knee conditions Flashcards
mechanism of medical collateral tear
excessive valgus force (e.g. side tackle)
medial collateral tear presentation
- swelling and effusion
- pain and tenderness over ligament insertion
- pain and laxity on valgus stressing over the knee
medial collateral tear management
rest and firm brace
mechanism of lateral collateral tear
varus stress on the knee
lateral collateral tear presentation
- foot drop
- swelling and effusion
- pain and tenderness over ligament insertion
- pain and tenderness on varus stressing
lateral collateral tear management
- conservative
- surgical intervention if unstable
complication of lateral collateral tear
peroneal nerve damage
mechanism of ACL tear
- common injury in football and skiing
- lateral twisting of the body when the foot is planted on the ground, causing excessive internal rotation
ACL tear presentation
- pop heard at time of injury
- deep pain within the knee
- rotational instability (feels like knee is going to give way)
- swelling that developed within a few hours of time of injury
- positive Lachman’s test or anterior drawer test
ACL tear diagnosis
- x-ray to rule out any concurrent fractures
- consider MRI
ACL tear management
- rest and physiology
- 1/3 have no long term problems, 1/3 continue with most daily activities but not sports, and 1/3 are unstable and have trouble with most daily activities
- surgery can be considered to replace the ligament
what will a PCL tear usually occur with
LCL tear
mechanism of PCL tear
valgus stress, hyper-extension and direct blow to a flexed knee
PCL tear presentation
- pain, instability and hyper-extension
- instability when walking downstairs
- positive posterior drawer test
PCL tear management
conservative
PCL tear complication
peroneal nerve injury
risk factors for extensor mechanism rupture
- diabetes
- rheumatoid arthritis
- tendinitis
- steroid use
mechanism of extensor mechanism rupture
rapid contraction of extensor muscles when lifting a heavy object
most common site of extensor mechanism rupture
- < 40: patellar
- > 40: quadriceps
extensor mechanism rupture: presentation
- reduced ability to extend knee
- reduced power in quadriceps
- palpable gap in extensor tendons
extensor mechanism rupture diagnosis
ultrasound
extensor mechanism rupture management
- rest if partial
- repair if full
mechanism for meniscal tear in younger patients
due to rotational force on a loaded knee (similar mechanism to ACL damage)
mechanism for meniscal tear in elderly patients
occur spontaneously or due to innocuous injury due to age related degeneration
what is a bucket handle tear
large longitudinal tear where the torn fragment flips out of place causing locking of the knee
meniscal tear presentation
- pain localised to side of tear (medial more common)
- instability and feeling that knee is going to give way
- catching sensation during extension or complete instability due to locking
- swelling, which develops over 24 hours
- McMurray’s test positive
meniscal tear diagnosis
MRI
meniscal tear management
- conservative
- only 10% are suitable for repair
mechanism of pre-patellar bursitis (housemaid’s knee)
excessive kneeling down
pre-patellar bursitis (housemaid’s knee) presentation
swelling on anterior and inferior patella
pre-patellar bursitis (housemaid’s knee) management
analgesia
Baker’s cyst causes
- osteoarthritis
- rheumatoid arthritis
what is a Baker’s cyst
swelling caused by herniation of synovial fluid
Baker’s cyst presentation
pain and calf swelling associated with a fluctuant mass
Baker’s cyst diagnosis
ultrasound to rule out DVT
Baker’s cyst management
self resolves
