Late MRI-detected patellar sleeve fracture: A case report and review of the literature

This is a detailed report of a case and a review of literature concerning the patellar sleeve fracture. The diagnosis of this type of fracture is often missed in the emergency room, which the mentioned case also stresses. The fracture is a subtype of patellar fractures, and is mostly seen among children between eight between sixteen years of age. The trauma mechanism is an indirect powerful extension of the knee with a simultaneous contraction against a resistance of the quadriceps muscle group. Inflicted patients have often been trampolining, skateboarding or playing soccer. A bruised, painful and immobile knee is the typical clinical presentation. Ultrasound or/and magnetic resonance imaging are alternatives when plain radiographs are inconclusive. The treatment is often an open surgical fixation of the bone fragment. Early treatment is essential for a good prognosis.