common orthopaedic conditions of the knee Flashcards
What kind of bone is the patella
sesamoid bone
What are the extensors of the knee
quadriceps
What are the flexors of the knee joint
hamstring
Where are the attachment points of the lateral collateral ligament
The tip of the fibula and the lateral femoral epicondyle
Why is the lateral meniscus more mobile then the medial meniscus
The medial meniscus is attached to the medial collateral ligament while the lateral ligament is not attached to the lateral collateral ligament
What does the anterior cruciate ligament attach to
The medial aspect of the lateral femoral condyle
What does the posterior cruciate ligament attach to
The medial femoral condyle
What is the common cause of an acute meniscal tear
twisting - normally in deep flexion
Which meniscal tear is more common
Medial meniscal as it is more fixed
How do meniscal tears present
Pain
clicking
Locking
intermittent swelling
What can be done on examination of meniscal tear
Look: effusion of the knee and quadricep wasting
Feel: tender joint on the side of the meniscal tear
Movement:
McMurrays test positive
Failed deep squat
Mechanical block to movement
Thassaly’s test positive
What are the investigations for meniscal tears
X-ray
MRI - the most sensitive test but has a lot of false positives
What is the most unlikely region on the meniscus for it to heal
White zone where it gets its nutrition from synovial fluid
What is the treatment for meniscal tears
rest
NSAIDs
physiotherapy: strengthening the hamstring and quadriceps
Surgical: arthroscopy - repair and resection
What is osteoarthritis
degeneration of the synovial joints
What is osteoarthritis characterised by
Pain and stiffness of the effected joint
bony swelling is common as well
How is osteoarthritis managed conservatively
Weight loss
analgesia
activity modification
NSAIDs
What are the surgical management of osteoarthritis
Most common (90%) - total knee replacement: cruciate retaining or cruciate sacrificing
Medial uni-compartmental knee replacement is the most common uni-compartmental knee replacement
What is the function of the anterior cruciate ligament
Primary restraint to anterior translation of the tibia relative to the femur
How does an ACL injury most commonly occur
Non contact pivot injury
Who is ACL injuries more common in
females
How does an ACL tear present
Acute incident where they heard a pop or crack
Immediate swelling
Deep pain
What is done on examination of an ACL tear
Look: effusion
Feel
Move - anterior draw
Lachmann’s test
Pivot shift test
What investigations are done for ACL injuries
X-ray
MRI
What is the treatment for ACL tear
Focussed quadricep programme - strengthening the muscle
Surgical : ACL reconstruction
What is the most common ligament injury in the knee
Medial collateral ligament (MCL)
What causes MCL tear
Severe valgus stress which is usually contact related
How does MCL tear present
Heard a pop or crack
pain on the medial side of the affect knee
Bruising of the medial knee and swelling
What is done on examination for MCL tear
Look - medial swelling and bruising
Feel - tender on the medial side and tender at the femoral insertion of the MCL
Movement - painful in full extension
What is the investigations done for MCL tear
X-ray
MRI - the best way of looking at MCL tears
What is the treatment for MCL tears
Conservative treatment is the most common:
Rest and NSAIDs
Physiotherapy and brace for comfort
analgesia
Operative - in severe tears or failed conservative treatment
What is osteochondritis dissecans
Pathological lesion affecting articular cartilage and subchondral bone
What are the causes of osteochondritis dissecans
Hereditary
trauma
vascular
What location is most common for osteochondritis dissecans
The lateral aspect of the knee
How does osteochondritis dissecans present
Activity related pain
poorly localised
recurrent effusions
Mechanical symptoms - lockiun
What is the treatment of osteochondritis dissecans
Reduced weight bearing
Surgical: arthroscopy and open fixation
