Patellofemoral instability

The injury may be associated with pain and swelling in the front of the knee. Patellofemoral instability can be classified into two main groupings:

Primary Patellofemoral instability

This type of instability can evolve from a number of different mechanisms, such as: Lax or over-flexible ligaments around the knee The location of the patella being too high within the knee joint (patella alta) The tibial tuberosity may lie anatomically towards the outside (lateral) surface of the tibia.

Secondary Patellofemoral instability

This condition results from a primary knee dislocation. The medial patellofemoral ligament is the main stabilizer of the patella in preventing the patella from shifting laterally. During a knee dislocation this structure may be severely compromised resulting in patellofemoral instability.

Treatment of Primary Patellofemoral instability

Treatment may be non-surgical or surgical

Non- Surgical

If the knee is swollen and painful a knee extension brace can help to immobilize the knee. Quadriceps strengthening, in particular of the VMO (vastus medialis obliquus) muscle, may be advised. Patellar taping techniques may provide help in facilitating correct patellar tracking.

Surgical

In some cases surgery may be needed to correct the alignment of the patella. This may involve; Lateral release of retinaculum and other muscle fibres VMO tendon advancement Tibial tubercle transfer.

Treatment of Secondary Patellofemoral instability

Non-surgical

The same treatment principles apply for secondary patellofemoral instability as they do for primary instability. If the knee is swollen and painful a knee extension brace can help to immobilize the knee. Quadriceps strengthening, in particular of the VMO (vastus medialis obliquus) muscle, may be advised. Patellar taping techniques may provide help in facilitating correct patellar tracking.

Surgical

Repair of the medial patellar ligament may be necessary the structure is badly torn