MPFL Reconstruction

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. As Dr. Burnham has emphasized, treating patients with recurrent patellar instability requires an individualized, anatomic approach, much like the evolution seen in ACL reconstruction.

Why is MPFL Reconstruction Surgery Performed

Reconstruction of the MPFL is performed when 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 reconstructing 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.

Who Needs MPFL Reconstruction?

Not every patient with a dislocated kneecap needs MPFL reconstruction surgery. The decision depends on several patient-specific factors that an orthopedic surgeon evaluates during a thorough clinical workup. Candidates for MPFL reconstruction typically include patients who meet one or more of the following criteria:

Recurrent patellar dislocations. Patients who have experienced two or more episodes of kneecap dislocation are strong candidates for surgery. After the first dislocation, the risk of a second episode is approximately 15 to 40 percent, and that risk climbs significantly with each subsequent dislocation. When the kneecap keeps dislocating despite bracing and physical therapy, surgical stabilization offers the most reliable path to long-term stability.

First-time dislocation with significant risk factors. In some cases, even a first-time dislocation may warrant surgical discussion. Patients with anatomic risk factors such as trochlear dysplasia (a shallow groove for the kneecap), patella alta (a high-riding kneecap), an elevated TT-TG distance (a measurement indicating the kneecap’s pull is shifted too far laterally), or significant knee valgus (knock knees) may benefit from earlier surgical intervention. A systematic review by Burnham et al. found that addressing these anatomic factors, sometimes with concomitant procedures such as a tibial tubercle transfer, improves outcomes and reduces redislocation rates.

Young, active athletes. Athletes who need to return to cutting, pivoting, and contact sports place high demands on knee stability. For these patients, the combination of a torn MPFL and the physical requirements of their sport often tips the scale toward reconstruction.

Failed non-surgical treatment. Patients who have completed a structured physical therapy program focused on quadriceps and hip strengthening but continue to experience instability episodes, apprehension, or giving-way symptoms are candidates for surgical stabilization.

Loose bodies or cartilage damage. When a patellar dislocation causes a piece of cartilage or bone to break off inside the knee joint, surgical intervention is often necessary to remove the loose body and address the underlying instability simultaneously.

Video Overview of MPFL Recon

How is Medial Patellofemoral Ligament Reconstruction Performed

Reconstruction of the medial patellofemoral ligament is performed by replacing the torn or stretched ligament with a new one. Sources of the new ligament are varied. This can include the patient’s 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 on 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 kneecap too far to the medial side.

MPFL Surgery Recovery Timeline

Recovery after MPFL reconstruction follows a structured, phased protocol designed to protect the reconstructed ligament while progressively restoring range of motion, strength, and function. Every patient’s timeline varies slightly depending on whether additional procedures (such as a tibial tubercle transfer or cartilage procedure) were performed at the same time, but the general framework follows the milestones below.

Day of surgery (Day 0). MPFL reconstruction is performed as an outpatient procedure, meaning patients go home the same day. A nerve block is administered before surgery to manage pain for the first 12 to 24 hours. Patients leave the surgical center with crutches, a knee brace locked in extension, and specific instructions for icing and elevation.

Weeks 1 to 2. The focus during the first two weeks is on controlling swelling and managing pain. The knee brace is worn at all times, and patients remain partial weight bearing with crutches. Gentle range of motion exercises, quad sets, and straight leg raises begin immediately under the guidance of a physical therapist. Most patients can return to light desk work within 1 to 2 weeks.

Weeks 2 to 6. Progressive range of motion is the primary goal during this phase. Patients work toward achieving 90 degrees of flexion by week 4 and full flexion by week 6. Weight bearing is gradually increased as tolerated. The knee brace may be unlocked for controlled range of motion exercises. Gluteal and quadriceps strengthening exercises continue to build the muscular support around the knee.

Weeks 6 to 12. The stationary bike is introduced around week 6, which helps restore range of motion and build endurance. Patients transition off crutches as their strength and gait normalize. Closed-chain strengthening exercises such as leg presses, step-ups, and mini squats are introduced. The brace is typically discontinued during this phase.

Months 3 to 4. Functional progression begins, including balance and proprioception training. Patients start light jogging on flat surfaces when adequate quadriceps strength is demonstrated (typically when the operative leg reaches 70% or more of the strength of the non-operative leg). Sport-specific movement patterns are introduced gradually.

Months 4 to 6. Advanced sport-specific training begins, including cutting, pivoting, and agility drills. Patients must demonstrate adequate strength, stability, and confidence before progressing to contact activities. Functional testing is performed to objectively measure readiness for return to sport.

Months 6 to 9 (return to sport). According to a systematic review published in the American Journal of Sports Medicine, the average time to return to sport after MPFL reconstruction is 6.7 months. Return-to-sport decisions are based on objective functional testing, not simply the calendar. Athletes must pass sport-specific testing criteria before being cleared for full, unrestricted competition.

View the MPFL Postoperative Protocol for physical therapy here.

MPFL Reconstruction Success Rate

Medial patellofemoral ligament surgery has been researched extensively. A systematic review and meta-analysis published in AJSM found that 92.8% of patients were able to return to 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%).

A systematic review by Burnham et al. examining MPFL reconstruction with concomitant tibial tubercle transfer found that addressing multiple anatomic risk factors simultaneously can further improve outcomes in patients with complex patellar instability. The key is matching the surgical plan to each patient’s unique anatomy, a principle Dr. Burnham has advocated for in the orthopedic literature.

MPFL Surgery Alternatives

Surgery is not always the first step in treating patellar instability. Several non-surgical and surgical alternatives to MPFL reconstruction exist, and the right approach depends on the severity and frequency of instability, the patient’s anatomy, and their activity goals.

Physical therapy and bracing. For first-time dislocations without significant structural risk factors, a structured physical therapy program is typically the first-line treatment. Therapy focuses on strengthening the quadriceps (especially the VMO, or vastus medialis oblique), the hip abductors, and the core. A patellar stabilizing brace may be used during activity to provide additional support while the muscles rebuild. Many patients achieve satisfactory stability through therapy alone.

MPFL repair. In select cases where the MPFL is torn at a specific location (usually from the kneecap), a repair rather than a full reconstruction may be appropriate. Repair involves reattaching the native ligament tissue using surgical anchors and sutures. However, reconstruction is generally preferred when the ligament is stretched or attenuated rather than cleanly torn, as reconstruction provides a stronger, more reliable restraint.

Tibial tubercle transfer (osteotomy). In patients with an elevated TT-TG distance or patella alta, a tibial tubercle osteotomy may be performed either as a standalone procedure or in combination with MPFL reconstruction. This procedure repositions the attachment point of the patellar tendon on the tibia to improve patellar tracking. Research by Burnham et al. has examined outcomes when these procedures are combined.

Trochleoplasty. For patients with severe trochlear dysplasia (a flat or convex femoral groove), trochleoplasty reshapes the groove to better accommodate the kneecap. This is a more involved procedure reserved for significant anatomic abnormalities and is often combined with MPFL reconstruction.

Frequently Asked Questions About MPFL Surgery

MPFL Reconstruction in Baton Rouge, Louisiana

Dr. Jeremy Burnham is a board-certified orthopedic surgeon and sports medicine specialist at Ochsner-Andrews Sports Medicine Institute in Baton Rouge, Louisiana. With peer-reviewed research specifically focused on MPFL reconstruction and patellar instability, Dr. Burnham brings an evidence-based, individualized approach to every patient. The surgical team treats patients from across Baton Rouge, Gonzales, Denham Springs, Hammond, Lafayette, and throughout Louisiana.

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.