Knee Flashcards
Femoral shaft fracture
What causes it in young and old people?
What is position of proximal and distal fragments and why?
What is the complication?
- Young : high velocity trauma (raod traffic collisions)
Old : osteoporotic bones that fall from standing position
- Proximal : abducted (glut med and min), flexed (ilipsoas on lesser trochanter)
- Distal : adducted (adductor muscles), extended (gastrocnemius pull on posterior femur)
- Hypovolaemic shock
Distal femoral fractures
What causes it in young and old people?
What is the complication ?
- Young : high energy sporting injury
Old : osteoporotic bone - fall from standing position
- Disrupted popliteal artery
Tibial plateau fractures
What causes it?
What are the types of tibial plateau fractures?
What are the complications?
- Loading with varus or valgus angulation of knee
- Unicondyclar or bicondylar
- mesical tear, ACL
Patellar fractures
What causes it?
What are the clinical examinations?
What are the treatments for displaced and undisplaced patellar fractures?
Why can the patellar be mistaken for fracture?
- direct impact injury, eccentric contraction of quadriceps
- palpable defect in patella, haemarthrosis, unable to perform straight leg raise
- Displaced : surgical fixation, Undisplaced : splinitng
- some people have bipartite patella
Patella dislocation
What is it?
What is the common dislocation direction?
What muscle stabilise the patella?
What is the common cause?
What are the predisposing factors?
What are the treatments?
- patella completely displaced out of normal alignment in trochlear groove
- Laterally
- Vastus Medialis Obliquus (VMO) - control tracking of patella during knee flexion and extension, stabilise patella in trochlear groove
- Internal rotation of femur on planted foot whilst knee is flexed
- weakness of VMO, shallow trochlear
- knee extension with manual reduction of patella, physiotherapy of VMO
Meniscal injury
What causes it?
What are the symptoms?
What are the clinical examinations?
What are the treatments?
- sudden twisting motion of weight bearing knee
- intermittent pain, knee clicking, catching, locking, chronic effusion due to synovitis
- joint line tenderness, restricted motion, mechanical block to motion
- meniscectomy or meniscal repair
Collateral ligament injury
What causes it?
Which ligament injure more commonly?
Why LCL injury causes more knee instability?
- Acute varus and valgus angulation of knee
- MCL
- lateral tibia is less deep > less tsable socket for femoral condyle > LCL plays more critical role in stabilising knee
Unhapy triad
What is it?
What causes it?
- Injury to MCL, Medial meniscus and ACL
- strong force applied to lateral aspect of knee
ACL injury
Which cruciate ligament injury is more common and why?
What causes it?
What are the symptoms?
What is the clasic presentation?
- ACL - weaker than PCL
- Sudden change in direction during sports
- popping sensation, swelling, knee “giving way”
- tibia rotate medially during knee flexion, opening up laterally
PCL injury
What causes it?
What is the classic presentatiion?
What test is used to detect A/PCL injury?
- dashboard injury
- tibia displaced posteriorly on femur
- a & p drawer test
Dislocation of knee joint
What causes it?
How many ligaments must be torn to cause dislocation?
What is the complication?
- High energy trauma
- 3/4
- Popliteal artery disrupted > haematoma
Knee effusion
What is it?
What are the types of acute knee effusions?
What causes it?
- accumulation of fluid inside knee joint
- Haemarthrosis - ACL rupture util proven otherwise
Lipo haemarthrosis - fracture until proven otherwise
- OA, RA, Infection, Gout, repetitive microtrauma
Housemaid’s knee
What is it?
What are the symptoms?
What causes it?
- prepatellar bursitis
- knee pain, swelling, erythema
- repetitive trauma to bursa (scrubbing the floor), fall onto knee, blunt trauma to knee
Clergyman’s knee
What is it?
What causes it?
- infrapatellar bursitis
- repeated microtrauma like kneeling
Popliteal/baker’s cyst
What is it?
How does it occur?
- Semimembranosus bursitis
- Knee effusion > fluid forced into semimembranosus bursa
