Patella Stabilisation
What is patella stabilisation surgery?
Instability of the patella (kneecap) can cause pain and prevent normal activities due to a feeling of apprehension that the patella will dislocate. A stabilisation procedure is performed to change the tracking of the patella and strengthen the soft tissues that prevent it from dislocating. Although there are many procedures that fall under this category, the two most commonly performed procedures are a medial patellofemoral ligament (MPFL) reconstruction and a tibial tuberosity osteotomy.
The medial patellofemoral ligament acts as a restraint to the patella dislocating outwards. The tibial tuberosity is bony prominence at the front of the knee where the patella tendon inserts onto.
What is involved in MPFL reconstruction surgery?
The steps involved in MFPL reconstruction surgery include:
Diagnostic knee arthroscopy
2-3 small (< 1cm) portals are created to allow passage of a camera and surgical tools within the knee joint. The whole joint is inspected for damage and to confirm the patella is out of its normal groove.
Graft harvest
This involves taking one hamstring tendon (usually gracilis) to be used for the reconstruction of the MPFL ligament.
Creation of bone tunnels
Tunnels are created in the patella (kneecap) and the femur to allow for passage of the graft. The positions of the tunnels are confirmed using X-rays to ensure accuracy.
Graft passage and tensioning
The hamstring graft is then passed through the bone tunnels and tensioned until the patella is in a normal position within the groove of the femur. The graft is held in position using screws and suture anchors.
What is involved in tibial tuberosity surgery?
The steps involved in a tibial tuberosity transfer include:
Performing the osteotomy
An oscillating saw is used to detach the tibial tuberosity which has the patella tendon attached to it.
Repositioning of osteotomy fragment
Depending on your pre-operative scans, a plan is calculated on how the tibial tuberosity will be pulled down and medially.
Fixation of the osteotomy fragment
Once the tibial tuberosity has been moved to its new position, it is held in place using a low-profile plate and accompanying screws. This will stabilize the fragment and allow it to heal.
What is my follow-up schedule after the operation?
Approximately 2-4 weeks of leave from work is required for a desk-based job.
2 weeks
The wound dressings will be removed and the wound will be reviewed to ensure it has healed. The sutures will be removed at this stage.
8 weeks
The range of motion in the knee will be assessed. It is expected that you will be able to fully straighten the knee and bend it more than ninety degrees. If a tibial tuberosity osteotomy was performed, an X-ray is taken at this stage to ensure the osteotomy site has healed.
4 months
The patella will be assessed for stability. The knee should have a full range of motion but may have residual swelling around it. Return to sports will commence from 4-6 months post-operatively. If things have progressed as expected, this will be the final appointment.