Knee and Tib Fib Flashcards
What are Lower Leg Fractures?
The lower leg forms a bony ring, meaning a fracture in one bone may also involve a fracture in the other or a joint disruption.
What is a Syndesmosis Injury?
Affects the distal tibiofibular ligaments and commonly occurs due to external rotation of the ankle. Can be difficult to assess on X-ray unless there is an accompanying fracture. Occurs in 13% of all ankle fractures.
How is Syndesmosis Injury assessed radiographically?
A clear space >4-5mm between the tibia and fibula on X-ray is indicative of syndesmotic injury. A gravity stress view may be used to assess for widening or talar shift.
What is a Toddler’s Fracture?
Common in children aged ~10 months to ~2 years (early walkers/runners). Non-displaced spiral or oblique fracture through the distal third of the tibia. Can be subtle on initial imaging. Oblique views or follow-up X-rays (10–14 days) may be needed for diagnosis.
What are Tibial Stress Fractures?
Caused by chronic mechanical stress from repetitive force. Common in running or jumping athletes.
What are Insufficiency Tibial Fractures?
Occur due to abnormal bone with normal forces. Common in older patients.
What is Effusion in the knee?
Homogeneous, well-defined soft tissue density in the suprapatellar recess. Can obliterate the posterior border of the quadriceps tendon.
What is Lipohaemarthrosis?
Presence of blood and fat within the joint space. Fat is less dense than blood and floats on top. Best visualized in the suprapatellar pouch.
What is a Ruptured Patellar Ligament?
An avulsion fracture of the inferior patella resulting in patella alta and inability to extend the knee.
Patella alta refers to a high-riding patella, which can lead to functional limitations in knee extension.
Define Schatzker I – Lateral Tibial Plateau Fracture.
A valgus stress injury without depression, common in younger patients with stronger bones, often caused by a bumper injury.
A bumper injury refers to a direct lateral impact to the knee.
What characterizes Schatzker II – Lateral Tibial Plateau Fracture?
A valgus stress injury with depression, most common tibial plateau fracture, occurring in older patients with osteoporosis.
Osteoporosis weakens bones, making them more susceptible to fractures.
Describe Schatzker III – Pure Compression Fracture of the Lateral Tibial Plateau.
A valgus force injury resulting in depression into the tibial metaphysis, common in older osteoporotic patients, often due to a fall.
CT is recommended for diagnosis as the depression may not be obvious on X-ray.
What is the mechanism of injury for Schatzker IV – Medial Tibial Plateau Fracture?
A varus force injury that may be a split fracture or split depression fracture, often due to severe trauma.
Involvement of the tibial spines and peroneal nerve is common.
Define Schatzker V – Bicondylar Tibial Plateau Fracture.
A fracture where the metaphysis remains in continuity with the diaphysis, caused by pure axial stress with severe trauma.
This type of fracture indicates significant force applied to the knee.
What occurs in Schatzker VI – Tibial Plateau Fracture with Metaphyseal-Diaphyseal Dissociation?
High-energy trauma causes separation of the articular surface from the diaphysis, potentially involving medial, lateral, or both articular surfaces.
This fracture type indicates severe injury and instability.
What is Osteochondritis Dissecans (OCD)?
A condition involving reduced blood flow to a specific area of bone, leading to avascular necrosis, often self-limiting but may cause brittleness and fragmentation.
Common in athletes due to repetitive stress.
List common locations for Osteochondritis Dissecans.
- Medial condyle of the femur (most common site)
- Capitellum (elbow)
- Proximal surface of the talus (ankle)
- Head of the 1st metatarsal (foot)
These locations are typically convex surfaces of bones.
Why is Osteochondritis Dissecans clinically important?
It is the most common cause of an intra-articular loose body, which may lead to pain, swelling, and joint locking if fragments dislodge.
Early detection and management are crucial to prevent further joint damage.
What is Osgood-Schlatter Disease?
Osteochondrosis of the tibial tubercle, commonly seen in adolescents
Caused by repetitive stress on the extensor mechanism (jumping, sprinting).
What causes Osgood-Schlatter Disease?
Repetitive stress on the extensor mechanism
Activities like jumping and sprinting can lead to micro-tears, fractures, and inflammation at the tibial tubercle.
What is another name for Osgood-Schlatter Disease?
Apophysitis of the tibial tubercle
This term reflects the inflammation of the growth plate at the tibial tubercle.
What is Osteosarcoma?
Aggressive malignant bone tumor
Commonly found in the metaphysis of long bones.
Where is Osteosarcoma commonly located?
Metaphysis of long bones (e.g., distal femur, proximal tibia)
It often presents with pain and swelling.
At what age group is Osteosarcoma frequently observed?
Adolescents and young adults
This demographic is particularly at risk for developing this type of bone tumor.
Define Exostoses / Osteochondroma.
Benign bone growth with a cartilage cap
Commonly affects metaphyseal regions of long bones.
What does multiple exostoses indicate?
Diaphyseal Aclasis (hereditary multiple osteochondromas)
This condition can lead to pathological fractures if they impinge on surrounding structures.
What is a Pathological Fracture?
A fracture occurring in weakened bone due to an underlying condition
Conditions may include tumor, osteoporosis, or infection.
Which tumors can be associated with Pathological Fractures?
Osteosarcoma or osteochondroma
These tumors weaken the bone structure, increasing fracture risk.
What are the characteristics of Osteoarthritis (OA)?
Joint space narrowing, osteophyte formation, subchondral sclerosis, subchondral cysts
Symptoms include pain, stiffness, and reduced mobility.
What leads to joint space narrowing in Osteoarthritis?
Cartilage degeneration
This degeneration reduces the space between the bones in a joint.
What are osteophytes?
Bony outgrowths formed in response to joint degeneration
They are characteristic of Osteoarthritis.
What is subchondral sclerosis?
Increased bone density beneath cartilage
This occurs as a response to stress on the bone underneath the cartilage.
What are subchondral cysts?
Fluid-filled sacs in bone
They can form in the subchondral bone due to Osteoarthritis.
