Imaging of the lower limb Flashcards
What is the ischial tuberosity?
Bony section of bum, origin of hamstrings
What do flakes of calcification in bones indicate?
Tendon pathology
Features of the pelvis
Sacroiliac joint Hip joint Iliac blade Superior pubic ramus Inferior pubic ramus
What are the three compartments of the knee?
Medial
Lateral
Patella-femoral
Features of the knee
Patella Tibia Medial/lateral tibial plateau Fibula head Femur Tibia and fibula
What does corticated bone indicate?
Old injury
Which bones make up the ankle joint?
Tibia and talus
What is the sub-tala joint?
Talus articulates with calcaneus
What is the talar-navicular joint?
Articulation between talus and navicular
Where is the fore foot?
Metatarsals onwards
Where is the mid foot?
Cuboid, navicular and cuneiform bones
Where is the hind foot?
Begins immediately below ankle
What are the two sesamoids?
Lateral and medial
Features of ankle
Tibia Talus Fibular Syndesmosis Medial/lateral malleolus
Bones in foot
Cuboid Lateral/middle/medial cuneiform Navicular Talus Calcaneus
Main arteries in pelvis?
Aorta
Common iliac artery
External iliac artery
Internal iliac artery
Which three blood vessels supply the femoral head?
Obturator
Lateral femoral circumflex
Medial femoral circumflex
What is an intracapsular fracture?
Vessels severed, head of femur replaced unless in child where cannulated screws can reattach head
What is an extra capsular fracture?
Vessels haven’t been severed so head isn’t at risk - a dynamic hip screw is used to repair
Arteries supplying femoral head
Branch of the obturator artery
Lateral femoral circumflex artery
Medial femoral circumflex artery
What is trifurcation?
Femoral artery gives rise to anterior tibial artery, perineal artery and posterior tibial artery
Which scan is used to visualise arterial system?
CT angiogram
What are the two venous systems in the lower limb?
Superficial and deep
What does DVT stand for?
Deep Vein Thrombosis
Why is proximal DVT dangerous?
Danger of travelling up the body and patient
What is a doppler ultrasound and how does it work?
Employs the ‘doppler’ effect to determine whether blood flow is toward or away the probe and its relative velocity. It is calculated by the shift in frequency of a particular sample. When the doppler shift falls in the audible range, the machine uses stereo speakers to produce pulsating sound
What does it indicate when it is red on a doppler ultrasound?
Coming towards probe
What does it indicate when it is blue on a doppler ultrasound?
Moving away from probe
What is a patent blood vessel?
Open and blood is flowing through
What does haziness on an x-ray indicate?
Stress fracture
Why is a stress fracture difficult to see on an x-ray?
Initially there will be no visible fracture but it develops and becomes visible on an x-ray over time as the wound heals
What is an insufficiency fracture?
Normal load, stress fractures associated with vitamin D deficiency and osteoporosis
What is a Lover’s fracture?
Calcaneal fracture
What is a lipohaemarthrosis?
Fracture of tibial plateau, bone fracture shows fat in joint
When should a fracture/vascular assessment be performed?
Before orthopaedic fixation
What is diabetic osteomyelitis?
Bone is ‘eaten’ by infection
