Common conditions of the knee Flashcards
What are the menisci?
What are their function?
Specialised C shaped cartilages in the knee. Formed of a medial and lateral menisci they both attach to the deep medial collateral ligament
Aid force transmission
Increase stability
How can the menisci tear?
Which menisci is more likely to tear and why?
Acute-twisting in deep flexion
Degenerative- osteoarthritis
Medial menisci more common as it is a more fixed structure
How does a meniscal tear present
Pain
Clicking
Locking
Intermittent swelling
What is assessed upon examination of a suspected meniscal tear
Look- effusion
Feel- Tender joint line at the point of a tear (especially medial tear)
Move- mechanical block to movement, McMurrays test positive, Fail deep squat, Thassaly’s test positive
How do you investigate a miniscal tear?
X-ray -arthritis, fracture
MRI- most sensitive test
High false positivity
How do you treat a meniscal tear
Unlikely to heal due to there being a poor blood supply
Non-operative- rest, NSAIDS, Physio (hamstring and quadriceps strengthening)
Operative- arthroscopy, resection
What is osteathritis?
Progressive loss of articular cartilage leading ti secondary bony changes. Characterised by worsening pain and stiffness of the affected joint.
Where does the anterior cruciate ligament run between?
What is the blood supply of it
What inenrvates it?
What is its function
Runs from behind tibial eminences to lateral wall of intercondylar notch of femur
Blood supply: middle geniculate artery
Innervation:posterior articular nerve
Prevents anterior translation of the tibia
How is the ACL torn
How does it present?
Non- contact pivot injury
Females:males 4:1
Heard a pop or cracking, immediate swelling
Immediate swelling (70%), haemarthrosis
Unable to continue playing, cant walk in a straight line
Deep pain
How should a suspected ACL be examined?
Look- effusion
Feel
Move- anterior draw
Lachmanns's test
Pivot shift (best done under anaesthetic)How should an ACL tear be investigated?
X-ray- segond fracture, avuslion
MRI- ACL
Minsici
MCL
How do you treat an ACL rupture?
Non-operative, focussed quadricep programme
Operative- ACL reconstruction
partial menisectomy, ligament repair or augmentation
Hamstring graft
What is the MCL
What is its function?
two ligaments- superficial and deep MCL
Superficial- primary restraint to valgus stress
Deep- contributes in full knee extension, attaches to medial meniscus
How is the MCL torn
What injuries are associated with it??
Most common ligament injury of the knee
Severe valgus stress- usually contact related
Associated injuries- ACL tear, Meniscal tear
How does an MCL tear present
Hear a pop or a crack Pain ++, medial side Unable to continue playing Bruising on the medial knee Localised
How should you examine and MCL tear
Look- medial swelling, bruising
Feel- Tender medial joint line,tender femoral insertion of MCL
Move- painful in full extension
opening on valgus stress
What imaging can be done for an MCL tear
X-ray-may be norma, calcification of femoral insertion
MRI- Modality of choice
Assess location and severity of injury
Identify other pathologies
How do you treat an MCL tear
Majority non-operaitive, rest, NSAIDS, physio, brace for comfort
operative- severe tears, failed non operative management, repair or reconstruction, repair, avulsion. Midsubstance tear with good tissue
Reconstruction, damaged tissue
What is osteochondritis dissecan
Pathological lesion affecting the articular cartilage and subchondral bone
2 forms: juvenile- 10-15 years while growth plates are still open
Adult
What causes osteochondritis diseecans
Where does it localise?
Hereditary, traumatic, vascular (adult form)
Location- knee (most common) posterolasteral aspect of medial femoral condyle (70%)
How does osteochondritis present?
Actively related pain (poorly localised)
Recurrent effusion
Mechanical symptoms
Locking, block to full movement
How is osteochondritis examined?
LOOK- May be normal, effusion
FEEL- localised tenderness
MOVE- stiffness, block to movement, Wilson’s test
How do you investigate Osteochondritis Dissecans
X-ray, add in tunnel view
MRI- lesion size, status of cartilage and subchondral bone, signal intensity (oedema suggests instability fragment)
How do you treat osteochondritis dissecans
Non- operative, restrict weight bearing ROM brace
Operatic- arthroscopy, subchondral drilling
Fixation of loose fragment
