Patella fractures often occur when you fall onto your knee or a receive a blow directly onto the kneecap. A patella fracture can also occur when the quadriceps muscle in the thigh contracts violently or when the lower leg is extended against a fixed resistance.

You’re likely to feel immediate and severe pain and swelling at the site of the fracture. Extending your knee and/or moving it forward and backward may prove difficult. Swelling and tenderness around the kneecap may develop, as well as catching or locking of the knee. The most obvious symptom might be the inability to walk.

If you have a simple break, an x-ray will ascertain if the bone is broken. It is often easier to diagnose a compound patella fracture because the bone is likely to break through the skin. An x-ray will still be necessary to confirm this injury.

During arthroscopic surgery, an incision is made over the front of the knee joint. The fractured ends of the patella are realigned and held in place with a combination of pins, screws, and wires. In some cases, a portion of the patella can simply be removed, but this is usually done for smaller fracture fragments.
Following a patella fracture, you will need to keep your knee in a straight position to allow for initial healing. Gentle motion can usually begin in the first weeks following surgery, on the complexity of the fracture and the resultant strength of the repair.