How Is Patellar Instability Surgically Corrected?

Patellar instability is surgically corrected through a combination of ligament reconstruction, osteotomy, and trochleoplasty. These procedures improve kneecap tracking, correct abnormal anatomy, restore knee stability, and reduce the risk of recurrent patellar dislocation.

At Total Orthopedics and Sports Medicine, Dr. Charles Ruotolo, a member of the American Medical Association, carefully evaluates the underlying causes of knee instability before recommending surgery. After that, he may perform MPFL reconstruction, trochleoplasty, or tibial tubercle transfer to prevent lateral subluxation and reshape the groove in the femur or thighbone. When alignment conditions, such as knock-knee, contribute to complex patellofemoral instability, he also performs osteotomy. Call us at 855-321-6784 to schedule a proper evaluation of patellar instability.

Which Surgical Procedures Correct Patellar Instability?

Surgical procedures used for patellar instability include medial imbrication. MPFL reconstruction, tibial tubercle transfer, trochleoplasty, and corrective osteotomy. From these options, surgeons select the appropriate procedure based on ligament damage, kneecap alignment, bone structure, and the causes of recurrent dislocation.

Before recommending treatment, the orthopedic surgeon also evaluates the knee joint, the femoral groove, and the surrounding ligaments. Here is how these surgical procedures help correct patellar tendon instability without any complications:

1. Medial Imbrication

Medial imbrication tightens the stretched tissues on the inner side of the knee. The surgeon folds and sutures the medial retinaculum or supporting tissues to pull the kneecap toward a more stable position. This procedure may help patients with mild instability and relatively normal bone alignment. However, surgeons may combine it with another procedure if tightening the soft tissues doesn’t provide sufficient stability.

2. MPFL Reconstruction

The medial patellofemoral ligament is the main ligament that prevents the kneecap from moving too far outward. However, repeated dislocations can stretch or tear this ligament, resulting in persistent patellofemoral instability. During MPFL reconstruction, the surgeon replaces this damaged ligament with an autograft or allograft. The graft is attached to the patella and femur to restore medial support. This procedure is stronger than the native MPFL and allows the kneecap to move naturally through the trochlear groove. In fact, an NCBI biomechanical study reported that the native MPFL had an average failure load of 130.6 N. Moreover, a FiberTape construct had a higher failure load of 175.9 N. In contrast, a semitendinosus graft fixed with soft anchors had a lower failure load of 102.7 N.

3. Tibial Tubercle Transfer

A tibial tubercle transfer changes the position of the bony attachment where the patellar tendon connects to the upper tibia. The surgeon cuts and repositions this section of bone before securing it with screws. Moving the tibial tubercle can improve kneecap alignment, reduce excessive pressure on damaged cartilage, and guide the patella more centrally within the groove. This procedure may be recommended for maltracking, patella alta, or abnormal tendon alignment. A PMC-separate systematic review also reported that tibial tubercle osteotomy produced significant improvements in pain, with an average of 78.7% of patients achieving good or excellent outcomes.

4. Trochleoplasty

Trochleoplasty reshapes an abnormally shallow or misshapen trochlear groove. A shallow groove cannot securely hold the patella, leading to multiple dislocations during bending or twisting movements. The surgeon deepens and contours the groove to allow the kneecap to track more securely. This procedure is generally reserved for patients with severe trochlear dysplasia and complex patellofemoral instability.

5. Corrective Osteotomy

A corrective osteotomy realigns the bones of the leg when abnormal limb alignment places excessive outward pressure on the patella. The surgeon carefully cuts and repositions the femur or tibia to improve the mechanical axis of the leg. This procedure may benefit patients with knock-kneed deformity (also called genu valgum), rotational deformities, or significant bone misalignment.

According to an NIH systematic review, distal femoral osteotomy also provides good-to-excellent clinical outcomes. These outcomes are observed in patients with recurrent patellar instability and genu valgum. Moreover, correcting the underlying deformity reduces the forces that contribute to recurrent instability and poor patellar tracking.

When Does Patellofemoral Instability Require Surgery?

Patellofemoral instability may require surgery when recurrent kneecap dislocations continue despite targeted exercises, bracing, and activity modification. Doctors also consider surgery when imaging shows major ligament damage, severe malalignment, trochlear dysplasia, patella alta, or cartilage and bone injury that impacts long-term knee function.

In fact, the PMC systematic review confirmed that trochlear dysplasia, increased TT–TG distance, and patella alta increase the chance of recurrent patellar dislocation. However, a first-time patellar dislocation often improves with conservative treatment, especially when no major cartilage, bone, or ligament injury is present. If repeated dislocations occur, it can stretch the medial patellofemoral ligament. This makes the kneecap unstable during walking, exercise, or routine knee movements. In such cases, an orthopedic surgeon may recommend surgery.

