Surgery to stabilise the kneecap is usually only offered when physiotherapy hasn’t been successful. It includes:
- Medial patella-femoral ligament (MPFL) reconstruction: this can be carried out using a combination of keyhole surgery and minimally invasive open surgery. During the procedure, a single hamstring tendon is used to reconstruct the MPFL.The procedure involves making a small tunnel in the kneecap and a second tunnel where the original ligament attached to the thigh bone. The new ligament is then passed as a loop through the tunnel in the kneecap, through the tunnel in the thigh, and secured in position. In most cases, you’ll be able to go home the next day and you should be able to take your own weight, supported by crutches, in a week or two. You can expect to get back to your usual activities around three months after surgery
- Bony realignment surgery: if your kneecap instability is caused by having an abnormal anatomy, such as a kneecap that is in a higher position than normal (patella alta), you may be offered a bony realignment procedure. The amount of deformity and how much it needs to be corrected is calculated from an MRI or CT scan of the knee. This is called a TTTG measurement. The procedure involves detaching the kneecap tendon, together with a small block of bone to which it is attached, and moving it towards the midline. It is then fixed in its new position with screws. Most patients are able to go home the next day, with the knee immobilised in a brace. You’ll be able to gradually bear your own weight after around two weeks and by six weeks most patients are able to bear their own weight without using a brace