The Knee Flashcards
What does the ACL stabilise? How does a tear normally occur and how’d ones it present?
The knee joint
Primary restraint limit anterior translation of tibia
Knee rotation stability
History twisting knee while weight bearing, landing for a jump
Joint swelling (haemarthrosis), pain, instability
What are two specific tests for an ACL tear?
Lachman’s test - placing knee 30d flexion, pull tibia forward assess amount anterior movement of tibia compared femur (more sensitive)
Anterior- draw test - flex knee 90d, thumbs on joint line & index fingers on hamstring tendon posteriorly, force applied anteriorly
Investigations & management of ACL tears
Plain film radiograph AP & lateral exclude bony injuries/ joint effusion/ lipohaemarthrosis
MRI knee ⭐️ >90% sensitivity (also picks up meniscal tears*)
*50% of ACL tears also have
Immediate management suspected: RICE
Conservative - rehab, strength training quadriceps, canvas knee splint
Surgical - tendon/ artificial graft, prehabillitation PhysioT months prio
What does the PCL do? How can it tear? Investigations & management
Primary restraint posterior tibial translation, prevents hyperflexion of knee
Less common, high energy trauma or lowe energy hyper flexion with plantar flexed foot
➕posterior draw test
⭐️mri
Knee brace + PhysioT
Continues symptomatic - surgery with graft
What is the most commonly injured ligament of the knee? How does it occur and how can it be graded?
MCL - valgus stabiliser
ER force applied lateral knee
Grade 1 - mild, minimally torn fibres, no loss MCL integrity
Grade 2 - moderate, incomplete tear, increased laxity MCL
Grade 3 - severe, complete tear, gross laxity MCL
Clinical findings and test for MCL tear, investigations, management
Trauma lateral aspect knee Pop -> joint line pain Swelling Increased laxity Valgus stress test
Plain film radiograph exclude fracture
⭐️mri
Management:
Grade 1 - RIcE, NSAIDs, strength training (-> full exercise 6wks)
Grade 2 - analgesia, knee brace, strength training (full exercise 10wks)
Grade 3 - knee brace, analgesia, crutches (exercise 12wks) if distal avulsion mri surgery considered
How do meniscal tears occur? What are the different types?
Trauma related or degenerative disease
Twisted knee whilst flexed & weight bearing
Types
Most common - Longitudinal/ bucket handle tear - central tear becomes separated from lateral fragment
Vertical, transverse, degenerative
Investigations & management of meniscal tears
Plain film radiograph exclude fracture
MRI ⭐️
Management:
RESt
Remain symptomatic - arthroscopic surgery, outer third tear sutured back, inner third tear trimmed
Difference between medial meniscus and lateral meniscus
Medial more circular and attached to MCL
Lateral not attached to LCL
How do tibial plateau fractures occur?
Most commonly following high energy trauma e.g. hall from height - impaction femoral condyle onto tibial plateau
(Less commonly elderly fall)
Varus-deforming force, often alongside other bony/ soft tissue injuries
If left -> rapid degenerative change
Investigations & management of tibial plateau fractures
First line plain film radiograph (lipohaemarthosis, fat in joint)
Ct almost all apart from undisplaced, severity
Uncomplicated - non-op trialled Hinged knee brace Non/ partial weight bearing 8-12wks PhysioT Analgesia
Operative - complicated or open or compartment syndrome
- ORIF
- hinged knee brace post op
- external fixation May warranted with delay ORIF
Cause of iliotibial band syndrome
Most common cause lateral knee pain in athletes
Exact pathology unknown - repetitive flexion & extension -> impingement band against lateral femoral condyle -> inflammation
Anatomical risk factors: genu Varum, XS internal tibial torsion, got probation, hip abductor weakness
Management iliotibial band syndrome
Modify activity
Analgesics
Long term
Local steroid injections
PhysioT
Surgery (symptomatic/ functionally limited 6mths)
Release iliotibial band from attachments on patella
