Knee injury Flashcards
Ruptured anterior cruciate ligament
Sport injury Mechanism: high twisting force applied to a bent knee Typically presents with: loud crack, pain and RAPID joint swelling (haemoarthrosis) Poor healing
Lachmann test positive
Management: intense physiotherapy or surgery
Ruptured posterior cruciate ligament
Mechanism: hyperextension injuries Tibia lies back on the femur Paradoxical anterior draw test
Rupture of medial collateral ligament
Mechanism: leg forced into valgus via force outside the leg Knee unstable when put into valgus position
Menisceal tear
Rotational sporting injuries Delayed knee swelling Joint locking (Patient may develop skills to ‘unlock’ the knee Recurrent episodes of pain and effusions are common, often following minor trauma
Chondromalacia patellae
Teenage girls, following an injury to knee e.g. Dislocation patella Typical history of pain on going downstairs or at rest Tenderness, quadriceps wasting
Dislocation of the patella
Most commonly occurs as a traumatic primary event, either through direct trauma or through severe contraction of quadriceps with knee stretched in valgus and external rotation Genu valgum, tibial torsion and high riding patella are risk factors Skyline x-ray views of patella are required, although displaced patella may be clinically obvious An osteochondral fracture is present in 5% The condition has a 20% recurrence rate
Fractured patella
types: i. Direct blow to patella causing undisplaced fragments ii. Avulsion fracture
Tibial plateau fracture
Occur in the elderly (or following significant trauma in young) Mechanism: knee forced into valgus or varus, but the knee fractures before the ligaments rupture Varus injury affects medial plateau and if valgus injury, lateral plateau depressed fracture occurs Classified using the Schatzker system (see below)
Describe the classification for tibial plateau fractures
How would a baker’s cyst present?
Painless lump in the popliteal fossa which is tense on standing. Develops following low level trauma. They are more likely to develop in patients with arthritis or gout and following a minor trauma to the knee. Foucher’s sign describes the increase in tension of the Baker’s cyst on extension of the knee.
What test would you use to assess a menisceal tear?
McMurrays test - Lie flat with knee bent and rotate foot internally listen for a click
How are the cruciate ligaments testse?
anterior and posterior draw tests and skyline test (looking for posterior sag in posterior cruciate ligament damage.
How does Osteoarthritis of the knee present?
patient typically overweight and over 50, severe pain, intermittent swelling, crepitus and limitation of movement
Describe a key feature of infrapatellar bursitis
Associated with kneeling
How are tibial plateau fractures classified?
Shatzker system
