If the kneecap has been completely dislocated, the kneecap may need to be repositioned back in its proper place in the groove. This usually happens in an emergency room under sedation. This process is called closed reduction.

The initial treatment of patellar instability is nonsurgical, comprising of pain medications, rest, ice and physical therapy to regain movement, and optimise the muscular control of the patella. Knee bracing may have a role during high risk activities.

If the instability continues, then surgery may become necessary, both to reduce the symptoms associated with instability, and to prevent damage to the joint surfaces in the long term.

In general the surgery may be either directed at the soft tissues alone, reconstructing the ligament on the inner side, or adding a bone operation whereby the attachment of the patellar tendon on the tibia is moved towards the inner side. Both procedures improve alignment and tracking. The examination and preoperative imaging will guide whether both are appropriate, and your surgeon will discuss these with you.

Your doctor will recommend pain medications to relieve pain. To help reduce the swelling you will be instructed to elevate the leg and apply ice packs over the knee. Crutches and a hinged knee brace are necessary, depending on which operation you have had. The rehabilitation will be supervised by expert physiotherapists.

The operation is effective in the majority of cases. The risks are low but may include:

• Stiffness
• Recurrent instability (10%)
• Persistent pain and weakness of the quadriceps muscle