What is MPFL Reconstruction

Medial patellofemoral ligament (MPFL) reconstruction is a surgical procedure to help stabilize the patella, or kneecap. The MPFL is a ligament on the inside of the knee that connects the end of the femur (thigh bone) to the patella (kneecap). It serves as a check rein on the kneecap and prevents it from moving too far to the outside of the knee.

In cases of patella dislocation or recurrent patellar instability, the MPFL can become torn or stretched out. Although non-surgical management is usually the first line of treatment, sometimes reconstruction of the torn or stretched ligament is needed.

Why is MPFL Reconstruction Surgery Performed

Reconstruction of the MPFL is performed with the ligament is stretched or torn due to repeated or severe dislocation of the patella. Although non-surgical treatment with a physical therapist, knee braces, and muscle strengthening are usually tried first, some tears of the MPFL will not heal sufficiently on their own.

Many factors lead to patellar instability. Some of these can be corrected and some cannot. Modifiable and non-modifiable risk factors must be assessed before deciding on definitive treatment. Sometimes a repair of the torn ligament is adequate, but replacing or reconstruction the ligament is shown to have improved outcomes compared to repair in most situations.

MPFL reconstruction is one of the most common procedures utilized when surgery is needed to stabilize the patella.

Video Overview of MPFL Recon

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How is Medial Patellofemoral Ligament Reconstruction Performed

Reconstruction of the medial patellofemoral ligament is performed by replacing the torn or stretch ligament with a new one. Sources of the new ligament are varied. This can include the your own hamstring tendon, or autograft. Allograft is tissue from a cadaver, or someone who donated their body to medicine. This is commonly used to make a new MPFL.

The new ligament is attached on the medial, or inside of the knee cap. It is then routed through the soft tissues to the place where it attaches one the femur. The native MPFL attaches on the medial femoral condyle. X-ray is often used to help locate the correct attachment site, known as Schottle’s point.

The knee is then brought through range of motion testing, and the graft is tensioned to ensure that it serves as a check rein preventing the kneecap from dislocating, but also to make sure it does not put undue pressure on the knee joint. The goal is to have normal patellar tracking without the MPFL graft pulling the knee cap to far to the medial side.

MPFL Surgery Postoperative Protocol

After surgery, patients are usually allowed to go home the same day. They are given crutches, pain medications, and specific instructions for their activity and range of motion.

For the first 4-6 weeks, patients are kept partial weight bearing and are required to used a knee brace. The focus is on controlling swelling, decreased inflammation, and protecting the reconstructed ligament. Gluts and quads are exercised to start regaining function and control of these important muscle groups.

The stationary bike is utilized starting at week 6, and functional progression towards sports activity usually starts around 4 months from surgery. The average time before return to sports is 6.7 months, according to a recent systematic review.

You can view our MPFL Postoperative Protocol for physical therapy here.

MPFL Reconstruction Success Rate

Medial patellofemoral ligament surgery has been researched extensively. A recent systematic review and meta-analysis found that 92.8% of patients were able to return sports after MPFL reconstruction. Furthermore, 71.3% of patients returned to or surpassed their preoperative activity level.

The overall complication rate was 8.8%. The most common complication was recurrent instability (1.9%).

FAQ. Frequently Asked Questions

Is MPFL reconstruction major surgery?

Yes, we consider medial patellofemoral ligament surgery a “major” surgery. It requires general anesthesia, and a portion the surgery is requires open incisions. However, it is performed as an outpatient surgery, which means you get to go home the same day. It also usually requires only two small incisions.

How painful is MPFL reconstruction surgery?

It is normal to have pain after MPFL surgery, especially on the inside of the knee. The pain usually starts to noticeably improve 1-2 weeks after surgery, though some pain may persist for 3-4 months.

A nerve block is usually administered prior to surgery. This usually lasts for the day of surgery. Depending on the MPFL reconstruction protocol, pain medications will be prescribed to help with pain after the nerve block wears off.

What is MPFL reconstruction?

Reconstruction the MPFL is a surgery performed to replaced a damaged or stretch medial patellofemoral ligament. This is needed to stabilize the knee and keep the kneecap from dislocating, or prevent patellar dislocation.

How long is MPFL reconstruction surgery?

The surgery to reconstruct the medial patellofemoral ligament usually takes between 1-2 hours, depending on how much work needs to be done.

Sometimes additional procedures are performed in conjunction with MPFL surgery. This can include cartilage regeneration procedures or tibial tubercle osteotomy (in cases of elevated tt-tg distance).

How much time do I need to take off from work after MPFL surgery?

Most patients can return to light duty or seated work in 1-2 weeks after medial patellofemoral ligament reconstruction. Return to heavy duty work will vary depending on the specific job requirements. Your return-to-work willed be based on your specific surgery and specific job factors according to the medial patellofemoral ligament reconstruction protocol.

What is the difference between MPFL repair and MPFL reconstruction?

MPFL repair is performed when a localized portion of the medialpatellofemoral ligament is torn, usually from the patella. Surgical anchors are implanted in the kneecap and strong sutures are used to pull the tissue back to the patella.

MPFL reconstruction involves replacing the torn or stretched ligament with new tissue. This can come from the patient’s own tissue, or from a donor. Surgical outcomes are generally better when reconstructions is performed compared to repair, depending on the circumstances.

Is it normal to have numbness after MPFL surgery?

Some numbness around the incision site is normal after surgery on the MPFL. This is due to the path of small superficial branches of the saphenous nerve and the way that surgical incisions and scarring affect those branches.

References:

  1. Platt BN, Bowers LC, Magnuson JA, Marx SM, Liu JN, Farr J, Stone AV. Return to Sport After Medial Patellofemoral Ligament Reconstruction: A Systematic Review and Meta-analysis. Am J Sports Med. 2022 Jan;50(1):282-291. doi: 10.1177/0363546521990004. Epub 2021 Mar 15. PMID: 33720789.
  2. Burnham JM. Editorial Commentary: Treating Patients With Recurrent Patellar Instability With an Individualized, Anatomic Approach Is Needed: Learn From the Anterior Cruciate Ligament. Arthroscopy. 2021 May;37(5):1680-1682. doi: 10.1016/j.arthro.2021.01.018. PMID: 33896516.
  3. Burnham JM, Howard JS, Hayes CB, Lattermann C. Medial Patellofemoral Ligament Reconstruction With Concomitant Tibial Tubercle Transfer: A Systematic Review of Outcomes and Complications. Arthroscopy. 2016 Jun;32(6):1185-95. doi: 10.1016/j.arthro.2015.11.039. Epub 2016 Feb 13. PMID: 26882966.

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