forelimb positioning 2/20/25

Evaluation of Lameness

• Lameness in animals is common in certain areas:

  • In the front limbs, lameness is usually located in the shoulder or paw.

  • In the rear limbs, the lameness is typically found in the hock or foot.

• For horses:

  • Front lameness is almost always related to the foot.

  • Rear lameness frequently involves the hock.

Challenges in Radiology

• Accurate positioning of animals during radiography presents significant challenges, particularly when dealing with fractious or uncooperative animals.

• Anesthesia is often used for better positioning in emergency settings.

• Collimation is crucial for enhancing radiographic contrast and decreasing scatter to protect both the patient and the practitioner.

Importance of Positioning

• When performing x-rays, proper leg positioning is vital for clear images.

• Radiographs should typically include comparison views of both limbs to help identify issues more effectively.

• Including joints above and below fractures is recommended to assess trauma accurately.

Radiographic Techniques

• Straight radiographs are usually performed in two planes, though oblique views are increasingly used to prevent superimposition.

• Key to reducing scatter and improving diagnostic quality is correct collimation and choosing appropriate exposure factors.

• Essential to have radiographs free from distortion and marked clearly to avoid misinterpretations.

Bone Density Evaluation

• Radiographic examination focuses on the mineralization of bones, identifying areas of fractures or soft tissue density changes.

• The contrast in radiographs is affected by the kVP (kilovolt peak) and MAS (milliamps seconds); lower kVP and higher MAS enhance contrast and clarity when imaging bones.

Terminology of Bone Structures

• Key elements to remember:

  • Radiolucency: Areas that appear darker on the film (indicating less dense material).

  • Radiopacity: Areas that appear whiter (indicating denser material).

• Common conditions:

  • Osteoarthritis, particularly prevalent in older dogs.

  • Osteoporosis and osteolysis signify degradation of bone strength.

Fracture Classification

• Fractures can be broadly classified into several categories:

  • Open fractures: The skin is broken.

  • Closed fractures: The skin remains intact.

  • Incomplete fractures (e.g., greenstick fractures): The bone bends but does not completely break.

  • Comminuted fractures: The bone is shattered into multiple pieces.

  • Salter-Harris fractures: Involves growth plates, commonly seen in pediatric patients (puppies).

Pathologies Seen in Bones

• Conditions such as osteosarcoma (particularly in large breeds) are serious concerns, usually affecting the distal limbs.

• Diagnosing cancers may involve checking for lymph node involvement; presence there could indicate a poor prognosis.

• Panosteitis shows significant inflammation and changes in the medullary cavity of bones.

Imaging Techniques for the Scapula

• Typical views for assessing the scapula include lateral, craniocaudal, and oblique views.

• Scapular pathologies may include luxations, fractures, and various forms of joint disease.

• In cases of osteochondrosis and bursitis, specific positioning is vital for accurate assessment.

Conclusion

• Team evaluations of radiographs allow for a more thorough investigation of bone health, improving diagnostic accuracy and treatment choices for affected animals.

• Continuous learning and practice in radiographic techniques and understanding of bone pathology are essential for effective veterinary practice.