What Is MPFL Reconstruction for Kneecap Instability?

MPFL reconstruction is a surgical procedure that creates a new medial patellofemoral ligament to stabilize the kneecap. It helps to treat recurrent patellar instability and repeated patellar dislocation by using a tendon graft from the patient’s body to maintain proper patellar tracking within the trochlear groove.

At Total Orthopedics and Sports Medicine, Dr. Charles Ruotolo reviews X-rays and MRI scans to identify a torn MPFL, cartilage injury, and other anatomic risk factors affecting the knee joint. During the surgery, he uses minimally invasive, arthroscopic-assisted surgical interventions to protect the surrounding soft tissues. Schedule your consultation in Long Island or Syosset at 855-321-6784 to reduce the risk of future recurrent dislocations.

How MPFL Reconstruction Surgery Stabilizes an Unstable Kneecap?

MPFL reconstruction surgery stabilizes an unstable kneecap by replacing the damaged ligament with a tendon graft. The new ligament limits excessive outward movement and improves patellar tracking within the femoral groove. It also reduces the risk of recurring kneecap dislocation during knee bending, twisting, exercise, and everyday activities.

However, for chronic or recurrent patellar dislocation, simply stitching the torn ligament back together may not provide reliable support. Therefore, surgeons reconstruct the medial patellofemoral ligament using a graft, commonly taken from the patient’s hamstring tendon or gracilis. For this purpose, an orthopedic surgeon creates small tunnels or fixation points in the kneecap and femur. The graft is then passed between these attachment points to reproduce the natural position and function of the MPFL.

After that, surgeons may use screws, anchors, or buttons to hold it securely in place. These screws will help to attach the healing graft firmly and prevent the kneecap from slipping outward without placing excessive pressure on the patellofemoral joint. In fact, an NCBI systematic review found that 92.8% returned to sports following MPFL reconstruction. Researchers also found that approximately 71.3% returned to or exceeded their previous activity level, while the rate of recurrent instability was only 1.9%.

Why Does My Kneecap Keep Slipping or Popping Out?

Kneecap slipping or popping usually occurs when the patella cannot stay centered in the femoral groove. It may occur when a torn or stretched medial patellofemoral ligament (MPFL), weak thigh muscles, poor leg alignment, a shallow groove, or a high-riding kneecap causes the kneecap to shift outward during twisting, running, climbing stairs, or bending the knee.

According to the PMC systematic review, trochlear dysplasia is also the strongest anatomical risk factor for both first-time and recurrent patellar dislocation. Another NCBI review reported MPFL injury in approximately 94.7% of patients following acute lateral patellar dislocation. Here’s how these conditions cause the kneecap to slip or pop out:

• Shallow Trochlear Groove: Some people are born with a shallow or uneven groove (trochlear dysplasia), which can make the kneecap more likely to slide out.
• Stretched or Torn Ligaments: A previous injury or an initial traumatic dislocation often stretches or tears the medial femoral condyle. Once damaged, it lacks the tension to maintain the bone alignment.
• Muscle Imbalances: If your quadriceps muscles, specifically the vastus medialis oblique on the inner side of the thigh, are weak, they cannot handle stronger external forces that pull the kneecap outward.
• High-SITTING Kneecap: A congenital condition known as patella alta causes the kneecap to rest too high on the thigh bone. As a result, the walls of the femoral groove cannot stabilize it.
• Generalized Joint Laxity: Individuals born with naturally “loose” joints or hypermobility are highly prone to multi-directional patellar shifting.

After the patella dislocates, the supporting ligament and surrounding tissues may heal in a stretched or weakened position. This reduces control over kneecap movement and increases the risk of acute patellar dislocation, especially during sports, sudden changes in direction, squats, or other weight-bearing activities.

What Symptoms Indicate Kneecap Instability?

When your kneecap becomes unstable, you may experience kneecap shifting, sudden knee buckling, persistent pain around the front of the knee, and swelling. In cases of lateral patellar instability, popping sensations may occur along with difficulty walking, running, climbing stairs, or changing direction.

Moreover, in severe cases, the kneecap dislocates from its normal position. After an episode of instability, your knee may also feel stiff, tender, weak, or difficult to straighten fully. If repeated episodes occur, it can irritate or damage the cartilage beneath the kneecap, resulting in persistent discomfort and reduced physical activity. NIH clinical research also indicates that recurrent lateral patellar dislocation can cause substantial pain and impair knee function. In such cases, it’s essential to seek immediate medical attention because untreated instability can lead to long-term cartilage damage and increase the risk of osteoarthritis in younger patients.

Do You Need Surgery After One Kneecap Dislocation?

No, surgery is usually not required after a first-time kneecap (patellar) dislocation. Most initial dislocations are successfully treated with non-surgical methods, which include a targeted exercise plan, medications, and knee braces. In some cases, our surgeons may suggest limiting knee motion to 90 degrees for the first two weeks.

