Lower Limb - Knee Flashcards
Patella fracture,
What type of bone is the patella, and where does it develop?
Sesamoid bone that develops within the quadriceps tendon
How does the patella increase the efficiency of the quadriceps muscle?
By increasing the distance of the quadriceps tendon from the knee joint’s centre of rotation, improving leverage and mechanical advantage
What is the function of the patella besides improving quadriceps efficiency?
protects the knee from physical trauma
How is the patella shaped in coronal and axial planes?
Roughly triangular
What type of fracture is commonly seen in direct patella injuries?
An undisplaced crack or comminuted fracture, usually with an intact extensor mechanism
What causes an indirect patella injury?
Forceful quadriceps contraction against a blocked extension, e.g., tripping and catching the foot
What fracture pattern is typical in indirect patella injury?
Transverse fracture with possible disruption of the extensor mechanism
What clinical sign indicates an intact extensor mechanism?
Ability to perform a straight leg raise
How can pain affect testing the extensor mechanism and how can it be improved?
Pain may limit movement; testing with the patient on their side reduces gravity and may help
What imaging is used to diagnose a patella fracture?
At least two plain X-ray views
How are undisplaced vertical patella fractures with an intact extensor mechanism managed?
Non-operatively with a hinged knee brace for 6 weeks and full weight bearing allowed
What are the indications for operative management of patella fractures?
Displaced fractures or loss of extensor mechanism
What long-term complication may result from disruption of the patellofemoral joint?
Secondary osteoarthritis
What is the typical cause of a meniscal tear?
results from twisting injuries
What is a common feature of pain in meniscal tears?
Pain is worse when straightening the knee
What is a common functional issue associated with meniscal tears?
The knee may ‘give way.’
What can displaced meniscal tears cause?
Knee locking
Where is tenderness typically felt in a meniscal tear?
Along the joint line
What is Thessaly’s test used for?
It is used to assess for a meniscal tear
How is Thessaly’s test performed?
The patient is weight-bearing at 20 degrees of knee flexion and supported by the doctor. They stand on affected leg with knee bent twisting
The test is positive if pain occurs on twisting the knee
A 22-year-old man presents to the minor injuries unit after twisting his left knee while playing rugby 5 hours ago. Although he was able to finish the game, he now reports that the knee locks intermittently and feels like it might give way. He is also experiencing intermittent knee pain and notes that the joint has started to swell within the last hour.
On examination, the left knee joint is swollen, left knee flexion and extension are reduced, and there ie tenderness along the anteromedial joint line. The right knee is unremarkable.
What is the diagnosis?
Meniscal tear
A 32-year-old Sunday league rugby player presents to the emergency department with a painful knee. Upon history taking, she describes feeling a popping sensation in her right knee during the match, and upon clinical examination the knee is swollen, and the patient is unable to fully extend her knee.
Which one of the following tests is most likely to reveal the underlying diagnosis?
MRI - most appropriate imaging modality to diagnose meniscal tears
A 22-year-old male presents to the emergency room with pain in the left knee following a twisting injury during a rugby match. He states that it has gradually swollen over the past 24 hours, and he is unable to fully extend it.
On examination, you note tenderness over the medial joint line, a joint effusion, and the joint is held in a flexed position. There is no laxity on the valgus stress test.
What is the most likely diagnosis?
Medial meniscus tear
‘A 38-year-old man is playing football when he slips over during a tackle. His knee is painful immediately following the fall. Several hours later he notices that the knee has become swollen.
Following a course of non-steroidal anti-inflammatory drugs and rest the situation improves.
However, complains of recurrent pain. On assessment in the clinic, you notice that it is impossible to fully extend the knee, although the patient can do so when asked’
What does this describe?
Torn meniscus
