Superior dislocation of the patella is a rare condition. We report a 70-year-old gentleman with his patella lower pole osteophyte interlocked with the anterior femoral condyles after hyperextension. The patella was reduced successfully with proper reduction technique under sedation. The active range of movement ranged from full extension to 120-degree flexion a few minutes after reduction. He walked unaided afterwards. There was no knee problem in two years of follow-up. On reviewing the literature, only 20 cases were reported till year 2007 worldwide and 19 cases could be treated by closed reduction with or without sedation. (Hong Kong j.emerg.med. Radiographs showed the patella was dislocated superiorly (Figure 1). His left knee got osteoarthritis with a big osteophyte over the lower pole of the patella. This osteophyte interlocked with the superior border of the femoral condyles. Thus the patella was locked in a superiorly dislocated position. Three milligrams of diazepam and 25 mg of pethidine were given to the patient intravenously. Closed reduction was performed by flexing the left hip to relax the quadriceps muscle. Then, the knee was hyper-extended in order to exaggerate the deformity. This manoeuvre helped to unlock the patella from the femoral condyles. Then with a gentle push to the lower pole of the patella, the patella fell back to its original position instantaneously. The whole manoeuvre required less than 30 seconds. A plaster-of-Paris slab was applied to keep the knee in 20-degree flexion temporarily to prevent re-dislocation A 70-year-old gentleman complained of left knee pain after trying to sit up from a supine position in his bed. Because of sudden loss of balance, he contracted his left thigh muscle, causing a hyperextension of his left knee and resulting in knee pain. He was ambulatory before the incident. With the painful knee, he could not walk. He also could not flex his knee. His left knee was kept in a hyperextended posture. He was then admitted to the United Christian Hospital, Hong Kong in April 2005.