MPFL reconstruction

What exactly is the MPFL?

The abbreviation MPFL stands for medial patellofemoral ligament. It is a ligament that connects the kneecap (patella) to the thigh bone (femur) on the inner side of the knee. It is the most important stabilizer of the patella, preventing lateral dislocation.

Such a patellar dislocation typically occurs due to sudden rotational movements in a flexed knee. It most commonly is a result of a sports injury. The peak incidence is between the ages of 10 and 20. A rupture of the MPFL occurs in almost all cases (94-100%) of first-time lateral patella dislocations. If the MPFL is ruptured, recurrent dislocations are significantly more likely to occur. These repeated injuries often lead to cartilage and bone damage and may result in premature knee osteoarthritis.

What is MPFL reconstruction?

During the construction of the MPFL, the damaged ligament is reinforced with tendon material to restore sufficient stability and prevent recurrent patellar dislocations. This procedure is more complex and associated with more complication than a simple suture of the MPFL, but it also provides a greater stabilizing effect. Various surgical techniques are available which will be described in more detail below.

When is a MPFL reconstruction necessary?

For patients with first-time patellar dislocations without accompanying bone or cartilage injuries, conservative treatment has been considered the gold standard. It involves a closed reduction, immobilization with a plaster splint, leg elevation at rest, cooling and appropriate pain management.

However, more recent studied have led to a differentiated approach. The stability of the affected knee joint must be individually assessed, and a corresponding decision must be made between conservative treatment, MPFL suture, or MPFL reconstruction. A helpful tool that is used for this assessment is the Patella Instability Severity Score, considering the patient’s age, instability of the unaffected knee, and various radiological criteria of instability.

In addition to an estimated instability of a high degree, further indications for surgical treatment include:

• accompanying rupture of the medial retinaculum (another stabilizer)
• Cartilage or bone injuries
• Irreducible or non-retainable dislocations (meaning the patella cannot be repositioned to its physiological position or does not remain in place)
• Failure of conservative treatment (e.g., recurrent patellar dislocations)

In the past, open growth plates in children were considered a contraindication for MPFL reconstruction. Nowadays, thanks to advanced surgical techniques the procedure can also be considered in patients with open growth plates.

How does the surgery proceed?

The surgery takes approximately one hour and can be performed under general anesthesia or spinal anesthesia, depending on the patient’s preference and anesthetic risk. A distinction is made between static and dynamic reconstructions.

During a static reconstruction tendon material from a muscle is harvested and used to strengthen the MPFL. The required tendon material is harvested using a minimally invasive technique, with a choice of various thigh muscles that can be used. An allograft, in other words tendon material from a donor, can also be used.

An incision is made on the inner side of the knee and the MPFL is located. The tendon graft is then fixed to the patella and femur using screws or suture anchors, improving stability to prevent patellar dislocation. If a graft is harvested from the quadriceps tendon, which is already attached to the patella, it only needs to be folded over and anchored to the femur.

During a dynamic reconstruction, the semitendinosus muscle, located on the inner posterior thigh, is used. Its tendon is normally attached to the inner side of the tibia at the knee joint. It is detached from its insertion point and passed through the medial collateral ligament of the knee.

What to expect from the aftercare, recovery, and rehabilitation after MPFL reconstruction?

MPFL reconstruction is a complex surgery that can lead to complications such as instability, reduced flexion, pain, or osteoarthritis, in up to 25% of cases. In very rare cases, it can even result in a fracture of the patella due to the drilling during the surgery. Thus, if such complications occur, revision surgery is may become necessary.

Six weeks after the operation, the surgeon checks the healing process. If the patient develops problems including newly emerged pain or worsening pain, stagnation in recovery, it is highly recommended to schedule an additional compensation to rule out complications to detect and treat them at an early stage.

The affected leg must be elevated in a splint for two weeks following surgery. Patients typically remain in the hospital for only two days. Sutures are removed after around ten to twelve days. Afterwards, a gradual return to weight bearing under physiotherapeutic supervision can begin.  Full weight-bearing is usually possible after 8-10 weeks. However, strenuous physical activities should not be resumed earlier than three months after the surgery. Particularly sports that place a high strain on the knee such as football, handball, or hockey, should be avoided for an additional three months.

Who covers the costs of treatment?

If a medical indication is made, the costs for a MPFL reconstruction are generally covered by statutory and private health insurance.

Which physicians & clinics are specialists in MPFL reconstruction?

Patellar dislocations and MPFL rupture are classified as trauma surgery conditions. Thus, they are diagnosed and treated by physicians with a board certification in trauma surgery and orthopedics. Since MPFL reconstruction is a complex procedure, the surgery should be carried out at a clinic with extensive knowledge and experience in this procedure.

Anyone seeking medical care wants the best possible medical care. Therefore, the question naturally arises: Where can I find the best clinic for me? Since this question cannot be answered objectively as a reputable physician would never claim to be the best, the patient must rely on the surgeon’s years of experience.

We help you find an expert for your condition. All listed doctors and clinics have been carefully selected and verified for their outstanding specialization in MPFL reconstruction. They look forward to receiving your enquiry or treatment request.