How is a wobbly or unstable kneecap treated?

Patellar femoral instability, otherwise known as an unstable kneecap, can cause a range of symptoms from pain in the joint to serious dislocations. Leading consultant orthopaedic surgeon and specialist knee surgeon Mr Bilal M. Barkatali details how instability in the kneecap develops and explains when surgery is necessary to correct the problem in this informative guide.

What is patellar femoral instability?

Patellar femoral instability is a condition that describes an unstable kneecap at the front of the knee. There’s a spectrum of instability which ranges from the kneecap feeling a little wobbly and perhaps as though it may want to come out through to true dislocation where the kneecap comes out to the side and remains dislocated which is quite a severe and debilitating problem.

What does patellar femoral instability feel like?

Patellar femoral instability presents as a spectrum of symptoms. It can be something as simple as pain at the front of the knee or a feeling that the kneecap may pop out to the side when performing certain activities such as twisting and turning or running and playing sport. In some patients, the patella actually fully dislocates to one side when some activities are performed, such as dancing, jumping, twisting or turning.

How is occasional and chronic unstable patella treated?

Cases of patellar femoral instability or dislocations can be split into two groups. The first category is traumatic instability where a patient has a serious accident or injury which results in the kneecap dislocating. Importantly, these patients will have had no problems in the knee whatsoever prior to the injury. Around fifty per cent of patients who experience a trauma related dislocation who have no prior history of knee issues go on to recover very well with physiotherapy alone and don’t require surgery.

The second group are patients who have underlying issues with their knee anatomy which predisposes the patella to be unstable and sometimes to dislocate. If those with trauma related dislocations go on to have multiple dislocations, surgery is indicated in order to stabilise the joint. Those who experience chronic dislocations usually require surgery without which, they usually can’t function very well.

What is involved in the surgical treatment of patellar femoral instability?

There are three different types of surgical procedures used to treat patellar femoral instability.

MPFL (medial patellofemoral ligament) reconstruction 

This is a reconstruction of a ligament that connects the inside of the patella to the inside of the femur. This helps restrain the patella in the correct position during the range of movement of the knee.

Tibial tubercle transfer

The patella is connected to the tibia at the tibial tubercle at the front of the knee. Sometimes the patella can be too high riding or be tracking abnormally to one side and to correct this the tibial tubercle is moved to a different location to help bring the patella down to the correct position and to help it track normally.

Trochleoplasty

The trochlea is the front of the femur on which the patella glides as the knee moves. In some patients, the trochlea has not formed correctly and instead of being a nice, deep groove is shallow or indeed domed. If the trochlea is shallow or domed there is nowhere for the patella to sit and glide during the range of movement. To correct this, a trochleoplasty is carried out where a deeper groove is created for the patient behind the cartilage at the front of the femur. This could be done in open surgery or arthroscopically by highly specialist surgeons.

What exercises can people do to strengthen their patellar stability?

The exercises involved in treating patellar femoral instability with physiotherapy and conservative management are quadriceps strengthening exercises, especially the VMO (vastus medialis oblique) muscle. Generally speaking, strengthening all of the quadriceps, with a particular focus on the VMO muscle is the best way of increasing the stability around the knee.

If you suffer from patellar femoral instability and would like to discuss treatment options, you can schedule a consultation with Mr Barkatali and learn more about him by visiting his Top Doctors profile.