Tibial Tubercle Transfer

What is a tibial tubercle transfer?

Usually, the patella (knee cap) sits in a groove on the end of the femur (thigh bone). The quadriceps muscles in the front of the thigh attach to the upper side of the knee cap. The patella tendon attaches to the lower end of the knee cap and then travels down to attach to the tibial tubercle on the tibia (shin bone). When the quadriceps muscles pull, they pull on the patella which pulls on the patella tendon. This, in turn, pulls on the tibia, which straightens the knee. As the knee bends and straightens, the patella glides up and down in the groove, which is known as the trochlear groove. In some people, the patella can be unstable and even dislocate (come out of the groove), usually with twisting movements of the knee. There are many possible causes for the patella to be unstable. Sometimes the patella rides up too high, so when the knee is straight it sits above or only just in the trochlear groove. The groove is therefore not able to hold the patella in place as well as it should. In this situation, the tibial tubercle can be shifted downward (distalised) to bring the whole patella lower.

How is a tibial tubercle transfer performed?

The procedure is performed under a general anaesthetic (fully asleep). An arthroscopy is performed through two small incisions to assess the joint and the way that the patella moves. A long 10-15cm incision is made over the front of the lower part of the knee. A saw is used to cut the tibial tubercle and an adjacent wedge of bone from the tibia. The bone piece is then shifted downward about 1 - 1.5 cm and fixed in place with screws. The screws are not usually removed.

A 2cm incision is then made over the inner side of the patella. The soft tissue in this region is tightened to help hold the patella in the right position.

How long will I be in hospital?

You will stay in hospital for one night after the operation.

How long is the recovery time after the operation?

You will be able to put your full weight on the operated leg but will need to wear a brace and use crutches when you walk for the first 6 weeks. When you are sitting or lying, you should take the brace off and practice bending and straightening your knee.

You will need to take 3-4 weeks off work.

Your physiotherapist will work with you to increase your range of movement and muscle strength. As long as the shifted piece of bone heals normally, you will be able to come out of the brace and come off crutches after 6 weeks. It will be about 4-6 months before you can return to sport.