knee revision - diagnostic radiography
what is the area of interest for an AP knee x-ray?
distal 1/3 of the femur and proximal 1/3 of the tibia and fibula
where should the patella be in an AP knee x-ray?
centralised
what should be slightly superimposed on an AP knee x-ray?
fibular head, should be slightly superimposed by the lateral tibial condyle
what should be superimposed in a lateral knee x-ray?
femoral condyles
what there should be a clear view of in a HBL knee x-ray?
suprapatellar pouch
why should the knee be rotated slightly in an AP knee x-ray?
to centralise the patella
what is the exposure factors for an AP, lateral and HBL knee x-ray?
63kV, 2.5 mAs
what is the exposure factor for a skyline knee x-ray?
65kV, 3.2 mAs
where should the apex of the patella not be in an AP knee x-ray?
in the intercondylar notch
what should not be visible in an lateral knee x-ray?
adductor tubercle
when is a knee x-ray not justified?
osgood-schlatter's disease or anything to do with the soft tissue structures of the knee
what is the most common cause of a platella fracture?
direct blow to the anterior knee
what should the suprapatellar pouch measure in a normal knee?
5mm or less
what is commonly mistaken for a platella fracture?
bipartite patella
how can a bipartite patella be differentiated from a fracture?
smooth edges
what is more common: lateral tibial plateau fractures or medial tibial plateau fractures?
lateral tibial plateau fractures
what is a valgus force?
distal aspect of the knee joint and the tib and fib are angled more laterally
what is a varus force?
distal aspect of the knee joint and the tib and fib are angled more medially
what is a layered effusion of fat and blood?
lipohaemarthrosis
where are tibial eminence fractures most commonly found in?
children / paediatrics
what are symptoms of osteoarthritis in the knee?
knee pain, stiffness, and swelling
what is OCD?
osteochondritis dissecans
what are the ligaments of the knee?
PCL, MCL, ACL & LCL
what muscle is underneath the patella?
patellar ligament
what muscle is above the patella?
platella tendon
what is crepitus?
bone on bone clicking
what does osgood-schlatter's diseasd affect?
the tibial tuberosity
what is lipoharmarthrosis sometimes only a clear indication of?
an intra-articular fracture
what kind of bone is the platella?
sesamoid bone
what type of joint is the knee joint?
synovial condylar joint
what are the movements of the knee?
flexion, extension, lateral and medial rotation
to which structures do the cruciate ligaments attach to?
intercondylar eminence
what is the function of the menisci?
shock absorption, acts as a cushion. also provides stabilisation for the joint
what is the function of the ACL?
prevents too much anterior translation of tibia in relation to the femur
what is the function of the pcl?
prevents too much posterior translation of tibia in relation to the femur
what are the functions of the MCL and the LCL?
stops lateral and medial movement
where does the platella ligament attach to?
tibial tuberosity
what does tenderness at the site of the platella ligament insertion normally mean?
osgood-schlatter's disease
in which age group does the knee ossify?
2 - 6
what is the function of the knee bursae?
reduce friction between moving surfacdd
what is bursitis?
inflammation of the bursae
what is a bursae that may extend in injury?
suprapatellar bursa
what are the cruciate ligaments?
PCL & ACL
what are the structures attached to the collateral ligaments?
MCL & LCL
what are some diseases of the knee?
kohlers, kienbox, frieburgs, severs (calcaneum)
what causes prepatellar bursitis?
repetitive kneeling on a hard surface