These non-surgical methods focus on reducing swelling, restoring knee movement, and strengthening the quadriceps, hips, and surrounding muscles. In addition, doctors may advise patients to resume sports 5 to 6 months after surgery. However, Dr. Charles Ruotolo, our orthopedic surgeon, may recommend surgery in the following cases:

• Structural damage: Cartilage or small pieces of bone have broken off (called “loose bodies”) and are floating in the joint.
• Ligaments are torn: Crucial stabilizers, such as the medial patellofemoral ligament (MPFL), are severely ruptured and need repair or reconstruction.
• High-risk anatomy: You have anatomical risk factors (like a shallow kneecap groove or severely bowed legs) that make future dislocations highly likely.
• Recurrent instability: The kneecap dislocates multiple times or continually feels unstable

What Tests Do Doctors Perform to Diagnose an MPFL Tear?

Dr. Charles Ruotolo diagnoses an MPFL tear by performing a patellar apprehension test to assess patellar tendon glide, tracking, and range of motion. He may even palpate the medial border of the patella to assess for pain and perform manual quadrant tests to assess the kneecap shifting in different directions

During the physical exam, Dr. Charles Ruotolo may also review the patient’s history, examine the kneecap stability, and check for tenderness, swelling, and knee flexion during movement. He may review X-rays to assess fractures and kneecap alignment. Additionally, in complex cases of lateral patellar subluxation, he performs an MRI to confirm ligament damage and identifies cartilage, bone, or other soft-tissue injuries. Besides that, he may review CT scan findings to obtain detailed measurements of bone structure or the position of the tibial tubercle when planning MPFL surgery.

When Orthopedic Surgeons Recommend MPFL Reconstruction?

Dr. Charles Ruotolo, our orthopedic surgeon, may recommend MPFL reconstruction when repeated kneecap dislocations, persistent instability, or a torn medial patellofemoral ligament do not improve with bracing and targeted therapy. He may also consider surgery after a first dislocation when severe ligament damage, cartilage injury, or major anatomical abnormalities are present.

However, before recommending surgery, Dr. Charles Ruotolo evaluates the patient’s symptoms, activity level, previous dislocations, and response to nonsurgical treatment. Furthermore, he may review imaging test results to determine the extent of ligament damage and identify structural risk factors. If these results indicate that the patellar ligament is torn or irreversibly stretched, he replaces the injured ligament with a tendon graft to improve patellar tracking. Schedule your consultation today for an accurate diagnosis and determine the most appropriate treatment plan.

How Surgeons Restore Kneecap Stability With MPFL Reconstruction?

Dr. Charles Ruotolo, our knee surgeon, restores kneecap stability by replacing a torn or stretched ligament with a new biological tendon graft during medial patellofemoral ligament reconstruction. This artificial “leash” safely prevents the kneecap (patella) from slipping out of its groove while allowing normal, pain-free joint movement.

During MPFL repair, he gave a spinal nerve block that numbs the lower half of the body. Then he harvests a strip of your tissue (autograft), such as the hamstring or quadriceps tendon, or uses a sterilized allograft. After that, he makes small incisions on the inner side of the knee. He then drills precise, small tunnels into the kneecap and the thigh bone. In the next step, he passes the graft beneath the soft tissues of the knee, bridging the patella and femur at a specific location known as Schöttle’s point. The knee is then bent to ensure the graft tension is tight enough to prevent dislocation.

To secure the reconstructed ligament, Dr. Charles Ruotolo anchors the graft ends firmly into the bone with modern surgical screws, anchors, or cortical buttons. This surgery typically takes about one hour to complete. Moreover, patients can return home the same day after MPFL reconstruction. However, if a patient has underlying structural or anatomical abnormalities, he may combine MPFL reconstruction with the following concomitant procedures, which may require more time:

1. Tibial Tubercle Osteotomy (TTO): Repositions the bony attachment of the kneecap tendon to alter the pull and alignment of the kneecap.
2. Trochleoplasty: Deepens or reshapes the natural groove on the femur if it is too shallow to hold the kneecap.
3. Lateral Retinacular Release: Lateral release of tight soft tissues that pull the patella outward.
4. Distal Femoral Osteotomy (DFO): Corrects valgus malalignment of the femur contributing to lateral patellar instability.

What Type of Graft Is Used In MPFL Repair?

MPFL reconstruction commonly uses a gracilis or semitendinosus hamstring tendon graft. The tissue may be an autograft taken from the patient or an allograft obtained from a screened donor. In selected cases, Dr. Charles Ruotolo may use part of the quadriceps tendon, depending on anatomy, age, prior surgery, and fixation technique.

Besides this, he may select the graft after evaluating the following factors:

Activity Demands

Highly active patients, competitive athletes, and individuals participating in pivoting or contact sports may require a strong graft capable of tolerating repetitive stress. In these cases, Dr. Charles Ruotolo may prefer a hamstring or quadriceps tendon autograft because it offers reliable biological incorporation. It also provides sufficient strength to improve surgical outcomes.

