MPFL

The medial patellofemoral ligament (MPFL) is a band of connective tissue that links the medial aspect of the patella (kneecap) to the femur near the medial epicondyle. It serves as a primary passive restraint against lateral displacement of the patella, particularly when the knee is near extension. The MPFL contributes to patellar stability in the early degrees of flexion (roughly 0–30 degrees) and works together with other stabilizing structures of the knee.

Injuries to the MPFL commonly occur with lateral patellar dislocations or subluxations, especially in athletes and active individuals. Symptoms include medial knee pain, a sense of instability, swelling, and limited range of motion. Diagnosis relies on clinical examination and imaging. Magnetic resonance imaging (MRI) can assess MPFL tears and associated injuries, while plain radiographs evaluate factors such as trochlear dysplasia or osteochondral damage.

Treatment varies by injury pattern. After a first-time dislocation, nonoperative management is often recommended, including bracing, activity modification, and a structured physical therapy program focused on quadriceps and hip muscle strengthening. Surgery is considered for recurrent instability, failure of nonoperative care, or significant MPFL rupture. MPFL reconstruction is a common surgical option in which a graft (often autograft or allograft) recreates the ligament with fixation at the femur and patella, aiming to restore the native anatomy and restraint. Some patients may require additional procedures addressing patellar tracking or bony anatomy, such as tibial tubercle transfer or trochleoplasty.

Outcomes with MPFL reconstruction are generally favorable for restoring stability and function, though results depend on proper indication, technique, and rehabilitation, with potential risks including stiffness, graft laxity, and persistent pain.