Dislocation of the patella or kneecap is a common problem occurring most frequently in the teens and twenties.
The patella sits in a groove on the front if the femur (thigh bone) and makes up an important part of the knee joint.
Dislocation occurs when the patella jumps out of this groove usually towards the outside of the knee. Recurrent dislocation is when the patella dislocates over and over again.
Treatment usually starts with physiotherapy, but surgery may be required if dislocations continue. Patella dislocation is a complex problem and often requires a number of investigations to determine the precise cause or causes in a particular patient.
Dislocation can be due to problems with the medial patelofemoral ligament (MPFL), tibial tubercle position, alignment of the leg, rotation of the bones, depth of the groove on the femur or any combination of these.
Surgery may need to deal with more than one of these issues in order to be successful.