Osteochondritis Dissecans Flashcards
How does osteochondritis dissecans typically present?
Subacute onset of joint swelling and tenderness (typically after exercise)
Catching, locking and/or giving way
Painful ‘clunk’ on knee flexion/extension
Symptoms more constant and severe if loose bodies are present
What is osteochondritis dissecans?
Acquired, ?reversible, idiopathic lesion of subchondral bone
Results in delamination + sequestration ± articular cartilage involvement and instability
Who does oesteochondritis dissecans typically affect?
Children and young adults (possibly due to earlier and higher-demand participation in sport, but evidence unclear)
What happens if osteochondritis dissecans is left untreated?
May progress to degenerative changes
What joint does osteochondritis dissecans typically affect?
Knee joint (but can also affect elbow and talus)
What are risk factors for osteochondritis dissecans?
Joint overuse (MAJOR RF):
Repetitive throwing/valgus stress
Gymnastics/WB on upper limb
Ankle sprain/instability
Competitive athletics
What can joint overuse cause?
Secondary effects on joint cartilage (pain, oedema, possible formation of free bodies, mechanical symptoms)
What are signs of osteochondritis dissecans of the knee?
Joint effusion
Tenderness on palpation of articular cartilage of medial femoral condyle when knee flexed
Wilson’s sign +ve
Antalgic gait or external rotation gait on ambulation
Loss of ROM
Quadriceps atrophy (if chronic)
What is Wilson’s sign?
Knee at 90 degree flexion + tibia internally rotated
+ = gradual joint extension causes pain at 30 degrees, external rotation of tibia at this point relieves pain
Ix for osteochondritis dissecans?
X-ray (AP, lateral, tunnel) - may show subchondral crescent sign of loose bodies
MRI - stage + assess stability of osteochondral lesion
CT - loose bodies
MRA - extra info abt articular surface
Diagnostic arthroscopy - most sensitive + specific, but invasive; limited role in initial dx
Early diagnosis of osteochondritis dissecans is important. How does this affect Ix?
Clinical signs may be subtle in early stages so
there should be a low threshold for imaging and/or orthopaedic opinion
Differentials for osteochondritis dissecans?
Osteochondral #
Meniscal tear
Septic arthritis
Bone or soft tissue contusion
Most important factor influencing mx for osteochondritis dissecans?
Stability of osteochondritis dissecans fragment
What is a stable osteochondritis dissecans lesion?
Maintains subchondral stability and remains located in bed
May or may not have intact articular cartilage
No mechanical symptoms
What is an unstable osteochondritis dissecans lesion?
Loss of subchondral stability
May or may not remain in bed, may or may not have intact articular cartilage
Mechanical symptoms
