tightly
Can split film:
Point toes the same direction
Collimate & shield other side
R Mediolateral carpus

6. Radiographic Concerns: Forelimb
Non-manual restraint (where possible)
Place label at:
Lateral view - dorsal or cranial aspect
Other views – lateral aspect
Keep bone ______________ to the cassette
Increase exposure factors if splints/casts remain in place
R Mediolateral Tarsus

7. The Forelimb: Radiographic Anatomy
Shoulder Joint – Mediolateral & CdCr
Scapula – Mediolateral & CdCr
Humerus – Mediolateral, CdCr or CrCd
Elbow – Mediolateral, CrCd
Radius/Ulna – Mediolateral, CrCd
Foot – Mediolateral, DPa

8. The Shoulder

9. Shoulder Joint (Mediolateral View)
Positioning:
Area of interest __________ to cassette
This means affected limb ____________.
Extend affected leg cranially & ventrally
Contralateral leg pulled out of way
Arch head & neck dorsally
Hind limbs in natural position
Margins: Proximal 1/3 of _________ & 1/3 of scapula

10. Shoulder Joint (Mediolateral View)
Tips:
Don’t over-rotate thorax!
Leads to an ____________ view
Make sure elbow is in lateral- this should ensure shoulder in correct orientation
Set-up:
Central ray at area of interest
Palpate shoulder joint by finding humeral head
Do not include both shoulders in measurement
Use settings for pelvis/thorax and change as needed

11. Shoulder Joint (Mediolateral View)

12. Scapula (Mediolateral View)

13. Shoulder Joint (Caudocranial View)

14. Shoulder & Scapula (Caudocranial View)
Positioning:
Dorsal, with head pulled away from affected limb
Extend both forelimbs cranially with humerus parallel to cassette
Body & ribs should fall away from affected scapula
Can rotate sternum away to avoid superimposition
Sedation is sometimes necessary for full extension.
Shoulder margins: Proximal third of humerus & distal third of scapula
Scapula margins: Entire scapula and shoulder joint
Tip: caudal aspect of scapula is at about 8th rib

15. CdCr Scapula

16. Humerus (Mediolateral View)
*Positioning is identical to shoulder and scapula

17. Humerus (Mediolateral View)
Lateral recumbency with affected leg towards image receptor
Affected leg is extended forward
Opposite leg drawn back
Head and neck extended dorsally
Center beam at mid humerus
Margins: proximal to ___________ joint & distal to ___________ joint

18. Humerus (Caudocranial View)
Same positioning as for shoulder/scapula
Be aware of distortion since forearm is away from cassette

19. Humerus (Craniocaudal View)
Use when extension above head cannot be achieved

20. Elbow (Mediolateral Extended View)
ML Flexed View
Move head & neck dorsally
Affected elbow joint is in an extended position
Extend other limb caudally (out of view)
Maintain symmetry!
May need to stabilize distal limb to keep anatomy parallel

21. Elbow (CrCa View) Pull head away from affected limb
Center beam on center of humeral condyles
Foam pad under unaffected limb
Margins: proximal 1/3 of __________/_________ & distal 1/3 of _________________
* Same positioning for other CrCa views (with different borders)

22. Radius & Ulna (Mediolateral View)
Same as for extended elbow view (with different margins)
Place foam under the humerus & cranial thorax to maintain alignment
Measure at mid-radius
Margins: include entire elbow and carpal joint

23. Radius & Ulna (CrCa View)
Positioning as for CrCd elbow view (with different borders)
Measure at mid-radius
Limb must be parallel
Olecranon must sit in between lateral condyles
Use tape to secure
Head must be pulled out of view

24. Fracture of the Radius/Ulna

25. Fracture of the Radius/Ulna

26. Carpus (Mediolateral Hyperflexed View)

27. Carpus (Mediolateral Hyperflexed View)
Lateral recumbency
Hyperflex carpus
Bring toes towards R/U
Helps evaluate carpal
joint laxity
Margins: Proximal third of metacarpus to distal third of radius/ulna
*Usually include the digits too

28. Foot (Mediolateral View)
Separate digits with tape
Tape the lateral phalanx and medial phalanx and pull apart
Measure & center primary beam at site of interest
Margins: carpus and everything distal
Cassette can be split
Point toes in same direction and collimate well!

29. Foot (Dorsopalmar View)
Sternal recumbency
Move head laterally
Extend both forelimbs & secure affected limb proximally
Place carpus flat on cassette
Abduct the elbow slightly to straighten carpus
Foam pad or rice sock next to elbow to prevent rotation.
Flexed or stressed views may be useful in detecting joint instability.
Use tape/wooden spoons

30. Foot (Dorsopalmar View)