Orthopaedic Knee Conditions Flashcards
What are the main ligaments of the knee?
Cruciate ligaments - Anterior and posterior
Collateral ligaments - medial and lateral
Transverse and ligament of Wristberg
Describe the meniscii
Specialised C-shaped cartilages - triangular in cross section
Medial is attached to deep MCL
Function is aid force transmission and increase stability
How can meniscal tear occur?
Acute - twisting esp. in deep flexion
Degenerative - OA
Medial meniscal tears are most common
What are some types of meniscal tear?
Flap (horizontal cleavage), radial, degenerative, Parrot’s beak and bucket handle
What is the presentation of acute meniscal tear?
Pain, clicking, locking and intermittent swelling
Mainly in people under 40
What is done in examination of meniscal tear?
Look for effusion of knee
Feel tender joint line at point at tear
Move - mechanical block to movement, McMurray’s test positive, fail deep squat and Thassaly’s test positive
What is the McMurray’s test?
Examiner places middle finer over lateral joint line and thumb over medial joint line
Patient knee is flexed and load is applied then rotate tibia on knee and under fingers there is clicking
What is the Thassaly’s test?
Patient stands and knees slightly flexed
Patient rotated and if lateral aspect of knee then lateral meniscal tear on external rotation
What investigations are done for meniscal tear?
X-ray - excludes arthritis and fractures
MRI - most sensitive test. Used for more unsure cases
What are the zones of the meniscus?
White zone - gain from synovial fluid so if tear then won’t heal
Red zone - if tears peripherally then can be repaired
What is the non-operative management for meniscal tears?
Rest
NSAIDs
Physio - hamstring and quadriceps strengthening
What is the operative treatment of meniscal tear?
Arthroscopy - repair and resection
Describe osteoarthritis
Degenerative change of synovial joints - progressive loss of articular cartilage and secondary body changes
Worsening pain and stiffness
What is the conservative management for OA?
Weight loss, analgesia, activity modification, braces, walking aids, visco-supplementation, and steroid injections
What is the operative management for OA?
Total knee replacement (most common) - cruciate retaining (keep PCL)and sacrificing
Uni-compartmental - medial (more common) and lateral
Medial can be mobile or fixed bearing
Describe the anterior cruciate ligament
32mm length x 7-12mm width
Runs from between tibial eminences to lateral wall of intercondylar notch of femur
Middle geniculate artery and posterior articular nerve
What is the function of the ACL?
Primary restraint to anterior translation of tibia relation to femur
Secondary restraint to tibial rotation and varus/ valgus stress
How does an ACL tear occur?
Non-contact pivot injury
More females to males - landing biomechanical and quad strength
How does an ACL tear present?
Heard a pop or crack
Immediate swelling - hemarthrosis
Unable to continue playing but can walk in straight line
Deep pain
What causes an ACL tear?
Bones of leg twist in opposite directions under full weight bearing - cruciate ligament tears
What is done during examination of ACL tear?
Look for effusion
Feel for tenderness
Move - Anterior draw (can see tibia translating on femur), Lachman’s test and pivot shift
What investigations are done for ACL tears?
X-ray - segond fracture (avulsion of anteriolateral ligament)
MRI - ACL, menisci and MCL
What is the non-operative treatment of ACL?
Focussed quadricep programme
What is the operative treatment for ACL tear?
ACL reconstruction
Possible partial menisctomy, ligament repair or augmentation
Hamstring graft
Describe the MCL
Superficial and deep medial collateral ligament
Superficial is primary restraint to valgus stress
Deep contributes in full knee extension
Describe MCL tear
Most common ligament injury
Severe valgus stress - usually contact related
Associated injuries - ACL tear and meniscal tear
What is the presentation of MCL tear?
heard a pop or crack
Pain on medial side
Unable to continue playing
Bruising medial knee
Localised swelling
What is done in examination for MCL tear?
Look for medial swelling and bruising
Feel tender medial joint line and femoral insertion of MCL
Move - painful in full extension and opening in valgus stress
What imaging is done for MCL tear?
X-ray - may be normal. Can have calcification at femoral insertion if taken after a long time
MRI - modality of choice. Assess severity and injury
What is the non-operative treatment of MCL tear?
Majority treated this way
Rest, NSAIDs, physio and brace for comfort
What is the operative treatment for MCL tear?
For severe tears and failed non-operative management
Repair or reconstruction
Repair avulsions and reconstruct damaged tissue
What is osteochondritis dissecans
Pathological lesion affecting articular cartilage and subchondral bone
2 forms - juvenile (10-15 yrs as growth plates still open) and adult
What is the cause of osteochondritis dissecans?
Hereditary, traumatic and vascular - adult form
What is the most common location of osteochondritis dissecans?
Knee - most common
Posterolateral aspect of medial femoral condyle
What is the presentation of osteochondritis dissecans?
Activity related pain - poorly localised
Recurrent effusions
Mechanical symptoms - locking and block to full movement if fragment breaks
What examination is done for osteochondritis dissecans?
May be normal
Look for effusion
Feel for localised tenderness
Move - stiffness, block to movement and Wilson’s test (flex knee over bed then extend and internally rotate then pain)
What investigations are done for osteochondritis dissecans?
X-ray - add in tunnel view
MRI - lesion size, status of cartilage and subchondral bone, and signal intensity (oedema suggests fragment)
What is the treatment for osteochondritis dissecans?
Restricted weight bearing and rom brace
Arthroscopy (subchondral drilling and fixation of loose fragment) and open fixation
