Patella Instability / Knee Cap Dislocation – Physiotherapy

By Dr Daniel Meyerkort, Knee Surgeon, Perth Orthopaedic & Sports Medicine Centre

Overview of Patella Instability

Dislocation of the patella is common after a sporting or twisting injury. Often patients describe ‘the knee being dislocated.’ The patella can relocate itself, or rarely needs to be enlocated in the Emergency Department. Most dislocations occur with the patella moving laterally (towards the outside part of the knee). Some patients are at higher risk of patella instability which is due to their bony and soft tissue anatomy. Most patella dislocations can be treated without surgery.

Do you require an MRI scan after patella dislocation?

If the knee is very swollen after the patella is reduced it may be a sign that a large cartilage / bone injury has occurred. The large swelling is blood within the knee. In patients who have a large swelling after knee cap dislocation a MRI is recommended to assess the cartilage around the patella and distal femur. A large cartilage injury can be fixed if treated early.

The MRI shows rupture of the MPFL ligament? What does this mean?

The MPFL ligament is a thin ribbon like ligament on the inner, medial aspect of the patella. It is commonly ruptured after patella dislocation. Physiotherapy is focused on building the strength of your inner VMO quadriceps muscle. This helps the MPFL ligament to stabilise and heal. Surgery is rarely required for MPFL rupture (reserved for multiple dislocations).

Physiotherapy treatment for Patella Instability

Most patella dislocations can be treated with Physiotherapy. Most dislocations have not caused a large loose cartilage fragment and do not require surgery. Physiotherapy focuses on swelling control, range of motion of the knee and quadriceps strengthening, particularly the inner quadriceps (VMO muscle). Most patients will make a good recovery with a Physiotherapy muscular strengthening program.

Is bracing required and can you start weight bearing?

A knee brace for a short period of time may be required according to your symptoms for a first time patella dislocation. If multiple dislocations have occured in the past bracing is not usually required. Weight bearing can be commenced as tolerated by your pain and swelling.

When is surgery required?

For a first time dislocation, surgery is rarely required unless a large loose cartilage fragment is demonstrated on the MRI scan. For patients who suffer from multiple dislocations despite a Physiotherapy program surgery can be useful to stabilise the knee cap. Surgery most commonly involves reconstruction of the MPFL ligament and realignment of the tibial tuberosity.