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Orthopedics

Anatomy, Bony Pelvis and Lower Limb: Medial Patellofemoral Ligament

The medial patellofemoral ligament (MPFL) extends from the femur to the superomedial patella and is trapezoidal in shape. It plays a substantial role in stabilizing the medial aspect of the patella, especially in early flexion (0-30°). It restrains the patella and inhibits its lateral displacement. Injuries to the MPFL are rare but may occur in athletes during sporting accidents or during a traumatic event. If the patella is dislocated laterally, the MPFL is ruptured more than 90% of the time. P

v1 · Reviewed Nov 8, 2026 by Automated Clinical Reviewer (Strict Verbatim v1)
  • If the patella is dislocated laterally, the MPFL is ruptured more than 90% of the time.
  • Patients are at a significantly higher risk of suffering from patellar instability and potentially another patella dislocation if this occurs.
  • MPFL injuries occur most frequently in young athletes secondary to a sports accident or traumatic event and are a leading cause of traumatic knee hemarthroses.
  • In cases of patellar dislocation, the MPFL is ruptured in over 90% of cases.
  • In cases of repeat dislocation, it is ruptured nearly 100% of the time.
  • Patients with an MPFL rupture present with pain and tenderness to palpation over the medial retinaculum and the medial border of the patella.
  • Often, the patella's lateral displacement can be visualized.
  • An axial image plain film radiograph is sensitive to revealing patellar dislocation.
  • Magnetic resonance imaging is the most sensitive for evaluating MPFL injuries.
  • Common injury patterns seen on magnetic resonance imaging in MPFL injuries include a tear at the patellar attachment, a tear at the femoral attachment, a tear at both attachments, or attenuation.
  • Magnetic resonance imaging in these patients may also show other injuries.
  • Guerrero et al found that these patients often have loose bodies present and may suffer from patella avulsion fractures, meniscal tears, medial collateral ligament tears, and osteochondral lesions.
  • The Schottle point is a radiographic landmark used to identify the origin of the MPFL.
  • During MPFL reconstruction surgery, fluoroscopy is used intraoperatively to locate this point.
Quadriceps-angle (Q-angle)
A Q-angle of 20° or greater tends to track the patella laterally, causing pain and increasing the patient's risk of dislocation.
  • After an initial dislocation, conservative treatment with physical therapy and short-term immobilization is often recommended.
  • A patient with multiple dislocations is considered to have patellar instability and may be treated surgically.
  • Evidence shows that surgery is preferred in the acute setting when there is a patellar- or femoral-based avulsion.
  • Multiple surgical techniques have been reported for MPFL tears, with differences in both fixation and graft selection.
  • If surgery is pursued, the MPFL is typically reconstructed from the patient's own tissue or a cadaveric donor.
  • The surgeon harvests a graft of this tissue, restructures it to the appropriate dimensions, and then implants it into the patient.
  • This is typically performed using a combination of arthroscopic and open surgical techniques.
  • Patients can be discharged on the same day as surgery with a knee brace for short-term joint immobilization.
  • Athletes can typically return to sport 4 to 7 months after reconstruction.
  • MPFL reconstructions are often successful with good outcomes, and redislocations are rare.
  • Although redislocations are rare, other postoperative complications such as apprehension and subluxation have been reported.
  • it is important to consider surrounding anatomy and other possible injuries following dislocations, as concurrent injuries may substantially contribute to knee instability.
  • In these cases, multiple procedures may be necessary to restore joint stability rather than MPFL repair alone.
  • Patients with a large Q-angle may be candidates for surgical procedures such as an osteotomy of the tibial tubercle or distal femur to correct patellar mal-tracking.
  • MPFL reconstructions are often successful with good outcomes, and redislocations are rare.
  • Although redislocations are rare, other postoperative complications such as apprehension and subluxation have been reported.
  • it is important to consider surrounding anatomy and other possible injuries following dislocations, as concurrent injuries may substantially contribute to knee instability.
  • In these cases, multiple procedures may be necessary to restore joint stability rather than MPFL repair alone.
  • review
    Anatomy, Bony Pelvis and Lower Limb: Medial Patellofemoral Ligament. StatPearls [Internet] — Dylan Luxenburg, Michael G. Rizzo — StatPearls Publishing, 2023

Decision support only. Verify against local protocols and current labeling. Source: www.ncbi.nlm.nih.gov