A PMC study involving pediatric sports-medicine specialists also found 99% agreement for initially treating a first-time dislocation without an osteochondral fracture non-surgically. However, 84% recommended surgery when patellar subluxation continued after six months of nonoperative care. In contrast, 81.5% supported knee stabilization surgery when the first dislocation included an osteochondral fracture.

How Doctors Identify Complex Patellofemoral Instability?

Dr. Charles Ruotolo uses a combination of detailed medical history, targeted physical examinations, and advanced diagnostic imaging to diagnose complex patellofemoral instability. The imaging results help him identify tears in the MPFL, cartilage damage, loose bone fragments, and bone bruising.

Besides this, Dr. Charles Ruotolo may use CT scans, which provide highly accurate measurements of bone alignment. These scans help him measure the TT-TG distance, which indicates whether the kneecap attachment is misaligned. Based on the test results and an evaluation of the surrounding bone geometry, he chooses an appropriate treatment plan.

Moreover, during physical examination, Dr. Charles Ruotolo first assesses the frequency of subluxations (partial slips) or full dislocations. He also checks the following parameters:

• The Apprehension Sign: The doctor gently pushes the kneecap outward to assess for anxiety or discomfort in the patient, mimicking a dislocation.
• The J-Sign: The patient bends and straightens the knee, while our doctor observes if the kneecap moves in a straight line or suddenly veers outward at the end, forming a “J” shape.
• Joint Hyperlaxity: Using scoring systems like the Beighton score, our doctors assess overall joint flexibility, which can affect knee stability.

In addition to these tests, Dr. Charles Ruotolo may identify structural risk factors, such as trochlear dysplasia, which can make it easier for the kneecap to slide out. Similarly, to identify complex instabilities, he also observes anatomic twists in the thigh or shin bones that force the knee into unfavorable tracking mechanics. Schedule a consultation today for a proper knee evaluation.

Why Do Doctors Combine Procedures for Patellar Instability?

Doctors may combine procedures to address multiple overlapping causes of patellar instability. These causes include a torn medial patellofemoral ligament, patella alta, an increased TT-TG distance, trochlear dysplasia, or abnormal leg alignment. When multiple disorders cause knee dislocation, treating only one problem doesn’t address other risk factors.

As a result, the kneecap continues to move outside the trochlear groove. Therefore, Dr. Charles Ruotolo may combine MPFL reconstruction with a tibial tubercle transfer when ligament damage is accompanied by poor alignment of the kneecap. In some cases, many patients with a shallow femoral groove may require trochleoplasty. Similarly, those with severe knock-knee alignment also need a corrective osteotomy.

However, before planning surgery, our surgeon evaluates the patient’s age, growth status, cartilage condition, previous operations, frequency of dislocations, and underlying bone anatomy. This approach helps correct the specific causes of instability while avoiding unnecessary procedures and supporting smoother knee movement. Additionally, after these procedures, patients may have to stay in the hospital for 2-3 nights.

When Do Doctors Perform a Lateral Release?

Dr. Charles Ruotolo performs a lateral release when an abnormally tight lateral retinaculum pulls the kneecap outward, causing excessive patellar tilt, restricting medial movement, and producing pain or maltracking. He also recommends a lateral release when 6 months of non-surgical knee treatments, such as activity modification, bracing, and anti-inflammatory medications, are unsuccessful.

Other than that, before recommending this procedure, he evaluates kneecap tracking, patellar tilt, cartilage condition, and the amount of inward patellar movement. During surgery, our surgeon carefully divides the tight tissues along the outer side of the kneecap. This helps to reduce pressure and allows the patella to move more centrally within the trochlear groove. In complex cases, a lateral release alone does not correct recurrent dislocations caused by an injured MPFL, patella alta, trochlear dysplasia, increased TT-TG distance, or abnormal leg alignment. These conditions may require MPFL reconstruction, tibial tubercle transfer, trochleoplasty, or corrective osteotomy.

Additionally, in some cases, he may perform controlled lateral retinacular lengthening to loosen the tissue while preserving lateral support. However, our surgeons will avoid performing a lateral release if the patient has:

• Significant knee arthritis (patellofemoral arthritis)
• A kneecap that is generally loose or hypermobile rather than tightly compressed on the outside.
• Lack of objective imaging showing a confirmed outward (lateral) tilt of the patella

What Are the Risk Factors of Patella Instability Surgery?

Risk factors that may increase the chance of patellar surgery failure include severe trochlear dysplasia, patella alta, abnormal TT-TG distance, and limb malalignment. Generalized ligament laxity, cartilage damage, obesity, smoking, and poor rehabilitation adherence also increase complications after patella instability surgery.

