Patella / Knee Cap Dislocation / Stabilisation Surgery

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

Summary of Patella Dislocation

Knee cap dislocation is a very common injury particular in young adults / teenagers who play sport. It is generally the result of a twisting injury in a patient who is susceptible. The reason patients are more prone to dislocation is a combination of reasons related to the bone and soft tissue anatomy. First time dislocation is usually treated non surgically with Physiotherapy unless a large cartilage injury has been sustained at the same time.

Surgical Treatment for Patella Dislocation

Surgical reconstruction for patella dislocation is to stabilise the knee cap by addressing soft tissue and bone issues that are resulting in instability. Surgery usually involves:

  • Knee arthroscopy – To assess and address cartilage issue within the knee. The soft tissue on the outer part of the knee may be released as this can be related to patella dislocation. This is known as a lateral release procedure.

  • Soft tissue reconstruction (MPFL reconstruction) – The medial patellofemoral ligament (MPFL) is a natural stabiliser of the knee. Most patients suffer lateral patella dislocation which results in tearing or stretch of the MPFL ligament. This ligament can be reconstructed, most often using one of the hamstring tendons around the knee.

  • Bone realignment surgery (Tibial tubercle transfer, TTT) – The bone anatomy of some patients can make lateral patella dislocation more likely. The most common form of bone surgery that is used for patella dislocation is a realignment of the tibial tubercle. This is known as a tibial tubercle transfer (TTT). Rarely large bone surgery is required such as a femoral osteotomy or groove deepening (trochleoplasty).