Skeletal Maturity

In children and adolescents with open growth plates, graft selection and fixation must minimize the risk of damaging the developing bone. In such cases, our surgeon may choose a soft-tissue graft and use growth plate–sparing techniques. However, in skeletally mature patients, standard femoral tunnel placement and a wider range of graft fixation methods may be considered.

Tissue Quality

The strength, thickness, and overall condition of the patient’s tendons impact whether an autograft is suitable. Previous surgery, tendon injury, generalized ligamentous laxity, or inadequate tendon size may reduce the suitability of the patient’s own tissue. In cases like these, Dr. Charles Ruotolo may select a donor allograft or an alternative autograft.

Kneecap Size

The size and thickness of the patella affect graft fixation and the risk of complications. Patients with a small or thin kneecap may not be suitable for large bone tunnels, as these can increase the risk of patellar fracture. Therefore, our surgeon may choose a smaller graft and use suture anchors, soft-tissue fixation, or techniques requiring minimal bone removal.

How Long Does Recovery Take After the Surgery?

Recovery after MPFL reconstruction typically takes 4 to 6 months to regain functional knee stability and approximately 6 to 9 months to continue higher-level physical demands. However, this recovery time may vary depending on graft healing, muscle strength recovery, and your biological response.

In some cases, surgeons may advise patients to wear a brace for 4 to 6 weeks post-surgery. Moreover, weight bearing is allowed after 6 weeks post-MPFL reconstruction. In the initial postoperative period, your focus should be on alleviating pain, reducing swelling, protecting the reconstructed ligament, and restoring early knee extension. After 9-12 months, you can slowly transition to movements like zig-zag cuts, pivoting maneuvers, depth jumps, and single-leg lateral jumps.

You can also practice complex agility drills and high-intensity plyometrics to rebuild quadriceps strength and improve neuromuscular control. In fact, an NCBI study reported that the return-to-play rate after MPFL reconstruction is 85.1%, with 68.3% returning to the same level within 7.0 months.

What Is the Success Rate of MPFL Reconstruction?

After MPFL reconstruction, the overall return-to-sport rate was 92.8%, and 71.3% of patients successfully returned to or exceeded their pre-injury level of activity, according to NIH research. Researchers also found that Kujala scores increased from 60.3% preoperatively to 90.0% postoperatively, demonstrating restoration of knee function.

Another PMC systematic review reported an 84% rate of return to sport and improved clinical outcomes after MPFL reconstruction. Moreover, the NCBI review found that the patients returned to sports after isolated MPFL surgery at a rate of 80.8%. The study also reported that 65.4% of patients returned to “strenuous” sports and 15.4% to “moderate” sports.

What Are the Risks of Medial Patellofemoral Ligament Surgery?

Knee stiffness, persistent pain, infection, blood clots, recurrent kneecap instability, patellar fracture, and graft failure are the common risks linked with medial patellofemoral ligament surgery. Other complications may include bleeding, nerve irritation, numbness near the incision, and adverse reactions to anesthesia.

In fact, PMC research found that postoperative complications after MPFL reconstruction can occur in up to 26.1% of cases. When graft placement is incorrect or tension is excessive, it can restrict motion or increase pressure on the kneecap cartilage, sometimes requiring revision surgery. Scar tissue, prolonged immobilization, or inadequate rehabilitation can also make it difficult to fully bend or straighten the knee. Additionally, drilling fixation tunnels into the kneecap can occasionally weaken the bone and cause a fracture.

How Much Does MPFL Surgery Cost?

In New York, MPFL (Medial Patellofemoral Ligament) surgery typically costs between $12,000 and $25,000 for an isolated procedure. When considering insurance, your actual out-of-pocket expenses depend on your deductible, co-insurance, and whether you use an in-network surgeon or facility.

Moreover, greater surgical complexity may increase the cost of kneecap instability treatment by increasing operating room time, implant fees, anesthesia charges, and hospital fees. You may also account for expenses that may be billed separately, including specialist consultations, diagnostic imaging, postoperative medication, knee bracing, and follow-up appointments. Therefore, before scheduling surgery, confirm that the surgeon, anesthesiologist, facility, and rehabilitation provider are in-network.

Consult Dr. Charles Ruotolo in Syosset for MPFL Reconstruction

If you have kneecap instability, it can cause functional limitations during your routine physical tasks. Due to this instability, you may also experience the kneecap shifting, slipping, or partially dislocating during routine activities. Over time, repeated instability can lead to cartilage wear, inflammation, and increasing difficulty in performing athletic activities.

At Total Orthopedics and Sports Medicine, Dr. Charles Ruotolo provides advanced MPFL reconstruction while focusing on accurate graft positioning, appropriate tensioning, and balanced kneecap tracking to restore medial support without overconstraining the joint. Moreover, our team provides online patient convenience and clear surgical instructions to streamline your treatment. Visit at 115 Eileen Way, Syosset, NY 11791, or contact us at 855-321-6784 to improve your knee stability.

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