Patellar dislocation Flashcards
What is the most common mechanism of patellar dislocation?
This is usually caused by sudden quadraceps contraction with a flexing knee
What is the most common direction of patellar dislocation?
Lateral
Why are most patellar dislocations lateral?
The medial patellofemoral ligament (Retinaculum) is more likely to tear than the lateral patellofemoral ligament (Retinaculum)
Who is most likely to dislocate their patella?
Teenagers
Females
What are some conditions that can increase risk of patellar dislocation?
- Hyper-mobility
- Under-developed (Hypoplastic) lateral femoral condyle
- Increased Q angle (Genu valgum (in), increased femoral neck anteversion)
- Weak lateral quads insertions or weak vastus medialis
In who is the Q angle physiologically increased?
Females
Adolescents
Shorter statured people
Physiological variations to the femur or tibia
How will patellar dislocation present?
Obvious movement of the patella
Pain medially due to torn retinaculum
Possible effusion from haemarthrosis
What clinical test can be used in patellar dislocation?
Patellar apprehension test
What is shown in this X-ray?
Patellar dislocation and knee dislocation
How is patellar dislocation usually managed?
It is usually self relocating, but reduction with knee extension may be required
Aspiration
Bracing
Physiotherapy
When may surgery be indicated in patellar dislocation?
In cases of repeat dislocation
What surgical options may be required in repeat patellar dislocations?
Lateral release
Medial reconstruction
Patellar tendon realignment
