Irreducible lateral dislocation of patella.

To cite: Yerimah G, Eisenstein N, Turner R. BMJ Case Rep Published online: [please include Day Month Year] doi:10.1136/bcr-2013009832 DESCRIPTION A fit and well 21-year-old man received a blow to the medial side of his knee while dancing in a pub. He became immediately non-weight-bearing and attended the emergency department. On examination, his knee was held in partial flexion and there was a palpable hard mass lateral to the lateral femoral condyle (figure 1). Radiographs demonstrated a lateral patella dislocation (figure 2). Despite giving the patient 20 mg of intravenous morphine, several litres of entonox and 20 mg of midazolam, the emergency department and orthopaedic on-call teams could not reduce the patella. The patient was taken to theatre the next day