Patellar Instability
Patellar instability occur when the patella, or knee cap is displaced from its resting place.
CAUSES
- A hand blow or a fall
- Traumatic ligament laxity
- Atraumatic
Patellar instability can be classified into
- Acute traumatic
- Occur after a direct blow – collision in the foots or hit against a hard surface during a fall
- Chronic recurrent subluxation episodes occur more in women associated with maliagments
- Habitual-usually painless
- Occur during flexion
- Could be because of tight lateral structures like ITB, vastus laterals
SYMPTOMS
- Instability
- Anterior knee pain
- Medial side tenderness
- Patella apprehension
DIAGNOSIS
Clinical pattelar apprehension test.
IMAGING
- MRI- To rule out
- MPFL team
- Trochlea hypoplasia
- Osteochondrol lesion/ or bone brushing on medial patellar facet
TREATMENT
Non operative
- Acute dislocation – immobilization in cast for 3 week followed by supervised rehab for 6 weeks. Main emphasis on VMO strengthening with ITB release.
- Patellar stabilizing brace.
Operative
MPFL repair- if no significant underlying malaligment. Tibial tubercle transfer is done in addition to MPFL reconstruction or in isolation with significant malalignment.