Meniscus Flashcards
ESSENCE
Damage to the meniscus, which is the cartilage around knee joint
ANATOMY
How many meniscus and what function
A lateral and medial, function is to act as shock absorber and help stabilise joint
ANATOMY
What is attached to patella, and what attached it to the tibia
Quadriceps tendon attached to patella
Patella attached to tibia by patellar ligament
ANATOMY
What are the 4 ligaments of knee
- Anterior cruciate ligament
- Posterior cruciate ligament
- Lateral collateral ligament
- Medial collateral ligament
AETIOLOGY
Most common cause
- Sports injuries in young
- During normal activities in elderly
AETIOLOGY
Risk factors
- Acute trauma (twisting injury)
- Knee joint arthritis
- Knee instability
- History of anterior cruciate injury
- Malalignment of knee joint
- Weather conditions/rough ground
CLINICAL FEATURES
Presentation
- Pop sound or sensation at initial injury
- Pain - can be referred to hip or lower back
- Swelling
- Stiffness
- Restricted range of motion
- Locking of knee
- Instability of knee
CLINICAL FEATURES
Examination findings
- Localised tenderness on joint line
- Swelling
- Restricted range of motion
2 special tests
- They are generally not used or recommended in clinical practice as can cause pain or worsen injury
- McMurrays test
- Apley grind test
What is McMurrays test
- Patient lies supine and examiner takes the leg and flexes knee
- While internally rotating tibia and applying varus pressure to knee, knee is carefully extended, pain or restriction indicates lateral meniscal damage
- Repeating the flexed to extended movement with external rotation and valgus pressure, pain indicates medial meniscal damage
What is Apley grind test
- Patient lies supine and flexes knee to 90 with thight flat on couch
- Downwards pressure applied through leg into knee and tibia is internally and externally rotated
- Pain indicates positive result, suggesting meniscal damage, it is localised to area of damage (lateral or medial meniscus)
What are key general differentials for knee injury
Bone fractures
What criteria is used to determine if x-ray required after acute knee injury
Ottawa knee rules
Describe Ottawa knee rules
- Requires x-ray if any of following present
- Age > 55
- Patella tenderness (no tenderness elsewhere)
- Fibular head tenderness
- Cannot flex knee to 90
- Cannot weight bear
INVESTIGATIONS
First choice
- MRI scan - first line imaging for establishing diagnosis
- Arthroscopy - visualise meniscus, gold standard investigation for diagnosing meniscal tear
