dislocated patella is a very common ED presentation in the adolescent and young adult in particular.
classically they present by ambulance with it still dislocated and holding a Penthrane analgiser stick.
ED Mx
diagnosis is clinical and is usually very obvious that the patella is dislocated
most patients can be rapidly managed by simple closed reduction even whilst on ambulance trolley while they breathe on the Penthrane
reduction is achieved by pushing medially on the lateral aspect of the patella with your thumbs while an assistant extends the knee
post-reduction Mx
Xray with patella sky-line views should be done to exclude osteochondral avulsion fragments which can be large and may require operative Mx if present.
patients with no significant fracture are usually discharged home with Zimmer splint, crutches and analgesics and advised to have physiotherapy follow up to reduce the risk of subsequent dislocations.