Patello Femoral replacement is performed for osteoarthritis affecting the back of the kneecap. In about 10% of arthritis patients the majority of their knee symptoms are coming from a worn kneecap. These people suffer from pain when crouching, climbing and descending stairs, walking up slopes and getting out of low chairs. Patients with this condition are usually able to walk with minimal pain on the level.
Initially Patello Femoral Arthritis can be treated with painkillers, anti-inflammatories, physiotherapy and, in the earlier stages, arthroscopy (keyhole surgery) but as the knee progressively wears, joint replacement surgery may be required to relieve the pain and improve mobility. If the majority of the joint is free from arthritis (or displays minimal symptoms) it may be possible to replace the back of the patella and the front of the femur (thigh bone) to provide relief. If other parts of the knee are also affected a total knee replacement is the better option.
What happens in surgery?
The surgery involves removing a small thickness of the damaged bone from the front of the femur (thigh bone) and the back of the patella (kneecap). The Patello Femoral replacement fits inside the space and is fixed to the bone with cement.
The operation takes about 40 minutes and involves a 10-15cm incision over the front of the knee. The wound is closed with either clips or an absorbable suture.
The component parts of the PFR
The Patello Femoral Replacement comes in 2 parts. The Femoral component is made of metal and is highly polished. The back of the patella is covered with a plastic button, which sits in a shallow groove on the front of the metal femoral component. Essentially a Patello Femoral Replacement is the front part of a Total Knee Replacement, but leaves the unworn cartilage over the rest of the joint intact.
After a Patello Femoral Replacement
The day after the operation your exercise regime begins. With the aid of a physiotherapist you will get out of bed and begin to exercise your new knee replacement. With perseverance, you should be able to climb stairs by day 2 and go home the following day.
You will need to continue attending physiotherapy as an outpatient. This can be done closer to your home with one of our recommended group of physiotherapists.
For most people it will take around 6 weeks to be walking reasonably with only one stick. After four months you should be able to walk well without pain, climb stairs (leading with your operated leg) and be capable of a range of movement with your new knee from 0 degrees to at least 120 degrees.
It is important to remember that an artificial knee is not a normal knee; you may well be able to carry out many normal activities of daily living. However, this range of movement may not be as good as it was before surgery and you may never be able to kneel after your Patello Femoral Replacement.
Lifespan of the PFR
Studies suggest that a Patello Femoral Replacement has around an 85% probability of lasting for 10 years after surgery. It is frequently done in a younger age group, such as patient’s aged 50 or over, as it is relatively easy to convert to a TKR if it wears out. It is performed less often in older patients as they frequently have osteoarthritis that affects the rest of the knee as well, making a TKR a better option.