knee imagine Flashcards
week 7
What is the primary purpose of the Ottawa Knee Rules?
To determine the need for radiographs after acute knee injury due to the risk of fracture.
List the indications for radiographs according to the Ottawa Knee Rules.
- Age > 55
- Tenderness at the head of the fibula
- Isolated tenderness of the patella during palpation
- Inability to flex the knee to 90 degrees
- Inability to bear weight immediately and upon ER evaluation
What is one advantage of applying the Ottawa Knee Rules?
Decreased use of knee radiography, reduction in waiting times and costs.
What limitation exists regarding the application of the Ottawa Knee Rules in children?
Evidence is conflicting; safer not to use in children under 18.
What are the criteria for performing radiographs according to the Pittsburgh Knee Rules?
- Patient is younger than 12 or older than 50
- Inability to walk four weight-bearing steps
What was the sensitivity and specificity of the Pittsburgh Knee Rules according to Seaberg et al.’s study?
Sensitivity of 0.99 and specificity of 0.60.
What are the standard views for knee radiography?
- Anteroposterior
- Lateral
- Posteroanterior (PA) axial ‘tunnel’ view
- Tangential view of the patellofemoral joint
What does the ‘tunnel’ view in knee radiography help visualize?
Intercondylar fossa, posterior aspects of the femoral and tibial condyles.
What is the definition of ‘patella alta’?
Abnormally superior positioning of the patella.
What is the definition of ‘patella baja’?
Abnormally inferior positioning of the patella.
What is the primary indication for advanced imaging using Computed Tomography (CT) for the knee?
Evaluation of severe trauma and alignment of fracture fragments.
What is the basic CT protocol for knee imaging?
Extends from the suprapatellar region to the proximal tibia, aligned with the tibial plateau.
What are some indications for Magnetic Resonance Imaging (MRI) for the knee?
- Meniscal disorders
- Ligament abnormalities
- Extensor mechanism abnormalities
- Osteochondral abnormalities
- Articular cartilage abnormalities
Fill in the blank: MRI may be indicated for prolonged, refractory, or unexplained knee _______.
pain
What are some common conditions that MRI can help evaluate?
- Arthritis
- Bone and soft tissue tumors
- Fractures and dislocations
What is the significance of the ‘Sunrise View’ in knee imaging?
It helps measure the sulcus angle and congruence angle of the patellofemoral joint.
True or False: The Pittsburgh Knee Rules apply to individuals who present more than 6 days after injury.
False
What is the scanning plane for a CT knee exam?
Aligned with the tibial plateau.
What does the term ‘osteochondritis dissecans’ refer to?
A condition involving osteochondral abnormalities.
What is the significance of identifying loose bodies in the joint with CT?
It helps in the evaluation of knee conditions and planning treatment.
What is the role of MRI in assessing muscle and tendon disorders?
Diagnosis of strains, tears, tendonitis, and inflammation.
What is the clinical significance of the tibial plateau in knee imaging?
Assessment of tibial plateau depression fractures.
What are the potential findings in a ‘tunnel’ view if there are osteochondral defects?
The fossa may appear squared-off instead of inverted U.
