patella tilt

Definition

Repeated dislocation of patella with minimal trauma

- 15-20% of paediatric acute patella dislocations

- more common girls 

- often bilateral

Dislocation occurs unexpectedly when quadriceps contracted with knee in flexion 

Direction

AP / Long Leg Views

Quantify Valgus Malalignment

Lateral Xray

1.  Assess Patella Alta

30^o flexion

Epidemiology

1 in 10 patients with symptomatic knees have isolated PFJ OA

Aetiology

Obesity

Repetitive deep flexion

Malalignment

Lateral patella tightness

Blunt trauma

Symptoms

Anterior knee pain

- rising from chair