Correcting Patellofemoral Instability with Kneecap Realignment
The surgical procedure that is performed to re-align the kneecap (patella) is called tibial tubercle transfer, also termed as bony realignment or osteotomy. This serves as a treatment option for patellofemoral instability and other disorders such as arthritis and cartilaginous defects affecting the joint between the kneecap and femur.
Your surgeon will move a small portion of the bone that held the patellar tendon to a position on the tibia in order to ensure proper tracking of the kneecap while bending the knee. The patients with the following conditions may be advised to undergo kneecap realignment surgery:
- Patellar or femoral pain
- Chronic knee pain due to patellar maltracking
- Having knee subluxations or dislocations multiple times
- Non-surgical treatment methods including physical therapy have failed
In some cases, tibial tubercle osteotomy is performed along with autologous chondrocyte implantation with an intention to treat both patellar maltracking and the resultant cartilage damage.
Knee Realignment Surgical Procedure
The surgery will be performed under general anesthesia or spinal anesthesia and it depends on your surgeon’s as well as your preference. Your surgeon will make a cut on the upper portion of your shinbone, just behind the tibial tubercle, the portion of the shinbone where the patellar tendon is attached. This cut across the bone allows relocation of the tibial tubercle to a more suitable position, thereby correcting patellar maltracking. Once the tibial tubercle is repositioned, it will be held in place to your upper shinbone with the help of two screws. These screws remain there and support the bone during healing. The skin incision is closed with sutures that dissolve on their own.
Post-operative Care after Knee Realignment Surgery
Postoperatively, a leg brace will be provided to maintain your leg in a straight position and it is important to wear this brace while walking. You will also be using crutches for a period of 6-8 weeks. A continuous passive motion (CPM) machine that subjects your knee to a preset range of motion will be provided to prevent stiffness and should be used 4-6 hours a day.
Your hospital stay may range between 1-3 days during which you will be taught some exercises and the way to use the crutches. You may start weight-bearing after 6 weeks postoperatively. After 6 weeks, you may use a knee immobilizer for about a week to bear weight without using crutches and then gradually wean out the knee immobilizer. You may start with normal, low-impact activities such as walking, swimming, and bike riding by three months postoperatively. Running and other sports activities can be resumed only after one year. Your postoperative follow-up visits will be scheduled at regular intervals, the first one is within 2-3 weeks of the surgery.