Knee Pathology Flashcards
Name four types of extensor mechanism rupture
- rectus femoris tear
- quadriceps tendon rupture
- patellar fracture
- patellar tendon rupture
How does an extensor mechanism rupture usually occur?
Patient falls onto flexed knee with quads contracted
What are the risk factors for extensor mechanism rupture?
Previous tendonitis
Steroids
Chronic Renal Failure
Antibiotics
How will patients with an extensor mechanism rupture present?
Palpable gap, unable to straight leg raise
How is extensor mechanism rupture treated?
Surgical repair/reattachment
X-ray/US
What is the function of menisci?
Shock absorbers that act to evenly distribute load from femoral condyles to tibial articular surfaces
Describe the difference between the medial and lateral meniscus
Medial - more concave and fixed
Lateral - more mobile
Name two types of meniscal tears
Bucket Handle Tear
Degenerative Tear
Describe a Bucket Handle Tear
Presents with a locked knee, medical emergency if not repaired may cause problems with femoral condyle
Requires surgery
What injury also occurs with a bucket handle tear?
ACL rupture
Describe degenerative tears
Oestoarthritis, inflammation
Injection may help
Why does the meniscus have limited healing potential?
Peripheral blood supply
When would a arthroscopic meniscectomy be indicated?
Mechanical symptoms
Irrepairable tears
Failed meniscal repair
Describe an MCL tear
MCL resists valgus stress
Rupture may lead to values instability but usually heals completely
Describe the treatment of an MCL tear
Hinged knee brace
Early motion physiotherapy
Describe a ACL tear
ACL resits anterior subluxation and internal rotation
Rupture will lead to rotatory instability
What is the rule of 1/3 in ACL tears?
1/3 compensate
1/3 avoid instability by avoiding certain activities
1/3 do not compensate and have frequent instability
Name two types of ligament reconstruction
Autograft - hamstring/patellar tendon
Allograft - achilles
What is the difference between tendons and ligaments?
Tendons lack nerves and do not treat pain or prevent arthritis
What causes PCL rupture?
Direct impact, recurrent hyperextension or instability going down stairs
Blow to anterior tibia presents with popliteal knee pain and bruising
What can LCL tears cause?
Common fibular nerve palsy
What will knee dislocation cause?
Rupture of all four ligaments
Artery injury
Nerve injury
Compartment syndrome
How is knee dislocation treated?
Emergency reduction, multi-ligament reconstruction may need temporary stabilisation by external fixation
What are the risk factors for patellar dislocation?
Ligamentous laxity Female Shallow trochlear groove genu valgum high riding patella
What injury can occur at the same time as patellar dislocation?
Medial patellofemoral ligament tear and osteochondral fracture
