MPFL Tear and Patellar Instability Surgery in Atlanta
A kneecap dislocation can tear the medial patellofemoral ligament and damage the cartilage inside the knee. We evaluate the ligament, cartilage, trochlear groove and overall alignment to determine why the kneecap dislocated and whether treatment should involve bracing, extensive physical therapy or surgical stabilization.
What Is the MPFL?
The medial patellofemoral ligament, or MPFL, is the main soft-tissue restraint that helps prevent the kneecap from sliding too far toward the outside of the knee.
When the kneecap dislocates laterally, the MPFL is commonly stretched or torn. Some patients recover after one event, while others continue to experience recurrent dislocations, shifting or a persistent feeling that the kneecap may come out again.
First-Time and Recurrent Dislocations Are Different
Most first-time patellar dislocations can be treated with a stabilizing brace followed by extensive physical therapy.
Recurrent dislocations are different. When the kneecap repeatedly comes out, there is often a mechanical reason—such as an abnormal trochlear groove, alignment problem, patella alta or insufficient MPFL—that should be identified and corrected.
We Obtain an MRI Promptly After a Kneecap Dislocation
A patellar dislocation can break off a piece of cartilage or cartilage with underlying bone. This fragment may not be obvious on standard X-rays.
We generally obtain an MRI promptly after a dislocation to evaluate the MPFL and make sure there is no cartilage defect or loose fragment inside the knee. When a significant cartilage or osteochondral fragment is present, surgery is commonly recommended to repair, restore or remove the damaged fragment and address the instability as appropriate.
A large swollen knee, locking, catching or inability to fully move the knee increases concern for an associated cartilage injury or loose body.
Common Signs of Patellar Instability
Symptoms may continue even after the kneecap has returned to its normal position.
Kneecap Dislocation
The patella may visibly move out of place during sports, twisting, a fall or even a relatively low-energy movement.
Shifting or Giving Way
Patients may feel the kneecap slide, catch or threaten to dislocate during stairs, squatting, running or cutting.
Pain and Swelling
Pain is often felt around the kneecap, and swelling may develop from the ligament injury or associated cartilage damage.
We Look for the Mechanical Reason It Dislocated
Patellar instability is not caused by the MPFL alone. We assess the shape and depth of the trochlear groove because a shallow or abnormally shaped groove may allow the kneecap to escape more easily.
Alignment is also essential. Standing and specialized knee X-rays help us evaluate kneecap position, tilt, patella height and overall limb alignment. MRI provides additional information about the MPFL, cartilage, trochlea and loose fragments.
First-Time Patellar Dislocation
When the MRI shows no loose cartilage fragment or major repairable cartilage injury, most first-time dislocators are treated without ligament surgery.
Recurrent Patellar Instability
Repeated dislocations usually suggest a mechanical problem that should be identified rather than repeatedly treated with another brace alone.
MPFL Reconstruction Is Not Always the Entire Solution
The operation must match the reason the kneecap is unstable.
MPFL Insufficiency
Recurrent instability with a torn or stretched MPFL may be treated with ligament reconstruction.
Trochlear Abnormality
The groove must be evaluated because severe trochlear dysplasia can contribute substantially to recurrent dislocation.
Alignment Abnormality
Patella alta, abnormal tracking or malalignment may require treatment in addition to MPFL reconstruction.
Do Not Ignore Repeated Kneecap Dislocations
Every dislocation can cause additional cartilage damage. Repeated instability, a locked knee, severe swelling, catching or inability to bear weight should be evaluated promptly. Identifying the cartilage injury and mechanical cause early helps guide the correct treatment.
MPFL and Patellar Instability Evaluation in Atlanta
Atlanta Bone and Joint Specialists evaluates first-time and recurrent kneecap dislocations for patients from Atlanta, Decatur, Snellville, Loganville and surrounding communities. We use MRI to evaluate cartilage and the MPFL, X-rays to assess alignment, and a complete mechanical evaluation to determine whether the knee needs bracing and therapy or surgical stabilization.
This page provides general educational information and does not replace an examination or individualized medical advice. Treatment depends on cartilage injury, number of dislocations, skeletal maturity, alignment, trochlear anatomy and the complete clinical evaluation.