Therefore, careful preoperative assessment is necessary to help surgeons select the appropriate procedure and reduce the risk of recurrent instability. Additionally, some other risk factors may also occur after the surgery, such as:

1. Arthrofibrosis: The formation of thick, fibrous scar tissue around the joint, which can permanently restrict the full extension or flexion of the knee.
2. Improper Graft Tension or Tunnel Malposition: During ligament reconstruction, if the graft is overtensioned or the bone tunnels are placed incorrectly, it can lead to cartilage damage or anterior knee pain.
3. Bone Healing Complications: For distal realignment procedures, bones are repositioned, which carries the risk of nonunion, fracture of the osteotomized bone plate, or overcorrection.
4. Medial Instability: Aggressive lateral release can destabilize the kneecap in the opposite (medial) direction.
5. Recurrent Instability: Even after surgery, there is a risk that the kneecap may continue to subluxate or dislocate if the underlying anatomical risk factors are not fully corrected.

In a prospective NIH study of 64 knees treated with sulcus-deepening trochleoplasty, 11 patients developed arthrofibrosis. Researchers also found that 9 patients required arthroscopic lysis of adhesions. Another PMC systematic review found that femoral tunnel malposition accounted for 38.1% of indications for revision MPFL reconstruction.

When Can Patients Return to Sports After Surgery?

Patients can usually return to sports 4 to 9 months after patellar instability surgery, although recovery may take longer when procedures such as tibial tubercle osteotomy are performed. In such cases, clearance for return to sports depends on pain-free movement, full knee motion, restored strength, stable kneecap tracking, and successful sport-specific functional testing.

In fact, an NCBI meta-analysis after MPFL reconstruction reported a 92.8% return-to-sport rate, with 71.3% returning to or exceeding their previous activity level. The average return time was approximately 6.7 months. During the initial weeks of healing, patients have to use crutches and wear a knee brace. Within three months, patients are off crutches and out of a brace. During this time, weight-bearing limits and range-of-motion restrictions are strictly monitored to protect the reconstructed graft.

After 9 to 12 months, patients can resume full sports activity. However, the rehabilitation programs last 8 to 12 months post-surgery because procedures that alter the bone environment typically take longer to heal. PMC research also reported that patients receiving the combined procedure returned to sports after approximately 13 months, and 66% returned at the same or a higher level

What Should You Avoid After Patella Surgery?

After patella surgery, you should avoid bearing full weight without your brace, bending or straightening the knee improperly, and submerging the wound in water. You should also avoid high-impact activities, crossing your legs, and twisting your recovering knee.

Similarly, you should never put a pillow directly under the back of your knee while resting in bed. This keeps the knee bent and can cause permanent stiffness. Instead, place a pillow or pad under your heel to keep the leg fully straight. Moreover, avoid running, jogging, jumping, skiing, and aggressive contact sports. These activities exert massive, sudden pressure on your kneecap. Also, never return to high-impact activities too soon, as this can lead to chronic swelling and disrupt muscle healing.

Besides that, you must avoid placing any ointments, lotions, or unprescribed dressings directly over your healing incisions. In addition, do not operate a vehicle or heavy machinery while taking narcotic pain medications. You should also avoid smoking, as it severely restricts blood vessels and slows down tissue healing.

How Can Patellar Instability Be Treated Without Surgery?

First-time patellar dislocations can be treated without surgery through activity modification, a stabilizing brace, and short-term swelling control. You can also perform targeted exercises that strengthen the quadriceps and hip muscles, improve kneecap tracking, and gradually restore movement.

Other than this, you can use the following approaches to treat patellar instability without surgery:

1. Balance training can improve coordination and reduce the risk of the knee giving way during movement.
2. Wearing a patellar-stabilizing brace or knee sleeve to limit movement.
3. Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen can help reduce pain and swelling.

In addition, you can use ice, elevation, compression, or doctor-approved medication to control early discomfort and swelling. Once swelling has reduced, you can perform low-impact exercises like cycling or swimming to strengthen the knee without putting excessive stress on it. According to an NIH study, you can also use patellar taping, as it provides higher Lysholm knee scores than cylinder-cast immobilization. However, if you experience recurrent dislocations, bone fragments, or severe anatomical abnormalities, you may need surgical treatment.

Schedule Patellar Instability Treatment With Dr. Charles Ruotolo in East Meadow!

When your kneecap repeatedly slips, partially dislocates, or feels unstable, you may experience persistent pain, swelling, weakness, and difficulty walking. Without appropriate treatment, recurrent patellar instability can contribute to cartilage damage, reduced knee function, and early joint degeneration.

At Total Orthopedics and Sports Medicine, Dr. Charles Ruotolo performs advanced surgical procedures to correct kneecap instability, improve patellar tracking, and restore long-term knee stability. Furthermore, our team offers online patient convenience tools, including a patient portal, easy online bill payment, and clear surgical instructions to streamline your treatment. Visit at 2339 Hempstead Turnpike, East Meadow, NY 11554, or contact us at 855-321-6784 to get expert surgical treatment for your unstable kneecap.

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