MPFL

The MPFL is the most important of several stabilising ligaments around the patella.

What does the MPFL do?

The MPFL supports the patella, acting as a restraint on the medial side for the first few degrees of bending of the knee.

This helps to keep it aligned in the underlying groove of the femur during walking and running.

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Patellar dislocation and torn MPFL

During a traumatic dislocation of the patella, the MPFL may become injured and the patella may become more unstable.

The tear may be an avulsion, a simple sprain, a partial tear or a full substance tear, and may be accompanied by tears of the VMO muscle (vastus medialis obliquus) and the medial retinaculum.

Initially the doctor may choose to treat the problem without surgery, and sometimes the instability settles down, but if dislocations recur, reconstructive surgery may be advised.

• Quote from peer-reviewed paper:

  "Up to 94–100% of patients suffer from medial patellofemoral ligament rupture after first time patellar dislocation."

  Citation: Krebs C, Tranovich M, Andrews K, Ebraheim N. The medial patellofemoral ligament: Review of the literature. J Orthop. 2018 May 7;15(2):596-599. doi: 10.1016/j.jor.2018.05.004. PMID: 29881201; PMCID: PMC5990246.

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MPFL reconstruction

The knee surgeon may elect to repair the torn ligament to improve stability.

A variety of natural and synthetic materials have been used for such reconstructions, but the jury seems to be still out on which is best.

• Quote from peer-reviewed paper:

  "....MPFL reconstruction is a reliable technique for the treatment of patellofemoral instability. However, many details of the operation are controversial....overtension should be avoided, because it could provoke overloading on the cartilage of the medial patellofemoral joint, which would lead to cartilage degeneration and patellar tilt, and in severe cases can induce medial patellar dislocation....."

  Citation: Zhang YQ, Zhang Z, Wu M, Zhou YD, Tao SL, Yang YL, Li Y, Liu JL, Li P, Teng YS, Guo YM. Medial patellofemoral ligament reconstruction: A review. Medicine (Baltimore). 2022 Jan 7;101(1):e28511. doi: 10.1097/MD.0000000000028511. PMID: 35029909; PMCID: PMC8735765.

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Forum discussions

• Scar Tissue MPFL Reconstruction

  A patient struggles with regaining normal movement after an MPFL reconstruction for patellar dislocation.

• Scar Tissue MPFL Reconstruction (2)

  Discussion of symptoms after MPFL reconstruction.

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