4- Knee Problems Flashcards
What makes up the knee joint
Medial and lateral compartments of the tibiofemoral joint and the patellofemoral joint
Where is the thickest hyaline cartilage in the body found
The retropatellar surface in the knee joint
What are the menisci
Fibrocartilaginous plates in the knee joint
They act as shock absorbers and help distribute load equally
List the 4 main ligaments of the knee
Anterior cruciate
Posterior cruciate
Medial collateral
Lateral collateral
What is the main role of the ACL
Prevent abnormal internal rotation of the tibia
What is the main role of the PCL
Prevents hyperextension and anterior translation of femur
What is the main role of the MCL
Resists valgus force
What is the main role of the LCL
Resists varus force and abnormal external rotation of tibia
What can predispose you to OA of the knee
Previous meniscal tears Ligament injuries Malalignment Genetic Hobbies - sport
When would you consider a knee replacement
Patient has significant pain and disability
Conservative management isn’t work
List some potential complications of TKR
Infection
Thrombosis
Medical complications
Knee replacements have a lower risk of dislocation compared to hips = true or false
True
How does an meniscal tear present
Localised pain
Effusion develops the day after injury
Locking of the knee
Might feel like knee is giving way
What is a haemarthrosis
Effusion due to bleeding in the joint
Can occur after ACL rupture
What might you find on clinical examination of meniscal tears
Effusion
Joint line tenderness
Pain on tibial rotation - positive Steinman’s test
What is a bucket handle tear
Where a large meniscal fragment is able to flip out of normal position and causes mechanical obstruction
Knee ‘locks’
How do degenerate meniscus tears occur
Meniscus weakness with age
Can tear spontaneously or with seemingly minor injury
Common in early OA
Why does the meniscus have limited healing potential
Only has arterial blood supply in outer 1/3
Potential also decreases with age
How do you treat meniscal tears
Usually they don’t heal and aren’t suitable for repair
Steroid injections can ease symptoms
May settle with tie
If it doesn’t then you can take out the torn meniscus
What will be the main complaint with ACL deficiency
Instability when rotating knee
Feeling like it is giving way when turning
Is isolated PCL rupture common
No
usually part of multi-ligament injury
How do you treat acute MCL tears
Hinged knee brace
Good healing potential
How does an MCL tear present
Laxity
Pain on valgus stress
Tenderness over origin or insertion of MCL
How do you manage chronic MCL insatbilty
MCL tightening
Reconstruction with tendon graft
How do you treat LCL rupture
Surgery
Early repair or late reconstruction (tendon graft)
LCL injury has a high incidence of vascular injury
True
Popliteal injury
How do you treat multi-ligament injury
Surgical reconstruction due to the high degree of instability
What damage can a complete knee dislocation do to ligaments etc
Results in rupture of all 4 main knee ligaments
High incidence of neurovascular injury
Which age groups are commonly affected by extensor mechanism ruptures
Patellar tendon ruptures in younger age group (<40)
Quad tendon rupture in older patients (>40)
List some predisposing factors for extensor mechanism rupture
History of tendonitis
Chronic steroid use or abuse
RA
Renal failure
Can you treat tendonitis of extensor mechanism with steroid injection
No
You should avoid steroid due to high risk of tendon rupture
How do you treat extensor mechanism ruptures
Surgery
Tendon to tendon repair
Reattachment of tendon to the patella
What is patellofemoral dysfunction
Disorders of the patellofemoral articulation
Causes anterior knee pain
How do you manage patellofemoral dysfunction
Most improve with physio (try to rebalance quads)
Taping can help
Surgery is a last resort
What mechanisms can cause dislocation of the patella
Direct blow
Sudden twist of the knee
Which direction does the patella normally dislocate
Laterally
What factors predispose you to patella dislocation
Ligamentous laxity Female gender Shallow trochlear groove Genu valgum Femoral neck anteversion A high riding patella
What decreases risk of recurrent patellar dislocation
Physio to strengthen the quadriceps
As you age, risk goes down
