Superior Dislocation of Patella - A RareClinicalEntity

Abstract

Introduction: Superior dislocation of patella is a rare injury. Patient usually presents with painful locking of the knee. The authors describe here a case of 54-year-male, who bumped his right knee on the edge of the bed. The patient was unable to extend his right knee. This was diagnosed as superior dislocation of patella and then managed with closed reduction with intramuscular analgesia.

Case report: A 54-year-old male presented with acute painful locking of knee after his knee struck on the edge of the bed while trying to attain a kneeling position on the bed. On clinical examination, the superior pole of patella protruded anteriorly and was very tender. The patellar tendon was found to be intact. Radiographs confirmed the diagnosis of superior dislocation of patella. The dislocation was reduced by closed method using intramuscular analgesia. The knee was immobilized for three weeks in a posterior long knee brace.

Conclusion: Superior dislocation of patella is quite uncommon. High index of suspicion, mechanism of injury, clinical examination, and radiographs are helpful to arrive at the diagnosis. Immediate closed reduction provides pain relief and a good knee range of movements.

Keywords: Patellar dislocation; interlocking osteophyte; painful locking.

Figure 1

Clinical appearance of knee.

Figure 2

Radiographs.