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Patellar Instability – (Medial Patellofemoral Ligament Reconstruction)

Patellar Instability

When the knee is functioning properly, the kneecap runs smoothly in a grove of the femur called the trochlear groove. If the kneecap slides out of this groove, the kneecap will become unstable. Anatomy anomalies like shallow or uneven grooves may cause the kneecap to slide out, or an injury such as a heavy fall or sharp blow to the kneecap may cause it to dislocate. Bracing and strengthening exercises treat minor and single episode dislocations while surgery is advised to correct multiple dislocation injuries.

What does surgery involve?

  • Persistent pain should not be ignored as recurrent dislocations can cause damage to the delicate chondral surfaces of the knee joint and predispose to arthritis.
  • There are a number of surgical procedures that may help in this situation  depending on your anatomy.
  • A Medial Patellofemoral Ligament Reconstruction (MPLF) is a surgical procedure indicated in patients with more severe patellar instability.
  • An MPFL reconstruction will reconstruct and tighten loose medial ligaments; a lateral release will release tight lateral structures; while a tibial ubercle transfer will realign the whole extensor mechanism by breaking the bone that the patella tendon is attached to and moving it with the patella into a more suitable position.
  • Dr Herald will work with you to find the most appropriate surgery and the rehabilitation for you.


Patellar Tendinitis or Tendon Tears

  •  The patellar tendon is a very strong tendon and resistant to injury.
  • Frequent running or jumping can cause a weakening of the tendon via overuse tendinitis or caused by disrupted blood flow to the tendon.
  • X-Ray and MRI scans will confirm degeneration and tearing or even a rupture of the patellar tendon, which is best treated by surgical repair.
  • Most tendon re-attachments are done as inpatient procedures, however, some treatments for tendinitis such as PRP may be done as outpatient procedures.
  • Post-surgery, a combination of knee immobilizer, crutches or walker may be used to prevent you from placing too much weight on the repaired knee.
  • Most tendinitis treated early with physiotherapy can avoid surgery.